Portal de Periódicos da CAPES

The electrolyte comprising more robust water and superhalides transforms Zn‐metal anode reversibly and dendrite‐free

2020; Wiley; Volume: 3; Issue: 2 Linguagem: Inglês

10.1002/cey2.70

2096-9570

Chong Zhang, Woochul Shin, Liangdong Zhu, Cheng Chen, J. Neuefeind, Yunkai Xu, Sarah I. Allec, Cong Liu, Zhixuan Wei, Aigerim Daniyar, Jia‐Xing Jiang, Chong Fang, P. Alex Greaney, Xiulei Ji,

Perovskite Materials and Applications

Abstract A great challenge for all aqueous batteries, including Zn‐metal batteries, is the parasitic hydrogen evolution reaction on the low‐potential anode. Herein, we report the formula of a highly concentrated aqueous electrolyte that mitigates hydrogen evolution by transforming water molecules more inert. The electrolyte comprises primarily ZnCl 2 and LiCl as an additive, both of which are inexpensive salts. The O–H covalent bonds in water get strengthened in a chemical environment that has fewer hydrogen bonding interactions and a greater number of Zn–Cl superhalides, as suggested by integrated characterization and simulation. As a result, the average Coulombic efficiency of zinc‐metal anode is raised to an unprecedented >99.7% at 1 mA cm −2 . In the new electrolyte, the plating/stripping processes leave the zinc‐metal anode dendrite‐free, and the zinc‐metal anode delivers stable plating/stripping cycles for 4000 hours with an areal capacity of 4 mAh cm −2 at 2 mA cm −2 . Furthermore, the high Coulombic efficiency of zinc‐metal anode in the ZnCl 2 ‐LiCl mixture electrolyte is demonstrated in full cells with a limited anode. The V 2 O 5 ·H 2 O||Zn full cell with an N / P mass ratio of 1.2 delivers a stable life of more than 2500 cycles, and the LiMn 2 O 4 ||Zn hybrid cell with an N / P mass ratio of 0.6 exhibits 1500 cycles in its stable life.