Multiple Hydrogen Bond Channel Structural Electrolyte for an Enhanced Carbon Fiber Composite Battery

Structural batteries made of carbon fiber composites have been receiving great attention for automotive application in the last decade. However, a structural battery electrolyte (SBE) for the structural batteries is conventionally dependent on utilizing highly volatile carbonate-derivative liquid electrolytes to provide moderate ionic conduction. This study introduces a SBE which fabricates as a two-phase system via reaction-induced phase transition as well as includes a hybridized electrolyte, consisting of a low flammability electrolyte with a solid additive-inducing multihydrogen bond. The proposed SBE is composed of a vinyl ester polymer containing triethylene glycol dimethyl ether (TriG) and cyclohexanedimethanol (CHDM) as a quasi-solid additive. Confirmed by Fourier transform infrared, Raman, and 7Li-nuclear magnetic resonance results, the contents of CHDM in the SBE structure play a crucial role not only through the plasticizing effect but also through the formation of a multidimension channel via a hydrogen bond, thereby contributing to enhancing the motion of the cation in the SBE. The optimized SBE (Li-TriG-CHDM10) shows an ionic conductivity of 2.0 × 10-4 S cm-1 with an E′ of ∼300 MPa at ambient temperature. To exhibit the possibility for a structural battery, the carbon fiber composite lamina was fabricated using an optimized SBE and evaluated as a battery half-cell, showing the potential of a high bearing mechanical load and ion transport between the carbon fibers and the electrolytes.