Preparation Of CC@NiAl@GO@NiCo Composites Based On Carbon Cloth And Study Of Electrochemical Properties

With the improvement of consumption level,electric vehicles and increasingly complex functions of mobile communication devices become the hotspot of modern consumption.These can drive the rapid development of the energy storage industry,while updating and iterating in order to meet the increasing demand of people’s consumption.New and green renewable energy sources（such as geothermal,wind,solar,tidal,biomass,etc.）are gaining attention.Supercapacitor is an environmentally friendly and efficient new energy storage device.According to the storage method and conversion mechanism of electrical energy,supercapacitors are divided into double layer capacitors with activated carbon as electrode and Faraday pseudocapacitors with metal（hydrogen）oxide or conducting polymer as electrode.The ultimate goal of this paper is to prepare CC@NiAl-LDH@GO@NiCo-LDH（later abbreviated as CC@NiAl@GO@NiCo）electrode materials.Therefore,this paper focuses on the preparation of electrode materials with optimal performance through three parts.They are the preparation of CC@NiCo-LDH（later abbreviated as CC@NiCo）with different Ni,Co ratios to investigate the optimal ratio;the preparation of CC@NiAl-LDH@NiCo-LDH（later abbreviated as CC@NiAl@NiCo）with different surfactants to investigate the optimal experimental protocol;the preparation and investigation of the final target material CC@NiAl@GO@NiCo for the electrochemical properties.The main research results are as follows.1.NiCo-LDH prepared by different ratios of Ni:Co,and Ni:Co=1:2 was explored as the best ratio.After the electrochemical performance,it was found that the Ni:Co=1:2group had the highest specific capacity of 963.63F/g in the charge/discharge test,which was much higher than the materials under other ratios,and at the same time,it could still maintain 712.73F/g under a high current of 8A/g,which indicated a good multiplicative performance.After testing,The residual performance of the CC@NiCo electrode after1500 cycles is 83.56%of the maximum specific capacity which proved that it has good cycling performance.2.Preparation of CC@NiAl@NiCo electrode and its electrochemical performance study.In order to further improve the electrochemical performance of CC@NiCo prepared in the previous chapter,this chapter prepared CC@NiAl@NiCo by two surfactants,NH₄F and CTAB,to explore its optimal electrochemical performance,and finally was able to reach 1262.5 F/g under NH₄F and 1143.6 F/g under CTAB,and its impedance performance test,the impedance of the former was significantly The impedance of the former is significantly smaller than that of the latter.However,the multiplicity performance of the electrode material prepared under CTAB was significantly better than that of the electrode material under NH₄F method.By testing the cycling performance,the electrode material under NH₄F could maintain 87.8%after 1500cycles.The decrease in cycling performance relative to the CC@NiCo electrode material is attributed to the tendency of structural collapse of the multilayer structure material during the cycling process.3.the preparation of CC@NiAl@GO@NiCo electrode and its electrochemical properties were investigated by a simple hydrothermal method of NiAl-LDH and NiCo-LDH and a special preparation method of growing graphene,and a new sandwich-like CC@NiAl@GO@NiCo heterostructured composite material was prepared on carbon cloth（CC）.the CC@NiAl@GO@NiCo provides a high capacitance of 2365.9 F/g at a current density of 1 A/g,with a retention rate of 93.1%after 1500 cycles.In addition,the energy storage device assembled with activated carbon（AC）as the negative electrode material and CC@NiAl@GO@NiCo as the positive electrode material was able to achieve an energy density of 52.0 Wh/kg at a power density of 796.7 W/kg and maintain38.3 Wh/kg even at a very high power density of 12015 W/kg.