摘要
Solid-state electrolytes are desired for reliable systems in the battery industry. In this study, high entropy oxide (HEO) composites of Li x (CoCrFeMnNi) 3-x O 4-y were introduced into a polyethylene oxide (PEO)-based solid composite polymer electrolyte (SCE). Li doping of the HEO compound induces more oxygen vacancies than traditional methods, and this facilitates Li ion transport through the three-dimensional (3D) channel of HEO composites and increases ionic conductivity. The ionic conductivity of the HEO/PEO SCE reached 1 × 10 −4 S cm −1 (40°C), significantly higher than that of the PEO solid polymer electrolyte (SPE; 2.8 × 10 −5 S cm −1 ). The tensile strength and elongation of the HEO/PEO SCE were greater by 140.1 % and 138 %, respectively than those of the PEO SPE, resulting in more effective suppression of Li dendrite formation. A solid-state LiFePO 4 /Li coin cell with the HEO/PEO SCE exhibited a maximum discharge capacity of 127 mAh g −1 at 0.1 C and a high rate capability of 97.2 % at room temperature. The HEO/PEO SCE exhibited superior ionic conductivity, structural integrity, and high thermal and electrochemical stability, making it suitable for safe and high-energy storage systems in Li-ion battery development.