Tailoring the Salt Concentration in a Gel‐Solid Polymer Electrolyte to Stabilize High‐Voltage LiCoMnO₄ Cathode

Abstract Here, an attempt is made to depict the role of salt concentration on the electrochemical stability of a gel interface formed by the in‐situ polymerization of a commercial liquid electrolyte on solid‐polymer support, which is the so‐called gel‐solid polymer electrolyte (G‐SPE). The electrochemical characterization of the electrolyte exhibits high ionic conductivity in the order of ≈10⁻³ S cm⁻¹ at ambient temperature, while the same increases as the LiPF₆ concentration varies from 1 to 3 m. Further, the flammability test has shown the flame‐retardant nature of the G‐SPE compared to the liquid electrolyte. The stability of the G‐SPE is analyzed in a half‐cell configuration with a high‐voltage LiCoMnO₄ cathode. Also, anode and anode‐less cell configurations with LiCoMnO₄ cathode against Li₄Ti₅O₁₂ and Cu are carried out with G‐SPE‐2 m as the electrolyte. In addition, post‐mortem analysis, like XRD, XPS, EDS, SEM, etc., of the cycled LiCoMnO₄ electrode and G‐SPE is carried out to understand the occurrence of any material degradation or electrolyte decomposition during cycling.