Improving Cycling Stability of the Lithium Anode by a Spin-Coated High-Purity Li3PS4 Artificial SEI Layer

Hongjiao Wang; Lilin Wu; Bai Xue; Fang Wang; Zhongkuan Luo; Xianghua Zhang; Laurent Calvez; Ping Fan; Bo Fan

doi:10.1021/acsami.1c25224

Improving Cycling Stability of the Lithium Anode by a Spin-Coated High-Purity Li₃PS₄ Artificial SEI Layer

ACS Appl Mater Interfaces. 2022 Apr 6;14(13):15214-15224. doi: 10.1021/acsami.1c25224. Epub 2022 Mar 22.

Authors

Hongjiao Wang^{1

2}, Lilin Wu³, Bai Xue¹, Fang Wang³, Zhongkuan Luo³, Xianghua Zhang², Laurent Calvez², Ping Fan¹, Bo Fan¹

Affiliations

¹ Shenzhen Key Laboratory of Advanced Thin Films and Applications, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China.
² Laboratory of Glasses and Ceramics, Institute of Chemical Science, University of Rennes 1, Rennes 35042, France.
³ College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China.

PMID: 35316015
DOI: 10.1021/acsami.1c25224

Abstract

Controlling the composition and microstructure of the solid electrolyte interphase (SEI) layer is critical to improving the cycling stability of the high-energy-density lithium-metal electrode. It is a quite tricky task to control the properties of the SEI layer which is conventionally formed by the chemical reactions between a Li metal and the additives. Herein, we develop a new route to synthesize a lithium-compatible sol of the sulfide electrolyte Li₃PS₄, so that a Li₃PS₄ artificial SEI layer with a controllable nanoscale thickness and high phase purity can be prepared by spin-coating. The layer stabilizes the lithium/electrolyte interface by homogenizing the Li-ion flux, preventing the parasitic reactions, and alleviating concentration polarization. Consequently, a symmetrical cell with the Li₃PS₄-modified lithium electrodes can achieve stable lithium plating/stripping for 800 h at a current density of 1 mA cm^-2. The Li-S batteries assembled with the Li₃PS₄-protected Li anodes show better capacity retention than their bare Li counterparts, whose average decay rate from the 240th cycle to the 800th cycle is only 0.004%/cycle. In addition, the Li₃PS₄ layer improves the rate capacity of the batteries, significantly enhancing the capacity from 175 to 682 mA h g^-1 at a 2 C rate. The spin-coated Li₃PS₄ artificial SEI layer provides a new strategy to develop high-performance Li metal batteries.

Keywords: Li3PS4; Lithium anode; artificial SEI layer; cycle stability; lithium−metal batteries; spin-coated; sulfide solid electrolyte.