| In recent years,electrochemical capacitor has been proverbially studied as a new energy storage device,because it has better energy density,charge and dischargeperformence and cycle stability.At present,the research core of electrochemical capacitors is still the preparation of high-performance electrode materials.However,there are still poor conductivity,low transmission speed between ions and easy stacking of grains,which will result in small active area and pore density,which makes the intrinsic capacitance of many electrode materials unable to be fully utilized.Polythiophene(PTh)is used in electrochemical capacitor applications because of its excellent redox performance,high conductivity and environmental stability.However,due to its easy agglomeration and accumulation,electrode materials with better performance can be obtained by compounding with two-dimensional materials.Therefore,MXene has been widely studied.as a two-dimensional material,MXene is also a promising candidate for electrochemical capacitors because of its unique hydrophilicity and metal conductivity.In addition,the embedding of polymer chains will reduce the re-stacking of MXene flakes and improve the stability by preventing them from contacting with oxygen.Furthermore,the composite material formed with MXene can not only increase the conductivity,but also avoid the structural collapse caused by expansion and contraction during repeated charging and discharging.Therefore,its specific capacitance needs to be further improved.In view of the above problems as electrode materials of electrochemical capacitors,this paper has done some research work and achieved the following results.(1)The key step in the activation process of carbon fiber cloth is to achieve the oxygen-containing groups on the carbon overall,plays a momentous role in improving the electrochemical performance of the carbon fiber cloth.At the same time,polythiophene was electrochemically deposited on potassium permanganate activated carbon fiber cloth(ACC)by a simple and controllable electrochemical method,which further improved the conductivity of the material and further improved the electrochemical performance of polythiophene.With the rapid development of modern society,it is imperative to develop flexible energy storage equipment.A few layers or even a single layer of MXene nanosheets were directly deposited on ACC@PTh,and new ACC@PTh/MXene electrode materials were prepared.With the loading of 3mg·cm-2,the prepared electrode has a high surface capacitance of 224.88 F·g-1 at a current density of 30 m V·s-1.After activated by potassium permanganate,The specific surface area,the hydrophilicity containing oxygen-containing functional group and the carbon fiber cloth is significantly improved.Conductivity,electron transmission efficiency and ion diffusion rate of carbon fiber cloth were improved after the MXene nanosheets were formed on the carbon fiber cloth activated by potassium permanganate,which significantly enhanced the electrical properties of ACC@PTh/MXene new materials.(2)In order to reduce the influence of the base material on the composite electrode material,a self-supporting MXene/PTh composite was synthesized by vacuum-assisted filtration,and MXene was mixed with charged polythiophene(PTh)to produce polymer/MXene composite.The prepared composite material is flexible,and the embedding and restriction of polymer between MXene sheets not only increases flexibility,but also enhances cation embedding,and MXene nanosheets provide polythiophene particles with comprehensive functions of dispersion,combination,conductivity and flexible substrate;At the same time,polythiophene particles are not only used as high pseudo-capacitance materials,but also as interlayer conductive pillared components,which are used to reduce MXene accumulation and enable electrons and ions to be transmitted,thus obtaining excellent synergistic effects.The results show that the PTh/M-3 composite has the best capacitance,and the highest capacitance of PTh/M-3 is265.96 F·g-1.After 500 cycles,the specific capacitance reaches 91.5%,which shows good cycle stability. |
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