Multifunctional Zwitterionic Self‐Healing Polymer Electrolytes for Anode‐Free Lithium‐Metal Batteries: a Computational Perspective

Abstract The practical application of anode‐free lithium‐metal batteries (AFLMBs) is limited by their poor cycling performance and unstable solid electrolyte interphase (SEI). Self‐healing solid polymer electrolytes (SHSPEs) offer excellent flexibility and healing capabilities, which are expected to mitigate dendrite growth and improve AFLMB cycling performance. In this study, a novel zwitterionic SHSPE, P(SBMA‐co‐BA):LiTFSI, is proposed, and its suitability for AFLMBs is evaluated through density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. The sulfonate (RSO₃⁻) group promotes Li⁺ ion transport, and the electrostatic interaction between RSO₃⁻ and NR₄⁺ groups drives the electrolyte's self‐healing after material damage. Electrolyte degradation on the Cu current collector during Li‐nucleation and on the Li metal surface during extensive Li metal plating is further examined. The SEI components are identified using atomic charge distribution analysis, which is typically compared with X‐ray photoelectron spectroscopy (XPS) data. The resulting organic/inorganic hybrid SEI demonstrates excellent flexibility and stability, and the long‐chain sulfonate‐containing compound facilitates rapid Li‐ion conduction and uniform Li metal plating. The multifunctional zwitterionic SHSPE, P(SBMA‐co‐BA):LiTFSI, thus shows significant potential to enhance the cycling performance of AFLMBs, paving the way for their practical application.