High-Performance Rechargeable Anionic Zn–Cu Batteries with Facile Recyclability
Yan Wu, Huaqing Zhang, Dechen Dong, Peng Liang, Yuanzhuo Li, Jiajie Zheng, Xichen Zhou, Jingwen Zhou, Yilin Sun, Zhikang Deng, Shuting Fu, Mingyue Wang, Xiantao Hu, Zuochao Wang, Zijian Jiang, Haoran Liu, Hongjie DaiAbstract
Aqueous batteries with high safety are ideal large-scale energy storage systems, but still face challenges in cycle life, self-discharge, cost, and environment-related issues. Here, we report a rechargeable aqueous zinc–copper battery with high performance, environmental friendliness, and sustainability. We employed widely available metal foils as electrodes and developed a novel zinc–bromide and cuprous–bromide complex anion-containing anolyte and catholyte, respectively, separated by a cation exchange membrane (CEM), utilizing strong coordination between soft bromide ions and zinc/cuprous ions. The battery exhibited a high areal capacity of 4 mAh/cm2 with stable cycling over 2700 h (>900 cycles), energy efficiency up to ∼90%, excellent 99.6% capacity retention against self-discharge over 3 days, and facile scalability to Ah-level Zn/Cu batteries. Importantly, all elements were recycled at the end of the battery cycle life by simple, cost-effective processes with recovery efficiencies of ∼97% for Zn and ∼100% for Cu. This drastically lowered the battery cost and made the anionic Zn–Cu (AZC) battery promising for energy storage at a low cost with high performance and long-term sustainability.