Hong Kong Center for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong SAR, Shatin, N. T, 999077, China.
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, Kowloon, 999077, China.
Nat Commun. 2023 Apr 1;14(1):1828. doi: 10.1038/s41467-023-37524-7.
Aqueous zinc metal batteries are appealing candidates for grid energy storage. However, the inadequate electrochemical reversibility of the zinc metal negative electrode inhibits the battery performance at the large-scale cell level. Here, we develop practical ampere-hour-scale aqueous Zn metal battery pouch cells by engineering the electrolyte solution. After identifying the proton reduction as the primary source of H evolution during Zn metal electrodeposition, we design an electrolyte solution containing reverse micelle structures where sulfolane molecules constrain water in nanodomains to hinder proton reduction. Furthermore, we develop and validate an electrochemical testing protocol to comprehensively evaluate the cell's coulombic efficiency and zinc metal electrode cycle life. Finally, using the reverse micelle electrolyte, we assemble and test a practical ampere-hour Zn||ZnVO•nHO multi-layer pouch cell capable of delivering an initial energy density of 70 Wh L (based on the volume of the cell components), capacity retention of about 80% after 390 cycles at 56 mA g and ~25 °C and prolonged cycling for 5 months at 56 mA g and ~25 °C.
水系锌金属电池作为电网储能的候选者极具吸引力。然而，锌金属负极的电化学可逆性不足限制了其在大规模电池层面的性能。在此，我们通过对电解液进行工程设计，开发了实用的安时级水系锌金属软包电池。在确定质子还原是锌金属电镀过程中析氢的主要来源后，我们设计了一种含有反胶束结构的电解液，其中环丁砜分子将水约束在纳米域中以阻止质子还原。此外，我们开发并验证了一种电化学测试方案，以全面评估电池的库仑效率和锌金属电极的循环寿命。最后，我们使用反胶束电解液组装并测试了一种实用的安时级 Zn||ZnVO•nHO 多层软包电池，该电池在 56 mA g 和 ~25°C 下以 56 mA g 和 ~25°C 循环 5 个月的条件下，初始能量密度为 70 Wh L（基于电池组件的体积），容量保持率约为 80%，可提供 70 Wh L 的初始能量密度，在 56 mA g 和 ~25°C 下循环 390 次后容量保持率约为 80%，并具有长达 5 个月的循环寿命。
