Li2ZrF6 protective layer enabled high-voltage LiCoO2 positive electrode in sulfide all-solid-state batteries

Xing Zhou; Chia-Yu Chang; Dongfang Yu; Kai Zhang; Zhi Li; Shi-Kai Jiang; Yizhou Zhu; Yongyao Xia; Bing Joe Hwang; Yonggang Wang

doi:10.1038/s41467-024-55695-9

Li₂ZrF₆ protective layer enabled high-voltage LiCoO₂ positive electrode in sulfide all-solid-state batteries

Nat Commun. 2025 Jan 2;16(1):112. doi: 10.1038/s41467-024-55695-9.

Authors

Xing Zhou^{1

2}, Chia-Yu Chang³, Dongfang Yu⁴, Kai Zhang¹, Zhi Li¹, Shi-Kai Jiang⁵, Yizhou Zhu⁶, Yongyao Xia⁷, Bing Joe Hwang^{8

9

10

11}, Yonggang Wang¹²

Affiliations

¹ Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, China.
² Contemporary Amperex Technology Ltd. (CATL), Ningde, China.
³ Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology (NTUST), Taipei, Taiwan.
⁴ Research Center for Industries of the Future and School of Engineering, Westlake University, Hangzhou, China.
⁵ Department of Chemical Engineering, National Taiwan University of Science and Technology (NTUST), Taipei, Taiwan.
⁶ Research Center for Industries of the Future and School of Engineering, Westlake University, Hangzhou, China. [email protected].
⁷ Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, China. [email protected].
⁸ Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology (NTUST), Taipei, Taiwan. [email protected].
⁹ Department of Chemical Engineering, National Taiwan University of Science and Technology (NTUST), Taipei, Taiwan. [email protected].
¹⁰ National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan. [email protected].
¹¹ Sustainable Electrochemical Energy Development Center, National Taiwan University of Science and Technology (NTUST), Taipei, Taiwan. [email protected].
¹² Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, China. [email protected].

Abstract

The application of high-voltage positive electrode materials in sulfide all-solid-state lithium batteries is hindered by the limited oxidation potential of sulfide-based solid-state electrolytes (SSEs). Consequently, surface coating on positive electrode materials is widely applied to alleviate detrimental interfacial reactions. However, most coating layers also react with sulfide-based SSEs, generating electronic conductors and causing gradual interface degradation and capacity fading. To address this, we propose a Li₂ZrF₆ coating layer on LiCoO₂, which exhibits minimal reaction with SSEs, and its decomposition products are electron-conductive-free. Furthermore, this coating layer also efficiently mitigates the layered-to-spinel/rock-salt surface structural transformation in LiCoO₂. As a result, the In-Li|Li₆PS₅Cl | Li₂ZrF₆-LiCoO₂ all-solid-state cell demonstrates an initial areal capacity of 5.2 mAh cm^-2 and a capacity retention of 80.5% after 1500 cycles at 70 mA/g with high LiCoO₂ areal mass loading (30.19 mg cm^-2) and a cut-off voltage of 3.9 V (corresponding to potential of 4.5 V versus Li⁺/Li), at 25 °C.

Grants and funding

22225201/National Natural Science Foundation of China (National Science Foundation of China)