Ni(OH)2与不同碳质材料复合制备超级电容器电极材料研究进展

Research progress on composite of Ni(OH)2 with different carbonaceous materials as electrode material for supercapacitors

超级电容器具有功率密度大、寿命长、生产成本低等优点,被认为是最有发展前途的储能系统之一。然而,超级电容器的低能量密度阻碍了其实际应用。由于存储的能量与CV2成正比,可以通过增加材料的电容"C"或操作电压窗口"V"或两者同时增加来提高超级电容器的能量密度。然而具有宽电位窗口的有机电解质离子往往电导率差,成本高,容易引起环境问题。因此为改善能量密度,应采用高比电容的电极材料,故而设计出具有高比电容的适合电极材料就成为研究热点。Ni(OH)2作为超级电容器电极材料,具有理论容量大、成本低、天然丰富、易于合成等优点,近年来备受关注。但由于Ni(OH)2导电率低、比表面积小,其容量劣化严重。碳质材料作为双电层超级电容器的电极材料,其能量存储机制取决于电极表面的电解质离子吸附和解离,具有导电率好、原料丰富、成本较低、电化学稳定性高等优点而应用广泛。因此,有必要将高导电碳质材料引入Ni(OH)2组成复合材料以提高电容性能。笔者综述了Ni(OH)2基材料的合成方法,特别是与碳质材料复合来提高Ni(OH)2基材料的循环稳定性和倍率性能方面的研究新进展。

Supercapacitor has the advantages of high power density,long life and low production cost,which is considered to be one of the most promising energy storage systems. However,the practical application of supercapacitors is prevented due to its low energy density.Because the stored energy is directly proportional to CV2,the energy density of the supercapacitor can be increased by increasing the capacitance " C" of the material or the operating voltage window " V" or both. Organic electrolytes with wide potential windows in batteries have poor ionic conductivity,high cost,and easily cause environmental problems. Therefore,in order to improve the energy density,an electrode material with a high specific capacitance should be used. Therefore,the design of suitable electrode materials with high specific capacitance has become a research hotspot. As a supercapacitor electrode material,Ni(OH)2 has attracted more and more attention in recent years due to its outstanding theoretical capacity,low cost,natural richness and easy synthesis. However,since Ni(OH)2 has a low conductivity and a small surface area,its capacity is deteriorated severely. Carbonaceous materials are electrode materials for electric double layer supercapacitors,and their energy storage mechanism depends on the dissociation of the electrode surface and the adsorption of electrolyte ions. It is widely used due to its good conductivity,abundant raw materials,low cost,and high electrochemical stability. Therefore,it is necessary to make composite of Ni(OH)2 with a highly conductive carbonaceous material to improve the capacitance performance. In this paper,the synthesis of Ni(OH)2-based materials was reviewed,especially for the synthesis of Ni(OH)2 combined with different carbonaceous materials to improve their cycle stability and rate performance as electrode materials.