Design And Research Of 3D Metal Collector Composite Oxides Material For Supercapacitors

With the development of human society and the progress of technology,there has been a problem of fossil energy pollution environment and depletion,which leads to the research of new energy and new energy storage equipment.Because of the advantages of environmental protection,high power density,long life and fast charge and discharge rate,the supercapacitor has become the mainstream of research.Metal oxides are gradually replacing carbon based electrode materials with the advantages of abundant resources,low cost,environmental friendliness and high specific capacity.However,the low conductivity and short cycle life of metal oxide materials affect their electrochemical properties.Therefore,we designed a new type of nickel nanotube arrays as the collector of the electrode material,combined with the oxide material to enhance the performance of the electrode material of the supercapacitor.Here,we used a simple way to synthesize the 3D Ni nanotube arrays.with template of ZnO,the gold layer is beneficial to nickel collector's electro-deposition,so the nickel collector we synthesized showing a subtle and stable nanostructure.Using this kind of nickel nanotube array as the collector,we further use the electro-deposition method to growth the Fe2O3 nanoneedles and MnO2 nanosheets,respectively,as the anode and cathode material of the supercapacitor.The capacitance of Fe2O3 nanoneedles anode up to 418.7F g-1,and The capacitance of MnO2 nanosheets cathode material reach 440.7F g-1.Thanks to the exquisite core/branching hybrid nanostructures,which we have design for the electrode materials,our anode and cathode show a performance of high specific capacity,low resistivity,high rate and excellent cycle stability.The ingenious design of the core/branch nanostructures,composed by nano metal collector and the nano oxide,provides a new way to improve the performance of the electrode material of the supercapacitor.In order to explore the prospect of the application of electrode materials,we assembled a liquid asymmetric supercapacitors(LASCs),the Fe2O3 nanoneedles @Ni as negative electrode,MnO2 nanosheets @Ni as positive electrode,1 M Na2SO4 as electrolyte.We also assembled a solid asymmetric supercapacitors(SASCs),which use PVA/Na2SO4 gel electrolyte.The two ASCs have high power density and energy density,the maximum energy density of 34.1 Wh kg-1 was obtained at the power density of 3197.7 W kg-1 for LASC,it has the energy density of 22.8Wh kg-1 even in the power density of 50981.4W kg-1.Moreover,the calculated maximum energy and power density of SASC(32.2 Wh kg-1 at the power density of 3199.5 W kg-1).Moreover,this facile methodology enables a new function combination of ultrafine metal current collectors and active materials for high-capacitive and stable systems,and may inspire further exploration in electrochemical devices.These kinds of novel electrode materials we designed have the general prospects in high performance energy storage system practical application.