Synthesis Of Nickel-based Composite Nanomaterials And Its Application In Supercapacitor

Supercapacitor is a highly efficient,environmentally friendly,new electrochemical energy storage device between the battery and the traditional capacitor.It has the advantages of high power density,long service life and high current fast charge and so on.It has broad application space and development prospect.In the research of supercapacitor electrode materials,we have found that cheap metal oxides/ hydroxides have become a research hotspot of scientific and technological workers in recent years due to their excellent electrochemical properties,abundant raw materials and environmental protection.In this paper,binary or ternary metal oxide composites were prepared by using nickel,cobalt,molybdenum and manganese as raw materials to solve the problem of low conductivity and poor cycling stability of metal oxide electrode materials.The effects of synthesis conditions and material composition on the morphology,structure and electrical properties of the electrode materials were systematically explored.The results are as follows:(1)NiMnO3 composites with two-dimensional nanosheet structure were grown on the carbon cloth substrate by hydrothermal method using nickel nitrate and manganese chloride as raw materials.Using XRD and SAED observe and study the phase of the sample;Using SEM and TEM system studied the morphology and crystal structure of materials;and the electrical properties of material were detailed study by CHI660 e.The results show that NiMnO3 has a large capacity,high current rate characteristics.At the Ni:Mn molar ratio of 3:3and 6h hydrothermal conditions,the corresponding NiMnO3 composites have high specific capacity,the highest 2330 F/g(1A/g),1640 F/g at the current density of 20A/g,The retention ratio of the capacitance is 70.3%,and the residual specific capacitance of the Ni MnO3 material is 67.2% of the initial specific capacity after 1000 times of continuous charge and discharge,which indicates that NiMnO3 has a low cycle performance.(2)Co-Ni LDH composites with two-dimensional nanosheet structure were grown on the carbon cloth substrate by hydrothermal method using cobalt nitrate and nickel nitrate asraw materials.Using XRD and SAED observe and study the phase of the sample;Using SEM and TEM system studied the morphology and crystal structure of materials;and the electrochemical properties of material were study by CHI660 e.According to the test results,Co-Ni LDH electrode material has a larger capacitance,high current rate performance.At the Ni/Mn molar ratio of 3:3 and 6h hydrothermal conditions,the corresponding Co-Ni LDH composites have high specific capacity,the highest 2766F/g(1A/g),2360F/g at the current density of 20A/g,the specific capacitance of the retention rate of 85.3%,and the remaining specific capacitance is 77.2% of the initial specific capacitance after 1000 times of constant current charge-discharge.Based on the above experimental results,and the advantages of low cost of cobalt and nickel,simple synthesis method and high specific capacitance,we believe that Co-Ni LDH composites has a high application value and has a good development space.(3)Nickel-cobalt hydroxide and molybdenum oxide composites with two-dimensional nanosheet structure were grown on the carbon cloth substrate by hydrothermal method using cobalt nitrate,nickel nitrate and sodium molybdate as raw materials.Using XRD and SAED observe and study the phase of the sample;Using SEM and TEM system studied the morphology and crystal structure of materials;and the electrochemical properties of material were detailed study by CHI660 e.According to the test results,nickel cobalt hydroxide and molybdenum oxide composites electrode material has a larger specific capacitance,high current rate performance and excellent cycle performance.The specific capacitance of the nickel cobalt hydroxide and the molybdenum oxide composite is 2562F/g(1A/g)and 2260F/g at a current density of 10A/g,the specific capacitance of the retention rate of 88%,and after1000 continuous charge-discharge cycles under current density of 10A/g,the degradation in specific capacitance of nickel cobalt hydroxide and molybdenum oxide composite material is only 9%,the results show that nickel cobalt hydroxide and molybdenum oxide composites are the most promising electrode materials.