A sustainable, high ionic conductivity, semi-interpenetrating double-network ionogel film composed of phosphorylated corn straw-derived cellulose and polyaspartamide derivatives

Abstract

The extensive consumption of non-renewable energy resources poses significant environmental challenges. Consequently, the innovation of sustainable, secure, and high-efficiency energy storage and conversion technologies is imperative for improving energy efficiency and advancing environmental sustainability. A sustainable and renewable semi-interpenetrating double network ionogel film (AE-Cel) is fabricated using phosphorylated corn straw-derived cellulose and a polyaspartamide derivative, PolyAspAm(API/EA). The ionic liquid 1,3-dimethylimidazolium methyl phosphite [DMIM][MeO(H)PO₂] enhances the conductivity of the ionic gel and facilitates acid-induced dissolution of straw cellulose, thereby overcoming its inherent insolubility. The incorporation of glutaraldehyde (GA) as a crosslinking agent induces secondary chemical crosslinking of hydroxyl groups along the polymer chains, culminating in the development of a semi-interpenetrating double-network ionogel. The as-synthesized ionogel films as solid electrolytes demonstrate impressive ionic conductivity (2.8 mS cm⁻¹), with optimized tensile strength (529 kPa) at room temperature. Moreover, as flexible strain sensors, the AE-Cel ionogels can be seamlessly attached to human finger joints, where they adeptly transmit precise and stable changes in relative resistance signals upon joint bending.