MXene/Cellulose-based Supercapacitor Electrode Preparation And Performance

With the rapid development of electronic technology,there are more and more researches on portable wearable devices.Polypyrrole(PPy)and it's derivatives are often used as electrode active materials because of their high conductivity,good environmental stability and high energy density.Bacterial cellulose(BC)has a specific ultra-fine network structure,and has special significant characteristics,such as high porosity,high tensile strength,high water holding capacity and excellent biodegradability.It is often combined with polypyrrole to enhance the flexibility and permeability of composite electrode.In this paper,bacterial fiber and mxene were used as substrates for in-situ growth of polypyrrole.Bacterial cellulose was modified by different methods to prepare MXene/Cellulose composite electrode materials.The main research contents are as follows:(1)To BC nanofibers with smaller diameter were prepared by 2,2,6,6-tetramethylpiperidine-1-oxygen radical(tempo)oxidation of bacterial cellulose.By combining tobc with mxene and using cellulose intercalation,the stacking problem of mxene in the molding process was effectively avoided.Polypyrrole was synthesized by in-situ polymerization.The electrode material has a high area specific capacity of 928.87 m F/cm² at a current density of 0.4 m A/cm²,and has excellent cycle stability.The capacity retention rate can reach 81.2%after 5000 charge discharge cycles.(2)Stannous chloride(Sn Cl₂)was used to modify bacterial cellulose,and mxene could be uniformly and continuously deposited on the surface of bacterial cellulose through the adsorption of Sn²⁺.Then polypyrrole was synthesized by in situ growth BSM@PPy The composite electrode has a specific capacity of 2496.6 m F/cm² at a current density of 0.5m A/cm² and an energy density of 280.3?Wh/cm² at a power density of 459.7?W/cm2.When hydroquinone was added to the electrolyte,the electrochemical performance of the electrode material was significantly improved,the specific capacity reached 3153.9 m F/cm²(0.78m A/cm²),and the capacity remained 87.5%after 10000 charge discharge cycles.(3)Using bacterial cellulose/polyvinyl alcohol system and MXene to prepare aerogels with high loading rate and high anisotropy,and then prepare electrode materials with polypyrrole compound.The results show that when the concentration of mxene is 2 wt%,BPV@PPy-2wt%The area specific capacity can reach 1974 m F/cm²(0.47 m A/cm²),and the capacity retention rate can still reach 85.7%after 5000 charge discharge cycles.