Li-N Interaction Induced Deep Eutectic Gel Polymer Electrolyte for High Performance Lithium-Metal Batteries

Xiaopeng Pei; Yiju Li; Ting Ou; Xuechen Liang; Yun Yang; Erna Jia; Ying Tan; Shaojun Guo

doi:10.1002/anie.202205075

Li-N Interaction Induced Deep Eutectic Gel Polymer Electrolyte for High Performance Lithium-Metal Batteries

Angew Chem Int Ed Engl. 2022 Aug 1;61(31):e202205075. doi: 10.1002/anie.202205075. Epub 2022 Jun 14.

Authors

Xiaopeng Pei^{1

2

3}, Yiju Li², Ting Ou⁴, Xuechen Liang^{1

3}, Yun Yang^{1

3}, Erna Jia^{1

3}, Ying Tan^{1

3}, Shaojun Guo²

Affiliations

¹ Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325000, China.
² School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
³ Oujiang Laboratory, Wenzhou, 325000, China.
⁴ Institute of Theoretical and Computational Chemistry, Shaanxi Key Laboratory of Catalysis, School of Chemical & Environment Science, Shaanxi University of Technology, Hanzhong, 723001, China.

PMID: 35611865
DOI: 10.1002/anie.202205075

Abstract

As emerging eutectic mixtures, deep eutectic electrolytes (DEEs) show unique properties for Li-metal batteries (LMBs). However, the limited choice and inferior electrode compatibility hinder their further development in LMBs. Herein, we report a new 1,2-dimethylimidazole (DMIm)-based deep eutectic gel polymer electrolyte induced by Li-N interaction. We demonstrate that incorporating electron-withdrawing polyvinylidene difluoride (PVDF) polymer into the DMIm-based DEE changes the coordination environment of Li⁺ ions, leading to a high transference number of Li⁺ ions (0.65) and superior interface stability between the electrolyte and Li anode. The deep eutectic gel polymer electrolyte exhibits excellent non-flammability, high ionic conductivity (1.67 mS cm^-1 at 30 °C), and high oxidation voltage (up to 4.35 V vs. Li/Li⁺ ). The Li||LFP cell based on the newly developed deep eutectic gel polymer electrolyte can achieve superior long-term cycling stability at a wide range of rates.

Keywords: 1,2-Dimethylimidazole; Deep Eutectic Electrolytes; Eutectic Gel Electrolytes; Lithium-Metal Batteries; Polyvinylidene Difluoride.

Abstract

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