用化学沉淀法在活性炭(AC)表面和微孔内掺杂不同量的氢氧化镍,制备了氢氧化镍一活性炭[Ni(OH)2—AC]复合材料.用X射线衍射(XRD)和氮气吸附等温线等对活性炭和复合材料进行表征,结果表明,所制材料为β-Ni(OH)2-AC复合材料.对不同掺杂量的β-Ni(OH)2—AC复合材料的电化学性能进行了研究,循环伏安、恒流充放电实验表明,少量氢氧化镍掺入活性炭表面和微孔中,所得材料的比电容较活性炭有所提高,并具有良好的充放电性能:当氢氧化镍的掺入量为6%(ω)时,所制备的超级电容器单电极表现出优良的电化学性能.以活性炭电极作负极,复合材料作正极制成复合型超级电容器,循环性能测试发现,掺入6%(ω)氢氧化镍的复合材料制成的Ni(OH)2—AdAC复合型超级电容器比电容高达330.7F/g,比活性炭(AC/AC)超级电容器比电容(245.6F/g)提高了34.6%,且Ni(OH)2-AC/AC复合型超级电容器具有更好的循环充放电性能.
Nickel hydroxide/activated carbon (AC) composite was prepared by a chemical precipitation method. The structure and morphology of nickel hydroxide--AC composite were characterized by X-ray diffraction (XRD) and the measurements of nitrogen gas adsorption isotherm (BET). The results showed that β-nickel hydroxide was loaded into the activated carbon. Electrochemical performance of the composite electrodes with different loadings was studied by cyclic voltammetry and galvanostatic charge-discharge measurement. It was demonstrated that the introduction of small amount of nickel hydroxide could promote the specific capacitance of composite. The composite electrode had good electrochemical performance and high charge-discharge properties. Moreover, when the optimal loading nickel hydroxide was 6%(ω), the electrode showed better electrochemical behavior. A hybrid supercapacitor was fabricated using an Ni(OH)2-AC composite as positive electrode and an activated carbon as negative electrode. The electrochemical properties of the electrodes and the capacitive behavior of the resulting supercapacitor were studied by cyclic voltammetry and constant current charge-discharge tests. The specific capacitance of activated carbon supercapacitor was 245.6 F/g, while the hybrid supercapacitor had a higher specific capacitance of 330.7 F/g, which was increased by 34.6%. Moreover, the hybrid supercapacitor had better charge-discharge and cycling performance in 6 mol/L KOH electrolyte.