In situ induced crosslinking highly conductive solid polymer electrolyte with intimated electrodes interfacial compatibility for safe Li-ion batteries

Abstract

Nowadays, lower ionic conductivity and interfacial issue are hindering industrial development of solid-state lithium batteries. Herein, we prepare cross-linking solid polymer electrolytes (CSPEs) with a certain amount of additive fluorosulfonamide (FSA) by employing lithium bis(fluorosulfonyl)imide (LiFSI) as an initiator for catalyzing cationic ring-opening polymerization (CROP) via an in-situ thermal strategy. a series of technologies have used to investigate the physiochemical properties and electrochemical performances of as-prepared CSPEs. The ionic conductivity of as-prepared CSPE-2 is 1.46 mS/cm at 25 °C. Its electrochemical anodic oxidation potential is stable up to 5.2 V. Its lithium transference number (tLi+) reaches to 0.61 at room temperature (RT). Furthermore, the assembled half-cell of LiFePO4/CSPE-2/Li delivers an excellent initial discharge capacity of 165 mAh/g at 0.1C and shows Coulombic efficiency (CE) of 96.7%. It retains its capacity at 136 mAh/g after 200 cycles. Full cell configuration of LiFePO4/CSPE-2/graphite shows an initial discharge capacity of 142 mAh/g at 0.1C, retains its capacity at 122 mAh/g, and achieves a CE of 90.2% after 200 cycles. Field emission scanning electron microscope (FE-SEM) reveals an intimate interface compatibility with additive FSA. This study may provide a strategy to design and fabricate solid-state electrolytes for lithium-ion batteries.