Studies On Composite Electrode Materials Of Diatomite As The Support For Supercapacitors

The supercapacitor is a new type electrochemical energy storage device, because it canprovide higher energy density and power density compared with the traditional electriccapacitor and have longer cycle life compared with the battery. And it also has otheradvantages of less pollution and environment-friend. Supercapacitors have achieved muchattention in many fields, such as mobile telecommunication, information technology,consumer electronics, aerospace, military force, and so on. According to the principle ofenergy-storage there are two types of supercapacitors: carbon-based electric double-layercapacitor and conduct polymer or metal oxide-based pseudocapacitor. Supercapacitorsmainly are composed of electrode materials, electrolytes, the fluid, and the diaphragm.Among these, studies on supercapacitors are mainly focused on the preparation of highperformance electrode material. Electrode materials mainly include carbon material，metaloxide and conducting polymer. In the present paper, we prepare the composite electrodematerials of ditomite as the support for supercapacitors. X-ray diffraction (XRD), cyclicvoltammetric, electrochemical impedance spectroscopic, and cycle lifetime were used tocharacterize the composites. The main results and innovations are as follows:1. Composite electrode materials for supercapacitor were prepared by hydrothermalmethod in this study. The effect of support on the electrochemical performance of thecomposite electrode materials was investigated. The result shows that the compositeprepared by using diatomite support exhibits higher specific capacitance than thoseprepared by using SBA-15and Ti-Si molecular sieve, which delivers the specificcapacitance of1162.7F/g at the scan rate of5mV/s.2. In the research, nickel nitrate hydroxide hydrate was prepared by using cheapditomite, and nickel nitrate by the hydrothermal reaction. Its factor was optimized by thesingle factor method. The experimental results show that the specific capacitance of70% loaded by ditomite is1000F/g when the temperature is175℃and the reaction time is5h.Due to its excellent electrochemical performance, reaction safety and less pollution, thiscomposite is the ideal electrode materials.3. In the research, manganese dioxide was prepared by using cheap ditomite andmanganese nitrate by the hydrothermal reaction. Its factor was optimized by the singlefactor method. The experimental results show that the specific capacitance of25%loadedby ditomite is734.7F/g when the temperature is180℃and the reaction time is5h.4. In the research, zinc nitrate hydroxide hydrate was prepared by using cheap ditomiteand zinc nitrate by the hydrothermal reaction. Its factor was optimized by the single factormethod. The experimental results show that the specific capacitance of25%loaded byditomite is630F/g when the temperature is175℃and the reaction time is5h.5. According to the research of2,3,4, the composite prepared by cheap ditomite andnickel nitrate is the best in the electrochemical performance. So, the research was foucs onthe composite that nickel mixed with cheap ditomite and manganese nitrate. Its ratio wasoptimized and the results show its capacitance is1188.4F/g when the ratio of Ni:Mn is2:8.6. According to the research of2,3,4, the composite prepared by cheap ditomite andnickel nitrate is the best in the electrochemical performance. So, the research was foucs onthe composite that nickel mixed with cheap ditomite and zinc nitrate. Its ratio wasoptimized and the results show its capacitance is700F/g when the ratio of Ni:Zn is1:9.