Designing Anion-Derived Solid Electrolyte Interphase in a Siloxane-Based Electrolyte for Lithium-Metal Batteries

Jianyang Wu; Tianyi Zhou; Bing Zhong; Qian Wang; Wen Liu; Henghui Zhou

doi:10.1021/acsami.2c05098

Designing Anion-Derived Solid Electrolyte Interphase in a Siloxane-Based Electrolyte for Lithium-Metal Batteries

ACS Appl Mater Interfaces. 2022 Jun 22;14(24):27873-27881. doi: 10.1021/acsami.2c05098. Epub 2022 Jun 7.

Authors

Jianyang Wu¹, Tianyi Zhou^{2

3}, Bing Zhong³, Qian Wang⁴, Wen Liu⁵, Henghui Zhou^{1

6}

Affiliations

¹ College of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, China.
² CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Institute of Energy Innovation, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
⁵ State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, 100092 Beijing, China.
⁶ Beijing Engineering Research Center of Power Lithium-ion Battery, Beijing 102202, China.

PMID: 35671243
DOI: 10.1021/acsami.2c05098

Abstract

The rational electrolyte design with weak solvation is regarded as an effective way to regulate the electrolyte/electrode interface (SEI) that profoundly affects the performance of Li-metal batteries. Herein, we propose a newly developed siloxane-based weakly solvating electrolyte (SiBE) with contact ion pairs (CIPs) or aggregates (AGGs) dominating the solution structure, which enables the dendrite-free Li deposition and long cycle stability of Li-metal batteries. By altering the combination of Li salts, the SiBE leads to the formation of an inorganic anion-derived solid electrolyte interphase, which is highly stable and Li⁺-conductive. Based on SiBE, the Li||LiFePO₄ (LFP) full cell can stably cycle for 1000 cycles at a 2C rate with a capacity retention of 76.9%. Even with a limited Li-metal anode, it can maintain a capacity retention of 80% after 110 cycles with a high average Coulombic efficiency of 99.8%. This work reveals that siloxane can be a promising solvent to obtain weakly solvating electrolytes, which opens a new avenue for SEI composition regulation of Li-metal batteries.

Keywords: Li-metal batteries; anion-derived solid electrolyte interphases; electrolyte designs; siloxane-based electrolytes; solvation structures; weakly solvating electrolytes.