Performance and behavior of LLZO-based composite polymer electrolyte for lithium metal electrode with high capacity utilization

A thin membrane (approximate to 47 mu m) of a Celgard separator-reinforced cross-linked LiTESI-PEO-Pyr(14)TESI-LLZO composite polymer electrolyte (CgCPE) was prepared and investigated for its ability to suppress the formation and propagation of high surface area lithium (HSAL) with dendritic morphology. The membrane shows superior cycling stability in Li parallel to Li-symmetric cells under high capacity utilization (5 mAh/cm(2)) for up to 2000 h. Using a combination of conventional laboratory techniques and nondestructive synchrotron X-ray tomography, the synergetic effect of the membrane components towards homogenous lithium electrodeposition/dissolution was revealed. The modulated ion migration in CgCPE and decreased interfacial/interphasial resistance ensures an evenly regulated Li-ion flux during deposition. While, the good mechanical properties of the CgCPE membrane were maintained up to a capacity utilization of 15 mAh/cm(2). Based on the results, an approach for a hybrid solid electrolyte to control lithium electrodeposition for Li metal electrodes with high capacity utilization is provided, and furthermore, such an approach could be further used for lithium metal batteries with high energy density and safety.