A Long Cycle Life, All-Solid-State Lithium Battery with a Ceramic–Polymer Composite Electrolyte

All-solid-state lithium batteries are receiving ever-increasing attention to both circumvent the safety issues and enhance the energy density of Li-based batteries. The combinative utilization of Li+-ion conductive polymer and ceramic electrolytes is an attractive strategy for the development of all-solid-state lithium metal batteries. Such a strategy can take advantages of the relatively high ionic conductivity of ceramic superionic conductors and the elastic feature of the ionic polymers. In this study, a poly(ethylene oxide)–lithium aluminum titanium phosphate (PEO-LATP) composite solid electrolyte has been developed with a facile slurry-casting method. The composite solid electrolyte shows enhanced Li+-ion conductivity, improved dendrite-suppression capability, reduced interfacial problems, and elastic features. With the PEO-LATP composite solid electrolyte, all-solid-state batteries with a lithium–metal anode and a lithium iron phosphate (LiFePO4) cathode show stable cycling performances over 1000 cycles with a capacity degradation rate of <0.03% per cycle.