Poly(ethylene oxide) (PEO)-based solid polymer electrolyte (SPE), as a key component connecting the internal channels, can improve the safety performance for lithium secondary battery, but it is still challenged by limited ionic conductance due to high polymer crystallinity at room temperature. Here, we develop a SPE by blending PEO with star-shaped polymer of polyethylene glycol methyl ether methacrylate-co-polyhedral oligomeric silsesquioxane (POSS-(PPEGMEM)₈), which is synthesized by atom transfer radical polymerization (ATRP) under octa (2-bromoisobutyryloxyethyl sulfide) octasilsesquioxane (POSS-Br₈) as initiator and poly(ethylene glycol) methyl ether methacrylate (PEGMEM) as polymerization monomer. The unique star-shaped structure of POSS-(PPEGMEM)₈ is helpful to increasing the segmental motion by reducing the crystallinity of PEO polymer and supporting more ion transport channels to obtain higher ion conductivity. The mixed electrolyte containing 40% POSS-(PPEGMEM)₈ exhibits the highest ionic conductivity (1.4 × 10⁻⁴ S cm⁻¹, 50 °C) with a Li⁺ transference number of 0.51 and a wide electrochemical window (5.0 V vs. Li/Li⁺) and a high mechanical strength. The LiFePO₄||Li battery, assembled with PEO/POSS-(PPEGMEM)₈–40%, carries out 100 cycles at a current density of 0.1C, provides a stable reversible capacity of 129.4 mAh g⁻¹ and a high capacity retention rate due to the high ratio of free volume of polymer electrolyte formed by the star-shaped POSS-(PPEGMEM)₈, which indicates that PEO/POSS-(PPEGMEM)₈ has good application prospects in high-performance all-solid-state lithium secondary battery.

聚环氧乙烷（PEO）基固体聚合物电解质（SPE）作为连接内部通道的关键成分，可以提高锂二次电池的安全性能，但由于聚合物结晶度高，离子电导受限，仍面临挑战在室温下。在这里，我们通过将 PEO 与聚乙二醇甲基醚甲基丙烯酸酯-共聚多面体低聚倍半硅氧烷 (POSS-(PPEGMEM) _{8 ) 的}星形聚合物共混开发了一种 SPE ，该聚合物通过原子转移自由基聚合 (ATRP) 在 octa (2 -溴异丁酰氧基乙基硫醚）八聚倍半硅氧烷（POSS-Br ₈）作为引发剂，聚（乙二醇）甲基醚甲基丙烯酸酯（PEGMEM）作为聚合单体。独一无二的明星POSS-(PPEGMEM) ₈的-形结构有助于通过降低PEO聚合物的结晶度和支持更多的离子传输通道以获得更高的离子电导率来增加分段运动。含有 40% POSS-(PPEGMEM) ₈的混合电解质表现出最高的离子电导率（1.4 × 10 ^-4  S cm ^-1 , 50 °C），Li ⁺迁移数为 0.51，电化学窗口宽（5.0 V vs. Li/Li ⁺ ) 和高机械强度。LiFePO _{4 ||Li 电池由8} –40%的 PEO/POSS-(PPEGMEM) 组装而成，在 0.1C 的电流密度下进行 100 次循环，提供 129.4 mAh g ^{-1的稳定可逆容量}_{并且由于星形POSS-(PPEGMEM) 8}形成的聚合物电解质的自由体积比高，容量保持率高，表明PEO/POSS-(PPEGMEM) ₈在高性能全电池领域具有良好的应用前景。 -固态锂二次电池。