复合固态电解质及其制备方法、固态锂电池及其制备方法

本发明涉及固态锂电池技术领域，具体提供一种复合固态电解质及其制备方法、固态锂电池及其制备方法。该制备方法包括以下步骤：将聚己内酯、聚己内酯衍生物中的至少一种聚合物与锂盐溶于有机溶剂中，得到第一溶液；向所述第一溶液中加入石榴石氧化物，混匀，获得第二溶液；对所述第二溶液进行浇铸、干燥处理，得到复合固态电解质。本发明的制备方法具有工艺简单、能耗少、无污染、价格低廉等特点；更重要的是得到的复合电解质具有离子电导率高、电化学窗口大于4.5V、离子迁移数高、界面电阻小、机械性能好等特点。

The invention relates to the technical field of solid-state lithium batteries, and particularly provides a composite solid-state electrolyte and a preparation method thereof, a solid-state lithium battery and a preparation method thereof. The preparation method comprises the following steps of dissolving at least one polymer of polycaprolactone and a polycaprolactone derivative and a lithium saltin an organic solvent to obtain a first solution; adding garnet oxide into the first solution, and uniformly mixing to obtain a second solution; and casting and drying the second solution to obtain the composite solid electrolyte. The preparation method disclosed by the invention has the characteristics of simple process, low energy consumption, no pollution, low price and the like; more importantly, the obtained composite electrolyte has the characteristics of high ionic conductivity, electrochemical window greater than 4.5 V, high ion mobility, small interface resistance, good mechanical properties and the like.