Construction of Inorganic-Rich Cathode Electrolyte Interphase on Co-Free Cathodes

Jinxing Li; Hanying Xu; Jie Li; Xinping Chen; Yujuan Zhang; Wei Liu; Wenting Li; Ce Han; Shengli An; Xindong Wang; Xinping Qiu

doi:10.1021/acsami.3c02553

Construction of Inorganic-Rich Cathode Electrolyte Interphase on Co-Free Cathodes

ACS Appl Mater Interfaces. 2023 Jun 7;15(22):26627-26636. doi: 10.1021/acsami.3c02553. Epub 2023 May 23.

Authors

Jinxing Li^{1

2}, Hanying Xu², Jie Li², Xinping Chen², Yujuan Zhang², Wei Liu², Wenting Li², Ce Han², Shengli An^{1

3}, Xindong Wang¹, Xinping Qiu²

Affiliations

¹ School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, 100083 Beijing, China.
² Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, 100084 Beijing, China.
³ School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China.

PMID: 37220156
DOI: 10.1021/acsami.3c02553

Abstract

Lithium-rich layered oxides (LRLOs), with the chemical formula of xLi₂MnO₃·(1 - x)LiMO₂, delivering higher specific discharge capacity, are potential cathode materials for lithium-ion batteries. However, the dissolution of transition metal ions and the instability of the cathode-electrolyte interphase (CEI) hinder the commercial application of LRLOs. Herein, a simple and affordable method is developed for the construction of a robust CEI layer by quenching a kind of cobalt-free LRLO, Li_1.2Ni_0.15Fe_0.1Mn_0.55O₂ (denoted as NFM), in 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether solvent. This robust CEI, with well-distributed LiF, TMF_x, and partial organic component CF_x, performs as a physical barrier to prevent NFM from direct contact with the electrolyte, suppresses the oxygen release, and ensures the CEI layer stability. The customized CEI with LiF and TMF_x-rich phase considerably enhances the NFM cycle stability and the initial coulomb efficiency and inhibits voltage fading. This work provides a valuable strategy for designing stable interface chemistry on the cathode of lithium-ion batteries.

Keywords: CEI; HFE; electrode; lithium ion battery; lithium-rich material; quench.