Effects of the shapes of BaTiO3 nanofillers on PEO-based electrolytes for all-solid-state lithium-ion batteries

BaTiO 3 nanofillers can improve the electrochemical properties of PEO-based solid polymer electrolytes (SPEs). Therefore, we aimed to elucidate the effects of different shapes of BaTiO 3 nanofillers on PEO-based SPEs. Five weight percent of BaTiO 3 nanowires, nanocubes, and nanospheres were added into SPEs and membranes were prepared by solution casting method. Different BaTiO 3 nanofillers have different effects on the ionic conductivity and the electrochemical stable window of SPEs. For the SPE with BaTiO 3 nanospheres, it possesses the highest ionic conductivity of 1.8 × 10 −5  S cm −1 at 25 °C and 1.6 × 10 −3  S cm −1 at 80 °C. The LiFePO 4 /SPE with BaTiO 3 nanospheres/Li exhibits the highest initial discharge-specific capacity of 135.6 mAh g −1 at 0.1 C rate and the discharge-specific capacity remains 97.5% after 50 cycles at 80 °C. This work demonstrates that BaTiO 3 nanospheres are ideal nanofillers for SPEs, due to the highest specific surface area.