The increasing amounts of end-of-life lithium-ion batteries (EOL LIBs) require novel and safe solutions allowing for the minimisation of the health and environmental hazards. Arguably, the best approach to the problem of EOL LIBs is recycling and recovery of the metals contained within the cells. This allows the diversion of the EOL battery cells from the environment but also the recovery of precious metals that can be reused in the manufacturing of new products, allowing to reduce the requirements of virgin materials from the mining industry. The most significant hindrance to the recycling process of EOL LIBs is their unstable chemical nature and significant safety hazards related to opening the air-tight casings. To minimise these issues, the end-of-life cells must be stabilised in one of the few available ways. This review aims at a comprehensive presentation of the studied chemical methods of EOL LIB cells discharge and stabilisation. The advantages and disadvantages of the method and its variations are discussed based on the literature published to date. The literature review found that a significant number of authors make use of chemical stabilisation techniques without proper comprehension of the associated risks. Many authors focus solely on the cheapest and fastest way to stop a cell from producing an electrical charge without extra thought given to the downstream recycling processes of safety hazards related to the proposed stabilisation method. Only a few studies highlighted the risks and problems associated with chemical stabilisation techniques.

Over the past decade, the extensive consumption of finite energy resources has caused severe environmental pollution. Meanwhile, the promotion of renewable energy sources is limited by their intermittent and regional nature. Thus, developing effective energy storage and conversion technologies and devices holds considerable importance. Zinc-ion hybrid supercapacitors (ZISCs) merge the beneficial aspects of both supercapacitors and batteries, rendering them an exceptionally promising energy storage method. As an important cathode material for ZISCs, the tunnel structure MnO 2 has poor conductivity and structural stability. Herein, the Zn xMnO 2/PPy (ZMOP) electrode materials are prepared by hydrothermal method. Doping with Zn 2+ is used to enhance its structural stability, while adding polypyrrole to improve its conductivity. Therefore, the fabricated ZMOP cathode presents superb specific capacity (0.1 A g -1, 156.4 mAh g -1) and remarkable cycle performance (82.6%, 5000 cycles, 0.2 A g -1). Furthermore, the assembled aqueous ZISCs with ZMOP cathode and PPy-derived porous carbon nanotubes anode obtain a superb capacity of 109 F g -1 at 0.1 A g -1. Meanwhile, at a power density of 867 W kg -1, the corresponding energy density can achieve 20 Wh kg -1. And over 5000 cycles at 0.2 A g -1, the ZISCs can exhibit excellent cycle stability (86.4%). This suggests that ZMOP nanowires are potential cathode materials for superior-performance aqueous ZISCs.

A document by Jihun Jeon. Click on the document to view its contents.

Potassium-ion batteries (KIBs) represent a promising energy storage solution owing to the abundance of potassium resources. The efficacy of KIBs relies significantly on the electrochemical attributes of both their electrode materials and electrolyte. In the current investigation, we synthesized a layered compound K2[(VOHPO4)2(C2O4)]·2H2O via a heterogeneous nucleation approach and assessed its viability as a cathode material for KIBs. When integrated with a salt-concentrated electrolyte with oxidation stability over 6 V, the compounds exhibits a high discharge potential of 4.1 V (vs. K+/K) alongside a reversible capacity of 106.2 mAh g−1. Furthermore, there is no capacity decay after 500 cycles at 100 mA g−1. This study shows the promise of layered metal organic frameworks as high-potential materials for KIBs.

Sodium-ion batteries (SIBs) have attracted a lot of attention owing to the low cost, as well as similar working mechanism and manufacturing technique with Lithium-ion batteries (LIBs). However, the practical application of SIBs is severely hindered by limited electrode materials. Disordered carbons are reported to be promising as anode materials for SIBs. Here, for the first time, calcium lignosulfonate (LSCa), one papermaking waste, is explored as a novel low-cost precursor for carbon materials of SIBs. The optimized LSCa-derived carbon delivers a high reversible capacity of 317 mA h g -1 at 30 mA g -1 with ~ 60% plateau capacity and it retains a capacity of 170 mA h g -1 even at 3000 mA g -1. These achievements are ascribed to the larger d 002 value, smaller defects and more closed pores, compared to the original sample from the direct carbonization of LSCa.

Organic solar cells (OSCs) have received widespread attention due to light weight, low cost, semitransparency and ease of solution processing. By continuously improving materials design, active layer morphology, and device fabrication techniques, the power conversion efficiency (PCE) of OSCs have exceeded 20%. The morphology of the active layer, which includes the phase separation structure, the degree of crystallinity of molecules, and the domain sizes, plays a critically important role in the performance, which is significantly influenced by the crystallization dynamics of the donor and acceptor. Therefore, it is crucial to comprehensively understand how the dynamics impact the film structure and how to effectively employ the kinetic procedure to enhance the structure of the active layer in OSCs. In this review, the methods and principles of kinetics characterization were introduced. Afterwards, the latest advancements in the control of film-forming and the post annealing process are outlined, unveiling the underlying mechanism. In conclusion, the potential and future of OSCs were anticipated and projected. Researchers may gain a comprehensive comprehension of how the dynamic process affects the morphology through this review, potentially enhancing the performance of OSCs.

Currently, the main drivers for developing Li-ion batteries for efficient enery applications include energy density, cost, calendar life, and safety. The high energy/capacity anodes and cathodes needed for these applications is hindered by challengers like: 1) aging and degradation; 2) improved safety; 3) material costs, and 4) recyclability. The present begins by summarising the progress made from early Li-metal anode-based batteries to current commercial Li-ion batteries. Then discusses the recent progress made in studying and developing various types of materials for both anode and cathode electrodes, as well the various types of electrolytes and separator materials developed specifically for Li-ion battery operation. Battery management, handling and safety are also discussed at length. Also, as a consequence of the exponentially growth in the production of Li-ion batteries over the last ten years, the review identifies the challenge of dealing with the ever-increasing quantities of spent batteries. The review identifies the economic value of metals like Co and Ni contained with batteries and the extremely large numbers of batteries produced to date and the extremely large numbers that are expected to be manufactured in the next ten years. Thus, highlighting the need to develop effective recycling strategies to reduce the levels of mining for raw materials and prevents harmful products from entering the environment through landfill disposal.

VO2(B) is considered as a promising anode material for the next-generation sodium-ion batteries (SIBs) due to its accessible raw materials and considerable theoretical capacity. However, the VO2(B) electrode has inherent defects such as low conductivity and serious volume expansion, which hinder their practical application. Herein, a flower-like VO2(B)/V2CTx (VO@VC) heterojunction was prepared by a simple hydrothermal synthesis method with in situ growth. The flower-like structure composed of thin nanosheets alleviates the volume expansion, as well as the rapid Na+ transport pathways are built by the heterojunction structure, resulting in long-term cycling stability and superior rate performance. At a current density of 100 mA g-1, VO@VC anode can maintain a specific capacity of 276 mAh g-1 with an average coulombic efficiency of 98.7% after 100 cycles. Additionally, even at a current density of 2 A g-1, the VO@VC anode still exhibited a capacity of 132.9 mAh g-1 for 1000 cycles. The enhanced reaction kinetics can be attribute to the fast Na+ adsorption and storage at interfaces, which has been confirmed by the experimental and theoretical methods. These results demonstrate that the tailored nanoarchitecture design and additional surface engineering are effective strategies for optimizing vanadium-based anode.

Alloy-type antimony (Sb) is considered as an attractive candidate anode for high-energy lithium-ion batteries (LIBs) because of its high theoretical specific capacity and volumetric capacity. However, Sb suffers from enormous volume variation during cycling, which causes electrode cracking and pulverization, and hence the fast capacity decay and poor cyclability, limiting its practical applications as a LIB anode. Herein, we report a facile, scalable, low-cost and efficient route to successfully fabricate BiSb/C composites via a two-step high-energy mechanical milling (HEMM) process. The as-prepared BiSb/C composites consist of nanosized BiSb totally embedded in a conductive carbon matrix. As LIB anodes, BiSb/C-73 (with 30 wt % carbon) electrodes exhibit excellent Li storage properties in terms of stable high reversible capacities, long-cycle life, and high-rate performance. Reversible capacities of ∼583, ∼466, ∼433 and ∼425 mAh g–1 at a current density of 500 mA g–1 after 100, 300, 500 and 1000 cycles, respectively, were achieved. In addition, a high capacity of ∼380 mAh g−1 can still be retained at a high rate of 5 A g−1. Such outstanding cycling stability and rate capability could be mainly attributed to the synergistic effects between the ability of nanosized BiSb particles to withstand electrode fracture during Li insertion/extraction and the buffering effect of the carbon matrix. The as-prepared BiSb/C composites are based on commercially available and low-cost Bi, Sb and graphite materials. Interestingly, HEMM is more convenient, efficient, scalable, green and mass-production route, making as-prepared materials attractive for high-energy LIBs.

Structural batteries have emerged as a promising alternative to address the limitations of conventional batteries, with the potential to integrate energy storage into stationary constructions or mobile vehicles/planes. Developing multifunctional composites is effective to realize the structural plus concept, which can reduce the inert weight and improve the performance of the energy storage beyond the material level (e.g., cell- or system-level). Specifically, multifunctional composites in structural batteries can work as both a functional composite electrode to store charges and a structural composite to bear mechanical loads. However, they suffer from the trade-off between mechanical properties and energy storage performance due to the scientific challenges of unstable interfaces and the lack of viable manufacturing approaches. In this review, we first introduce recent research developments of electrodes, electrolytes, separators, and interface engineering specific to structure plus composites for structure batteries, and then summarize the mechanical and electrochemical characterizations. We discuss in detail the reinforced multifunctional composites for structure batteries, the exploration of multifunctionalities on different composite structures and battery configurations, and then conclude with a perspective on future opportunities. The knowledge synthesized in this review contributes to the advancement of this field and facilitates the realization of efficient and durable energy storage systems integrated into structural components.

MXenes are mentioned in many applications due to their unique properties. However, the traditional etching method has a long synthesis time, dangerous process and high cost. Molten salt etching is not only short in time, but also safe and simple, laying a good foundation for industrialization. Here, we compare the traditional F–containing etching method with the molten salt etching method. TEM elemental mapping images and XPS show that the Ti3C2Tx surface end of traditional etching is terminated by –F, while the Ti3C2Tx surface end of molten salt etching is terminated by –Cl. Finally, the sodium–ion batteries is fabricated and the performance difference of the three etching methods is compared, the results show that the capacity of 102.1 mAh g–1 can still be reached when the molten salt etching MXene material returns to 0.1 A g–1 after the current density of 5 A g–1. After 500 cycles at 1 A g–1, there is no significant loss of capacity and the coulomb efficiency is close to 100%. This work describes that molten salt etching MXene has comparable sodium storage capacity to conventional F–containing etched MXene, making it a potential candidate for large–scale sodium–ion batteries production.

A document by Yun Zhao. Click on the document to view its contents.

Lead-acid battery system is designed to perform optimally at ambient temperature (25 °C) in terms of capacity and cyclability. However, varying climate zones enforce harsher conditions on the automotive lead acid batteries. Hence, they age faster and exhibit low performance when operated at either extremity of the optimum ambient conditions. In this work, a systematic study was conducted to analyze the effect of varying temperatures (-10, 0, 25 and 40 °C) on the sealed lead acid. Enersys® Cyclon (2V, 5Ah) cells were cycled at C/10 rate using battery testing system. The environmental aging results in shorter cycle life due to the degradation of electrode, and grid materials at higher temperature (25 and 40 °C), while at lower temperature (-10 and 0 °C) negligible degradation was observed due to slower kinetics and reduced available capacity. Electrochemical impedance spectroscopy, X-ray diffraction and Energy-dispersive X-ray spectroscopy analysis were used to evaluate the degradation mechanism, chemical and morphological changes.

Nowadays, a hybrid composite SiO2/C has been paid attention to improving battery performance in Li-ion batteries (LIBs) as the anode. However, this material unexpectedly suffers from initial active lithium loss caused by the solid electrolyte interface (SEI) formation leading to low initial Coulombic efficiency and significantly reducing the initial capacity. In order to solve these issues, pre-lithiation has been considered an effective approach to limit active lithium loss and increase cycling performance. This work focuses on the two most common techniques, including the direct contact method (CM) and the electrochemical method in half-cell (EM). After the pre-lithiation process, the anodes would be evaluated in full-cell with LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode. According to electrochemical properties evaluations, pre-lithiation could enhance discharged capacity and initial coulombic efficiency. Without the pre-lithiation method, the discharged capacity in full-cell only witnessed 66.9 mAh.g-1, while CM and EM methods illustrated a better battery performance. In detail, EM exhibited a higher discharged capacity and initial coulombic efficiency (137.06 mAh.g-1 and 99.08%, respectively) compared to CM (99.08 mAh.g-1 and 93.23%) method. Besides, the capacity retention using EM achieved 71.4% and the discharged capacity illustrated 97.87 mAh.g-1 after 100 cycles, which is better than using CM, which only showed 71.40 mAh.g-1.

The design and fabrication of flexible, porous, conductive electrodes with customizable functions become the prime challenge in the development of new-generation wearable electronics, especially for rechargeable batteries. Here, NiCo bi-alloy particulate catalysts loaded self-supporting carbon foam framework (NiCo@SCF) as a flexible electrode has been fabricated through one facile adsorption-pyrolysis method using a commercial melamine foam. Compared with the electrode with Pt/C and Ir/C benchmark catalysts, the NiCo@SCF electrode exhibited superior bifunctional electrocatalytic performance in alkaline media with a half-wave potential of 0.906V for oxygen reduction reaction, an overpotential of 286 mV at j=10 mA cm−2 for oxygen evolution reaction, and stable bifunctional performance with a small degradation after 20,000 voltammetric cycles. The as-assembled aqueous zinc-air battery (ZAB) with NiCo@SCF as a self-supporting air cathode demonstrated a high peak power density of 178.6 mW cm-2 at a current density of 10 mA cm−2 and a stable voltage gap of 0.94V a 540 h charge-discharge operation. Remarkably, the as-assembled flexible solid-state ZAB with self-supporting NiCo@SCF as air cathode presented an engaging peak power density of 80.1 mW cm-2 and excellent durability of 95 h undisrupted operation, showing promise for the design of wearable ZAB.