为提高普通活性炭材料的电化学性能,用Ni(NO3)2溶液浸渍法和高温热解对活性炭进行改性处理。分别采用氮气吸附法、SEM、XPS等方法分析研究改性炭材料的比表面积、孔结构、形貌和组成;用循环伏安、恒流充放电等电化学方法研究改性活性炭电极构成的电化学电容器性能。结果表明,由Ni(NO3)2热解产生的NiO有准电容效应,与活性炭原有的双电层电容构成了复合电容,因而改性炭的电容量有明显的提高,其质量比电容达到246.1F/g,比原样炭的130.1F/g提高了89.2%,表观体积比电容和面积比电容分别高达169.7F/cm^3和30.1μF/cm^2,均显著优于普通炭材料。
In order to improve electrochemical properties of activated carbon (AC),commercial AC was modified by means of soaking in nickel nitrate solution and subsequently pyrolysis. The nitrogen adsorption at 77K,SEM and XPS were used to study the surface area and porosity, profile and composition of modified carbons. The performanee of electrochemical capacitors using resultant carbons as electrode materials was investigated by eyelie voltammetry and constant current charge/discharge. The results showed that NiO produced from Ni(NO3)2 decomposition had obvious pseudo-capacitance effect. Thus both electrical double layer capacitance of carbon and pseudo-capacitance of NiO had contribution to the capacitor. As a result,the specific capacitance of modified AC could be as high as 246.1F/g,89.2% higher than of original carbon. The corresponding volume and surface specific capacity are extremely high, 169.7F/cm^3 and 30.1μF/cm^2 ,respectively.