Preparation And Electrochemical Capacitance Properties Of Nickel (Hydroxide) Oxide/Carbon Composite Electrode Materials

This thesis focuses on the preparation and supercapacitor applications of NiO/C andNi（OH）₂/C composite electrode materials using carbon as the carrier. This thesis is dividedinto three chapters:The first chapter outlines the development of electrochemical capacitors, the researchbackground, application scopt, development, energy storage mechanism, characteristics andelectrode material type, and describes the latest research on three types of electrodematerials. Finally, some research ideas and methods to improve the capacitor performanceare put forward.The second chapter is to study the preparation and electrochemical capacitanceproperties of NiO/C composite. This chapter is divided into three parts.1. NiO/GNS composite materials with good dispersion are synthesized byhydrothermal method. The morphology and structure of NiO and NiO/GNS compositematerials are analyzed and discussed. And their electrochemical capacitance behaviors ofNiO and NiO/GNS composite in alkaline electrolyte are studied and compared anddiscussed. The results indicate that, through the combination of graphene with NiO, theelectrochemical behavior of NiO was improved obviously.2. New NiO/P-CNT composite with3D network structure is synthesized by in-situprecipitation-calcination method. The samples are characterized and analyzed, The resultsindicate that whisker-like NiO is loaded uniformly on PPy-derived carbon nanotubesurfaces to generate a composite forming complex three-dimensional network structure.Electrochemical tests indicate that Ni（OH）₂/P-CNT composite has high specific capacitance and good rate performance.3. New NiO/P-CNT composite with3D network structure is synthesized byin-situ-precipitation calcination method through the controlling of pH values. And hascarried on the structure and morphology characterization and large electrochemical testseries. The results show that, in the pH=9.5, and when the content of P-CNT is35%incomposite, the electrochemical capacitance performance of electrode materials is best.The third chapter is to study the preparation and electrochemical capacitance propertiesof NiO composite materials, this chapter is divided into three parts.1. The successful implementation of the flower-like microspheres Ni（OH）₂on thegraphene surface evenly growth, by hydrothermal method, and ultimately the formation ofthe three-dimensional network structure of Ni（OH）₂/GNS composite materials. TheNi（OH）₂/GNS composite materials possess good energy capacity and rate performance.2. Ni（OH）₂/P-CNT networks with three–dimensional electron–transport channels aresynthesized via a facile and general surface–decoration approach. Ni（OH）₂nanofibers areintertwined and wrapped homogenously on carbon networks, leading to the formation ofmore complex networks. After the electrochemical tests show that, Ni（OH）₂/P-CNTcomposite material possess good energy capacity and rate performance.3. New Ni（OH）₂/P-CNT composite is synthesized by hydrothermal microemulsionmethod，which to form a three-dimensional network structure. This special porous networkstructure not only improves the utilization of Ni（OH）₂during electrochemical process, butalso benefites good channel for ion diffusion and electron transportation.