No abstract

Over the past few years, rechargeable aqueous Zn-ion batteries have garnered significant interest as potential alternatives for lithium-ion batteries because of their low cost, high theoretical capacity, low redox potential, and environmentally friendliness. However, several constraints associated with Zn metal anodes, such as the growth of Zn dendrites, occurrence of side reactions, and hydrogen evolution during repeated stripping/plating processes result in poor cycling life and low Coulombic efficiency, which severely impede further advancements in this technology. Despite recent efforts and impressive breakthroughs, the origin of these fundamental obstacles remains unclear and no successful strategy that can address these issues has been developed yet to realize the practical applications of rechargeable aqueous Zn-ion batteries. In this review, we have discussed various issues associated with the use of Zn metal anodes in mildly acidic aqueous electrolytes. Various strategies, including the shielding of the Zn surface, regulating the Zn deposition behavior, creating a uniform electric field, and controlling the surface energy of Zn metal anodes to repress the growth of Zn dendrites and the occurrence of side reactions, proposed to overcome the limitations of Zn metal anodes have also been discussed. Finally, the future perspectives of Zn anodes and possible design strategies for developing highly stable Zn anodes in mildly acidic aqueous environments have been discussed.

Summary Sb‐based intermetallic materials have been extensively studied as electrodes for lithium‐ion batteries (LIBs) owing to the high discharge capacity and acceptable working voltage range. In this study, InSb nanocrystallites were homogeneously distributed and embedded into a combined matrix of amorphous carbon and rutile TiO2 by a facile two‐time ball‐milling process. The nanostructure of the composite exhibited a favorable synergistic effect of the three components (InSb: high‐capacity active material, TiO2: inorganic crystalline robust matrix, and C: carbonaceous amorphous conductive matrix), which not only supplied a buffering network to suppress the volume expansion of InSb during the Li+ ion intercalation/deintercalation process, but also enhanced the ionic/electronic conductivity of the anode material. Consequently, the InSb‐TiO2‐C anode delivered a long lifespan and remarkable rate performance. In addition, the anode showed a high reversible discharge capacity of 540 mAh g−1 even after 400 cycles at a high current rate of 500 mA g−1. Furthermore, the anode exhibited good capacity retention (87% at 2 A g−1 relative to the capacity at 0.1 A g−1). These results indicate the potential of InSb‐TiO2‐C nanocomposites for LIBs anode materials.