Preparation And Electrochemical Properties Of High Performance Flexible Electrode Materials

With the rapid development of the society,people face more and more problems,such as environment pollution,energy shortage and so on.To solve the above problems,people have made tremendous efforts to develop clean energy,such as solar energy,wind energy,tidal energy and search for energy storage equipment,such as lithium-ion batteries,sodium batteries,supercapacitor.The performance of supercapacitors depended on the electrode material,therefore,this paper mainly uses the ternary metal oxide and the core-shell structure nanometer material as the core,and the preparation of the electrode material on the flexible substrate of the super capacitor mainly by hydrothermal method and chemical vapor deposition.The main work is as follows:(1)Because of its excellent pseudopolecular properties,this paper has synthesised the preparation method of ultra-thin NiMn2O4 nanosheets and tested them as electrochemical performance of the electrode materials of supercapacitors.In this paper,ultrathin NiMn2O4 nanosheets were fabricated based on the manganese,nickel metal oxide.Then the electrochemical test was carried out on ultrathin NiMn2O4 nanosheets which were applied in supercapacitor.The precursor of NiMn2O4 nanosheets were synthesized on a flexible nickel foam by simple hydrothermal processing and followed calcination in air atmosphere.Research has shown that in 3 mol/L KOH solution,ultrathin NiMn2O4 nanosheets electrode material demonstrated outstanding pseudocapacitive behavior when the san rate ranged from 5 to 50 mV s-1.In addition,at the current density of 2 A g-1,the specific capacitance value of ultrathin NiMn2O4 nanosheets electrode material could up to 1321.6 F g-1 and specific capacitance still remained 97.2 % after 150 cycles.The electrode made of NiMn2O4 nanosheets exhibited an excellent electrochemical performance,long cycling lifespan and good rate stability.(2)The core-shell structure can achieve the synergistic effect of each material component on electron or ionic conductivity,stability and energy storage mechanism.Therefore,the ZnO@ZnS core-shell structure nanomaterials were prepared mainly through hydrothermal processing and chemical vapor deposition method.First,well-aligned and vertical growth ZnO nanorods were fabricated on a flexible stainless mesh by a chemical vapor method,then the ordered ZnO@ZnS core-shell structures were synthesized by the sulfuration of ZnO nanorods through hydrothermal processing.The ZnO@ZnS electrode material delivered a specific capacitance of 603.8 F g-1 at the current density of 2 A g-1 in 2 mol/L Na OH solution.In addition,the specific capacitance degradation of 9.4 % after 3000 continuous cycles,which indicated ZnO@ZnS composites,possessed good electrochemical stability.And then the effects of different curing time on the formation of ZnS morphology are investigated and its electrochemical performance as a super capacitor electrode was studied.Research has demonstrated that when the sulfuration time controlled at 12 h,the material could present the best electrochemistry performance.The excellent electrochemical performance of this material mainly depended on the well-aligned and vertical growth ZnO nanorods,which acted as a conductive path contributed to the transfer of electron.In addition,ZnS acted as active electrode material possessed larger surface area.