A propanesultone-based polymer electrolyte for high-energy solid-state lithium batteries with lithium-rich layered oxides

Abstract

Polymer electrolyte-based solid-state lithium batteries (SSLBs) with lithium-rich layered oxide (LLO) cathode materials can provide high energy density and safety. However, the development of these batteries is hindered by the poor anti-oxidation ability of polymer electrolytes. Herein, a propanesultone-based polymer electrolyte (PPS-PE) is designed, and a wide electrochemical stability window (∼5.0 V vs. Li⁺/Li) and high ion transference number (∼0.78) at 25 °C can be achieved. The strong anti-oxidation ability of PPS-PE is contributed by the design of the chain-like molecular structure, and the hydrogen bond interactions are beneficial for inhibiting the anion movement of Li salt. The PPS-PE-based SSLBs with LLO cathode materials show characteristic charge/discharge profiles with a high initial discharge capacity of ∼270 mA h g⁻¹ and good cycling stability at 25 °C. Therefore, this work not only reports a novel polymer electrolyte to couple with high-voltage cathodes but also promotes the application of LLO cathode materials in high-energy SSLBs.