Electromechanical properties of embedded multifunctional energy storage composite with activated carbon fiber/PVDF gel electrolyte

Abstract

ABSTRACT This paper presents a standardized process for fabricating multifunctional energy storage composites that involves using activated carbon fiber (CF) electrodes and a poly(vinylene fluoride) (PVDF)-based gel polymer electrolyte (GPE) as building materials for embedded supercapacitors. A two-step packaging method was used to fabricate composites that can simultaneously bear mechanical loads and store energy. CF electrodes were subjected to three activation procedures, and the optimal composition of the PVDF-based GPE was determined by comparing the performance of PVDF-based GPEs of various compositions through electrochemical tests. The specific capacitance and energy density of a supercapacitor embedded with a glass-fiber-reinforced composite was 168 mF/g and 140 J/kg, respectively. The aforementioned values were 15.3% and 21.9% higher, respectively, than the corresponding values obtained for a bare cell. Mechanical tests indicated that the average tensile strength of the aforementioned composite was 350.1 MPa. With a gradual increase in the tensile load, the supercapacitor energy density increased by approximately 10% and then plateaued until fracture. Under cyclic tensile loads, the fabricated supercapacitors functioned normally until the composite failed.