Stable Solvent-Derived Inorganic-Rich Solid Electrolyte Interphase (SEI) for High-Voltage Lithium-Metal Batteries

Ziyu Chen; Bin Wang; Yan Li; Fengwei Bai; Yongchao Zhou; Chengzong Li; Tao Li

doi:10.1021/acsami.2c06934

Stable Solvent-Derived Inorganic-Rich Solid Electrolyte Interphase (SEI) for High-Voltage Lithium-Metal Batteries

ACS Appl Mater Interfaces. 2022 Jun 22;14(24):28014-28020. doi: 10.1021/acsami.2c06934. Epub 2022 Jun 7.

Authors

Ziyu Chen¹, Bin Wang¹, Yan Li¹, Fengwei Bai¹, Yongchao Zhou¹, Chengzong Li¹, Tao Li¹

Affiliation

¹ School of Resource Environment and Safety Engineering, University of South China, Hengyang 421001, P. R. China.

PMID: 35671045
DOI: 10.1021/acsami.2c06934

Abstract

The inorganic-rich solid electrolyte interphase (SEI) has attracted wide attention due to its good compatibility with the lithium (Li) metal anode. Herein, a stable solvent-derived inorganic-rich SEI is constructed from a hydrofluoroether-diluted low-concentration electrolyte, which simultaneously possesses the merits of nonflammability and low cost (0.5 M LiPF₆). The addition of hydrofluoroether enhances the coordination strength between Li⁺ and solvents, altering the decomposition path of solvents to yield more Li₂O. The abundant Li₂O crystals endow the SEI with improved passivating ability and ion conductivity. The 30 μm Li|NCM523 (3.8 mAh cm^-2) batteries with solvent-derived Li₂O-rich SEI deliver 96.1% capacity retention after 200 cycles. Notably, a 1.1 Ah Li|NCA pouch cell delivers an energy density of 374 Wh kg^-1 and achieves 45 stable cycles. This study points out that tuning the decomposition of solvents provides a new approach to construct stable inorganic-rich SEI for practical Li-metal batteries.

Keywords: Li-metal batteries; inorganic-rich SEI; low-concentration electrolyte; nonflammability; solvent-derived.