Ultrasmall nanocrystalline CeO2 Fillers Improving the Performance of PVDF-based Polymer Electrolytes for Lithium Metal Batteries

PVDF-based polymer electrolyte has been widely studied because of its good mechanical strength, easy processing, excellent thermal/chemical stability. However, pure PVDF has the problems of low ionic conductivity and insufficient interface stability with the electrodes. Herein, this research presents a facile strategy for fabricating Ce-MOF-derived rodlike nanocrystalline CeO2 to incorporate composite polymer electrolytes for Li-metal batteries. The CeO2-PVDF-HFP composite polymer electrolytes (CPEs) could achieve enhanced ionic conductivity and interfacial stability.Notably, the ultrasmall nanocrystalline CeO2-PVDF-HFP CPEs demonstrates superior Li⁺ transport kinetics (5.04×10⁻⁴ S cm⁻¹), lithium dendrite suppression and an extended electrochemical stability window up to 4.6 V. When applied in Li| LiMn0.6Fe0.4PO4 full batteries, the quasi-solid polymer electrolyte system could maintain a discharge capacity of 94 mAh g⁻¹ after 100 cycles at 0.5 C, deliver good cycling stability and rate capability retaining 99% capacity after prolonged 500 circles at 1 C. These advancements highlight special functional nanocrystalline fillers improve the performance of PVDF-based polymer electrolyte, offering a promising pathway for developing reliable solid-state lithium metal batteries.