Dimension-combined Zn anode coated with Cu for use in enhanced aqueous Zn-ion batteries

초록

Zn-ion aqueous batteries (ZIBs) have emerged as promising candidates for the next-generation energy sources owing to their compatibility with aqueous electrolytes, enhanced stability and ionic conductivity, nontoxicity, and cost-effectiveness. This study investigated the electrochemical performance and stability of Cu-coated Zn particles on a Zn foil (3D-pZn@Cu) compared to those of pristine Zn powder (3D-pZn) and Zn foil (2D-Zn foil). 2D-Zn foil and 3D-pZn electrodes inherently face an uneven electric field distribution, dendrite growth, and side reactions, which degrade the battery life and performance. 3D-pZn@Cu overcomes these issues by reducing the nucleation energy barrier, random dendrite growth, corrosion, and side reactions. 3D-pZn@Cu exhibited a stable overpotential (similar to 70 mV at 1 mA cm(-2) and 1 mAh cm(-2)) for 4300 h in symmetric cells, significantly outperforming 3D-pZn and 2D-Zn foil in terms of both stability and duration. Electrochemical impedance spectroscopy and cyclic voltammetry analyses showed that 3D-pZn@Cu exhibited a lower charge transfer resistance and higher ionic conductivity than 3D-pZn. In a full cell configuration using V2O5-C (20 wt%) as the cathode, the battery delivered a capacity of 107.4 mAh g(-1) after 300 cycles. These findings highlight the potential of the 3D-pZn@Cu electrode for the development of high-performance, stable aqueous batteries. This study highlights the importance of the surface modification of Zn anodes for improving the efficiency and durability of next-generation energy storage systems.

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