Ion-Dipole-Interaction-Induced Encapsulation of Free Residual Solvent for Long-Cycle Solid-State Lithium Metal Batteries

Menglu Li; Hanwen An; Yajie Song; Qingsong Liu; Jian Wang; Hua Huo; Shuaifeng Lou; Jiajun Wang

doi:10.1021/jacs.3c07482

Ion-Dipole-Interaction-Induced Encapsulation of Free Residual Solvent for Long-Cycle Solid-State Lithium Metal Batteries

J Am Chem Soc. 2023 Nov 29;145(47):25632-25642. doi: 10.1021/jacs.3c07482. Epub 2023 Nov 9.

Authors

Menglu Li^{1

2

3}, Hanwen An^{1

2

3}, Yajie Song^{1

2}, Qingsong Liu^{1

2

3}, Jian Wang⁴, Hua Huo^{1

2}, Shuaifeng Lou^{1

2

3}, Jiajun Wang^{1

2

3}

Affiliations

¹ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
² State Key Laboratory of Space Power-Sources, Harbin Institute of Technology, Harbin 150001, China.
³ Chongqing Research Institute of HIT, Chongqing 401135, China.
⁴ Canadian Light Source Inc., University of Saskatchewan, Saskatoon, SK S7N 2V3, Canada.

PMID: 37943571
DOI: 10.1021/jacs.3c07482

Abstract

Owing to high ionic conductivity and mechanical strength, poly(vinylidene fluoride) (PVDF) electrolytes have attracted increasing attention for solid-state lithium batteries, but highly reactive residual solvents severely plague cycling stability. Herein, we report a free-solvent-capturing strategy triggered by reinforced ion-dipole interactions between Li⁺ and residual solvent molecules. Lithium difluoro(oxalato)borate (LiDFOB) salt additive with electron-withdrawing capability serves as a redistributor of the Li⁺ electropositive state, which offers more binding sites for residual solvents. Benefiting from the modified coordination environment, the kinetically stable anion-derived interphases are preferentially formed, effectively mitigating the interfacial side reactions between the electrodes and electrolytes. As a result, the assembled solid-state battery shows a lifetime of over 2000 cycles with an average Coulombic efficiency of 99.9% and capacity retention of 80%. Our discovery sheds fresh light on the targeted regulation of the reactive residual solvent to extend the cycle life of solid-state batteries.