Preparation and Performance of PVDF-HFP/PAN-Based Gel Polymer Electrolytes.

Solid-state electrolytes are widely expected to enhance the performance of lithium-ion batteries, providing higher energy density and improved safety. However, challenges still need to be solved in their practical application due to low ionic conductivity and high interfacial resistance at room temperature. In this study, we successfully developed a high-performance gel polymer electrolyte (GPEs) by blending poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) and polyacrylonitrile (PAN) through UV curing, cross-linking with ethoxylated trimethylolpropane triacrylate (ETPTA), and incorporating LiLaZrTaO (LLZTO). At room temperature, the ionic conductivity of the GPEs was 2.8 × 10 S/cm, with a lithium-ion transference number of 0.6. Moreover, during lithium plating/stripping tests, the assembled Li/PPEL/Li symmetric cell exhibited stable cycling for up to 600 h at a current density of 0.1 mA/cm. Notably, the GPEs enabled the LiFePO/GPEs/Li battery to achieve excellent performance, delivering high discharge capacities at room temperature (164.3 mAh g at 0.1 C and 88.8 mAh g at 1 C), with a capacity retention of 89.4% after 200 cycles at 0.5 C. Therefore, solid-state batteries using this electrolyte exhibit excellent performance, including adequate capacity and cycling stability.