Recycling lithium-ion batteries from electric vehicles

Simultaneously Blocking Chemical Crosstalk and Internal Short Circuit via Gel-Stretching Derived Nanoporous Non-Shrinkage Separator for Safe Lithium-Ion Batteries

The separator, an ionic permeable and electronic insulating membrane between cathode and anode, plays a crucial role in the electrochemical and safety performance of batteries. However, commercial polyolefin separators not only suffer from inevitable thermal shrinkage at elevated temperature, but also fail to inhibit the hidden chemical crosstalk of reactive gases such as O₂ , leading to often reported thermal runaway (TR) and hence preventing large-scale implementation of high-energy-density lithium-ion batteries. Herein, a nanoporous non-shrinkage separator (GS-PI) is fabricated via a novel gel-stretching orientation approach to eliminate TR. In situ synchrotron small angle X-ray scattering during heating clearly shows that the as-prepared thin GS-PI separator exhibits superior mechanical tolerance at high temperature, thus effectively preventing internal short circuit. Meanwhile, the unique nanoporous structure design further blocks chemical crosstalk and the associated exothermic reactions. Accelerating rate calorimetry tests reveal that the practical 1 Ah LiNi_0.6 Co_0.2 Mn_0.2 O₂ (NCM622)/graphite pouch cell using GS-PI nanoporous separator show a maximum temperature rise (dT/dt_max ) of only 3.7 °C s^-1 compared to 131.6 °C s^-1 in the case of Al₂ O₃ @PE macroporous separator. Moreover, despite the reduced pore size, the GS-PI separator demonstrates better cycling stability than conventional Al₂ O₃ @PE separator at high temperature without sacrificing specific capacity and rate capability.

The Influence of Temperature on the Capacity of Lithium Ion Batteries with Different Anodes

Temperature is considered to be an important indicator that affects the capacity of a lithium ion batteries. Therefore, it is of great significance to study the relationship between the capacity and temperature of lithium ion batteries with different anodes. In this study, the single battery is used as the research object to simulate the temperature environment during the actual use of the power battery, and conduct a charge and discharge comparison test for lithium iron phosphate battery, lithium manganate battery and lithium cobalt oxide battery. In the test of capacity characteristics of lithium ion batteries of three different cathode materials at different temperatures, the optimal operating temperature range of the lithium ion battery is extracted from the discharge efficiencies obtained. According to the research results, the discharge capacity of a lithium ion battery can be approximated by a cubic polynomial of temperature. The optimal operating temperature of lithium ion battery is 20–50 °C within 1 s, as time increases, the direct current (DC) internal resistance of the battery increases and the slope becomes smaller. Between 1 s and 10 s, the DC internal resistance of the battery basically shows a linear relationship with time. In the charge and discharge process, when state of charge (SOC) 0% and SOC 100%, the internal resistance of the battery is the largest. The SOC has the greatest impact on the polarization internal resistance, and the smallest impact on the ohmic internal resistance.

Cobalt Recovery from Li-Ion Battery Recycling: A Critical Review

The increasing demand for Li-ion batteries for electric vehicles sheds light upon the Co supply chain. The metal is crucial to the cathode of these batteries, and the leading global producer is the D.R. Congo (70%). For this reason, it is considered critical/strategic due to the risk of interruption of supply in the short and medium term. Due to the increasing consumption for the transportation market, the batteries might be considered a secondary source of Co. The outstanding amount of spent batteries makes them to a core of urban mining warranting special attention. Greener technologies for Co recovery are necessary to achieve sustainable development. As a result of these sourcing challenges, this study is devoted to reviewing the techniques for Co recovery, such as acid leaching (inorganic and organic), separation (solvent extraction, ion exchange resins, and precipitation), and emerging technologies—ionic liquids, deep eutectic solvent, supercritical fluids, nanotechnology, and biohydrometallurgy. A dearth of research in emerging technologies for Co recovery from Li-ion batteries is discussed throughout the manuscript within a broader overview. The study is strictly connected to the Sustainability Development Goals (SDG) number 7, 8, 9, and 12.

Positive Role of Fluorine Impurity in Recovered LiNi0.6Co0.2Mn0.2O2 Cathode Materials

Lithium-ion battery (LIB) recycling is considered as an important component to enable industry sustainability. A massive number of LIBs in portable electronics, electric vehicles, and grid storage will eventually end up as wastes, leading to serious economic and environmental problems. Hence, tremendous efforts have been made to improve the hydrometallurgical recycling process because it is the most promising option for handling end-of-life LIBs owing to its wide applicability, low cost, and high productivity. Despite these advantages, some extra elements (Al, Fe, C, F, and so forth) remain as impurities in the removal process and are retained in the solution, which is a great challenge to obtain high-quality cathode materials. In this work, the impacts caused by fluorine impurity on the LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) cathode are intensively investigated via hydrometallurgical coprecipitation for the first time. Our results show that up to 1 at. % fluorine impurity brings a positive influence on the recovered material due to a higher Ni²⁺ ratio on the surface of cathode particles. In addition, the presence of fluoride ions during coprecipitation could lead to the formation of holes in cathode particles, which improves the rate capability and cyclability dramatically. Compared to the virgin material, the capacity of the NCM622 material with 0.2 at. % fluorine impurity is boosted by ∼8% (167.7 mA h/g) with a remarkable capacity retention of 98.0% after 100 cycles at 0.33 C. Besides, the cathode with 0.2 at. % fluorine impurity shows a far better rate performance, especially at high rates (∼7% increased at 5 C) than that of virgin. These results convince that a low concentration of fluorine impurity is desirable in the hydrometallurgical recycling process. More importantly, this study offers implications in the design of high-performance NCM622 cathode materials via coprecipitation production with ion doping in the near future.

Uncertain Future of American Lithium: A Perspective until 2050

During the 20th century, the United States went from being the largest producer and user of lithium to being heavily reliant on imports from Asia, particularly lithium-ion batteries. To explore different futures for U.S. lithium, we here generate four scenarios─including COVID-19 implications─that model lithium use for its main applications: electric and hybrid vehicles, stationary energy storage systems, and small electronics. We find that the "Sustainable Future" scenario requires the highest amount of lithium (cumulatively 1281 Gg in the period 2020-2050, peak inflow in 2040 at 53 Gg); in contrast, "Fossil Fuel Everything" requires only 500 Gg and peaks in 2050 at 26 Gg. COVID-19 implications appear to be negligible in the long run. The future electrification of the U.S. vehicle fleet and energy storage systems will depend upon a reliable and resilient international supply chain of lithium chemicals and/or batteries as well as vigorous recycling efforts.

Hetero-Element-Doped Molybdenum Oxide Materials for Energy Storage Systems

In order to meet the growing demand for the electronics market, many new materials have been studied to replace traditional electrode materials for energy storage systems. Molybdenum oxide materials are electrode materials with higher theoretical capacity than graphene, which was originally used as anode electrodes for lithium-ion batteries. In subsequent studies, they have a wider application in the field of energy storage, such as being used as cathodes or anodes for other ion batteries (sodium-ion batteries, potassium-ion batteries, etc.), and electrode materials for supercapacitors. However, molybdenum oxide materials have serious volume expansion concerns and irreversible capacity dropping during the cycles. To solve these problems, doping with different elements has become a suitable option, being an effective method that can change the crystal structure of the materials and improve the performances. Therefore, there are many research studies on metal element doping or non-metal doping molybdenum oxides. This paper summarizes the recent research on the application of hetero-element-doped molybdenum oxides in the field of energy storage, and it also provides some brief analysis and insights.

Porous Co2VO4 Nanodisk as a High-Energy and Fast-Charging Anode for Lithium-Ion Batteries

The Li⁺ diffusion coefficient of Co₂VO₄ is evaluated by theoretical calculation to be as high as 3.15 × 10^–10 cm² s⁻¹, theoretically proving Co₂VO₄ a promising anode in fast-charging lithium-ion batteries.

A hexagonal porous Co₂VO₄ nanodisk (PCVO ND) structure is designed, featuring a high specific surface area of 74.57 m² g⁻¹ and numerous pores with a pore size of 14 nm.

The PCVO ND shows excellent fast-charging performance (a high average capacity of 344.3 mAh g⁻¹ at 10 C for 1000 cycles with only 0.024% capacity loss per cycle for 1000 cycles).

High-energy–density lithium-ion batteries (LIBs) that can be safely fast-charged are desirable for electric vehicles. However, sub-optimal lithiation potential and low capacity of commonly used LIBs anode cause safety issues and low energy density. Here we hypothesize that a cobalt vanadate oxide, Co₂VO₄, can be attractive anode material for fast-charging LIBs due to its high capacity (~ 1000 mAh g⁻¹) and safe lithiation potential (~ 0.65 V vs. Li⁺/Li). The Li⁺ diffusion coefficient of Co₂VO₄ is evaluated by theoretical calculation to be as high as 3.15 × 10^–10 cm² s⁻¹, proving Co₂VO₄ a promising anode in fast-charging LIBs. A hexagonal porous Co₂VO₄ nanodisk (PCVO ND) structure is designed accordingly, featuring a high specific surface area of 74.57 m² g⁻¹ and numerous pores with a pore size of 14 nm. This unique structure succeeds in enhancing Li⁺ and electron transfer, leading to superior fast-charging performance than current commercial anodes. As a result, the PCVO ND shows a high initial reversible capacity of 911.0 mAh g⁻¹ at 0.4 C, excellent fast-charging capacity (344.3 mAh g⁻¹ at 10 C for 1000 cycles), outstanding long-term cycling stability (only 0.024% capacity loss per cycle at 10 C for 1000 cycles), confirming the commercial feasibility of PCVO ND in fast-charging LIBs.

Degradation of Lithium-Ion Batteries in an Electric Transport Complex

The article provides an overview and comparative analysis of various types of batteries, including the most modern type—lithium-ion batteries. Currently, lithium-ion batteries (LIB) are widely used in electrical complexes and systems, including as a traction battery for electric vehicles. Increasing the service life of the storage devices used today is an important scientific and technical problem due to their rapid wear and tear and high cost. This article discusses the main approaches and methods for researching the LIB resource. First of all, a detailed analysis of the causes of degradation was carried out and the processes occurring in lithium-ion batteries during charging, discharging, resting and difficult operating conditions were established. Then, the main factors influencing the service life are determined: charging and discharging currents, self-discharge current, temperature, number of cycles, discharge depth, operating range of charge level, etc. when simulating a real motion process. The work considers the battery management systems (BMS) that take into account and compensate for the influence of the factors considered. In the conclusion, the positive and negative characteristics of the presented methods of scientific research of the residual life of LIB are given and recommendations are given for the choice of practical solutions to engineers and designers of batteries. The work also analyzed various operating cycles of electric transport, including heavy forced modes, extreme operating modes (when the amount of discharge and discharge of batteries is greater than the nominal value) and their effect on the degradation of lithium-ion batteries.

Coupling regeneration strategy of lithium-ion electrode materials turned with naphthalenedisulfonic acid

The resource exhaustion and environmental assessment driven by sustainable development make recycle of spent LIBs urgent to be achieved. However, the conventional recycling processes are quite complicated in terms of the tedious steps and secondary contamination. In this paper, hydrosoluble naphthalenedisulfonic acid is firstly proposed to selectively extract valuable metals (Co and Li) for the regeneration of battery materials. Lithium is selectively recovered as lithium enriched solution with a high yield of 99%, while 96.6% cobalt remains in a complex-precipitate benefited from the high acidity and coordination role of naphthalenedisulfonic acid. The leaching of Li fits well with the logarithmic rate law model with an activation energy of 32.42 kJ/mol. Additionally, the regenerated lithium-ion battery active materials (Co₃O₄ anode and LiCoO₂ cathode) prepared from the cobalt complex-precipitate and lithium-enriched solution exhibit excellent discharged-charged performances and rate capability. This feasible strategy assisted by multifunctional naphthalenedisulfonic acid may offer an alternative option for the simultaneous recovery of Li and Co and the rational resource utilization of spent lithium-ion batteries.

From mine to mind and mobiles - Lithium contamination and its risk management

With the ever-increasing demand for lithium (Li) for portable energy storage devices, there is a global concern associated with environmental contamination of Li, via the production, use, and disposal of Li-containing products, including mobile phones and mood-stabilizing drugs. While geogenic Li is sparingly soluble, Li added to soil is one of the most mobile cations in soil, which can leach to groundwater and reach surface water through runoff. Lithium is readily taken up by plants and has relatively high plant accumulation coefficient, albeit the underlying mechanisms have not been well described. Therefore, soil contamination with Li could reach the food chain due to its mobility in surface- and ground-waters and uptake into plants. High environmental Li levels adversely affect the health of humans, animals, and plants. Lithium toxicity can be considerably managed through various remediation approaches such as immobilization using clay-like amendments and/or chelate-enhanced phytoremediation. This review integrates fundamental aspects of Li distribution and behaviour in terrestrial and aquatic environments in an effort to efficiently remediate Li-contaminated ecosystems. As research to date has not provided a clear picture of how the increased production and disposal of Li-based products adversely impact human and ecosystem health, there is an urgent need for further studies on this field.

Enabling Intelligent Recovery of Critical Materials from Li-Ion Battery through Direct Recycling Process with Internet-of-Things

The rapid market expansion of Li-ion batteries (LIBs) leads to concerns over the appropriate disposal of hazardous battery waste and the sustainability in the supply of critical materials for LIB production. Technologies and strategies to extend the life of LIBs and reuse the materials have long been sought. Direct recycling is a more effective recycling approach than existing ones with respect to cost, energy consumption, and emissions. This approach has become increasingly more feasible due to digitalization and the adoption of the Internet-of-Things (IoT). To address the question of how IoT could enhance direct recycling of LIBs, we first highlight the importance of direct recycling in tackling the challenges in the supply chain of LIB and discuss the characteristics and application of IoT technologies, which could enhance direct recycling. Finally, we share our perspective on a paradigm where IoT could be integrated into the direct recycling process of LIBs to enhance the efficiency, intelligence, and effectiveness of the recycling process.

Global research on the air quality status in response to the electrification of vehicles

Electric vehicles (EVs) can substantially decrease atmospheric pollutant emissions, thereby improving air quality, decreasing global warming, and improving human health. In this study, we performed a comprehensive bibliometric analysis using Web of Science to understand the research developments and future perspectives in EVs between 1974 and 2021. The analysis of indicators such as research trends, publication growth, and keywords revealed that most research in the selected timeframe was focused on applying and optimizing the existing technologies of different types of EVs to decrease air pollution and mortality. The changes in air quality owing to such electrification received special attention, with approximately 441 publications preferably in the English language. Among all the retrieved documents, research articles were most common (n = 295; 66.89% of the global output), dominated by the research domains of environmental sciences, followed by energy fuels and transportation science technology. Journal analysis revealed that Sustainability (n = 19, 4.30%) was the leading journal, followed by Journal of Cleaner Production and Science of the Total Environment. The most frequently used keywords were "electric vehicles," "air quality," and "air pollution." The most highly impactful article was published by Jacobson et al. (2005) in Science, with 620 total citations and 38.82 average annual citations. Furthermore, the United States (n = 118; 26.75% of the global output) had the highest publication rate, followed by China and the United Kingdom. The leading institutions were Tsinghua University (n = 16; 3.62% of the global research output) in China, followed by the University of Michigan and Cornell University in the United States. The current analysis warrants more focus on comprehensive analysis employing transport and chemistry modeling and using the latest technology for long life and sustainable batteries. This study provides a basis for future studies on improving air quality through innovative work in the electrification of vehicles.

Efficient separation of aluminum foil from mixed-type spent lithium-ion power batteries

The disposal of spent lithium-ion power batteries (LIBs) has become an important research topic owing to the booming market for electric vehicles. However, the recovery efficiency of the alkaline solution and organic solvent methods currently used to separate Al foil from cathode materials still has room for improvement. The insufficient separation of Al foil and complexity of the battery types present obstacles to the extraction of valuable metals using simple processes. In this study, an efficient approach is developed to separate the Al foil in mixed-type spent LIBs (M-LIBs), namely, LiNi_xCo_yMn_zO₂ (NCM), LiFePO₄ (LFP), and LiMn₂O₄ (LMO) LIBs, by controlled pyrolysis. Hundred percent of the Al foil was recovered at the temperature of 450 °C, holding time of 60 min, and heating rate of 10 °C/min. The purity of Al in the recovered foil was 99.41 %, 99.83 % and 99.92 %, and the recovery efficiency of the active cathode materials was 96.01 %, 99.80 % and 99.15 % for NCM, LFP and LMO, respectively, without the loss of active cathode materials. The obtained active cathode materials exhibited a favorable crystalline structure, and the average particle diameter was reduced from 300.497 to 24.316 μm with a smaller and looser morphology. The process could be well fitted with the Friedman differential equation, and the correlation coefficients were higher than 0.99. The efficient separation could be attributed to the complete rupture of long chain -(CH₂CF₂)-_n bonds in the poly (vinylidene difluoride) (PVDF) binder, which resulted in the formation of HF, trifluorobenzene, alkanes, and gaseous single molecule CH₂CF₂. Therefore, this work potentially provides an alternative approach for the efficient separation of Al foil in M-LIBs, thereby simplifying the process and achieving lower cost, reduced loss of valuable metals, and higher recovery efficiency.

Selective cobalt and nickel electrodeposition for lithium-ion battery recycling through integrated electrolyte and interface control

Molecularly-selective metal separations are key to sustainable recycling of Li-ion battery electrodes. However, metals with close reduction potentials present a fundamental challenge for selective electrodeposition, especially for critical elements such as cobalt and nickel. Here, we demonstrate the synergistic combination of electrolyte control and interfacial design to achieve molecular selectivity for cobalt and nickel during potential-dependent electrodeposition. Concentrated chloride allows for the speciation control via distinct formation of anionic cobalt chloride complex (CoCl42-), while maintaining nickel in the cationic form ([Ni(H2O)5Cl]+). Furthermore, functionalizing electrodes with a positively charged polyelectrolyte (i.e., poly(diallyldimethylammonium) chloride) changes the mobility of CoCl42- by electrostatic stabilization, which tunes cobalt selectivity depending on the polyelectrolyte loading. This strategy is applied for the multicomponent metal recovery from commercially-sourced lithium nickel manganese cobalt oxide electrodes. We report a final purity of 96.4 ± 3.1% and 94.1 ± 2.3% for cobalt and nickel, respectively. Based on a technoeconomic analysis, we identify the limiting costs arising from the background electrolyte, and provide a promising outlook of selective electrodeposition as an efficient separation approach for battery recycling.

The Effect of Excessive Sulfate in the Li-Ion Battery Leachate on the Properties of Resynthesized Li[Ni1/3Co1/3Mn1/3]O2

In order to examine the effect of excessive sulfate in the leachate of spent Li-ion batteries (LIBs), LiNi_1/3Co_1/3Mn_1/3O₂ (pristine NCM) and sulfate-containing LiNi_1/3Co_1/3Mn_1/3O₂ (NCMS) are prepared by a co-precipitation method. The crystal structures, morphology, surface species, and electrochemical performances of both cathode active materials are studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and charge-discharge tests. The XRD patterns and XPS results identify the presence of sulfate groups on the surface of NCMS. While pristine NCM exhibits a very dense surface in SEM images, NCMS has a relatively porous surface, which could be attributed to the sulfate impurities that hinder the growth of primary particles. The charge-discharge tests show that discharge capacities of NCMS at C-rates, which range from 0.1 to 5 C, are slightly decreased compared to pristine NCM. In dQ/dV plots, pristine NCM and NCMS have the same redox overvoltage regardless of discharge C-rates. The omnipresent sulfate due to the sulfuric acid leaching of spent LIBs has a minimal effect on resynthesized NCM cathode active materials as long as their precursors are adequately washed.

Second life and recycling: Energy and environmental sustainability perspectives for high-performance lithium-ion batteries

Second life and recycling of retired automotive lithium-ion batteries (LIBs) have drawn growing attention, as large volumes of LIBs will retire in the coming decade. Here, we illustrate how battery chemistry, use, and recycling can influence the energy and environmental sustainability of LIBs. We find that LIBs with higher specific energy show better life cycle environmental performances, but their environmental benefits from second life application are less pronounced. Direct cathode recycling is found to be the most effective in reducing life cycle environmental impacts, while hydrometallurgical recycling provides limited sustainability benefits for high-performance LIBs. Battery design with less aluminum and alternative anode materials, such as silicon-based anode, could enable more sustainable LIB recycling. Compared to directly recycling LIBs after their electric vehicle use, carbon footprint and energy use of LIBs recycled after their second life can be reduced by 8 to 17% and 2 to 6%, respectively.

Layered Niobium Oxide Hydrate Anode with Excellent Performance for Lithium-Ion Batteries

Benefiting from the advantages of cost-effectiveness and sustainability, lithium-ion batteries (LIBs) are recognized as a next-generation energy technology with great development potential. Herein, niobium oxide hydrate (H₃ONb₃O₈) synthesized by a facile and inexpensive solvothermal method is proposed as the anode of LIBs. It is a layered two-dimensional material composed of negatively charged two-dimensional lamellae and positively charged interlayer hydronium ions. The former consist of NbO₆ octahedral units connected by bridging oxygen. Because of the mutual effect of hydronium ions and niobium oxide quantum dots, niobium oxide hydrate exhibits excellent electrochemical activity when used as an anode material. This compound is first applied to lithium-ion batteries, obtaining a high specific capacity (1232 mAh g^-1) at 100 mA g^-1 and maintaining an outstanding performance after 200 cycles. Therefore, this work not only proposes a simple preparation method of niobium oxide hydrate but also expands the variety of high-performance anode materials.

Assessment of end-of-life electric vehicle batteries in China: Future scenarios and economic benefits

A better understanding of the waste of end-of-life batteries from electric vehicles (EVs) is a basis for their sustainable management. This study aims to estimate the waste of end-of-life EV batteries during 2006-2040 in China and to analyze the opportunities and challenges of subsequent utilization, based on a developed numerical model, real market data, and elaborately developed scenarios. The result shows that end-of-life batteries would increase from 0.1 to 7.8 thousand tons during 2012-2018, and then to 1500-3300 thousand tons in 2040. Of the waste streams, around 50% are estimated to be metal materials, representing great opportunities for battery recycling for material recovery. Economically, battery recycling for energy storage is estimated to create more economic benefits compared with that for material recovery solely (147.8 versus 76.9 billion US dollars). However, the supply of end-of-life batteries can hardly meet the demand for renewable energy storage in the near future, and a spatial mismatch of the supply and demand of energy storage capacity exists between the eastern and western regions in China. Accordingly, this study highlights national coordination for the rational layout of the collection, disassembly, and remanufacture facilities for the second use of end-of-life EV batteries in China.

Ultra-High Sulfur-Doped Hierarchical Porous Hollow Carbon Sphere Anodes Enabling Unprecedented Durable Potassium-Ion Hybrid Capacitors

Sulfur doping is a promising path to ameliorate the kinetics of carbon-based anodes. However, the similar electronegativity of sulfur and carbon and the poor thermal stability of sulfur severely restrict the development of high-sulfur-content carbon-based anodes. In this work, ultra-high sulfur-doped hierarchical porous hollow carbon spheres (SHCS) with a sulfur content of 6.8 at % are synthesized via a direct high-temperature sulfur-doping strategy. An SHCS has sulfur bonded to the carbon framework including C-S-C and C-SO_x-C, which enlarges its interlayer distance (0.411 nm). In the K half-cell, benefiting from the considerable content and the reasonable architecture of sulfur, the SHCS exhibits significantly improved reversible specific capacity, initial Coulombic efficiency, and cyclability than hierarchical porous hollow carbon spheres without sulfur. Remarkably, the potassium ion hybrid capacitor device fabricated with the SHCS anode achieves excellent energy/power density (135.6 W h kg^-1/17.7 kW kg^-1) and unprecedented durability over 26,000 cycles at 2 A g^-1. This research provides a superior strategy to design high-sulfur-content carbon-based anodes with excellent potassium storage performance.

From Materials to Cell: State-of-the-Art and Prospective Technologies for Lithium-Ion Battery Electrode Processing

Electrode processing plays an important role in advancing lithium-ion battery technologies and has a significant impact on cell energy density, manufacturing cost, and throughput. Compared to the extensive research on materials development, however, there has been much less effort in this area. In this Review, we outline each step in the electrode processing of lithium-ion batteries from materials to cell assembly, summarize the recent progress in individual steps, deconvolute the interplays between those steps, discuss the underlying constraints, and share some prospective technologies. This Review aims to provide an overview of the whole process in lithium-ion battery fabrication from powder to cell formation and bridge the gap between academic development and industrial manufacturing.

A Flexible, Fireproof, Composite Polymer Electrolyte Reinforced by Electrospun Polyimide for Room-Temperature Solid-State Batteries

Solid-state batteries (SSBs) have attracted considerable attention for high-energy-density and high-safety energy storage devices. Many efforts have focused on the thin solid-state-electrolyte (SSE) films with high room-temperature ionic conductivity, flexibility, and mechanical strength. Here, we report a composite polymer electrolyte (CPE) reinforced by electrospun PI nanofiber film, combining with succinonitrile-based solid composite electrolyte. In situ photo-polymerization method is used for the preparation of the CPE. This CPE, with a thickness around 32.5 μm, shows a high ionic conductivity of 2.64 × 10⁻⁴ S cm⁻¹ at room temperature. It is also fireproof and mechanically strong, showing great promise for an SSB device with high energy density and high safety.

Mg3Si3(MoO6)2 as a High-Performance Cathode Active Material for Magnesium-Ion Batteries

The natural abundance of magnesium together with its high volumetric energy capacity and less-dendritic anodes makes Mg-ion batteries an appealing alternative to the widely used Li-ion batteries. However, Mg cathode materials under current investigation suffer from various shortcomings such as low operation voltage and high energy barrier for ion migration, resulting in poor battery performance. Here, we propose a garnet-type intercalation cathode active material, Mg₃Si₃(MoO₆)₂, for high-performance Mg-ion batteries. Through first-principles density functional theory calculations, it is demonstrated that Mg₃Si₃(MoO₆)₂ possesses a high average discharge voltage (2.35 V vs Mg/Mg²⁺), a low ion migration barrier (∼0.2 eV), and a minimal volume change (∼4%) concurrently, which comprises excellent intercalation cathode chemistry. The small energy barrier for ion migration is shown to arise from the favorable change in the Mg coordination along the migration route within the garnet host. These findings present an additional direction to develop competent Mg-ion batteries for future energy storage applications.

Electric car battery: An overview on global demand, recycling and future approaches towards sustainability

Li-ion batteries are daily present in our electronic devices. These batteries are used in electric and hybrid vehicles supporting the current agreements to decrease greenhouse gas emissions. As a result, the electric vehicle demand has increased in the world. As Li-ion batteries are composed of critical metals in which there is a risk of interruption of supply in the medium term, recycling is the key to a sustainable future without internal combustion vehicles. Understanding the current scenario and future perspectives is important for strategies of new battery design, recycling routes and reverse logistics, as well as policies for sustainable development. This paper presents an overview of current and future vehicles used worldwide. An increase from 1.3 to 2 billion vehicles is expected worldwide until 2030; an outstanding demand will occur mainly in BRICS countries. The data demonstrated a correlation between the number of vehicles in use and GDP. Patents and processes designed for recycling Li-ion batteries and the new developments on pyro-, hydro-, and bio-metallurgical routes have been revised. The manuscript describes the importance and benefits of recycling as regards the supply of critical metals and future trends towards a circular economy.

Resolving the Structural Defects of Spent Li1- x CoO2 Particles to Directly Reconstruct High Voltage Performance Cathode for Lithium-Ion Batteries

Effective and scalable recycling of spent lithium-ion batteries is an urgent need to address the environmental pollution and resource consumption caused by improper disposal. Herein, a practical solution is presented to recover and increase the stability of the layered structure from scrap Li_{1- x} CoO₂ via high-temperature supplementation of Li and Mg doping, without an extra synthesis step or cost. All the regenerated products exhibit better electrochemical performance compared with the commercial cathode material. Within the voltage window of 3.0-4.6 V, 5% Mg-recovery LiCoO₂ (LMCO) exhibits a high discharge capacity of 202.9 mA h g^-1 at 0.2 C, and 3% Mg-recovery LiCoO₂ shows enhanced capacity retention of 99.5% at 0.2 C after 50 cycles and maintains 96.8% at 1 C after 100 cycles. This is because high-temperature supplementing metal ions is beneficial for eliminating the cracks and nano-impurity particles on the surface of spent materials, thereby restoring the layered structure and electrochemical performance. The excellent electrochemical performances of Mg-recovery LiCoO₂ are attributed to Mg ions doping, which can inhibit the release of lattice oxygen and stabilize the surface structure. This process maximizes the utilization of the spent materials and provides a novel perspective for the non-constructive recovery of spent materials.

Amidine-based ionic liquid analogues with AlCl3: a credible new electrolyte for rechargeable Al batteries

Here we demonstrate the generation of novel ionic liquid analogue (ILA) electrolytes for aluminium (Al) electrodeposition that are based on salts of amidine Lewis bases. The electrolytes exhibit reversible voltammetric plating/stripping of Al, good ionic conductivities (10-14 mS cm^-1), and relatively low viscosities (50-80 cP). The rheological properties are an improvement on analogous amide-based ILAs and make these liquids credible alternatives to ILAs based on urea or acetamide, or conventional chloroaluminate ionic liquids (IL) for Al battery applications.

Global Competition in the Lithium-Ion Battery Supply Chain: A Novel Perspective for Criticality Analysis

With the accelerated pace of energy transition, competition in the lithium-ion battery (LIB) supply chain is intensifying across a wide scope of countries. In order to understand the potential risk derived from the competitors, this study quantifies the global competition intensities of 15 categories of LIB-related commodities, which has not been well characterized by previous criticality analysis studies. On the basis of the collected data and designed treatment techniques, the "competition index" is developed for this purpose. Here, we show that lithium hydroxides, LIBs, and lithium carbonates were the focal points of global competition in the LIB supply chain in 2019, and there will be more competition for lithium hydroxide in the future. The competition for commodities related to LIBs among Korea, Japan, and the USA are the most notable. Such insights into the global conflict potential of LIB-related commodities provide a reference for underlying competitors and corresponding transition strategies of regional industrial structures. The index developed by us complements the criticality analysis framework, which could be expanded to assess the criticality of materials relevant with other industries.

Reaction mechanism of antibiotic bacteria residues as a green reductant for highly efficient recycling of spent lithium-ion batteries

In this study, antibiotic bacteria residues (ABRs) is proposed as a novel green reducing agent and it is found that the reducing agent can realize the efficient recovery of the valuable metals in spent cathode powder (SCP), reduce the environmental pollution and realize the high-value utilization of the biomass waste. The leaching efficiency of Ni, Co, Mn and Li can reach 99.57%, 98.50%, 98.99% and 99.90% respectively under the optimal conditions of 3 mol L^-1 H₂SO₄, mass ratio of ABRs to SCP of 0.8:1, liquid/solid ratio of 30:1 mL g^-1, the temperature of 363 K and time of 2.5 h. Leaching kinetics results shows that the reaction process is controlled by the chemical reaction with apparent activation energy exceeding than 40 kJ/mol. More importantly, the detailed ABRs leaching mechanism is proposed that the metabolite of CaC₂O₄ and reducing sugar in ABRs provide a synergistic reduction effect on the recovery of valuable metals. Furthermore, acid leaching residue can be regenerated to obtain lithium-ion anode materials with excellent electrochemical properties. The entire process is a sustainable green recycling strategy by using waste ABRs waste to treat spent lithium-ion batteries (LIBs), recovering valuable metals efficiently and minimizing environmental pollution.

Probing Mechanistic Insights into Highly Efficient Lithium Storage of C60 Fullerene Enabled via Three-Electron-Redox Chemistry

Renewable organic cathodes with abundant elements show promise for sustainable rechargeable batteries. Herein, for the first time, utilizing C₆₀ fullerene as organic cathode for room-temperature lithium-ion battery is reported. The C₆₀  cathode shows robust electrochemical performance preferably in ether-based electrolyte. It delivers discharge capacity up to 120 mAh g^-1 and specific energy exceeding 200 Wh kg^-1 with high initial Coulombic efficiency of 91%. The as-fabricated battery holds a capacity of 90 mAh g^-1 after 50 cycles and showcases remarkable rate performance with 77 mAh g^-1 retained at 500 mA g^-1 . Noteworthily, three couples of unusual flat voltage plateaus recur at ≈2.4, 1.7, and 1.5 V, respectively. Diffusion-dominated three-electron-redox reactions are revealed by cyclic voltammogram and plateau capacities. Intriguingly, it is for the first time unveiled by in situ X-ray diffraction (XRD) that the C₆₀ cathode underwent three reversible phase transitions during lithiation/delithiation process, except for the initial discharge when irreversible polymerization in between C₆₀ nanoclusters existed as suggested by the characteristic irreversible peak shifts in both in situ XRD pattern and in situ Raman spectra. Cs-corrected transmission electron microscope corroborated these phase evolutions. Importantly, delithiation potentials derived from density-functional-theory simulation based on proposed phase structures qualitatively consists with experimental ones.

Copper niobate nanowires boosted by a N, S co-doped carbon coating for superior lithium storage

With the development of electric vehicles, more and more attention has been paid to the kinetic performance of batteries, which is related to rapid charge/discharge and safety issues. To improve this aspect, Cu₂Nb₃₄O₈₇ nanowires covered by nitrogen and sulfur co-doped carbon (Cu₂Nb₃₄O₈₇/NSC nanowires) are prepared by electrospinning combined with surface coating. As-prepared Cu₂Nb₃₄O₈₇/NSC nanowires present a high ion diffusion coefficient and electronic conductivity, showing good a kinetic performance. Specifically, they deliver a splendid capacity of 311.2 mA h g^-1 at 1 C and a superior cycling stability with a capacity fading of 0.031% per cycle upon 1000 cycles. At the same time, the electrochemical and structural reversibility is fully discussed and demonstrated by ex situ XRD, ex situ SEM and ex situ XPS based on the redox couples of Cu²⁺/Cu⁺, Nb⁵⁺/Nb⁴⁺, and Nb⁴⁺/Nb³⁺. Contributing to peculiar physico-chemical properties, Cu₂Nb₃₄O₈₇/NSC nanowires are expected to be a candidate material for the anode in lithium-ion batteries.

Highly efficient re-cycle/generation of LiCoO2 cathode assisted by 2-naphthalenesulfonic acid

The explosively growing demand for electrical energy is generating a great deal of spent lithium-ion batteries (LIBs). Therefore, a simple and effective strategy for the sustainable recycling of used batteries is urgently needed to minimize chemical consumption and to reduce the associated environmental pollution. In this work, 2-naphthalenesulfonic acid is innovatively proposed for the highly-selective recovery of valuable metals. Impressively, lithium and cobalt are simultaneously separated through a single-step process, in which 99.3% of lithium is leached out as Li⁺ enriched solutions while 99% of cobalt is precipitated as cobalt-naphthalenesulfonate. The obtained lithium enriched solutions are recovered as Li₂CO₃. The cobalt-naphthalenesulfonate with high purity (99%) is ready to be transformed into Co₃O₄, and then generated into LiCoO₂ by reacting with the above-obtained Li₂CO₃. The cathode material LiCoO₂ with micro/nanostructures exhibits excellent electrochemical properties. Characterization results confirm the coordination structure of the extracted cobalt complex (Co(NS)2•6H₂O). Finally, compared to other selective metal extraction techniques, this strategy avoids additional separation and purification processes, thus improving the recycling efficiency. Overall, this route can be extended to selectively extract valuable metals from other types of cathode materials in spent LIBs as a sustainable approach.

Recovering large-scale battery aging dataset with machine learning

Batteries are crucial for building a clean and sustainable society, and their performance is highly affected by aging status. Reliable battery health assessment, however, is currently restrained by limited access to sufficient aging data, resulting from not only complicated battery operations but also long aging experimental time (several months or even years). Refining industrial datasets (e.g., the field data from electric vehicle batteries) unlocks opportunities to acquire large-volume aging data with low experimental efforts. We introduce the potential of combining industrial data with accelerated aging tests to recover high-quality battery aging datasets, through a migration-based machine learning. A comprehensive dataset containing 8,947 aging cycles with 15 operational modes is collected for evaluation. While saving up to 90% experimental time, aging data can be recovered with ultra-low error within 1%. It provides an alternative solution to significantly improve data shortage issues for assessment of battery and energy storage aging.

A sustainable approach to cathode delamination using a green solvent

Designing an environment-friendly delamination process for an end-of-life (EoL) composite cathode is a crucial step in direct cathode recycling. In this study, the green solvent dimethyl isosorbide (DMI) is explored to extract cathode active materials (AMs) from the Al current collector via dissolving the polyvinylidene fluoride (PVDF) binder. Mechanistic insight suggests that binder removal from the Al substrate proceeds via reducing polymer interchain interaction through DMI penetrating into the PVDF crystalline region. Polymer–solvent interaction may increase via establishing hydrogen bond between PVDF and DMI, which facilitates binder removal. Analytical characterizations including ¹H NMR, FTIR, XRD and SEM-EDS reveal that the molecular, micro, and crystal structures of the recovered cathode AMs, PVDF and Al foil are preserved. This finding is expected to provide a replacement for the toxic organic solvent N-methylpyrrolidone (NMP) and offers an effective, ecofriendly, and sustainable direct cathode recycling approach for spent Li-ion batteries.

A green solvent-based methodology was developed for delaminating cathode active materials from aluminium current collectors in end-of-life Li-ion batteries.

Prussian Blue Analogues in Aqueous Batteries and Desalination Batteries

In the applications of large-scale energy storage, aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature. However, carrier ions always exhibit huge hydrated radius in aqueous electrolyte, which brings difficulty to find suitable host materials that can achieve highly reversible insertion and extraction of cations. Owing to open three-dimensional rigid framework and facile synthesis, Prussian blue analogues (PBAs) receive the most extensive attention among various host candidates in aqueous system. Herein, a comprehensive review on recent progresses of PBAs in aqueous batteries is presented. Based on the application in different aqueous systems, the relationship between electrochemical behaviors (redox potential, capacity, cycling stability and rate performance) and structural characteristics (preparation method, structure type, particle size, morphology, crystallinity, defect, metal atom in high-spin state and chemical composition) is analyzed and summarized thoroughly. It can be concluded that the required type of PBAs is different for various carrier ions. In particular, the desalination batteries worked with the same mechanism as aqueous batteries are also discussed in detail to introduce the application of PBAs in aqueous systems comprehensively. This report can help the readers to understand the relationship between physical/chemical characteristics and electrochemical properties for PBAs and find a way to fabricate high-performance PBAs in aqueous batteries and desalination batteries.