In Situ Self-growth Of NiO And NiO Composite Materials On Nickel Foam Substrate And Research Of Their Electrochemical Properties

Supercapacitor is a new type of energy storage component which has theadvantages of both capacitors and batteries. Supercapacitor is one of the hottestresearch topics in the energy related field. The electrochemical properties of electrodematerials play the decisive role for the performance of supercapacitor, therefore howto improve the electrochemical performance of electrode materials is an importantapproach to improve the energy storage capacity of supercapacitor. In this paper, thepurpose is to improve the specific capacity of nickel oxide electrode materials, thenickel foam played not only substrate but also growth source. We studied theinfluence of preparation methods and preparation conditions on specific capacitanceof the product and obtained the nickel oxide electrode materials which approach thetheory of specific capacitance. On the basis of this work, we in situ synthetisedSnO2/NiO, PANI/NiO composite electrode materials, respectively. The morphologystructure and electrochemical properties were analyzed.We took nickel foam and oxalic acid as raw materials, calcined the nickel foamwith high temperature through oxygen, a hydrothermal reaction was taken only withthe calcined nickel foam and oxalic acid, then the NiO electrode matertial was gotafter calcined the product which was after hydrothermal reaction. The operation issimple and the cost is low, and its microstructure is composed of uniform microscopicparticles, the electrochemical test results also show that the NiO electrode material hasa good cycle characteristics, its discharge specific capacity can reach126F/g. On thebasis of this work, we ignored the first calcination procedure, a hydrothermal reactionwas taken only with nickel foam and oxalic acid, the results show that the microstructures of the two products are similar, but the NiO electrode material usingthe improved method has a good electrochemical property, and the specific capacitycan reach250F/g. To further optimize the reaction process, we completely omittedthe calcination process, using electrochemical decomposition method to prepare theNiO electrode material after hydrothermal synthesis, the microstructure of the producthas changed, and the morphology presents in a tremella shape, electrochemical testwas taken and found that the specific capacity can reach up to2049.4F/g.On the basis, we prepared to obtain NiO composite materials, willing to be ableto get electrode materials with more specific storage. We use SnCl4, NH3·H2O andoxalic acid as raw materials, using sol-gel method to obtain Sn(OH)4collosol, thehydrothermal reaction was taken with Sn(OH)4collosol and nickel foam, themorphology of the product presents a nanoparticles shape which uniformly coveredon the surface of nickel foam substrate, the results of the electrochemical tests showthat it has a good electrochemical stability and cycle life, the maximum specificcapacity can reach to1460F/g.After synthesized metal oxide composite electrode materials, we studied furthersynthesis of conductive polymer composite electrode materials. We use ammoniumpersulfate solution and aniline as raw materials, using the product which was obtainedafter hydrothermal reaction with nickel foam and oxalic acid as the substrate, in situpolymerized PANI/NiO composite materials under room temperature. We discussedthe influence of different proton acid and its polymerization conditions on theelectrochemical properties of the product respectively, and we achieved optimal effectby using hydrochloric acid as the proton acid, the product presents a nanoflower shape,and the electrochemical performance is good, the maximum specific capacity canreach2565.45F/g.