▎ 摘　　要

NOVELTY - Preparation of fiber-type supercapacitor involves dripping potassium chloride solution and ferric chloride solution in cellulose nanocrystal-polyaniline suspension, stirring, then adding large-diameter high-concentration graphene oxide solution, stirring to obtain homogeneous mixture, centrifuging to obtain spinning solution, loading the spinning solution into a syringe with a rotating nozzle, then injecting the spinning solution into coagulation bath of calcium chloride-ethanol aqueous solution, washing with water and ethanol, collecting the obtained fibers, drying at room temperature, vacuum-drying, reducing the fibers, taking 2 sheets of polyethylene terephthalate coated with gold layer as supporting substrates and current collectors, placing the reduced fibers on the substrates to form two electrodes, soaking cellulose paper in electrolyte, and placing soaked paper as a solid electrolyte in between the two electrodes to form a sandwich-type symmetrical capacitor. USE - Preparation of fiber-type supercapacitor for flexible antibacterial electronic skin. ADVANTAGE - The preparation method effectively improves cellulose nanocrystal-based fibers through polycarboxylation and synergistic effect between cellulose nanocrystals and polyaniline, and uses potassium chloride to improve the electrical conductivity and strain sensitivity of fibers, so that the capacitors can eliminate bacteria by releasing ferric ion, and prepares graphene oxide with abundant carboxyl active sites on surface and increased dispersibility. The graphene sheets are pulled into fibers to be attached to each other like scales on a fish. If the fiber is knotted, the strength at the knot depends on the bending coefficient of the fiber, and since the bending coefficient of graphene oxide is very low, it seems that the knot does not exist, so the strength of fiber is high. DETAILED DESCRIPTION - Preparation of fiber-type supercapacitor involves adding microcrystalline cellulose to circulating acid mixture, stirring at 80-90°C to obtain suspension, rapidly cooling to room temperature; filtering, separating obtained functionalized cellulose nanocrystals from the circulating acid mixture, washing the cellulose nanocrystals with water by continuous centrifugation, dialyzing to remove the remaining acid, and freeze-drying to obtain cellulose nanocrystals, adding graphite nanosheets to chromic acid washing solution for ultrasonic dispersion, mechanically stirring, pouring into water, suction filtering, washing with water and ethanol, calcining, cooling to room temperature, centrifuging light orange solution to remove unoxidized graphite to obtain large-diameter graphene oxide, adding to water, stirring to obtain large-diameter high-concentration graphene oxide solution, adding hydrochloric acid and aniline monomer to the cellulose nanocrystal water suspension, stirring in an ice bath to obtain a uniform mixture to prevent agglomeration, adding ammonium sulfate to water, vigorously stirring and oxidizing at 0-5℃ to obtain cellulose nanocrystal-polyaniline suspension, dripping potassium chloride solution and ferric chloride solution in the cellulose nanocrystal-polyaniline suspension, stirring, so that potassium ion and ferric ion, dynamic metal ion coordination bonds and weak hydrogen bonds are formed, then adding the large-diameter high-concentration graphene oxide solution, stirring to obtain homogeneous mixture with synergistic soft-hard hierarchical structure, centrifuging the homogeneous mixture to obtain spinning solution, loading the spinning solution into a syringe with a rotating nozzle, then injecting the spinning solution into coagulation bath of calcium chloride-ethanol aqueous solution, coagulating, washing with water and ethanol, collecting the obtained fibers, drying at room temperature, and vacuum-drying to completely eliminate the solvent in the fibers, reducing the fibers in hydrogen iodide aqueous solution, washing with absolute ethanol, vacuum-drying, reducing in argon atmosphere at 750-800°C for 2.5-3 hours, 950-1000°C for 1.5-2 hours and 1150-1200°C for 0.5-1 hour, taking 2 sheets of polyethylene terephthalate coated with gold layer as supporting substrates and current collectors, placing the reduced fibers on the substrates to form two electrodes, soaking cellulose paper in electrolyte, and placing soaked paper as a solid electrolyte in between the two electrodes to form a sandwich-type symmetrical capacitor.