Hierarchical α-Ni(OH)2 grown on CNTs as a promising supercapacitor electrode

Metal hydroxides are welcomed in supercapacitor electrode applications. However, pristine metal hydroxides usually suffer from disadvantages of poor conductivity or agglomeration which may hinder their utilization. Hierarchical α-Ni(OH)2/CNTs hybrid is fabricated through one-step water bath method. Hierarchical α-Ni(OH)2 grows along the direction of CNTs backbones. The electrochemical performance of α-Ni(OH)2/CNTs hybrid is superior to pristine α-Ni(OH)2 according to electrochemical tests. High specific capacitance of the composite electrode reaches 2325 F g−1 at a sweep rate of 1 mV s−1. Furthermore, longer cycle life of the hybrid is achieved. The hybrid displays 83.6% specific capacitance retention after 10000 cycles in contrast to pristine α-Ni(OH)2 with only 49.5% capacitance retention. Hierarchical α-Ni(OH)2/CNTs composite with remarkable electrochemical performance may attribute to synergistic effects: good conductivity, redox property and high charge storage capacity. It is beneficial for the hybrid to get better electron storage capacity because of the Schottky barrier formed at interface between α-Ni(OH)2 and CNTs. Those properties demonstrate that the hybrid has a potential application as supercapacitor electrode.