Highly stretchable, non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte for stable and safe flexible lithium batteries

TLDR: In this article, a highly stretchable (extensibility > 4000% and stress > 130 kPa), non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte (SHSPE) was prepared based on the combination of a poly(HFBM-co-SBMA) network, imidazole-based ionic liquid (EMI-TFSI) and LiTFSI.

Abstract: Solid-state polymer electrolytes (SPEs) with superior self-healing capacity are urgently required for next-generation flexible energy storage devices Herein, a highly stretchable (extensibility > 4000% and stress > 130 kPa), non-flammable and notch-insensitive intrinsic self-healing solid-state polymer electrolyte (SHSPE) was prepared based on the combination of a poly(HFBM-co-SBMA) network, imidazole-based ionic liquid (EMI–TFSI) and LiTFSI The incorporation of the imidazole cation and fluorine atom contributed to the formation of supramolecular bonds (ion–dipole interactions) inside the electrolyte framework, thus endowing SHSPE with prominent self-healing ability (recovery time 200 g) The as-assembled Li/SHSPE3/LiFePO4 battery delivered a high discharge capacity of 1448 mA h g−1 at 02C, and its capacity retention ratio reached 82% after 100 cycles with a coulombic efficiency of 97% In particular, the mechanical properties and conductivity of SHSPE3 could fully recover after repeated damage, conferring the derived soft-pack battery excellent anti-fatigue capability The use of intrinsic self-healing principles in the field of SPEs provides new insight for developing reliable and safe flexible electronic devices