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

BaTiO3 nanofillers can improve the electrochemical properties of PEO-based solid polymer electrolytes (SPEs). Therefore, we aimed to elucidate the effects of different shapes of BaTiO3 nanofillers on PEO-based SPEs. Five weight percent of BaTiO3 nanowires, nanocubes, and nanospheres were added into SPEs and membranes were prepared by solution casting method. Different BaTiO3 nanofillers have different effects on the ionic conductivity and the electrochemical stable window of SPEs. For the SPE with BaTiO3 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 LiFePO4/SPE with BaTiO3 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 BaTiO3 nanospheres are ideal nanofillers for SPEs, due to the highest specific surface area.