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The capacity and cycling performance of cathodes are key factors in aqueous zinc batteries (AZBs). The search for cathode materials with long cycle lives and high specific capacities is of paramount importance. In this study, a bimetallic telluride with a hollow polyhedral structure was synthesized using a hydrothermal method followed by vapor deposition. This composite exhibits high conductivity, facilitates rapid diffusion of electrolyte ions into the interior, and accelerates redox reactions, thereby enhancing electrochemical performance. The CoTe2-NiTe2 electrode demonstrates an impressive specific capacity of 188.8 mAh/g at 1 A/g, highlighting its efficiency in storing a significant amount of charge per unit mass during electrochemical reactions. The assembled CoTe2-NiTe2//Zn battery shows favorable capacity retention (76.4%) after 10000 cycles. The energy density is remarkably high, reaching 290.3 Wh/kg, while maintaining a power density of 1.75 kW/kg. This bimetallic telluride strategy holds great promise as an alternative cathode for AZBs.

Non-flow aqueous zinc-bromine batteries without auxiliary components (e.g., pumps, pipes, storage tanks) and ion-selective membranes represent a cost-effective and promising technology for large-scale energy storage. Unfortunately, they generally suffer from serious diffusion and shuttle of polybromide (Br−, Br3−) due to the weak physical adsorption between soluble polybromide and host carbon materials, which results in low energy efficiency and poor cycling stability. Here, we develop a novel self-capture organic bromine material (1,1′-bis [3-(trimethylammonio)propyl]-4,4′-bipyridinium bromine, NVBr4) to successfully realize reversible solid complexation of bromide components for stable non-flow zinc-bromine battery applications. The quaternary ammonium groups (NV4+ ions) can effectively capture the soluble polybromide species based on strong chemical interaction and realize reversible solid complexation confined within the porous electrodes, which transforms the conventional “liquid–liquid” conversion of soluble bromide components into “liquid–solid” model and effectively suppresses the shuttle effect. Thereby, the developed non-flow zinc-bromide battery provides an outstanding voltage platform at 1.7 V with a notable specific capacity of 325 mAh g−1NVBr4 (1 A g−1), excellent rate capability (200 mAh g−1NVBr4 at 20 A g−1), outstanding energy density of 469.6 Wh kg−1 and super-stable cycle life (20,000 cycles with 100% Coulombic efficiency), which outperforms most of reported zinc-halogen batteries. Further mechanism analysis and DFT calculations demonstrate that the chemical interaction of quaternary ammonium groups and bromide species is the main reason for suppressing the shuttle effect. The developed strategy can be extended to other halogen batteries to obtain stable charge storage.

Abstract Aqueous copper-based batteries have many favourable properties and have thus attracted considerable attention, but their application is limited by their low operating voltage originating from the high potential of copper negative electrode (0.34 V vs. standard hydrogen electrode). Herein, we propose a coordination strategy for reducing the intrinsic negative electrode redox potential in aqueous copper-based batteries and thus improving their operating voltage. This is achieved by establishing an appropriate coordination environment through the electrolyte tailoring via Cl− ions. When coordinated with chlorine, the intermediate Cu+ ions in aqueous electrolytes are successfully stabilized and the electrochemical process is decoupled into two separate redox reactions involving Cu2+/Cu+ and Cu+/Cu0; Cu+/Cu0 results in a redox potential approximately 0.3 V lower than that for Cu2+/Cu0. Compared to the coordination with water, the coordination with chlorine also results in higher copper utilization, more rapid redox kinetics, and superior cycle stability. An aqueous copper-chlorine battery, harnessing Cl−/Cl0 redox reaction at the positive electrode, is discovered to have a high discharge voltage of 1.3 V, and retains 77.4% of initial capacity after 10,000 cycles. This work may open up an avenue to boosting the voltage and energy of aqueous copper batteries.

Abstract Flexible aqueous zinc batteries (FAZBs) with high safety and environmental friendliness are promising smart power sources for smart wearable electronics. However, the bare zinc anode usually suffers from damnable dendrite growth and rampant side reaction on the surface, greatly impeding practical applications in FAZBs. Herein, a composite polymer interface layer is artificially self‐assembled on the surface of the zinc anode by graft‐modified fluorinated monomer (polyacrylic acid‐2‐(Trifluoromethyl)propenoic acid, PAA‐TFPA), on which an organic–inorganic hybrid (PAA‐Zn/ZnF2) solid electrolyte interface (SEI) with excellent ionic conductivity is formed by interacting with Zn2+. Both the pouch cell and fiber zinc anode exhibit excellent plating/stripping reversibility after protecting by this organic–inorganic SEI, which can be stably cycled more than 3000 h in symmetric Zn||Zn cells or 550 h in fiber Zn||Zn cells. Additionally, this interface layer preserves zinc anode with excellent mechanical durability under various mechanical deformation (stably working for another 1200 h after bending 100 h). The corresponding PAA‐Zn/ZnF2@Zn||MnO2 full cell displays an ultra‐long life span (79% capacity retention after 3000 cycles) and mechanical robustness (85% of the initial capacity for another 3000 cycles after bending 100 times). More importantly, the as‐assembled cells can easily power smart wearable devices to monitor the user's health condition.

The growing demand for sodium-ion batteries (SIBs) in commercial applications has made it imperative to meet the commercial requirements. However, SIBs face significant challenges because of their poor cyclability and low reversible capacity compared with their rival lithium-ion batteries (LIBs). To address these challenges, various techniques, design strategies, surface engineering, and structural modifications have been developed to enhance the electrochemical performance of SIBs. This review focuses on recent developments in improving the electrochemical performance and cyclability of novel promising electrode materials for SIBs. We discuss several unique state-of-the-art research studies of the past five years that demonstrated excellent electrochemical performance through effective methodologies, surface modulations, and substitution of novel elements into the structure, and boosted the efficiency of the materials. Furthermore, we propose that it is important to adopt a nuanced approach when designing SIBs. Rather than copying the designs and methods used for LIBs, ideas should be absorbed from them and approaches should be tailored to meet the specific requirements of SIBs. This will enable the development of SIBs that are optimized for their intended applications and will avoid the challenges that have hindered the commercial success of earlier attempts at constructing SIBs. Thus, the key to creating high-performance SIBs is to draw inspiration from the best practices used in LIBs, while simultaneously innovating and developing new approaches tailored to the unique characteristics of SIBs.