Graphite carbon-encapsulated metal nanoparticles derived from Prussian blue analogs growing on natural loofa as cathode materials for rechargeable aluminum-ion batteries

High Performance and Long-cycle Life Rechargeable Aluminum Ion Battery: Recent Progress, Perspectives and Challenges

The rising energy crisis and environmental concerns caused by fossil fuels have accelerated the deployment of renewable and sustainable energy sources and storage systems. As a result of immense progress in the field, cost-effective, high-performance, and long-life rechargeable batteries are imperative to meet the current and future demands for sustainable energy sources. Currently, lithium-ion batteries are widely used, but limited lithium (Li) resources have caused price spikes, threatening progress toward cleaner energy sources. Therefore, post-Li, batteries that utilize highly abundant materials leading to cost-effective energy storage solutions while offering desirable performance characteristics are urgently needed. Aluminum-ion battery (AIB) is an attractive concept that uses highly abundant aluminum while offering a high theoretical gravimetric and volumetric capacity of 2980 mAh g^-1 and 8046 mAh cm^-3 , respectively. As a result, intensified efforts have been made in recent years to utilize numerous electrolytes, anodes, and cathode materials to improve the electrochemical performance of AIBs, and potentially create high-performance, low-cost, and safe energy storage devices. Herein, recent progress in the electrolyte, anode, and cathode active materials and their utilization in AIBs and their related characteristics are summarized. Finally, the main challenges facing AIBs along with future directions are highlighted.

Novel One-Dimensional Nanofiber MnSe/CMK-3 High-Performance Cathode Material for Aluminum Batteries

Transition metal selenides have shown outstanding performance as cathode materials for aluminum-ion batteries and have thus become a popular choice for cathode materials. Herein, Mn-based carbon fibers (Mn/CNFs) were first synthesized by electrospinning as a precursor, and then MnSe composites were prepared by a melt-diffusion method. However, due to polyselenides and selenides being generated during electrochemical reactions, the cycling stability of MnSe cathode materials is poor. After 200 cycles, the discharge specific capacity is only 176 mA h/g. To suppress the shuttle effect of selenides and polyselenides, a CMK-3-modified separator was used instead of a glass fiber separator. Compared with MnSe-800, the replaced MnSe-800/CMK-3 has a great capacity improvement; the initial discharge specific capacity is 1029.85 mA h/g, which after 3000 cycles, still remains at 297.84 mA h/g. The soft pack battery can still light up the LED normally under different degrees of folding, which proves the application of this material in wearable devices. This work provides a new way to improve the performance of transition metal selenides.

Physicochemical properties of raw starches and their impact on electrochemical activity - Biomolecule-based anode material

Starch is a modern and prospective biodegradable material, which could improve lithium-ion batteries by making them safer and thus increasing the energy density and capacity of the cells. The main aim of this study was to research the influence of the physical and chemical properties of different botanical origin starches on their electrochemical properties. The investigation was carried out by examining the colloid stability of starches in water solution at room temperature, and the size of particles, which gave really good stability results. Moreover, the vibrations and the functional groups structure were described by Fourier Transform Infrared Spectroscopy (FTIR). The surface properties were characterized by determining the specific surface area, pore diameter and volume diameter. The structures of the granules were determined by scanning electron microscope (SEM) measurement. The results of the electrochemical investigations showed good cyclic reversibility and stability. The research was aimed at improving and modifying current lithium-ion cells using biodegradable material as an active anode material, which is connected with the currently well-known "Green Chemistry".

Covalent Organic Frameworks: Emerging Organic Solid Materials for Energy and Electrochemical Applications

Covalent organic frameworks (COFs), materials constructed from organic building blocks joined by robust covalent bonds, have emerged as attractive materials in the context of electrochemical applications because of their high, intrinsic porosities and crystalline frameworks, as well as their ability to be tuned across two- and three-dimensions by the judicious selection of building blocks. Because of the recent and rapid development of this field, we have summarized COFs employed for electrochemical applications, such as batteries and capacitors, water splitting, solar cells, and sensors, with an emphasis on the structural design and resulting performance of the targeted electrochemical system. Overall, we anticipate this review will stimulate the design and synthesis of the next generation of COFs for use in electrochemical applications and beyond.

Electrochemical activity of Samarium on starch-derived porous carbon: rechargeable Li- and Al-ion batteries

Rechargeable metal-ion batteries are considered promising electric storage systems to meet the emerging demand from electric vehicles, electronics, and electric grids. Thus far, secondary Li-ion batteries (LIBs) have seen great advances in terms of both their energy and their power density. However, safety issues remain a challenge. Therefore, rechargeable Al-ion batteries (AIBs) with a highly reliable safety advantage and active electrochemical performances have gathered intensive attention. However, the common issue for these two metal-ion batteries is the lack of cathode materials. Many advanced electrode materials reported provide greatly enhanced electrochemical properties. However, their inherent disadvantages-such as complicated fabrication procedures, restricted manufacturing parameters, and the requirement of expensive instruments-limits their potential for further applications. In this work, we demonstrate the high electrochemical activity of the lanthanide element, Sm, towards storing charges when used in both LIBs and AIBs. Lanthanide elements are often overlooked; however, they generally have attractive electrochemical properties owing to their unpaired electrons. We employed starch as both a low-cost carbon source and as a three-dimensional support for Sm metal nanoparticles. The composite product is fabricated using a one-pot wet-chemical method, followed by a simultaneous carbonization process. As a result, highly improved electrochemical properties are obtained when it is used as a cathode material for both LIBs and AIBs when compared to bare starch-derived C. Our results may introduce a new avenue toward the design of high-performance electrode materials for LIBs and AIBs.

Rendering Redox Reactions of Cathodes in Li-Ion Capacitors Enabled by Lanthanides

Capacitors allow extremely fast charge and discharge operations, which is a challenge faced by recent metal-ion batteries despite having highly improved energy densities. Thus, combined type electric energy storage devices that can integrate high energy density and high power density with high potentials, can overcome the shortcomings of the current metal-ion batteries and capacitors. However, the limited capacities of cathode materials owing to the barren redox reactions are regarded as an obstacle for the development of future high-performance hybrid metal-ion capacitors. In this study, we demonstrate the redox-reaction-rendering effect of the much overlooked lanthanide elements when used as the cathode of lithium-ion capacitors using the mesoporous carbon (MC) as a matrix material. Consequently, these lanthanide elements can effectively enrich the redox reaction, thus improving the capacity of the matrix materials by more than two times. Typically, the Gd-elemental decoration of MC surprisingly enhances the capacity by almost two times as compared with the underacted MC. Furthermore, the La nanoparticles (NPs) decoration depicts the same behavior. Evident redox peaks were formed on the original rectangular cyclic voltammetry (CV) curves. This study provides the first example of embedding lanthanide elements on matrix materials to enrich the desired redox reactions for improving the electrochemical performances.

Carbon and graphene quantum dots: a review on syntheses, characterization, biological and sensing applications for neurotransmitter determination

Neuro-transmitters have been considered to be essential biochemical molecules, which monitor physiological and behavioral function in the peripheral and central nervous systems. Thus, it is of high pharmaceutical and biological significance to analyze neuro-transmitters in the biological samples. So far, researchers have devised a lot of techniques for assaying these samples. It has been found that electro-chemical sensors possess features of robustness, selectivity, and sensitivity as well as real-time measurement. Graphene quantum dots (GQDs) and carbon QDs (CQDs) are considered some of the most promising carbon-based nanomaterials at the forefront of this research area. This is due to their characteristics including lower toxicity, higher solubility in various solvents, great electronic features, strong chemical inertness, high specific surface areas, plenty of edge sites for functionalization, and versatility, in addition to their ability to be modified via absorbent surface chemicals and the addition of modifiers or nano-materials. Hence in the present review, the synthesis methods of GQDs and CQDs has been summarized and their characterization methods also been analyzed. The applications of carbon-based QDs (GQDs and CQDs) in biological and sensing areas, such as biological imaging, drug/gene delivery, antibacterial and antioxidant activity, photoluminescence sensors, electrochemiluminescence sensors and electrochemical sensors, have also been discussed. This study then covers sensing features of key neurotransmitters, including dopamine, tyrosine, epinephrine, norepinephrine, serotonin and acetylcholine. Hence, issues and challenges of the GQDs and CQDs were analyzed for their further development.

Carbon and graphene quantum dots for biological and sensing applications of neurotransmitters.

Developments and applications of nanomaterial-based carbon paste electrodes

This review summarizes the progress that has been made in the past ten years in the field of electrochemical sensing using nanomaterial-based carbon paste electrodes. Following an introduction into the field, a first large section covers sensors for biological species and pharmaceutical compounds (with subsections on sensors for antioxidants, catecholamines and amino acids). The next section covers sensors for environmental pollutants (with subsections on sensors for pesticides and heavy metal ions). Several tables are presented that give an overview on the wealth of methods (differential pulse voltammetry, square wave voltammetry, amperometry, etc.) and different nanomaterials available. A concluding section summarizes the status, addresses future challenges, and gives an outlook on potential trends.

This review summarizes the progress that has been made in the past ten years in the field of electrochemical sensing using nanomaterial-based carbon paste electrodes.