Lithium Diffusion‐Efficient Ionogels as Polymer Solid Electrolyte for Next‐Gen Lithium‐Ion Batteries

Abstract

The search for safer next‐generation lithium‐ion batteries (LIBs) has driven significant research on non‐toxic, non‐flammable solid electrolytes. However, their electrochemical performance often falls short. This work presents a simple, one‐step photopolymerization process for synthesizing biphasic liquid–solid ionogel electrolytes using acrylic acid monomer and P111i4FSI ionic liquid. We investigated the impact of lithium salt concentration and temperature on ion diffusion, particularly lithium‐ion (Li+) mobility, within these ionogels. Pulsed‐field gradient nuclear magnetic resonance (PFG‐NMR) revealed enhanced Li+ diffusion in the acrylic acid (AA)‐based ionogels compared to their non‐confined ionic liquid counterparts. Remarkably, Li+ diffusion remained favorable in the ionogels regardless of salt concentration. These AA‐based ionogels demonstrate very good ionic conductivity (>1 mS cm−1 at room temperature) and a wide electrochemical window (up to 5.3 V vs Li+/Li0). These findings suggest significant promise for AA‐based ionogels as polymer solid electrolytes in future solid‐state battery applications.