焦粉活性炭/Al-Ni(OH)2复合电极材料的制备及其超级容器性能

以焦粉为原料,用HNO3预处理除灰,采用KOH浸渍-煅烧活化法制备焦粉活性炭(CPAC),通过场发射扫描电子显微镜、X射线衍射等表征其形貌,采用BET测试其比表面积、孔结构及孔径分布。初步考察了活化温度、活化时间等对焦粉活性炭电极材料电化学性能的影响。采用共沉淀法制备CPAC/Al-Ni(OH)2复合电极材料,通过恒电流充放电测试及循环伏安测试表征CPAC/Al-Ni(OH)2复合电极材料的电化学性能。结果表明,当活化温度为800℃、活化时间为3 h制得的焦粉活性炭电极材料的电化学性能最佳,比电容达到211 F/g。CPAC-800℃-3 h/Al-Ni(OH)2复合电极材料随Al掺杂量的增大呈现先增大后减小的趋势。在固定Al质量掺杂量为4%,炭镍质量比为1∶1时所得复合材料的比电容量最大:1173.6 F/g。恒电流充放电及循环伏安测试表明Al掺杂量为4%、炭镍比为1∶1的复合材料具有较好的电化学性能。

Supercapacitors Prepared with Coke Powder Activated Carbons/Al-Substituted Ni (OH)2 Composite Electrode Materials

With coke powder as raw materials, coke powder activated carbons(CPAC) were prepared by pretreatment via HNO3 and activated through dipping-calcined activation method by the modifier of KOH. The physical properties of the product were characterized by field emission scanning electron microscopy(SEM), X-ray diffraction(XRD). Nitrogen adsorption was used to characterize the BET surface area, pore structure and pore size distribution, and the influence on electrochemical properties under the different activated temperatures and time was investigated. The composite electrode materials of CPAC/Al-substituted Ni(OH)2 were synthesized through the method of co-precipitation, and the electrochemical performances of CPAC/Al-substituted Ni(OH)2 composite electrode materials were characterized by the constant current charge/discharge testing and cyclic voltammetry testing. The experimental results show that coke powder activated carbon electrode materials has the best electrochemical performance when the activation temperature is 800 ℃ and the activation time is 3 h. Under such conditions, the specific capacitance of the product achieves 211 F/g. CPAC-800 ℃-3 h/Al-substituted Ni(OH)2 composite electrode materials have the trend to increase initially, but start to decrease with the increase of doping amount present of aluminium. The specific capacitance of composite material can reach 1173.6 F/g when the mass ratio of CPAC to nickel is 1∶1 by maintaining the doping quantity of aluminium at 4%(mass fraction). The composite electrode material with the doping quantity of aluminium as 4% and the mass ratio of CPAC to nickel as 1∶1 has the best electrochemical performance after the constant current charge/discharge and cyclic voltammetry tests.