Structural electrolytes have both mechanical strength and ionic conductivity which make them attractive for applications in electrochemical devices and supercapacitors. In this work we used molecular dynamics simulations to investigate structural electrolytes composed of an ionic liquid in an epoxy polymer. The glass transition temperature, Young's modulus, diffusivity, and ionic conductivity of the highly cross-linked, epoxy-based structural electrolytes were found to vary significantly as a function of ionic liquid content, providing an option to improve the performance of devices. Our computational protocol provides a platform to elucidate the molecular-level interactions between epoxy polymers and ionic liquids, leading to an enhanced understanding of the multifunctional solid polymer electrolytes and enabling their development to meet future demands for energy storage devices.