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

Abstract

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 × 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 high-conductivity green CPEs with potential applications in optoelectronic and electrochemical devices.