A novel and facile process for preparing green composite poly(ethylene oxide) electrolytes with highly enhanced ionic conductivity and electrochemical stability

In this study, we propose a novel and simple method to produce green composite polymer electrolytes (CPEs) with significantly enhanced electrochemical performance through electrospinning. Unlike the commonly used method of immersing electrospun polymers in a liquid electrolyte solution, our approach employs a direct blending method by mixing polymer, salt, and solvent to create nanofibrous solid polymer electrolytes. Our method employs water as a solvent and eco-friendly poly (ethylene oxide) (PEO) as the polymer matrix, incorporating varying amounts of environmentally benign inorganic nanofiller silica (SiO2). The electrospinning process, combined with the addition of SiO2, induces a noticeable reduction in the crystallinity of PEO, leading to a significant enhancement in ionic conductivity. The electrospun nanofiber CPEs exhibit an impressive maximum ionic conductivity of 4.67 x 10-4 S cm- 1. The addition of SiO2 to PEO increases conductivity by reducing crystallinity and creating pathways for easier ion movement. Furthermore, linear sweep voltammetry validates that the addition of SiO2 significantly improves the electrochemical stability of CPEs. Capacitors utilizing our fabricated CPEs with SiO2 demonstrate superior ideal double-layer capacitor behaviors and high charge- discharge efficiency. This innovative and non-toxic manufacturing process holds promise for developing highconductivity green CPEs with potential applications in optoelectronic and electrochemical devices.