Due to massively growing demand arising from energy storage systems, sodium ion batteries (SIBs) have been recognized as the most attractive alternative to the current commercialized lithium ion batteries (LIBs) owing to the wide availability and accessibility of sodium. Unfortunately, the low energy density, inferior power density and poor cycle life are still the main issues for SIBs in the current drive to push the entire technology forward to meet the benchmark requirements for commercialization. Over the past few years, tremendous efforts have been devoted to improving the performance of SIBs, in terms of higher energy density and longer cycling lifespans, by optimizing the electrode structure or the electrolyte composition. In particular, among the established anode systems, those materials, such as metals/alloys, phosphorus/phosphides, and metal oxides/sulfides/selenides, that typically deliver high theoretical sodium-storage capacities have received growing interest and achieved significant progress. Although some review articles on electrodes for SIBs have been published already, many new reports on these anode materials are constantly emerging, with more promising electrochemical performance achieved via novel structural design, surface modification, electrochemical performance testing techniques, etc. So, we herein summarize the most recent developments on these high-performance anode materials for SIBs in this review. Furthermore, the different reaction mechanisms, the challenges associated with these materials, and effective approaches to enhance performance are discussed. The prospects for future high-energy anodes in SIBs are also discussed.

We report a bio-inspired design strategy for constructing anin situpolymeric SEI in aqueous Zn chemistry. This SEI can restrain interfacial side reactions, facilitate a uniform Zn²⁺flux, and consequently endow a highly stable Zn metal anode.

Progress towards the integration of technology into living organisms requires power devices that are biocompatible and mechanically flexible. Aqueous zinc ion batteries that use hydrogel biomaterials as electrolytes have emerged as a potential solution that operates within biological constraints; however, most of these batteries feature inferior electrochemical properties. Here, we propose a biocompatible hydrogel electrolyte by utilising hyaluronic acid, which contains ample hydrophilic functional groups. The gel-based electrolyte offers excellent anti-corrosion ability for zinc anodes and regulates zinc nucleation/growth. Also, the gel electrolyte provides high battery performance, including a 99.71% Coulombic efficiency, over 5500 hours of long-term stability, improved cycle life of 250 hours under a high zinc utilization rate of 80%, and high biocompatibility. Importantly, the Zn//LiMn₂O₄ pouch cell exhibits 82% capacity retention after 1000 cycles at 3 C. This work presents a promising gel chemistry that controls zinc behaviour, offering great potential in biocompatible energy-related applications and beyond.

Recent progress in battery recycling is critically reviewed, including closed-loop design of new batteries and recycling-oriented design of battery configurations and components, together with an appraisal of predicted future research.

The search for alternatives to traditional Li-ion batteries is a continuous quest for the chemistry and materials science communities. One representative group is the family of rechargeable liquid metal batteries, which were initially exploited with a view to implementing intermittent energy sources due to their specific benefits including their ultrafast electrode charge-transfer kinetics and their ability to resist microstructural electrode degradation. Although conventional liquid metal batteries require high temperatures to liquify electrodes, and maintain the high conductivity of molten salt electrolytes, the degrees of electrochemical irreversibility induced by their corrosive active components emerged as a drawback. In addition, safety issues caused by the complexity of parasitic chemical reactivities at high temperatures further complicated their practical applications. To address these challenges, new paradigms for liquid metal batteries operated at room or intermediate temperatures are explored to circumvent the thermal management problems, corrosive reactions, and challenges related to hermetic sealing, by applying alternative electrodes, manipulating the underlying electrochemical behavior via electrolyte design concepts, and engineering the electrode–electrolyte interfaces, thereby enabling both conventional and completely new functionalities. This report briefly summarizes previous research on liquid metal batteries and, in particular, highlights our fresh understanding of the electrochemistry of liquid metal batteries that have arisen from researchers’ efforts, along with discovered hurdles that have been realized in reformulated cells. Finally, the feasibility of new liquid metal batteries is discussed along with their distinct chemistries and performance characteristics to answer the question of how liquid metals can be accessible for next-generation battery systems.