电化学混合电容器用新型β-Ni(OH)_2/CNTs纳米复合物

A Novel β-Ni(OH)_2/CNTs Nano-composite Used in Electrochemical Hybrid Capacitor

采用水热合成法制备出一种新型β-Ni(OH)2/碳纳米管(CNTs)纳米复合物,Ni(OH)2微晶粒径控制在50～80nm之间,与CNTs直径相当,CNTs与Ni(OH)2质量比为1∶15.将纳米复合物应用于活性炭(AC)/NiOOH电化学混合电容器,电化学测试表明:在0.4A/g电流条件下,其放电比容量达279mAh/g,是β-Ni(OH)2理论容量的96.5%;当电流密度从0.4A/g增加至8A/g时,电容器的容量保持率在76.5%以上,高倍率充放电特性优异.此外,纳米复合物良好的电化学可逆性使AC/NiOOH电化学混合电容器更易活化,并具有较高的充放电效率和良好的循环稳定性能.

A novel β-Ni（OH）2/carbon nanotubes （CNTs） nano-composite was prepared by hydrothermal synthesis method in this work. The dimension of the β-Ni（OH）2 grain was controlled between 50～80 nm, as large as the diameter of the CNTs. The mass ratio of the CNTs to Ni（OH）2 was 1∶15. The nano-composite was applied to activated carbon （AC）/NiOOH electrochemical hybrid capacitor and the electrochemical performance of the capacitor was tested. The results showed that the discharge capacity of the nano-composite could reach 279 mAh/g at a 0.4 A/g current density, being about 96.5% of the theoretical capacity for β-Ni（OH）2. When the current density was increased from 0.4 to 8 A/g, the capacity of the hybrid capacitor could remain about 76.5%. The nano-composite showed an excellent high rate charge-discharge performance and furthermore a high electrochemical reversibility. The AC/NiOOH electrochemical hybrid capacitor using this nano-composite could be activated quickly and possessed high charge-discharge efficiency and good cycle performance.