Ecotoxicological effects of leachate from e-cigarettes and e-liquid on the performance of perennial ryegrass (Loliumperenne)

Once littered, disposable e-cigarettes present a complex type of waste in the environment. They typically contain a lithium battery, electronics to produce vapour and remnant e-liquid, all of which could leach into the environment. The effects of littered e-cigarettes are not well understood, and they have not been tested in terrestrial ecosystems. To address this, an experiment was set up to assess how leachate from e-cigarettes with or without a battery, but also e-liquid on its own can alter fundamental physical characteristics of Lolium perenne (perennial ryegrass) when irrigated with contaminated water. After 31 days, shoot length of L. perenne was not measurably affected, but the biomass was significantly reduced by 30% when e-liquid, and 24% when leachate from intact e-cigarettes was present compared to control plants. Plants grown with leachate or e-liquid displayed a significant level of early senescence of leaf apices, and the chlorophyll content was increased. Furthermore, root biomass was significantly less (29-46%) compared to the control. Leachate from used disposable e-cigarettes can affect the performance of plants when entering the soil ecosystem, therefore stricter regulations are needed to prevent this new type of electronic litter from becoming more widespread.

Eggshells & Eggshell Membranes- A Sustainable Resource for energy storage and energy conversion applications: A critical review

As the world strives to achieve a sustainable future, the exploration of alternative and renewable raw materials for energy storage and energy conversion has gained significant attention. A growing trend on "Waste to Energy" approach has attained prominence. Accordingly, chicken eggshells, a residual from poultry industry, have emerged as a promising candidate due to their abundant availability, low cost, and unique physical and chemical properties. This review article presents an overview of recent advancements in utilizing eggshell waste for energy storage and energy conversion applications. It discusses the transformation of eggshells usage into functional materials, along with their performance in various energy-related applications. The potential of eggshell-based materials in improving energy efficiency and reducing environmental impact is highlighted, providing insights into the future prospects of this sustainable resource.

Cobalt Oxide-Based Electrocatalysts with Bifunctionality for High-Performing Rechargeable Zinc-Air Batteries

In recent years, the rapid growth in renewable energy applications has created a significant demand for efficient energy storage solutions on a large scale. Among the various options, rechargeable zinc-air batteries (ZABs) have emerged as an appealing choice in green energy storage technology due to their higher energy density, sustainability, and cost-effectiveness. Regarding this fact, a spotlight is shaded on air electrode for constructing high-performance ZABs. Cobalt oxide-based electrocatalysts on the air electrode have gained significant attention due to their extraordinary features. Particularly, exploration and integration of bifunctional behavior for energy storage has remarkably promoted both ORR and OER to facilitate the overall performance of the battery. The plot of this review is forwarded towards in-depth analysis of the latest advancements in electrocatalysts that are based on cobalt oxide and possess bifunctional properties along with an introduction of the fundamental aspects of ZABs, Additionally, the topic entails an examination of the morphological variations and mechanistic details mentioning about the synthesis processes. Finally, a direction is provided for future research endeavors through addressing the challenges and prospects in the advancement of next-generation bifunctional electrocatalysts to empower high-performing ZABs with bifunctional cobalt oxide.

Bioresource Polymer Composite for Energy Generation and Storage: Developments and Trends

The ever-growing demand of human society for clean and reliable energy sources spurred a substantial academic interest in exploring the potential of biological resources for developing energy generation and storage systems. As a result, alternative energy sources are needed in populous developing countries to compensate for energy deficits in an environmentally sustainable manner. This review aims to evaluate and summarize the recent progress in bio-based polymer composites (PCs) for energy generation and storage. The articulated review provides an overview of energy storage systems, e. g., supercapacitors and batteries, and discusses the future possibilities of various solar cells (SCs), using both past research progress and possible future developments as a basis for discussion. These studies examine systematic and sequential advances in different generations of SCs. Developing novel PCs that are efficient, stable, and cost-effective is of utmost importance. In addition, the current state of high-performance equipment for each of the technologies is evaluated in detail. We also discuss the prospects, future trends, and opportunities regarding using bioresources for energy generation and storage, as well as the development of low-cost and efficient PCs for SCs.

Effect of Cobalt on Lifetime of Sb4 O5 Cl2 -Graphene Anode in Chloride-Ion Batteries

Anode materials based on metal oxychlorides hold promise in addressing electrode dissolution challenges in aqueous-based chloride ion batteries (CIBs). However, their structural instability following chloride ion deintercalation can lead to rapid degradation and capacity fading. This paper investigates a cobalt-doped Sb4 O5 Cl2 -graphene (Co-Sb4 O5 Cl2 @GO) composite anode for aqueous-based CIBs. It exhibits significantly enhanced discharge capacity of 82.3 mAh g-1 after 200 cycles at 0.3 A g-1 ; while, the undoped comparison is only 23.5 mAh g-1 in the same condition. It also demonstrated with a long-term capacity retention of 72.8 % after 1000 cycles (65.5 mAh g-1 ) and a favorable rate performance of 25 mAh g-1 at a high current density of 2 A g-1 . Undertaken comprehensive studies via in-situ experiments and DFT calculations, the cobalt (Co) dopant is demonstrated as the crucial role to enhance the lifetime of Sb4 O5 Cl2 -based anodes. It is found that, the Co dopant improves electronic conductivity and the diffusion of chloride ions beside increases the structural stability of Sb4 O5 Cl2 crystal. Thus, this element doping strategy holds promise for advancing the field of Sb4 O5 Cl2 -based anodes for aqueous-based CIBs, and insights gain from this study also offer valuable knowledge to develop high-performance electrode materials for electrochemical deionization.

Electrolyte Design for Low-Temperature Li-Metal Batteries: Challenges and Prospects

Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation. To get the most energy storage out of the battery at low temperatures, improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases. Herein, this review critically outlines electrolytes' limiting factors, including reduced ionic conductivity, large de-solvation energy, sluggish charge transfer, and slow Li-ion transportation across the electrolyte/electrode interphases, which affect the low-temperature performance of Li-metal batteries. Detailed theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen understanding. Emerging improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously compared. Perspectives on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries.

A Deeper Understanding of Metal Nucleation and Growth in Rechargeable Metal Batteries Through Theory and Experiment

Lithium and sodium metal batteries continue to occupy the forefront of battery research. Their exceptionally high energy density and nominal voltages are highly attractive for cutting-edge energy storage applications. Anode-free metal batteries are also coming into the research spotlight offering improved safety and even higher energy densities than conventional metal batteries. However, uneven metal nucleation and growth which leads to dendrites continues to limit the commercialisation of conventional and anode-free metal batteries alike. This review connects models and theories from well-established fields in metallurgy and electrodeposition to both conventional and anode-free metal batteries. These highly applicable models and theories explain the driving forces of uneven metal growth and can inform future experiment design. Finally, the models and theories that are most relevant to each anode-related cell component are identified. Keeping these specific models and theories in mind will assist with rational design for these components.

Review on recycling energy resources and sustainability

Shifting the production and disposal of renewable energy as well as energy storage systems toward recycling is vital for the future of society and the environment. The materials that make up the systems have an adverse effect on the environment. If no changes are made, the CO2 emissions will continue to increase while also impacting vital resources such as contaminating water sources and wildlife, manifesting in rising sea levels, and air pollution. The development of renewable energy storage systems (RESS) based on recycling utility and energy storage have been an important step in making renewable energy more readily available and more reliable. The emergence of RESS has revolutionized the way energy is obtained and stored for future uses. RESS such as those based on recycling utility and energy storage, provide a reliable and efficient means to harvest, store and provide energy from renewable sources on a large scale. The potential to reduce our dependence on fossil fuels, increase energy security, and help protect the environment makes RESS an important tool in the fight against climate change. As the technology evolves, such systems will continue to play a vital role in the green energy revolution, providing access to a reliable, efficient, and cost-effective power source. This paper provides an overview of the current research on recycling utility based renewable energy storage systems, including their components, power sources, benefits, and challenges. Finally, it assesses potential methods to overcome the challenges and improve the efficiency and reliability of the recycling utility based renewable energy storage systems.

Co-Intercalation of Dual Charge Carriers in Metal-Ion-Confining Layered Vanadium Oxide Nanobelts for Aqueous Zinc-Ion Batteries

Vanadium-based oxides with high theoretical specific capacities and open crystal structures are promising cathodes for aqueous zinc-ion batteries (AZIBs). In this work, the confined synthesis can insert metal ions into the interlayer spacing of layered vanadium oxide nanobelts without changing the original morphology. Furthermore, we obtain a series of nanomaterials based on metal-confined nanobelts, and describe the effect of interlayer spacing on the electrochemical performance. The electrochemical properties of the obtained Al_2.65 V₆ O₁₃  ⋅ 2.07H₂ O as cathodes for AZIBs are remarkably improved with a high initial capacity of 571.7 mAh ⋅ g^-1 at 1.0 A g^-1 . Even at a high current density of 5.0 A g^-1 , the initial capacity can still reach 205.7 mAh g^-1 , with a high capacity retention of 89.2 % after 2000 cycles. This study demonstrates that nanobelts confined with metal ions can significantly improve energy storage applications, revealing new avenues for enhancing the electrochemical performance of AZIBs.

Solids that are also liquids: elastic tensors of superionic materials

Superionics are fascinating materials displaying both solid- and liquid-like characteristics: as solids, they respond elastically to shear stress; as liquids, they display fast-ion diffusion at normal conditions. In addition to such scientific interest, superionics are technologically relevant for energy, electronics, and sensing applications. Characterizing and understanding their elastic properties is, e.g., urgently needed to address their feasibility as solid-state electrolytes in all-solid-state batteries. However, static approaches to elasticity assume well-defined reference positions around which atoms vibrate, in contrast with the quasi-liquid motion of the mobile ions in fast ionic conductors. Here, we derive the elastic tensors of superionics from ensemble fluctuations in the isobaric-isothermal ensemble, exploiting extensive Car-Parrinello simulations. We apply this approach to paradigmatic Li-ion conductors, and complement with a block analysis to compute statistical errors. Static approaches sampled over the trajectories often overestimate the response, highlighting the importance of a dynamical treatment in determining elastic tensors in superionics.

Environmental trade-offs and externalities of electrochemical-based batteries: Quantitative analysis between lithium-ion and vanadium redox flow units

This study aims to increase the scientific knowledge of the environmental impacts and externalities of two promising electrochemical-based techniques for large-scale stationary energy storage: lithium nickel cobalt manganese (NCM) and vanadium redox flow (VRF) batteries. The global warming potential (GWP) and cumulative energy demand (CED) for NCM and VRF batteries are 28 kg CO₂eq and 410 MJ and 186 kg CO₂eq and 3080 MJ, respectively, for the provision of 1 MWh of electricity. While the trend of the environmental externality results is proportional to the environmental impact results, the environmental costs from GWP and terrestrial ecotoxicity impacts contribute the largest share of the total environmental costs for both batteries. Overall, NCM batteries have favorable environmental performance in terms of their impact values and externalities but still show relatively higher contributions in human toxicity and ozone layer depletion impacts, based on their high resource uses. The VRF batteries, on the other hand, report higher impacts in abiotic depletion, GWP and terrestrial ecotoxicity, mainly due to their great mass of the electrolyte. Our results highlight the importance of substituting the active metals with low-impact metals or carefully considering the origin of key materials while also taking advantage of the properties of the battery to carefully assess possible advancements in battery design. The environmental externality results also provide essential information for the future development of battery industries for stationary applications with energy and environmental benefits.

Unmanned aerial vehicles (UAVs): practical aspects, applications, open challenges, security issues, and future trends

Recently, unmanned aerial vehicles (UAVs) or drones have emerged as a ubiquitous and integral part of our society. They appear in great diversity in a multiplicity of applications for economic, commercial, leisure, military and academic purposes. The drone industry has seen a sharp uptake in the last decade as a model to manufacture and deliver convergence, offering synergy by incorporating multiple technologies. It is due to technological trends and rapid advancements in control, miniaturization, and computerization, which culminate in secure, lightweight, robust, more-accessible and cost-efficient UAVs. UAVs support implicit particularities including access to disaster-stricken zones, swift mobility, airborne missions and payload features. Despite these appealing benefits, UAVs face limitations in operability due to several critical concerns in terms of flight autonomy, path planning, battery endurance, flight time and limited payload carrying capability, as intuitively it is not recommended to load heavy objects such as batteries. As a result, the primary goal of this research is to provide insights into the potentials of UAVs, as well as their characteristics and functionality issues. This study provides a comprehensive review of UAVs, types, swarms, classifications, charging methods and regulations. Moreover, application scenarios, potential challenges and security issues are also examined. Finally, future research directions are identified to further hone the research work. We believe these insights will serve as guidelines and motivations for relevant researchers.

Revealing the Electrochemistry of Solid-State Li-SeS2 Battery via In-Situ Transmission Electron Microscopy

Se_x S_y is considered as a promising cathode material as it can deliver higher energy density than selenium (Se) and offer improved conductivity and enhanced reaction kinetics compared with S. However, the electrochemistry of the Li-SeS₂ all-solid-state battery (ASSB) has not been well understood to date. Herein the electrochemistry of Li-SeS₂ battery was revealed by in-situ transmission electron microscopy. The charge products were phase-separated Se and S, rather than the widely believed SeS₂ . Among the various Se_x S_y cathodes, SeS₂ achieved the best electrochemical performance. The Li-SeS₂ ASSB delivered a high reversible capacity of 1052 mAh g^-1 at 1 A g^-1 over 350 cycles, and a high areal capacity of 4 mAh cm^-2 was also achieved with a high cathode mass loading of 7.6 mg cm^-2 . These results represent the best performance achieved to date in the Li-SeS₂ ASSB and brings us one step closer toward its practical applications.

Machine learning for a sustainable energy future

Transitioning from fossil fuels to renewable energy sources is a critical global challenge; it demands advances - at the materials, devices and systems levels - for the efficient harvesting, storage, conversion and management of renewable energy. Energy researchers have begun to incorporate machine learning (ML) techniques to accelerate these advances. In this Perspective, we highlight recent advances in ML-driven energy research, outline current and future challenges, and describe what is required to make the best use of ML techniques. We introduce a set of key performance indicators with which to compare the benefits of different ML-accelerated workflows for energy research. We discuss and evaluate the latest advances in applying ML to the development of energy harvesting (photovoltaics), storage (batteries), conversion (electrocatalysis) and management (smart grids). Finally, we offer an overview of potential research areas in the energy field that stand to benefit further from the application of ML.

Highly stable β-ketoenamine-based covalent organic frameworks (COFs): synthesis and optoelectrical applications

Covalent organic frameworks (COFs) are one class of porous materials with permanent porosity and regular channels, and have a covalent bond structure. Due to their interesting characteristics, COFs have exhibited diverse potential applications in many fields. However, some applications require the frameworks to possess high structural stability, excellent crystallinity, and suitable pore size. COFs based on β-ketoenamine and imines are prepared through the irreversible enol-to-keto tautomerization. These materials have high crystallinity and exhibit high stability in boiling water, with strong resistance to acids and bases, resulting in various possible applications. In this review, we first summarize the preparation methods for COFs based on β-ketoenamine, in the form of powders, films and foams. Then, the effects of different synthetic methods on the crystallinity and pore structure of COFs based on β-ketoenamine are analyzed and compared. The relationship between structures and different applications including fluorescence sensors, energy storage, photocatalysis, electrocatalysis, batteries and proton conduction are carefully summarized. Finally, the potential applications, large-scale industrial preparation and challenges in the future are presented.

Alloy-Type Anodes for High-Performance Rechargeable Batteries

Alloy-type anodes are one of the most promising classes of next-generation anode materials due to their ultrahigh theoretical capacity (2-10 times that of graphite). However, current alloy-type anodes have several limitations: huge volume expansion, high tendency to fracture and disintegrate, an unstable solid-electrolyte interphase (SEI) layer, and low Coulombic efficiency. Efforts to overcome these challenges are ongoing. This Review details recent progress in the research of batteries based on alloy-type anodes and discusses the direction of their future development. We conclude that improvements in structural design, the introduction of a protective interface, and the selection of suitable electrolytes are the most effective ways to improve the performance of alloy-type anodes. Furthermore, future studies should direct more attention toward analyzing their synergistic promoting effect.

Cellulose: Characteristics and applications for rechargeable batteries

Cellulose, an abundant natural polymer, has promising potential to be used for energy storage systems because of its excellent mechanical, structural, and physical characteristics. This review discusses the structural features of cellulose and describes its potential application as an electrode, separator, and binder, in various types of high-performing batteries. Various surface and structural characteristics of cellulose (e.g., fiber size, surface functional groups, the hierarchy of pores, and porosity levels) that contribute to its electrochemical performance are discussed. Cellulose structure/property/processing/function relationships are further focused and elucidated in terms of the latest developments in the emerging field of sustainable materials in Li-Ion, Na-Ion, and LiS batteries.

Occupational exposure to metals among battery recyclers in France: Biomonitoring and external dose measurements

In battery-recycling facilities, exposure to trace elements may occur through inhalation of contaminated dust or vapor emanating from the treatment processes. Exposure of battery-recycling workers to lead has been quite well covered in the literature. In contrast, we lack data on exposure to other elements contained in batteries. The aim of this study was to characterize the exposure of French battery recyclers to multiple elements using biomonitoring and airborne measurements. Eighty-six workers participated in the study. Inhalable metal concentrations were determined for personal airborne samples, and total exposure was determined from pre-shift and post-shift urine samples collected during the working week. In both types of sample, a total of 33 trace elements were measured using inductively coupled plasma mass spectrometry. Results showed battery recyclers to be mostly exposed to Cd, Co, Cr, Li, Mn, Ni, and Pb. Administrative and sorting workers were exposed at lower levels than maintenance, treatment, and dismantling workers. Cd, Co, Li, Mn, and Ni were detected at high levels in air samples, especially near the treatment facilities, with airborne cadmium levels of up to 79.4 µg/m³. Urinary sample analysis indicated exposure to Cd and Co, with levels measured at up to 27.6 and 3.34 µg/g of creatinine, respectively. Concentrations were compared to data reported for e-waste recycling companies. The data presented provide valuable information on exposure to trace elements for workers involved in battery-recycling. They also highlight the need to improve both collective and individual protective measures, which were not sufficient in the participating companies.

Metal-organic framework (MOF) composites as promising materials for energy storage applications

Metal-organic framework (MOF) composites are considered to be one of the most vital energy storage materials due to their advantages of high porousness, multifunction, various structures and controllable chemical compositions, which provide a great possibility to find suitable electrode materials for batteries and supercapacitors. However, MOF composites are still in the face of various challenges and difficulties that hinder their practical application. In this review, we introduce and summarize the applications of MOF composites in batteries, covering metal-ion batteries, lithium-sulfur batteries, lithium-oxygen batteries and zinc-air batteries, as well as supercapacitors. In addition, the application challenges of MOF composites in batteries and supercapacitors are also summarized. Finally, the basic ideas and directions for further development of these two types of electrochemical energy storage devices are proposed.

Farming for battery metals

Globally, there is a major shift to electric vehicles to combat climate change and these vehicles are currently powered by lithium-ion batteries that contain nickel cobalt manganese oxide materials. This technological change from internal combustion engines means that demand for battery minerals will need to increase by factors of >20 for the critical metals required for batteries in the next three decades. If this scenario plays out, it will require a dramatic increase in the worldwide capacity to produce nickel, manganese, cobalt, and lithium raw materials of sufficient purity. This demand could partly be met by agromining technology, which is a 'green technology' that extracts valuable products, including high-purity metal salts useful for the battery industry, from selected plants known as 'metal crops'. Farming for nickel, cobalt, and manganese is currently within reach, whereas lithium agromining has not yet been developed but has potential. SYNOPSIS: Agromining offers a sustainable approach to economically produce battery-grade raw materials from unconventional sources, thus, producing 'green technologies' from 'green sources'.

Recent progress on Sb- and Bi-based chalcogenide anodes for potassium ion batteries

Potassium ion batteries (PIBs) are potential alternative energy storage systems to lithium ion batteries (LIBs), due to elemental abundance of potassium, low cost and similar working principle to LIBs. Recently, metal chalcogenides (MCs) have gained enormous interests, especially antimony (Sb)-, bismuth (Bi) -based chalcogenides because they were able to undergo alloying/conversion dual mechanism, which can provide higher specific capacity and energy density (K 3 Sb~660 mA h g -1 , K 3 Bi~385 mA h g -1 ). However, several challenges hinder the development of Sb-, Bi-based chalcogenide anode materials for PIBs , such as huge volume expansion during potassiation, unstable solid-electrolyte interface (SEI), slow reaction kinetics, and polychalcogenide-induced shuttle effect . In this review, the current state-of-the-art Sb-, Bi-based chalcogenides are comprehensively summarized, including the reaction mechanism, electrochemical performance, ingenious nanostructures, electrolyte systems, and prospects for future development. This review contributes to understanding the K + storage mechanism and the interaction between active materials and electrolytes, providing guidance and foundation for the design of next-generation high-performance PIBs.

Charting a sustainable course for batteries

A panel of leading global experts working at the forefront of battery research and applications shares insights into how further development of this critical energy technology can effectively integrate sustainability principles.

Perspective on design and technical challenges of Li-garnet solid-state batteries

Solid-state Li-ion batteries based on Li-garnet Li₇La₃Zr₂O₁₂ (LLZO) electrolyte have seen rapid advances in recent years. These solid-state systems are poised to address the urgent need for safe, non-flammable, and temperature-tolerant energy storage batteries that concomitantly possess improved energy densities and the cycle life as compared to conventional liquid-electrolyte-based counterparts. In this vision article, we review present research pursuits and discuss the limitations in the employment of LLZO solid-state electrolyte (SSE) for solid-state Li-ion batteries. Particular emphasis is given to the discussion of pros and cons of current methodologies in the fabrication of solid-state cathodes, LLZO SSE, and Li metal anode layers. Furthermore, we discuss the contributions of the LLZO thickness, cathode areal capacity, and LLZO content in the solid-state cathode on the energy density of Li-garnet solid-state batteries, summarizing their required values for matching the energy densities of conventional Li-ion systems. Finally, we highlight challenges that must be addressed in the move towards eventual commercialization of Li-garnet solid-state batteries.

Crystal Channel Engineering for Rapid Ion Transport: From Nature to Batteries

Ion transport behaviours through cell membranes are commonly identified in biological systems, which are crucial for sustaining life for organisms. Similarly, ion transport is significant for electrochemical ion storage in rechargeable batteries, which has attracted much attention in recent years. Rapid ion transport can be well achieved by crystal channels engineering, such as creating pores or tailoring interlayer spacing down to the nanometre or even sub-nanometre scale. Furthermore, some functional channels, such as ion selective channels and stimulus-responsive channels, are developed for smart ion storage applications. In this review, the typical ion transport phenomena in the biological systems, including ion channels and pumps, are first introduced, and then ion transport mechanisms in solid and liquid crystals are comprehensively reviewed, particularly for the widely studied porous inorganic/organic hybrid crystals and ultrathin inorganic materials. Subsequently, recent progress on the ion transport properties in electrodes and electrolytes is reviewed for rechargeable batteries. Finally, current challenges in the ion transport behaviours in rechargeable batteries are analysed and some potential research approaches, such as bioinspired ultrafast ion transport structures and membranes, are proposed for future studies. It is expected that this review can give a comprehensive understanding on the ion transport mechanisms within crystals and provide some novel design concepts on promoting electrochemical ion storage capability in rechargeable batteries.

Intentional ingestion of batteries and razor blades by a prisoner: a true emergency?

PURPOSE

Few case studies in the literature report on adult patients with intentional foreign body ingestion. Prisoners deliberately ingest foreign bodies, such as cylindrical alkaline batteries and razor blades, to achieve hospitalization or commit suicide. The purpose of this paper is to present a case of deliberate ingestion of batteries and razor blades by an inmate.

DESIGN/METHODOLOGY/APPROACH

The authors present a case of an incarcerated man in Greece, who intentionally ingested three cylindrical alkaline batteries and three razor blades wrapped in aluminum foil.

FINDINGS

The patient was treated conservatively with serial radiographs and was subsequently discharged without complication. This paper discusses the complications and examine the current guidelines available.

ORIGINALITY/VALUE

To best of authors' knowledge, this is the first report of a simultaneous ingestion of batteries and razor blades.

A Review of Graphene: Material Synthesis from Biomass Sources

Single-atom-thick graphene is a particularly interesting material in basic research and applications owing to its remarkable electronic, mechanical, chemical, thermal, and optical properties. This leads to its potential use in a multitude of applications for improved energy storage (capacitors, batteries, and fuel cells), energy generation, biomedical, sensors or even as an advanced membrane material for separations. This paper provided an overview of research in graphene, in the area of synthesis from various sources specially from biomass, advanced characterization techniques, properties, and application. Finally, some challenges and future perspectives of graphene are also discussed.

Intranasal foreign bodies: A 10-year analysis of a large cohort, in a tertiary medical center

BACKGROUND

Nasal foreign bodies (NFB) are commonly seen in pediatric patients seeking medical attention in the emergency department (ED). We aim to describe the occurrence, clinical presentation and management, of these cases, and to assess various risk factors for complications.

METHODS

A retrospective analysis of a computerized patient directory of 562 children admitted to the emergency department during a 10-year period, with NFB, in a tertiary pediatric hospital.

RESULTS

Upon admittance, most of the children (82%) were asymptomatic. Among the symptomatic children (18%), the primary symptoms were nasal discharge (10%), epistaxis (8%) and pain (4%). Younger children (under 4 years) were more likely to insert organic materials, compared to older children. Younger children were also admitted sooner to the emergency department and were more likely to present with nasal discharge. The overall complication rate was 5%. None of the children had aspirated the foreign body. Complications included infection (2%), necrosis (0.7%), septal perforation (0.5%), deep mucosal laceration (1.5%) and loss of foreign body (1.9%). Significantly higher rates of symptoms and complications were associated with button batteries. Increased risk for complications were observed according to type of foreign body, multiple attempts to remove it, posterior insertion and left-side insertion.

CONCLUSIONS

Nasal foreign bodies in children are common. Mostly, patients are asymptomatic, therefore a high index of suspicion is required, for quick diagnosis and safe removal, without complications.

Advances in Electrochemical and Catalytic Performance of Nanostructured FeCo2 O4 and Its Composites

It is well established that the excessive and uncontrolled use of fossil fuels and organic chemicals have put a risk to the earth's environment and the life that sustains within it. Carbon-free, sustainable, alternative energy technologies have therefore become the prime focus of current research. Smart inorganic materials have emerged as the potential solution to suffice energy needs and remediate the organic pollutants discharged to the environment. One such promising, versatile material is FeCo₂ O₄ which has gained immense research interest in the present decade due to its high efficiency and performance in energy and environmental applications. Innovative material design strategies involving the interplay of nanostructured morphology, chemical composition, redox surface states, and defect engineering have significantly enhanced both electrochemical and catalytic properties of FeCo₂ O₄ . Therefore, this review article aims to provide the first-ever comprehensive account of the latest research and developments in design-synthesis strategies, characterization techniques, and applications of nanostructured FeCo₂ O₄ and its composites in various electrochemical as well as catalytic applications. A detailed account of the nanostructured FeCo₂ O₄ and its composites in various energy storage and conversion devices such as supercapacitors (SCs), batteries, and fuel cells has been presented. Furthermore, a special section has been devoted to highlight the role of FeCo₂ O₄ in enhancing the sluggish reaction kinetics of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in water splitting application. This review also highlights the role of nanostructured FeCo₂ O₄ in photocatalytic waste water treatment, gas sensing, and dual-phase membrane technologies wherein FeCo₂ O₄ has demonstrated promising performance.

Comparison of different ecotoxicological batteries with WOE approach for the environmental quality evaluation of harbour sediments

This study was conducted under the Italian Ministerial Decree D.M. 173/2016 which regulates the assessment of the Sediment Class Quality in Italy using ecotoxicological bioassay and chemical analysis (Weight-Of-Evidence model). The aim of this work was to evaluate the real classification obtained by the theoretically equivalent responses of nine different combinations of batteries based on six different species: Aliivibrio fischeri (inhibition of bioluminescence), Phaeodactylum tricornutum, Skeletonema costatum, Dunaliella tertiolecta (inhibition of algal growth), Paracentrotus lividus and Crassostrea gigas (embryotoxicity). Bioassays, in many cases, showed a non-bioavailability effect of the pollutants; these one highly revealed by the chemical analyses. Algal species showed responses very similar from each other. Otherwise, species used for embryotoxicity produced wide responses, consequently modifying the quality class of sediments and the handling management (i.e. landfill confinement or beach nourishment) allowed by the Law.

Template-free fabrication of 1D core-shell MoO2@MoS2/nitrogen-doped carbon nanorods for enhanced lithium/sodium-ion storage

A universal anode material of 1D core-shell MoO₂@MoS₂/nitrogen-doped carbon (MoO₂@MoS₂/NC) nanorods has been elaborately synthesized via a facile fabrication route for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), in which MoO₂ core not only acts as a conductive backbone for efficient electron transport, but creates structural disorders in MoS₂ nanosheets to prevent aggregation and expose more active sites for alkali-ions. Meanwhile, the MoO₂ core is tightly encapsulated by the parallelly aligned MoS₂ nanosheets to constrain the size of crystals, which greatly shortens the ionic diffusion path and accelerates diffusion rate, thus ensuring fast reaction kinetics. Additionally, the resilient and conductive N-doped carbon matrix in the hybrid could maintain the structural integrity and enhance the electrical conductivity of the electrodes, improving the rate capability and life span. The flexible 1D nanorods could contract freely during the charge/discharge process, further assuring the structural stability of the electrodes. Benefiting from the above-mentioned advantages, the MoO₂@MoS₂/NC electrodes still remains a specific capacity of 583.5 mA h g^-1 after 1500 cycles at a high current density up to 10 A g^-1 in LIBs, and a capacity of 419.8 mA h g^-1 is steadily kept over 800 cycles at 2 A g^-1 in SIBs.

Recycling of Primary Lithium Batteries Production Residues

Production waste of primary lithium batteries constitutes a considerable secondary lithium feedstock. Although the recycling of lithium batteries is a widely studied field of research, the metallic residues of non‐rechargeable lithium battery production are disposed of as waste without further recycling. The risks of handling metallic Li on a large scale typically prevent the metal from being recycled. A way out of this situation is to handle Li in an aqueous solution, from where it can be isolated as Li₂CO₃. However, the challenge in hydrometallurgical treatment lies in the high energy release during dissolution and generation of H₂. To reduce these process‐related risks, the Li sheet metal punching residues underwent oxidative thermal treatment from 300 to 400 °C prior to dissolution in water. Converting Li metal to Li₂O in this initial process step results in an energy release reduction of ∼70 %. The optimal oxidation conditions have been determined by experimental design varying three factors: temperature, Li metal sheet thickness, and residence time. With 96.9±2.6 % almost the entire Li amount is converted to Li₂O, after 2.5 h treatment at 400 °C for a Li sheet thickness of 1.99 mm. Final precipitation with CO₂ yields 85.5±3.0 % Li₂CO₃. Using pure Li sheets, the product Li₂CO₃ is obtained in battery‐grade quality (>99.5 %). Non‐precipitated Li is recirculated into the process on the stage of dissolving Li₂O, thus avoiding loss of material.

Elucidating Interfacial Stability between Lithium Metal Anode and Li Phosphorus Oxynitride via In Situ Electron Microscopy

Li phosphorus oxynitride (LiPON) is one of a very few solid electrolytes that have demonstrated high stability against Li metal and extended cyclability with high Coulombic efficiency for all solid-state batteries (ASSBs). However, theoretical calculations show that LiPON reacts with Li metal. Here, we utilize in situ electron microscopy to observe the dynamic evolutions at the LiPON-Li interface upon contacting and under biasing. We reveal that a thin interface layer (∼60 nm) develops at the LiPON-Li interface upon contact. This layer is composed of conductive binary compounds that show a unique spatial distribution that warrants an electrochemical stability of the interface, serving as an effective passivation layer. Our results explicate the excellent cyclability of LiPON and reconcile the existing debates regarding the stability of the LiPON-Li interface, demonstrating that, though glassy solid electrolytes may not have a perfect initial electrochemical window with Li metal, they may excel in future applications for ASSBs.

Environmental and economic optima of solar home systems design: A combined LCA and LCC approach

This paper compares the economic and environmental optimal design of Solar Home Systems (SHSs) and explores the role of economic incentives (such as tariffs and technology costs) in approximating the two optima. To achieve that, we present a methodology for the environmental and economic evaluation of grid-connected SHSs: user-scale electric systems involving a photovoltaic (PV) power system and a battery energy storage system. The proposed methodology is based on a mixed integer linear programming (MILP) optimization, life cycle assessment and life cycle costing. This methodological framework is applied to a case study involving a typical SHS installation in Italy. The results of the environmental optimal design brought to the evaluation of a 3.25 kW PV assisted by 8.66 kWh of nickel cobalt manganese batteries, whereas the costs of the SHS are minimized by a small PV system (less than 1 kW). Results underline that the environmental optimal configurations rely on battery technologies, which entails a significant cost compared to the grid connection. In contrast, the economic optimal design solutions is less impactful than the grid mix both from an environmental and economic points of view. Thanks to a reduction of batteries and PV costs, the environmental impact of the economic optimal design is expected to decrease in the future.

Emerging Potassium-ion Hybrid Capacitors

As a new type of capacitor-battery hybrid energy storage device, metal-ion capacitors have attracted widespread attention because of their high-power density while ensuring energy density and long lifespan. Potassium-ion capacitors (KICs) featuring the merits of abundant potassium resources, lower standard electrode potential, and low cost have been considered as potential alternatives to lithium-/sodium-ion capacitors. However, KICs still face issues including unsatisfactory reaction kinetics, low energy density, and poor lifetime owing to the large radius of the potassium ion. In this Review, the importance of emerging potassium-ion capacitor is addressed. The Review offers a brief discussion of the fundamental working principle of KICs, along with an overview of recent advances and achievements of a variety of electrode materials for dual carbon and non-dual carbon KICs. Furthermore, electrolyte chemistry, binders as well as electrode/electrolyte interface, are summarized. Finally, existing challenges and perspectives on further development of KICs are also presented.

Determining phase transitions of layered oxides via electrochemical and crystallographic analysis

The chemical diffusion coefficient in LiNi_1/3Mn_1/3Co_1/3O₂ was determined via the galvanostatic intermittent titration technique in the voltage range 3 to 4.2 V. Calculated diffusion coefficients in these layered oxide cathodes during charging and discharging reach a minimum at the open-circuit voltage of 3.8 V and 3.7 V vs. Li/Li⁺, respectively. The observed minima of the chemical diffusion coefficients indicate a phase transition in this voltage range. The unit cell parameters of LiNi_1/3Mn_1/3Co_1/3O₂ cathodes were determined at different lithiation states using ex situ crystallographic analysis. It was shown that the unit cell parameter variation correlates well with the observed values for chemical diffusion in NMC cathodes; with a notable change in absolute values in the same voltage range. We relate the observed variation in unit cell parameters to the nickel conversion into the trivalent state, which is Jahn-Teller active, and to the re-arrangement of lithium ions and vacancies.

Two-Dimensional Black Phosphorus Nanomaterials: Emerging Advances in Electrochemical Energy Storage Science

Two-dimensional black phosphorus (2D BP), well known as phosphorene, has triggered tremendous attention since the first discovery in 2014. The unique puckered monolayer structure endows 2D BP intriguing properties, which facilitate its potential applications in various fields, such as catalyst, energy storage, sensor, etc. Owing to the large surface area, good electric conductivity, and high theoretical specific capacity, 2D BP has been widely studied as electrode materials and significantly enhanced the performance of energy storage devices. With the rapid development of energy storage devices based on 2D BP, a timely review on this topic is in demand to further extend the application of 2D BP in energy storage. In this review, recent advances in experimental and theoretical development of 2D BP are presented along with its structures, properties, and synthetic methods. Particularly, their emerging applications in electrochemical energy storage, including Li-/K-/Mg-/Na-ion, Li-S batteries, and supercapacitors, are systematically summarized with milestones as well as the challenges. Benefited from the fast-growing dynamic investigation of 2D BP, some possible improvements and constructive perspectives are provided to guide the design of 2D BP-based energy storage devices with high performance.

Single-Step Synthesis of Mesoporous Carbon Nitride/Molybdenum Sulfide Nanohybrids for High-Performance Sodium-Ion Batteries

Molybdenum disulfide (MoS₂ ) is a promising candidate as a high-performing anode material for sodium-ion batteries (SIBs) due to its large interlayer spacing. However, it suffers from continued capacity fading. This problem could be overcome by hybridizing MoS₂ with nanostructured carbon-based materials, but it is quite challenging. Herein, we demonstrate a single-step strategy for the preparation of MoS₂ coupled with ordered mesoporous carbon nitride using a nanotemplating approach which involves the pyrolysis of phosphomolybdic acid hydrate (PMA), dithiooxamide (DTO) and 5-amino-1H-tetrazole (5-ATTZ) together in the porous channels of 3D mesoporous silica template. The sulfidation to MoS₂ , polymerization to carbon nitride (CN) and their hybridization occur simultaneously within a mesoporous silica template during a calcination process. The CN/MoS₂ hybrid prepared by this unique approach is highly pure and exhibits good crystallinity as well as delivers excellent performance for SIBs with specific capacities of 605 and 431 mAhg^-1 at current densities of 100 and 1000 mAg^-1 , respectively, for SIBs.

Life Cycle Inventory datasets for nano-grid configurations

Datasets concerning some user-scale Smart Grids, named Nano-grids, are reported in this paper. First several Solar Home Systems composed of a photovoltaic plant, a backup generator and different types of lithium-ion batteries are provided. Then, the inventory analysis of hybrid Nano-grids integrating batteries and hydrogen storage is outlined according to different scenarios. These data inventory could be useful for any academic or stakeholder interested in reproducing this analysis and/or developing environmental sustainability assessment in the field of Smart Grids. For more insight, please see "Environmental analysis of a Nano-Grid: a Life Cycle Assessment" by Rossi F, Parisi M.L., Maranghi S., Basosi R., Sinicropi A. [1].

Distinct Nanoscale Interphases and Morphology of Lithium Metal Electrodes Operating at Low Temperatures

While Li-ion batteries are known to fail at temperatures below -20 °C, very little is known regarding the low-temperature behavior of next-generation high-capacity electrode materials. The lithium metal anode is of particular interest for high-energy battery chemistries, but improved understanding of and control over its electrochemical and nanoscale interfacial behavior in diverse conditions is necessary. Here, we investigate lithium deposition/stripping, morphology evolution, and solid-electrolyte interphase (SEI) structure and properties down to -80 °C using an ether-based electrolyte (DOL/DME). As temperature is reduced, we find that the morphology of deposited lithium is significantly altered. Furthermore, cryogenic transmission electron microscopy coupled with vacuum-transfer X-ray photoelectron spectroscopy reveal that the SEI exhibits different structure, chemistry, thickness, and conductive properties at lower temperatures. These results show that Li is promising for batteries operating under extreme conditions, and the distinct nanoscale evolution of Li electrodes at different temperatures must be considered when designing high-energy batteries.

Cost analysis

Solar photovoltaic systems have become one of the most popular topics in the water management industry. Moreover, irrigation networks are water- and energy-hungry, and utility managers are likely to adapt water consumption (and consequently energy demand) to the hours in which there is energy availability. In countries such as Spain (with high irradiance values), solar energy is an available green alternative characterised by zero electricity costs and significantly lower environmental impact. In this work, several types of irrigation scheduled programmes (according to different irrigation sectors) that minimise the number of photovoltaic solar panels to be installed are studied; moreover, the effects of the variable costs linked to energy (energy and emissions costs) are presented. Finally, the effect of incorporating batteries for storing energy to protect the system against emergencies, such as unfavourable weather, is proposed. The irrigation hours available to satisfy water demands are limited by sunlight; they are also limited by the condition that the irrigation schedule type has to be rigid (predetermined rotation) and that the pressure at any node has to be above minimum pressure required by standards. A real case study is performed, and the results obtained demonstrate that there is no universal solution; this is because the portfolio of alternatives is based on investments for purchasing equipment at present and also on future energy savings (revenues). Apart from these two values, there is an economic value (equivalent discontinuous discount rate), which also influences the final results.

NASICON-Structured NaTi2(PO4)3 for Sustainable Energy Storage

Several emerging energy storage technologies and systems have been demonstrated that feature low cost, high rate capability, and durability for potential use in large-scale grid and high-power applications. Owing to its outstanding ion conductivity, ultrafast Na-ion insertion kinetics, excellent structural stability, and large theoretical capacity, the sodium superionic conductor (NASICON)-structured insertion material NaTi2(PO4)3 (NTP) has attracted considerable attention as the optimal electrode material for sodium-ion batteries (SIBs) and Na-ion hybrid capacitors (NHCs). On the basis of recent studies, NaTi2(PO4)3 has raised the rate capabilities, cycling stability, and mass loading of rechargeable SIBs and NHCs to commercially acceptable levels. In this comprehensive review, starting with the structures and electrochemical properties of NTP, we present recent progress in the application of NTP to SIBs, including non-aqueous batteries, aqueous batteries, aqueous batteries with desalination, and sodium-ion hybrid capacitors. After a thorough discussion of the unique NASICON structure of NTP, various strategies for improving the performance of NTP electrode have been presented and summarized in detail. Further, the major challenges and perspectives regarding the prospects for the use of NTP-based electrodes in energy storage systems have also been summarized to offer a guideline for further improving the performance of NTP-based electrodes.

Reversible Sodium Metal Electrodes: Is Fluorine an Essential Interphasial Component?

Alkaline metals are an ideal negative electrode for rechargeable batteries. Forming a fluorine‐rich interphase by a fluorinated electrolyte is recognized as key to utilizing lithium metal electrodes, and the same strategy is being applied to sodium metal electrodes. However, their reversible plating/stripping reactions have yet to be achieved. Herein, we report a contrary concept of fluorine‐free electrolytes for sodium metal batteries. A sodium tetraphenylborate/monoglyme electrolyte enables reversible sodium plating/stripping at an average Coulombic efficiency of 99.85 % over 300 cycles. Importantly, the interphase is composed mainly of carbon, oxygen, and sodium elements with a negligible presence of fluorine, but it has both high stability and extremely low resistance. This work suggests a new direction for stabilizing sodium metal electrodes via fluorine‐free interphases.

Solvate Ionic Liquids for Li, Na, K, and Mg Batteries

From the viewpoint of element strategy, non-Li batteries with promising negative and positive electrodes have been widely studied to support a sustainable society. To develop non-Li batteries having high energy density, research on electrolyte materials is pivotal. Solvate ionic liquids (SILs) are an emerging class of electrolytes possessing somewhat superior properties for battery applications compared to conventional ionic liquid electrolytes. In this account, we describe our recent efforts regarding SIL-based electrolytes for Li, Na, K, and Mg batteries with respect to structural, physicochemical, and electrochemical characteristics. Systematic studies based on crystallography and Raman spectroscopy combined with thermal/electrochemical stability analysis showed that the balance of competitive cation-anion and cation-solvent interactions predominates the stability of the solvate cations. We also demonstrated battery applications of SILs as electrolytes for non-Li batteries, particularly for Na batteries.

A novel energy storage system incorporating electrically rechargeable liquid fuels as the storage medium

We propose a novel concept of energy storage that incorporates electrically rechargeable liquid fuels made of electroactive species, known as e-fuels, as the storage medium. This e-fuel energy storage system comprises an e-fuel charger and an e-fuel cell. The e-fuel charger electrically charges e-fuels, while the e-fuel cell subsequently generates electricity using charged e-fuels whenever and wherever on demand. The e-fuel energy storage system possesses all the advantages of conventional hydrogen storage systems, but unlike hydrogen, liquid e-fuels are as easy and safe to store and transport as gasoline. The potential e-fuel candidates have been identified to include inorganic electroactive materials, organic electroactive materials, and suspension of solid electroactive materials. In this work, we demonstrate an example e-fuel energy storage system for large-scale energy storage using inorganic e-fuels composed of V²⁺/V³⁺ and VO²⁺/VO₂⁺ redox couples, and compare the performance of the e-fuel energy storage system with that of existing technologies. Results show that our e-fuel charger achieves a charge efficiency of as high as ∼94%, while the e-fuel cell is capable of delivering a peak power density of 3.4 W cm^-2, which is 1.7 times higher than that of hydrogen fuel cells. More excitingly, the e-fuel energy storage system exhibits a round-trip efficiency of 80.0% and an electrolyte utilization of 83.0% at an ultra-high discharge current density of 1,000 mA cm^-2, which are 19.9% and 67.3% higher than those of conventional vanadium redox flow batteries. This unprecedented performance allows a 27.0% reduction in the capital cost of the e-fuel energy storage system compared with that of vanadium redox flow batteries.

Second life batteries lifespan: Rest of useful life and environmental analysis

Road transportation is heading towards electrification using Li-ion batteries to power electric vehicles offering eight or ten years' warrant. After that, batteries are considered inappropriate for traction services but they still have 80% of its original capacity. On the other hand, energy storage devices will have an important role in the electricity market. Being Li-ion batteries still too expensive to provide such services with economic profit, the idea to reuse affordable electric vehicle batteries for a 2nd life originated the Sunbatt project, connecting the automotive and electricity sectors. The battery reuse is, by itself, a path towards sustainability, but the cleanliness of energy storage also depends on the electricity generation power sources and the battery ageing or lifespan. This paper analyses the rest of useful life of 2nd life batteries on four different stationary applications, which are: Support to fast electric vehicle charges, self-consumption, area regulation and transmission deferral. To do so, it takes advantage of an equivalent electric battery-ageing model that simulates the battery capacity fade through its use. This model runs on Matlab and includes several ageing mechanisms, such as calendar ageing, C-rate, Depth-of-Discharge, temperature and voltage. Results show that 2nd life battery lifespan clearly depends on its use, going from about 30 years in fast electric vehicle charge support applications to around 6 years in area regulation grid services. Additionally, this study analyses the day-to-day emissions from electricity generation in Spain, and states that grid oriented energy storage applications will hardly offer environmental benefits in the nearby future. On the other hand, applications that go by the hand of renewable power sources, such as self-consumption applications, are much more appropriate.

Effectiveness of deposit-refund systems for household waste in the Netherlands: Applying a partial equilibrium model

Deposit-refund schemes (DRS) are basically a combination of two instruments: a tax on the purchase of a certain product, and a subsidy on the separate collection of the same product in its after-use stage. They can be efficient policy instruments to encourage reuse and recycling. However, empirical studies on impact of DRS systems on recycling rates are hardly done. In this paper, we applied the Fullerton-Wu model, a partial equilibrium model, to simulate the impact of introducing mandatory DRS for small electric appliances and batteries in the Netherlands. For small electric appliances, a deposit-refund rate of €5 to €15 per appliance would lead to an increase in the recycling rate (recycled appliances as a percentage of total amount of appliances disposed of) from 60.7% to 64.7% and 76.4% respectively. For batteries, a DRS would increase the recycling rate from 86.9% to between 87.2 and 89.2% depending on the deposit tax level ranging from €5 to €20 per kg and the price elasticities assumed (low and high). Obviously, the performance of DRS in terms of additional recycling is stronger in cases where current recycling rates are relatively low. Moreover, the pre-existence of an infrastructure for separate collection would make small white goods an interesting candidate for this instrument.

Lithium recovery from brines: A vital raw material for green energies with a potential environmental impact in its mining and processing

The electrification of our world is driving a strong increase in demand for lithium. Energy storage is paramount in electric and hybrid vehicles, in green but intermittent energy sources, and in smart grids in general. Lithium is a vital raw material for the build-up of both currently available lithium-ion batteries, and prospective next generation batteries such as lithium-air and lithium sulphur. The continued availability of lithium can only rely on a strong increase of mining and ore processing. It would be an inconsistency if the increased production of lithium for a more sustainable society would be associated with non-sustainable mining practices. Currently 2/3 of the world production of lithium is extracted from brines, a practice that evaporates on average half a million litres of brine per ton of lithium carbonate. Furthermore, the extraction is chemical intensive, extremely slow, and delivers large volumes of waste. This technology is heavily dependent on the geological structure of the deposits, brine chemical composition and both climate and weather conditions. Therefore, it is difficult to adapt from one successful exploitation to new deposits. A few years of simulations and piloting are needed before large scale production is achieved. Consequently, this technology is struggling with the current surge in demand. At time of writing, only 5 industrial scale facilities are in operation worldwide, highlighting the shortcomings in this technology. Both mining companies and academics are intensively searching for new technologies for lithium recovery from brines. However, focus on the chemistry of brine processing has left unattended the analysis of the sustainability of the overall process. Here we review both the current available technology and new proposed methodologies. We make a special focus on an overall sustainability analysis, with particular emphasis to the geological characteristics of deposits and water usage in relation to mining processes.

A study of MR signal reception from a model for a battery cell

Number of NMR/MRI studies on batteries is rapidly increasing in the past decade. As the test batteries designed for the studies contain metal parts such as electrodes and lead wires as well as other conductive parts (electrolyte), which all present obstacles for good MR signal reception, understanding of the role of battery design and of battery interactions with magnetic field is of a key importance for a successful performance of the experiments. For the study, five different samples mimicking a real battery cell were made. All the samples had two parallel copper electrodes separated by a gel layer, however, they differed in electrode thickness, gel conductivity and separation between the electrodes. The samples were inserted in an MRI magnet in different orientations with respect to magnetic fields B₀ and B₁ and scanned with the spin-echo and single point imaging methods in 2D and 3D (spin-echo only). The performed experiments confirmed that the main reason for poor MR signal reception from a test battery are RF-induced eddy currents. These were found stronger with the sample with the smaller distance between the electrodes. The effect of RF-induced eddy currents was efficiently suppressed when the sample was oriented with the electrodes parallel to the B₁ field. However, in the orientation there were still susceptibility effects that caused a signal voiding in a narrow region near the electrodes. The susceptibility effects were found lower with the sample with thin electrodes and the non-conductive gel. The results of the study can help optimizing test battery and capacitor designs for NMR/MRI experiments.

Pastes and hydrogels from carboxymethyl cellulose sodium salt as supporting electrolyte of solid electrochemical supercapacitors

Different carboxymethyl cellulose sodium salt (NaCMC)-based pastes and hydrogels, both containing a salt as supporting electrolyte, have been prepared and characterized as potential solid state electrolyte (SSE) for solid electrochemical supercapacitors (ESCs).The characteristics of the NaCMC-based SSEs have been optimized by examining the influence of five different factors in the capacitive response of poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes: i) the chemical nature of the salt used as supporting electrolyte; ii) the concentration of such salt; iii) the concentration of cellulose used to prepare the paste; iv) the concentration of citric acid employed during NaCMC cross-linking; and v) the treatment applied to recover the supporting electrolyte after washing the hydrogel. The specific capacitance of the device prepared using the optimized hydrogel as SSE is 81.5 and 76.8 F/g by means of cyclic voltammetry and galvanostatic charge/discharge, respectively, these values decreasing to 60.7 and 75.5 F/g when the SSE is the paste.

Selecting Power-Efficient Signal Features for a Low-Power Fall Detector

Falls are a serious threat to the health of older people. A wearable fall detector can automatically detect the occurrence of a fall and alert a caregiver or an emergency response service so they may deliver immediate assistance, improving the chances of recovering from fall-related injuries. One constraint of such a wearable technology is its limited battery life. Thus, minimization of power consumption is an important design concern, all the while maintaining satisfactory accuracy of the fall detection algorithms implemented on the wearable device. This paper proposes an approach for selecting power-efficient signal features such that the minimum desirable fall detection accuracy is assured. Using data collected in simulated falls, simulated activities of daily living, and real free-living trials, all using young volunteers, the proposed approach selects four features from a set of ten commonly used features, providing a power saving of 75.3%, while limiting the error rate of a binary classification decision tree fall detection algorithm to 7.1%.Falls are a serious threat to the health of older people. A wearable fall detector can automatically detect the occurrence of a fall and alert a caregiver or an emergency response service so they may deliver immediate assistance, improving the chances of recovering from fall-related injuries. One constraint of such a wearable technology is its limited battery life. Thus, minimization of power consumption is an important design concern, all the while maintaining satisfactory accuracy of the fall detection algorithms implemented on the wearable device. This paper proposes an approach for selecting power-efficient signal features such that the minimum desirable fall detection accuracy is assured. Using data collected in simulated falls, simulated activities of daily living, and real free-living trials, all using young volunteers, the proposed approach selects four features from a set of ten commonly used features, providing a power saving of 75.3%, while limiting the error rate of a binary classification decision tree fall detection algorithm to 7.1%.