Preparation And Electrochemical Properties Of Manganese Oxide Composite Electrode Materials

Compared with traditional energy storage devices,supercapacitors have the advantages of no pollution,high power density,long cycle life and so on.It is considered to be one of the most potential energy storage equipment,which has been paid more and more attention by researchers.According to the energy storage mechanism,supercapacitors can be divided into two categories,namely the double layer supercapacitors and the pseudo capacitor supercapacitors.The supercapacitor electrode materials mainly include carbon materials,metal oxide materials and conductive polymer materials.These three kinds of materials have their own advantages and disadvantages.It will become an important trend to prepare high capacity,low cost and environment friendly composite materials by Combining the advantages of materials in the future development of supercapacitor materials.In this paper,we synthesized composite electrode materials with different doping amount,aimed to improve the electrochemical performance for supercapacitor.The structure,morphology appearance and elements composition of the materials were characterized by XRD,N2 adsorption-desorption,XPS,TEM and SEM.The corresponding electrochemical properties were tested by cyclic voltammetry(CV),galvanostatic charge/discharge measurements(GCD)and so on.(1)Mesoporous carbon was synthesized with SBA-15 as a template and furfuryl alcohol as carbon source.And manganese dioxide was used as manganese source to synthesize the composite of manganese dioxide and mesoporous carbon in situ composite method,Through XRD,TEM,SEM,XPS and other techniques,We can know that the mesopores of composite materials are not ordered,and exhibit some graphitization.With the increase of manganese dioxide,the ordered mesoporous structure is less,and the graphitization degree deepens.The electrochemical performance of the composite was studied.When the complex amount of manganese dioxide is 12.53%,composite material has the largest the specific capacitance of 411.9 F/g when the current density is 1 A/g.After 2000 cycles,the typical sample exhibits the retention of more than 80%.(2)Mesoporous manganese oxide was synthesized by sol-gel method,,followed by cobalt doping.Different samples were obtained by changing the amount of cobalt ions.XRD results show that with the addition of cobalt ions,the Mn-Co two element spinel structure oxide is formed.The manganese oxide is Mn2O3 when the cobalt ion is not added.The morphology and specific surface area of the samples were characterized.The results show that the manganese oxide crystals are clubbed.And with the increase of the amount of cobalt ions,the rod shape of the agglomeration becomes the approximately spherical particles of the agglomeration,gradually.The specific surface area has been improved,and average pore size decreases gradually.The electrochemical performances of the samples were tested.The redox reaction of CoMn2O4 is good.When the current density is 1A/g,the specific capacitance of CoMn2O4 is 614.8 F/g,and at the same time,the specific capacitance can be kept above 60%under the condition of large current.The cycle stability is good,indicating that it has good electrochemical performance.