The Preparation And Properties Of Structural Supercapacitor Composites Based On The Biomass Derived Carbon Modified Carbon Fiber

Carbon fiber composite structural supercapacitors combine the mechanical properties of carbon fiber composite materials and the electrochemical properties of supercapacitors,which can realize the integration of structural bearing and energy storage,which is expected to take into account the dual needs of modern equipment for structural lightweight and energy storage.Carbon fiber electrode material is the core component of composite structure supercapacitors,which undertakes the dual role of enrichment charge and mechanical loading.However,conventional carbon fiber has a smooth surface,small specific surface area and large chemical inertness,which is not conducive to charge storage and resin electrolyte infiltration,resulting in low energy storage and mechanical properties of structural supercapacitors,so the carbon fiber electrode must be modified.In this paper,activated carbon materials were prepared by using biomass materials with wide sources and low cost as precursors,and biomass-derived carbon-modified carbon fiber electrodes and composite structural supercapacitors were prepared by bonding modification,and the effects of carbon fiber electrode modification methods on the energy storage performance and mechanical properties of structural supercapacitors were studied,and the specific research contents and results are as follows:(1)Eggplant was selected as a biomass precursor to prepare eggplant-derived carbon materials.Using it as activated carbon material and egg white as binder,eggplant-derived carbon modified carbon fiber electrode and its composite structural supercapacitor were prepared the effect of egg white addition on the energy storage performance of carbon fiber electrode structure and structural supercapacitor was studied.The device has a specific capacitance of up to 24.2 m F/cm~2,and the capacitance retention rate is 80%after 5000 cycles,while its flexural strength is 13.1MPa and the modulus is 606 MPa,showing good structure-energy storage performance.(2)Yuzu peel was selected as a biomass precursor to prepare Yuzu peel-derived carbon materials.Using it as activated carbon material and polyvinylidene fluoride as binder,Yuzu peel-derived carbon modified carbon fiber electrode and its composite structural supercapacitor were prepared,and the effects of heteroatom doping and potassium hydroxide activation on the energy storage performance of carbon fiber electrode structure and structural supercapacitor were studied.After modification by Yuzu peel-derived carbon,the specific capacitance of the device can reach up to 88.8m F/cm~2,and the capacitance retention rate after 5000 cycles is 82%,and its flexural strength and modulus are 13.5 MPa and 737 MPa,respectively,which has good structure-energy storage characteristics.(3)Coffee grounds were selected as biomass precursors to prepare coffee grounds-derived carbon materials.Hexachlorocyclotriphosphazene(HCCP)was used as the coupling agent to graft polyethyleneimine(PEI)on the surface of coffee grounds-derived carbon materials,and then carbonized in one step to prepare N/P co-doped coffee grounds-derived carbon materials.N/P co-doped coffee grounds-derived carbon modified carbon fiber electrode was prepared using polyvinylidene fluoride as a binder,and the effect of N/P co-doped coffee grounds-derived carbon loading on the structure of carbon fiber electrode and the energy storage performance of structural supercapacitors was studied.After modification by N/P co-doped coffee grounds-derived carbon,the specific capacitance of the device can reach up to 75.6 m F/cm~2,and the capacitance retention rate after 10,000 cycles is 100%,and its flexural strength and modulus are 21.39 MPa and 1766 MPa,respectively,showing good structure-energy storage characteristics.