Influence of Current Collector Materials on the Electrochemical Performance of Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (ZIBs) have recently attracted increasing attention due to their intrinsic advantages, including high safety, the natural abundance of zinc, cost-effectiveness, and a reduced environmental footprint. However, ZIBs are still in the early stages of development for practical applications. Current research is focused on designing high-capacity cathodes, dendrite-free Zn anodes, and optimised electrolytes and separators. While much emphasis has been placed on electrode materials, the role of cathode current collectors is equally critical, as they support the cathode material and facilitate electron transport. The choice of current collector significantly influences the electrical, mechanical, and electrochemical performance of the battery. It serves as both the structural backbone for the active material and a conduit for efficient charge transfer, helping to minimise resistance and voltage losses. In this study, we investigate six different materials -carbon paper, graphene paper, carbon nanotube paper, titanium foil, stainless steel foil, and stainless-steel mesh -as cathode current collectors for ZIBs. Remarkably, batteries employing graphene paper and carbon paper current collectors demonstrate high specific capacities of 407 and 429 mAh g⁻¹, respectively, at a high current density of 2000 mA g⁻¹. In contrast, AZIBs using titanium foil and stainless-steel foil exhibit significantly lower capacities of 280 and 172 mAh g⁻¹, respectively. These findings underscore the critical role of current collector material and highlight carbon-based collectors as promising candidates for high-performance ZIBs, even when using the same VO₂(B) cathode material.