Stable ion transport enabled by self-supported membranes with direct interfacial driving effect for lithium metal batteries

Composite electrolyte membranes with 3D nanofiber network structure, which can adjust internal stress to achieve cyclic stability, has been proved to play an important role in the cycle process of lithium metal batteries. However, its application is greatly impeded by the inherent instability interface. Here, we have created an excellent ion transport system through simple interface engineering design. The system weakens the interaction between PEO and Li+ via a direct interfacial driving mechanism that establishes the ion bonds (Li-O/Zn-O) between LLZO/ZnO and PEO respectively, thereby achieving stable ion transport. As a result, Li | LPZ-5 CSE | Li battery displays highly stable Li plating/stripping cycling for over 1000 h at 0.1 mA cm-2. In addition, lithium metal batteries (LMBs) based on LiFePO4 cathode can stably cycle for 250 cycles with a specific capacity of 151.9 mAh g+1 (50 degrees C, 0.2 C). This work provides a straightforward and effective strategy that employs the stable ion transfer process at molecular-level to construct a self-supported membrane, which is positive to the development of long-cycle-life LMBs.