Passivating Lithiated Graphite via Targeted Repair of SEI to Inhibit Exothermic Reactions in Early-Stage of Thermal Runaway for Safer Lithium-Ion Batteries

Yuanke Wu; Ziqi Zeng; Sheng Lei; Mengchuang Liu; Wei Zhong; Mingsheng Qin; Shijie Cheng; Jia Xie

doi:10.1002/anie.202217774

Passivating Lithiated Graphite via Targeted Repair of SEI to Inhibit Exothermic Reactions in Early-Stage of Thermal Runaway for Safer Lithium-Ion Batteries

Angew Chem Int Ed Engl. 2023 Mar 1;62(10):e202217774. doi: 10.1002/anie.202217774. Epub 2023 Jan 31.

Authors

Yuanke Wu^{1

2}, Ziqi Zeng¹, Sheng Lei^{1

2}, Mengchuang Liu^{1

3}, Wei Zhong^{1

2}, Mingsheng Qin^{1

2}, Shijie Cheng¹, Jia Xie¹

Affiliations

¹ State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
² State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
³ School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.

PMID: 36646635
DOI: 10.1002/anie.202217774

Abstract

The self-exothermic in early stage of thermal runaway (TR) is blasting-fuse for Li-ion battery safety issues. The exothermic reaction between lithiated graphite (LiC_x ) and electrolyte accounts for onset of this behavior. However, preventing the deleterious reaction still encounters hurdles. Here, we manage to inhibit this reaction by passivating LiC_x in real time via targeted repair of SEI. It is shown that 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane (D₃ F) can be triggered by LiC_x to undergo ring-opening polymerization at elevated temperature, so as to targeted repair of fractured SEI. Due to the high thermal stability of polymerized D₃ F, exothermic reaction between LiC_x and electrolyte is inhibited. As a result, the self-exothermic and TR trigger temperatures of pouch cell are increased from 159.6 and 194.2 °C to 300.5 and 329.7 °C. This work opens up a new avenue for designing functional additives to block initial exothermal reaction and inhibit TR in early stage.

Keywords: Flame-Retardant; Lithium-Ion Batteries; Ring-Opening Polymerization; Targeted Repairing; Thermal Runaway.

Abstract

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