Improvement in cycle performance by suppression of surface reaction between electrolyte and LiV₃O₈ electrode using gel polymer electrolyte

Amorphous lithium trivanadate (LVO) exhibits a higher capacity than crystalline LVO. However, products are generated from the reaction between the surface of an amorphous LVO electrode and the surrounding electrolyte during charging and discharging. The continuous reaction between the electrode surface and surrounding electrolyte was inhibited using a gel-polymer electrolyte (GPE) instead of a conventional liquid electrolyte. After 100 cycles, the GPE-based cell shows 54% of capacity retention, which was 9% higher capacity retention than that of the conventional liquid electrolyte cell. The GPE is prepared as Kynar 2801 polymer and the charge and discharge performances of the cell were measured using a standard battery cycling test at a 0.5 C-rate and 1.5-4.0 V cut off voltage. The morphologies of the electrode surfaces and the various products formed on the electrode surfaces during the reaction were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy, respectively.