Recyclable Thermoplastic Structural Electrolytes Enabling Customized High-Strength Structural Batteries

Structural batteries capable of simultaneously bearing load and storing electrochemical energy represent a transformative paradigm for next-generation electric vehicles and aerospace systems. However, the intrinsically poor ion transport of conventional epoxy-based structural electrolytes hinders the practical implementation of structural batteries. Herein, a sustainable composite solid structural electrolyte is innovatively developed by employing polyethylene oxide as a highly ion-conductive matrix and cellulose acetate as a mechanically reinforcing phase. This uniquely synergistic design delivers a high ionic conductivity of 0.33 mS cm⁻¹ and a high tensile strength of 8.79 MPa, effectively reconciling electrochemical and mechanical functionalities. The thermoplastic structural electrolyte is directly integrated with the carbon fiber (CF)-based electrodes via standard compression molding to fabricate the resulting structural batteries, demonstrating a higher tensile strength of 371.36 MPa with an energy density of 13.69 Wh kg⁻¹, which surpasses that of the conventional CF-reinforced structural batteries. Notably, the cellulose-based thermoplastic architecture enables exceptional recyclability and processability, allowing secondary assembly into customized complex structural automobile/aerospace components without compromising energy storage performance. This forward-looking work presents a novel, viable strategy for designing recyclable structural solid electrolytes compatible with industrial compression molding process, offering a sustainable and scalable pathway for CF-based structural energy storage large-scale applications.