Solid-state polymer Li metal batteries have been regarded as a promising candidate for next-generation batteries due to their high-energy densities provided by the Li metal and the improved safety provided by the solid electrolyte. Polyester is one attractive polymer host, which could be an alternative to polyether-based solid electrolyte due to its excellent lithium ion transport ability and wide electrochemical stability window. Here, a BAB-type triblock copolymer is synthesized with poly(propylene carbonate) as A-block and poly(ε-caprolactone) as B-block. The triblock copolymer electrolyte exhibits a high ionic conductivity of 3×10⁻⁵ S cm⁻¹ at 30 °C with a high lithium ion transference number (0.4) and an extremely wide electrochemical window (5 V). A highly stable interface against Li metal is maintained for more than 760 h at a current density of 0.1 mA cm⁻². A LiFePO₄ cathode based solid state battery delivers a high discharge capacity of 142 mA h g⁻¹ at 0.05 C, room temperature, and 161mA h g⁻¹ at 0.1 C, 70 °C with a capacity retention of 90 % after 200 cycles. To understand the excellent electrochemical performance, the morphology and chemical information at both the anode and cathode interface are characterized and analyzed. The synthesis of this triblock copolymer demonstrates a new direction in developing high ionic conductivity solid polymer electrolyte for solid-state polymer batteries.

固态聚合物锂金属电池由于锂金属提供的高能量密度和固体电解质提供的更高的安全性而被认为是下一代电池的有前途的候选者。聚酯是一种有吸引力的聚合物主体，由于其出色的锂离子传输能力和宽的电化学稳定性窗口，它可以替代聚醚基固体电解质。在此，以聚碳酸亚丙酯为A嵌段，聚（ε-己内酯）为B嵌段来合成BAB型三嵌段共聚物。三嵌段共聚物电解质表现出3×10 ^-5 S cm ^-1的高离子电导率在30°C下具有高锂离子转移数（0.4）和极宽的电化学窗口（5 V）。在0.1 mA cm ^-2的电流密度下，与Li金属的高度稳定的界面保持了760小时以上。基于LiFePO ₄阴极的固态电池在0.05 C，室温和161mA hg ^-1时可提供142 mA hg ^-1的高放电容量在200°C下在0.1 C，70°C下保持90％的容量保持率。为了了解出色的电化学性能，对阳极和阴极界面的形貌和化学信息进行了表征和分析。该三嵌段共聚物的合成显示了开发用于固态聚合物电池的高离子电导率固体聚合物电解质的新方向。