Three-dimensionally ordered ZIF-8@ZIF-67 core-shell frameworks enable near-unity Li plus transference and fast-charging all-solid-state Lithium batteries

초록

Composite polymer electrolytes (CPEs) offer significant advantages for the development of all-solid-state batteries (ASSLBs) owing to their versatility, excellent thermal stability, and high safety. Solid fillers significantly affect the electrochemical performance of CPEs, and metal-organic frameworks (MOFs) are a new class of solid fillers that have recently gained significant attention for their ability to control ion migration. In this study, we report a three-dimensionally ordered porous core-shell ZIF-8@ZIF-67 framework (3DCS) designed to enhance Li+ transport and interfacial stability in PEO-LiTFSI composite polymer electrolytes. The PL3D1CS integrated electrolyte demonstrates a broad electrochemical stability window of 6.2 V at 60 degrees C and ionic conductivities ranging from 1.96 & times; 10(-4) to 4.23 & times; 10(-3) S cm(-1) between 25 and 100 degrees C. The electrolyte also shows an apparent Li+ transference number of 0.98 based on the Evans polarization method. Moreover, the Li symmetric cells using PL3D1CS can stably cycle at 0.2, 0.4, and 0.6 mA cm(-2) without short circuit at 60 degrees C, demonstrating that this electrolyte can reduce Li dendrite formation. Owing to these outstanding merits, the LiFePO4/PL3D1CS/Li cell displays excellent cycling stability at both room temperature and 60 degrees C.

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