The effects of the size and content of BaTiO3 nanoparticles on solid polymer electrolytes for all-solid-state lithium-ion batteries

For all-solid-state lithium-ion batteries, several disadvantages such as low ionic conductivity and poor interfacial stability have been concerned. According to previous studies, BaTiO 3 nanoparticles can improve the electrochemical properties of PEO-based solid polymer electrolytes (SPEs). This study elucidates the effects of different sizes and contents of BaTiO 3 fillers on SPEs. The BaTiO 3 nanoparticles with average size of 5 nm, 100 nm, and 500 nm and content from 4 to 20 wt% were incorporated into SPEs by solution casting method. For the SPE with 8 wt% 5 nm BaTiO 3 , it possesses the highest ionic conductivity of 2.2 × 10 −5  S cm −1 at 25 °C and 1.9 × 10 −3  S cm −1 at 80 °C. In the LiFePO 4 /SPE with 8 wt% 5 nm BaTiO 3 /Li cell, it indicates a high initial discharge specific capacity of 140.7 mAh g −1 at 0.1 °C rate and the specific capacity remains 97.8% after 50 cycles at 80 °C.