Composite polymer/oxide electrolyte (CPE) is a promising candidate for all-solid-state lithium metal batteries (ASSLMBs), but controlling the interactions between components in CPEs to achieve high efficient Li⁺-transport and stable CPE/electrode interface is a challenge. Here, we report a mesoporous black La_xCoO_3-δ nanofiber (NF) film with tunable cationic defects to regulate the molecular coordination with PEO/LiTFSI matrix and realize stable operations of ASSLMBs over 1000 cycles. By tuning the A-site defects from x = 1.0 to 0.8, the La_xCoO_3-δ NFs show gradually enhanced coordination with PEO/LiTFSI, achieving a high ionic conductivity of 2.5 × 10⁻⁴ S/cm at 30 °C. Moreover, the defective La_0.8CoO_3-δ can catalyze the formation of stable LiF/Li₃N interfacial layers, which possess high Li⁺-conduction kinetics and interfacial energy, thus enabling stable battery operations even at high currents. As a result, the LiFePO₄-based ASSLMBs show a long life of >1000 cycles at 0.2 C with a capacity retention of >75%, and they can deliver a high discharge capacity of 142 mA h g⁻¹ at 1 C with a capacity retention of 92.2% over 300 cycles. Importantly, this molecular coordination strategy is still effective when extended to other defective oxides, thus providing a universal method to design high-performance CPEs.

复合聚合物/氧化物电解质 (CPE) 是全固态锂金属电池 (ASSLMB) 的有前途的候选者，但控制 CPE 中各组分之间的相互作用以实现高效的 Li + -传输和稳定的 CPE/电极界面是^一个挑战. 在这里，我们报告了一种具有可调阳离子缺陷的介孔黑色 La _x CoO _3-δ纳米纤维 (NF) 薄膜，以调节与 PEO/LiTFSI 基质的分子配位，并实现 ASSLMBs 超过 1000 个循环的稳定运行。通过将 A 位缺陷从x  = 1.0 调整到 0.8，La _x CoO _3-δ NFs 显示出与 PEO/LiTFSI 的配位逐渐增强，实现了 2.5 × 10 ^{-4的高离子电导率} 30°C 时的秒/厘米。此外，有缺陷的La _0.8 CoO _3-δ可以催化形成稳定的LiF/Li ₃ N界面层，其具有高Li ⁺ -传导动力学和界面能，从而即使在大电流下也能使电池稳定运行。因此，基于 LiFePO _{4的 ASSLMB 在 0.2 C 下显示出 >1000 次循环的长寿命和 >75% 的容量保持率，并且它们可以在 1 C 下提供 142 mA hg} ^-1的高放电容量，容量为300 次循环后的保留率为 92.2%。重要的是，这种分子配位策略在扩展到其他有缺陷的氧化物时仍然有效，从而提供了一种设计高性能 CPE 的通用方法。