A Robust Dual‐Polymer@Inorganic Networks Composite Polymer Electrolyte Toward Ultra‐Long‐Life and High‐Voltage Li/Li‐Rich Metal Battery

Abstract

AbstractComposite polymer electrolytes (CSEs) that simultaneously possess superior electrochemical performances with robust mechanical properties are highly desired to the application of high‐energy lithium metal batteries. Herein, a novel dual‐polymer@inorganic network CSE (DNSE@IN) through a sequential nonhydrolytic sol‐gel reaction of tetraethoxysilane (TEOS) and the semi‐interpenetration of poly(vinylidene fluoride‐co‐hexafluoropropene)‐hexafluoropropylene (P(VDF‐HFP)) with poly(ionic liquid) (PIL) is proposed. DNSE@IN, which has a robust dual‐polymer@inorganic networks, not only has high ionic conductivity (0.53 mS cm−1 at 20 °C), but also exhibits an outstanding Young's modulus of 723.2 MPa. As a result, the DNSE@IN based Li/LiFePO4 and Li/Li1.17Ni0.27Co0.05Mn0.52O2 (Li‐rich) cells exhibit remarkable cycling stability from room temperature (RT) to 100 °C. As‐assembled Li/Li‐rich battery shows superior cyclability of 194.3 mAh g−1 after 70 cycles at 4.3 V under RT. Additionally, the scale‐up high‐voltage Li/Li‐rich pouch cells exhibit excellent cyclability (nearly 100% capacity retention after 93 cycles) and superior flexibility, safety at RT for potential practical applications. As such, the work of decoupling ionic conductivity and mechanical properties opens a novel route to develop novel CSEs for the construction of high‐energy lithium metal batteries.