In-situ Polymerization of Dicationic Pyrrolidinium-based Solid Polymer Electrolyte for High Performing and Long-Lasting Lithium-Ion Battery

Abstract

Solid-state polymer electrolytes (SPEs) are considered as a promising electrolyte for next-generation lithium-ion batteries because of their superior safety, long life and high energy density. In this study, we have developed advanced SPE via in-situ thermal polymerization of vinyl ethylene carbonate (VEC) with trimethylolpropane ethoxylate triacrylate (ETPTA) as a multifunctional crosslinker, incorporating a pyrrolidinium-based Dicationic ionic liquid (DIL).The in-situ crosslinking polymerization strategy resulted in a highly stable DIL incorporated SPE (DIL@SPE) with a uniform polymer network and enhanced interfacial compatibility with electrodes. The DIL@SPE exhibited an ultrahigh ionic conductivity of 3.85 × 10⁻³ S cm⁻¹ at 25 °C and a lithium-ion transference number (t Li ⁺) of 0.55. Consequently, Li|DIL@SPE|Li symmetric cells demonstrated stable lithium plating/stripping behaviour at 0.1 mA cm⁻² for 500 h. Moreover, the cell assembled with configuration LFP|DIL@SPE|Li delivered a high 2 discharge capacity of 133 mAhg⁻¹ at 0.5 C and retained 75% of its capacity after 500 cycles. This work offers a viable strategy towards the development of sustainable, high-performance, and stable SPEs for advanced LIBs technologies.