Improving the Interfacial Stability between Lithium and Solid‐State Electrolyte via Dipole‐Structured Lithium Layer Deposited on Graphene Oxide

Advanced Science

Chuying Ouyang¹  Wenwei Luo¹  Qiang Zhang²  Zhe Peng²  Muqin Wang²  Zhendong Li²  Yun Zhu²  Huan Lin²  Xiayin Yao²  Deyu Wang²  Liangting Cai² 

[1] Department of Physics Laboratory of Computational Materials Physics Jiangxi Normal University Nanchang 330022 China;Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China;

关键词: dipole structure;    graphene oxide;    lithium metal anodes;    lithium metal batteries;    solid electrolyte interfaces;   

DOI  :  10.1002/advs.202000237

来源: DOAJ

【 摘 要 】

Abstract Utilization of lithium (Li) metal anode in solid‐state batteries (SSBs) with sulfide solid‐state electrolyte (SSE) is hindered by the instable Li/SSE interface. A general solution to solve this problem is to place an expensive indium (In) foil between the SSE and Li, while it decreases the output voltage and thus the energy density of the battery. In this work, an alternative strategy is demonstrated to boost the cycling performances of SSB by wrapping a graphene oxide (GO) layer on the anode. According to density functional theory results, initial deposition of a thin Li layer on the defective GO sheets leads to the formation of a dipole structure, due to the electron‐withdrawing ability of GO acting on Li. By incorporating GO sheets in a nanocomposite of copper‐cuprous oxide‐GO (Cu‐Cu2O‐GO, CCG), a composite Li anode enables a high coulombic efficiency above 99.5% over 120 cycles for an SSB using Li10GeP2S12 SSE and LiCoO2 cathode, and the sulfide SSE is not chemically decomposed after cycling. The highest occupied molecule orbital/lowest unoccupied molecular orbital energy gap of this Li/GO dipole structure likely stretches over those of Li and sulfide SSE, enabling stabilized Li/SSE interface that can replace the expensive In layer as Li protective structure in SSBs.

【 授权许可】

Unknown