Development of structural supercapacitors with epoxy based adhesive polymer electrolyte

Epoxy based adhesive polymer electrolyte was prepared using polyvinylidene fluoride, lithium triflate, and epoxy. The effect of the composition of the adhesive polymer electrolyte on the ionic conductivity, viscosity, and tension strength was investigated. The ionic conductivity of an adhesive polymer electrolyte could reach the order of magnitude of 10⁻² S cm⁻¹. Structural supercapacitors with epoxy based adhesive polymer electrolyte were fabricated using a vacuum bagging method. The structural supercapacitors showed excellent electrochemical performance and acceptable mechanical strength simultaneously. The maximum specific energy was 2.64 Wh kg⁻¹ and the ultimate tensile strength was 80 MPa. The capacitance retention of the structural SC was 84% and the columbic efficiency was above 95% after 5000 cycles. The response of electrochemical performance of the structural supercapacitors to in-plane tensile stress was studied. Before fracture, both the specific power and the specific energy increased slightly with increasing the stress level.