Anion-enrichment interface enables high-voltage anode-free lithium metal batteries

Minglei Mao; Xiao Ji; Qiyu Wang; Zejing Lin; Meiying Li; Tao Liu; Chengliang Wang; Yong-Sheng Hu; Hong Li; Xuejie Huang; Liquan Chen; Liumin Suo

doi:10.1038/s41467-023-36853-x

Anion-enrichment interface enables high-voltage anode-free lithium metal batteries

Nat Commun. 2023 Feb 25;14(1):1082. doi: 10.1038/s41467-023-36853-x.

Authors

Minglei Mao^#^{1

2}, Xiao Ji^#², Qiyu Wang¹, Zejing Lin¹, Meiying Li¹, Tao Liu¹, Chengliang Wang², Yong-Sheng Hu¹, Hong Li¹, Xuejie Huang¹, Liquan Chen¹, Liumin Suo³

Affiliations

¹ Beijing Advanced Innovation Center for Materials Genome Engineering, Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Beijing, 100190, China.
² School of Integrated Circuits, School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics (WNLO), Optics Valley Laboratory, Huazhong University of Science and Technology, Wuhan, 430074, China.
³ Beijing Advanced Innovation Center for Materials Genome Engineering, Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, Beijing, 100190, China. suoliumin@iphy.ac.cn.

^# Contributed equally.

Abstract

Aggressive chemistry involving Li metal anode (LMA) and high-voltage LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811) cathode is deemed as a pragmatic approach to pursue the desperate 400 Wh kg^-1. Yet, their implementation is plagued by low Coulombic efficiency and inferior cycling stability. Herein, we propose an optimally fluorinated linear carboxylic ester (ethyl 3,3,3-trifluoropropanoate, FEP) paired with weakly solvating fluoroethylene carbonate and dissociated lithium salts (LiBF₄ and LiDFOB) to prepare a weakly solvating and dissociated electrolyte. An anion-enrichment interface prompts more anions' decomposition in the inner Helmholtz plane and higher reduction potential of anions. Consequently, the anion-derived interface chemistry contributes to the compact and columnar-structure Li deposits with a high CE of 98.7% and stable cycling of 4.6 V NCM811 and LiCoO₂ cathode. Accordingly, industrial anode-free pouch cells under harsh testing conditions deliver a high energy of 442.5 Wh kg^-1 with 80% capacity retention after 100 cycles.