Defective cerium-based metal-organic framework nanorod- reinforcing polymer electrolytes for lithium metal batteries

Effective design of fillers can improve the performance of polymer electrolytes (PEs). Herein, this study introduces an innovative filler defect-structured cerium-based metal-organic framework (Ce-BTC) nanorods into Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). These unique PEs with uniformly distributed fillers of nanocrystalline/amorphous cerium oxide (CeO₂) on Ce-BTC nanorods demonstrate a remarkable synergistic effect. This leads to more Li⁺ transport channels and better mechanical property, thereby elevating lithium-ion conductivity and promoting even lithium deposition and stripping. The experiment reveals that even with a mere 1 wt.% addition of CeO₂@Ce-BTC, the ionic conductivity of PEs reaches to 2.5 × 10⁻⁴ S cm⁻¹ at room temperature, and a high lithium-ion transference number improvement to 0.78, also obtains extended electrochemical voltage windows above 4.5 V and good flame retardancy. Using the designed gel polymer electrolytes (GPEs) with ionic conductivity up to 7.6 × 10⁻⁴ S cm⁻¹, the full Li/GPE/LiFePO₄ battery demonstrates an average coulombic efficiency of up to 99 % and maintains stable cycling performance (103.8 mAh g⁻¹ even after 100 cycles) at room temperature, reinforcing its promising application in practical battery systems.