Stabilizing a Lithium Metal Battery by an In Situ Li2S-modified Interfacial Layer via Amorphous-Sulfide Composite Solid Electrolyte

Chen Lai; Chengyong Shu; Wei Li; Liu Wang; Xiaowei Wang; Tianran Zhang; Xuesong Yin; Iqbal Ahmad; Mingtao Li; Xiaolu Tian; Pu Yang; Wei Tang; Naihua Miao; Guangyuan Wesley Zheng

doi:10.1021/acs.nanolett.0c03395

Stabilizing a Lithium Metal Battery by an In Situ Li₂S-modified Interfacial Layer via Amorphous-Sulfide Composite Solid Electrolyte

Nano Lett. 2020 Nov 11;20(11):8273-8281. doi: 10.1021/acs.nanolett.0c03395. Epub 2020 Oct 27.

Authors

Chen Lai^{1

2}, Chengyong Shu¹, Wei Li³, Liu Wang², Xiaowei Wang⁴, Tianran Zhang², Xuesong Yin⁵, Iqbal Ahmad¹, Mingtao Li¹, Xiaolu Tian¹, Pu Yang¹, Wei Tang^{1

6}, Naihua Miao³, Guangyuan Wesley Zheng^{2

5}

Affiliations

¹ School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
² Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
³ School of Materials Science and Engineering, Beihang University, Beijing 100191, People's Republic of China.
⁴ NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore.
⁵ Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore.
⁶ State Key Laboratory of Space Power-Sources Technology, Shanghai Institute of Space Power-Sources, Shanghai 200245, People's Republic of China.

PMID: 33108209
DOI: 10.1021/acs.nanolett.0c03395

Abstract

A novel strategy has been proposed to produce in situ Li₂S at the interfacial layer between lithium anode and the solid electrolyte, by using an amorphous-sulfide-LiTFSI-poly(vinylidene difluoride) (PVDF) composite solid electrolyte (SLCSE). Besides retarding the decomposition of PVDF in CSE, the Li₂S-modified interfacial layer (SMIL) also improves the wettability between lithium metal and SLCSE which in turn optimizes the lithium deposition process. Our density functional theory calculation results reveal that the migration energy barrier of Li passing through SMIL is much lower than that of Li passing through LiF-modified interfacial layer (FMIL) formed from the decomposition of PVDF. The as-prepared SLCSE shows a Li ionic transference number of 0.44 and Li ion conductivity of 3.42 × 10^-4 S/cm at room temperature, and the Li||SLCSE||LiFePO₄ cell exhibits an outstanding rate performance with a capacity of 153, 144, 131, and 101 mAh/g at a current density of 0.05, 0.10, 0.25, and 0.50 mA/cm², respectively.

Keywords: amorphous sulfide; composite solid electrolyte; interfacial layer; lithium metal batteries.