Abstract
The performance of Zn metal batteries (ZMBs) is significantly hindered by the poor cycling stability and dendrite growth of Zn metal anodes. Herein, Cs(2)SnCl(6) is introduced, a lead-free metal halide double perovskite, as a multifunctional electrolyte additive to address the challenges of Zn anodes. Utilizing a combination of molecular dynamics simulations, COMSOL simulations, and various characterization techniques, it is demonstrated that Cl(-), Sn(4+), and Cs(+) ions generated from partial hydrolysis of Cs(2)SnCl(6) in the 2 m ZnSO(4) electrolyte can optimize the electrolyte solvation structures, suppress side reactions, facilitate Zn nucleation process, and modulate Zn deposition behavior. As a result, Zn||Zn symmetric cells with Cs(2)SnCl(6)-enhanced electrolyte achieve remarkable cycling stability over 5000 h at 1 mA cm(-2), while the full cell also shows a capacity retention of 99.96% after 1000 cycles. This work provides insights into electrolyte-driven interface modulation strategies for next-generation aqueous ZMBs.