摘要
Lithium-rich antiperovskites are promising solid-state electrolytes for all-solid-state lithium-ion batteries because of their high structural tolerance and good formability.However,the experimentally reported proton-free Li_(3)OCl is plagued by its inferior interfacial compatibility and harsh synthesis conditions.In contrast,Li_(2)OHCl is a thermodynamically favored phases and is easier to achieve than Li_(3)OCl.Due to the proton inside this material,it exhibits interesting lithium diffusion mechanisms.Herein,we present a systematic investigation of the ionic transport,phase stability,and electrochemicalchemical stability of Li_(2)OHCl using first-principles calculations.Our results indicate that Li_(2)OHCl is thermodynamically metastable and is an electronic insulator.The wide electrochemical stability window and high chemical stability of Li_(2)OHCl against various electrodes are confirmed.The charged defects are the dominant conduction mechanism for Li-transport,with a low energy barrier of~0.50 eV.The Li-ion conductivity estimated by ab initio molecular dynamics simulations is about 1.3×10^(-4) S cm^(-1) at room temperature.This work identifies the origin of the high interfacial stability and ionic conductivity of Li_(2)OHCl,which can further lead to the design of such as a cathode coating.Moreover,all computational methods for calculating the properties of Li_(2)OHCl are general and can guide the design of highperformance solid-state electrolytes.
基金
supported by the National Key Research and Development Program of China(Grant No.2018YFB0905400)
the National Natural Science Foundation of China(Grant No.12004145)
the Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.GJJ201030)
the PhD Start-up Fund of Natural Science Foundation of Jinggangshan University(Grant No.JZB2013)
supported by the Faraday Institution(grant No.FIRG017).
