Liquid Metals with In Situ Polymerized Electrolyte for Anode-Free Lithium Metal Batteries

To address the safety and energy density challenges of conventional Li-ion batteries, anode-free or zero-lithium excess configurations using only a current collector in the anode part have been developed. However, major challenges such as rapid Li dendrite growth, low Coulombic efficiency, safety issues, and thickness problems hinder the practical application of anode-free batteries (AFBs) using liquid electrolytes (LEs) and solid electrolytes (SEs). Herein, we report on potential AFBs using polymer electrolyte (PE) and a Li metal-free anode. The current collector surface is modified by coating a nanocomposite layer comprising carbon and various liquid metal nanoparticles. We observe that the polymerization depends on the solvent composition and the concentration of Li salt, and that cells containing polymerized electrolyte show better performance compared to conventional LEs. Liquid metals (LMs) serve as materials that rapidly alloy with Li, reducing the nucleation energy barrier for uniform Li deposition. Finally, AFBs with an Ag-C composite on the current collector were fabricated and compared with our concept using LMs-C composite to examine differences in cell performance and working mechanism. We believe that our investigation can contribute to future studies related to AFBs using polymer electrolytes and composite interlayers for practical applications.