摘要
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 zincmetal anode is raised to an unprecedented>99.7%at 1mA 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 2mA 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.
基金
XJ thanks Oregon State University for AID program support.J-XJ thanks the financial support from the National Natural Science Foundation of China(21574077 and 21304055)
111 project(B14041)
the Fundamental Research Funds for the Central Universities(GK201801001)
CZ is supported by a fellowship from the China Scholarship Council(201706870033)
CF is grateful to the U.S.National Science Foundation CAREER grant(CHE-1455353)
the support of the femtosecond stimulated Raman instrumentation and the NSF MRI grant(DMR-1920368)for additional support.
作者简介
Correspondence:Jia-Xing Jiang,Key Laboratory of Applied Surface and Colloid Chemistry(Shaanxi Normal University),Ministry of Education,Shaanxi Key Laboratory for Advanced Energy Devices,School of Materials Science and Engineering,Shaanxi Normal University,Xi’an,Shaanxi 710062,China.Email:jiaxing@snnu.edu.cn;Correspondence:Chong Fang,Department of Chemistry,Oregon State University,Corvallis,OR 97331‐4003.Email:Chong.Fang@oregonstate.edu;Correspondence:P.Alex Greaney,Materials Science and Engineering,University of California,Riverside,CA 92521.Email:agreaney@engr.ucr.edu;Correspondence:Xiulei Ji,Department of Chemistry,Oregon State University,Corvallis,OR 97331-4003.Email:david.ji@oregonstate.edu。
