Abstract
Ga-doped Li7La3Zr2O12(Ga-LLZO)has long been considered as a promising garnet-type electrolyte candidate for all-solid-state lithium metal batteries(ASSLBs)due to its high room temperature ionic conductivity.However,the typical synthesis of Ga-LLZO is usually accompanied by the formation of undesired LiGaO2 impurity phase that causes severe instability of the electrolyte in contact with molten Li metal during half/full cell assembly.In this study,we show that by simply engineering the defect chemistry of Ga-LLZO,namely,the lithium deficiency level,LiGaO2 impurity phase is effectively inhibited in the final synthetic product.Consequently,defect chemistry engineered Ga-LLZO exhibits excellent electrochemical stability against lithium metal,while its high room temperature ionic conductivity(～1.9 × 10-3 S·cm-1)is well reserved.The assembled Li/Ga-LLZO/Li symmetric cell has a superior critical current density of 0.9 mA·cm-2,and cycles stably for 500 hours at a current density of 0.3 mA·cm-2.This research facilitates the potential commercial applications of high performance Ga-LLZO solid electrolytes in ASSLBs.
基金项目
National Natural Science Foundation of China(52171221)
National Key Research and Development Program of China(2019YFA0704900)
NETL
NSTL
万方数据