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.
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.
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.