Polymer-Tailored Nanostructure Of Metal Oxides And Electrochemical Performance Of Subsequently-Derived Composites

With the continuous development of this society,the people's demand of electrochemical energy storage components is more and more urgent,making it a major research hotspot in the field of scientific research.Among the many kinds of materials,the metal oxides have excellent electrochemical properties,such as higher theoretical specific capacitance,excellent electron conductivity and a wide range of voltage windows,so that it has a wide range of applications in electrochemical energy storage components.But its cycle stability performance is not ideal.Although the specific performance of carbon material is lower than the metal oxide material,the cycle life of carbon material is longer than metal oxide.Based on the advantages and disadvantages of the two materials,this paper mainly discusses the preparation of composite materials with better properties by iron-based metal oxides and carbon materials(graphene and other forms of carbon)through a series of means and studies their electrochemical performances.Related research works are as follows:The Prussian blue solution(PB)was first synthesized by mixing the polyvinylpyrrolidone(PVP K-30,Mw = 4 W),potassium ferrocyanide trihydrate(K4Fe(CN)6·3H2O)and hydrochloric acid solution at 80 ? through the immersion method with positive hexahedral structure.Later,we can get different sizes of Prussian blue by adjusting the amount of reactants PVP,relative molecular mass of PVP and hydrochloric acid concentration,the size is controlled within 200 nm finally.Adding a certain amount of polydiene dimethyl ammonium chloride solution(PDDA)into as-synthesized Prussian blue solution,Prussian blue combines with the PDDA under sedimentation,the positively charged PDDA is assembled with negatively charged graphite by the combination of positive and negative charge,and finally the Prussian blue/oxidized graphite composite material(PB/GO)is synthesized.Then the obtained Prussian blue/oxidized graphite composites are calcined under nitrogen to obtain iron oxide/graphene composites(Fe2O3/RGO).The resulting composite still retains the hexahedral structure.The increased specific surface area of porous Fe2O3 material make it more advantageous to ion exchange between the composite electrode material and the electrolyte solution.A series of electrochemical performance tests are carried out on the resulting composite using an electrochemical workstation.The results show that the resulting ferric oxide / graphene composites exhibit a higher specific capacitance than the monomer in the alkaline electrolyte In addition,the resulting composite material has the advantage of graphene,which overcomes the problem of poor performance and short cycle life of Fe2O3.(Fe Cl3·6H2O)and zinc chloride(Zn Cl2)are added on the block copolymer poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide)(PEO-PPO-PEO),the molar mass ratio of zinc ion to iron ion is 1: 2.The Zn Fe2O4/PEO-PPO-PEO is prepared via a solvothermal route in 200? for 4 h.After centrifugation,the resulting product is calcined in N2 to obtain Zn Fe2O4/C composites.The results show that the composite material still maintains the spherical structure of the Zn Fe2O4/EPO-PPO-PEO composite,and the size of the composite is uniform.Since the Zn Fe2O4 particles are small in size and large in number,they have a large specific surface area and increase the interface with carbon material.The widened charge transfer path of the composite material greatly improves the conduction rate of electrons.Finally,through a series of related electrochemical test,the obtained Zn Fe2O4/C composite shows excellent electrochemical performances.