A Bifunctional Chemomechanics Strategy To Suppress Electrochemo-Mechanical Failure of Ni-Rich Cathodes for All-Solid-State Lithium Batteries

Xingwei Sun; Longlong Wang; Jun Ma; Xinrun Yu; Shu Zhang; Xinhong Zhou; Guanglei Cui

doi:10.1021/acsami.2c02678

A Bifunctional Chemomechanics Strategy To Suppress Electrochemo-Mechanical Failure of Ni-Rich Cathodes for All-Solid-State Lithium Batteries

ACS Appl Mater Interfaces. 2022 Apr 20;14(15):17674-17681. doi: 10.1021/acsami.2c02678. Epub 2022 Apr 8.

Authors

Xingwei Sun^{1

2}, Longlong Wang¹, Jun Ma^{1

3}, Xinrun Yu¹, Shu Zhang¹, Xinhong Zhou², Guanglei Cui^{1

2

3

4}

Affiliations

¹ Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
² College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
³ Shandong Energy Institute, Qingdao 266101, China.
⁴ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35394744
DOI: 10.1021/acsami.2c02678

Abstract

Electrochemo-mechanical failure of Ni-rich cathodes leads to rapid performance degradation, and thus hinders their practical implementation in all-solid-state lithium batteries (ASSLBs). To solve this problem, herein, we propose a bifunctional chemomechanics strategy by protecting polycrystalline LiNi_0.6Co_0.2Mn_0.2O₂ (NCM) cathodes using a high-mechanical-strength fast ionic conductor LiZr₂(PO₄)₃ (LZP) coating layer. The coating layer's synergistic effect between mechanical strength and electrochemical stability is studied in Li₆PS₅Cl (LPSCl)-based ASSLBs for the first time. Using finite element method (FEM) simulations and various characterization techniques, we demonstrate that the robust and stable LZP (Young's modulus 140.7 GPa, electrochemical stability window >5 V) coating layer mitigates the volume change and particle disintegration of polycrystalline NCM and electrochemical decomposition of LPSCl on the LPSCl/NCM interface. As a result, the LZP-modified ASSLBs display remarkably improved reversible capacity, cycle life, and rate performance. The synergy of mechanical and electrochemical properties of the coating layer will provide valuable guidance for the development of high-energy-density ASSLBs.

Keywords: Ni-rich all-solid-state lithium battery; bifunctional chemomechanics strategy; electrochemical stability; electrochemo-mechanical failure; high mechanical strength.