Preparation And Research Of Metal Compound Based Supercapacitor Electrode Materials

Metal-based compounds have become strong candidates for the current study of electrode materials because of their special structure and wide range of sources.Two prominent metal-based compounds were studied in this paper:molybdenum disulfide and manganese dioxide.The basic test method is to combine molybdenum disulfide or manganese dioxide with biochar,graphene,and polypyrrole to prepare different functional electrode materials.Then the amount of a certain component of the composite is changed,to further study the effect of the change of the composition on the electrode material.The research content is mainly divided into the following three aspects:?1?MoS₂/C powdered electrode material was prepared.The biomass material was doped with nitrogen,then treated in a tube furnace at a high temperature to remove the impurity.Followed by combining with MoS₂ precursor by hydrothermal method to obtain the binary compound MoS₂/C.Since MoS₂ has a two-dimensional structure similar to graphene,MoS₂ becomes an effective substitute for graphene.The experimental results show that the biomass material greatly improves the electrochemical performance and electrochemical stability of MoS₂.At the same time,electrochemical tests were performed on two different electrolyte solutions?1M H₂SO₄ and 6M KOH?.The results showed that the performance of MoS₂/C electrode material under the former conditions was better.?2?The three-dimensional structure composite gel MoS₂/PPy?polypyrrole,PPy?/rGO?Reduced graphene oxide,rGO?was prepared by hydrothermal method.The MoS₂/PPy binary complex was prepared firstly,then it was combined with GO by hydrothermal method to obtain a three-dimensional structure gel.Pressure tests and electrochemical performance tests were performed on MoS₂/PPy/rGO.The experimental results show that the molding effect of the ternary composite gel is much better than that of the pure rGO gel,and the mass density of the ternary composite gel is 0.03 g/cm³,which meets the requirement of light weight and small size of gel.Besides,the electrochemical performance is also outstanding:MoS₂/PPy/rGO composite gel reach a high specific capacitance of 264 F/g at the scan rate of 0.2 V/s.?3?Manganese dioxide and graphene were loaded together on melamine sponge,then the obtained flexible electrode material was studied.The melamine sponge has good compressibility,but it does not have electrical conductivity and has a large internal resistance.Graphene and manganese dioxide were combined to give the melamine sponge electrochemical properties,and the electrode material we wanted was obtained.The experimental results show that the manganese dioxide-graphene-melamine sponge has excellent compression properties and can recover deformation in a short time after being pressurized.The specific capacitance value of the manganese dioxide-graphene-melamine sponge also reaches the requirement of use:at the scanning rate of 0.01 V/s,the specific capacitance at the initial state is 140 F/g,and the specific capacitance at the 50%compression ratio is 142 F/g.It shows that manganese dioxide and graphene can exert its excellent capacitance performance on the melamine sponge.The specific capacitances in the two states of before and after are basically the same,satisfying the performance requirements of flexible ultracapacitor.