The Preparation And Electrochemical Performance Of The Self-oxidizing Three-dimensional Nanoporous NiCoMn Controllable Electrode

As one of new type energy conversion and storage device,supercapacitor has the merits of high power density,long cycle life and environment friendly.The supercapacitoe assembled with metal oxides electrodes has a high energy density,then the metal oxides electrode draw more attention.But the metal oxide electrode prepared by traditional method face some problems,such as weak interface bonding force between oxides and substrate,oxides uneven load etc.The research shows,the metal oxides electrode prepared through the method of dealloy has a three dimensional self-supporting structure and can solve the problem as mentioned above.In our experiment,the new method combine dealloy and surface in-situ oxidation were used,and the NiCoMn nanoporous metal oxides electrode with a structure of three dimensional self-supporting was prepared.The treatment of anneal induce the manganese internal of the electrode migrate to the surface.The migrated manganese raised the mess of surface oxidation and induced the raise of vacancy defect inside.Finally enhance the volume specific capacities of electrode.The experiment result indicated:(1)The NiCoMn nanoporous electrode materials after annealed at 400~oC has a capacitance of 1464F/cm~3,at the current density of 1A/cm~3.And after 2000 cycles in a large current density the capacitance retention still maintain at 91%.(2)Plating nickel on single side surface of NiCoMn alloy can improve the flexibility of electrode materials.The experiment result shows that the final electrode with a plating time of 15min has a highest volume specific capacitance of 808.6F/cm~3at the current density of 1A/cm~3.(3)The NiCoMn membrane electrode prepared by the method of table plating and plain powder metallurgy has a distinguished flexibility,and it can directly assemble to batteries or supercapacitor.The test result indicted that it has an area capacitance advantage in little current density and the area capacitances was 1.66F/cm~2 at the current density of 1m A/cm~2.(4)The treatment of annealing made the manganese inside of the NiCoMn nanoporous electrode migrated to the surface,then oxide oxidation to oxide.The migration of manganese induced the raise of vacancy defect on the surface of electrode.Meanwhile the vacancy defect raised the quantity of active sides.Finally the volume specific capacity of the NiCoMn nanoporous electrode has been improved.