Highly liquid retentive, ordered ion transport quasi-solid polymer electrolytes for lithium metal batteries

Abstract

Solid-state lithium metal batteries (SSLMB) offer a compelling solution to address the low energy density issue present in current liquid lithium-ion batteries (LIB). Nevertheless, SSLMB electrolytes continue to face specific challenges that impede their commercial viability. These challenges encompass low ionic conductivity, high production cost, instability of interfacial contact, and other hurdles. In this context, a cost-effective quasi-solid polymer electrolyte (QPE) based on Polyvinylidene fluoride (PVDF) was developed to reshape the transport of lithium-ion (Li+) within the electrolyte, resulting in accelerated Li+ transport, with an achieved ionic conductivity of 0.71 mS cm−1 at 25 °C. The assembled LiFePO4|PVDF-OH|Li cell demonstrates exceptional battery performance, boasting an initial capacity of 145.9 mAh/g at 30 °C and maintaining an impressive capacity retention of 85.4 % even after 1000 cycles. The experimental findings underscore the critical role played by the immobilized solvent within the innovative PVDF-based QPE in facilitating the migration of Li+, consequently enhancing electrochemical performance. This study showcases a pioneering approach aimed at enhancing ionic conductivity, representing a significant stride towards the development of low-cost, high-performance, and easily processable solid polymer electrolytes, with potential implications for broader research in the field of energy storage systems.