Controllable synthesis of layered Co
By Yuan, Peng; Zhang, Ning; Zhang, Dan; Liu, Tao; Chen, Limiao; Ma, Renzhi; Qiu, Guanzhou; Liu, Xiaohe
Published in Journal of Physics and Chemistry of Solids
2016
Abstract
Abstract A facile solvothermal method is developed for synthesizing layered Co-Ni hydroxide hierarchical structures by using hexamethylenetetramine (HMT) as alkaline reagent. The electrochemical measurements reveal that the specific capacitances of layered bimetallic (Co-Ni) hydroxides are generally superior to those of layered monometallic (Co, Ni) hydroxides. The as-prepared Co0.5Ni0.5 hydroxide hierarchical structures possesses the highest specific capacitance of 1767 F g?1 at a galvanic current density of 1 A g?1 and an outstanding specific capacitance retention of 87% after 1000 cycles. In comparison with the dispersed nanosheets of Co-Ni hydroxide, layered hydroxide hierarchical structures show much superior electrochemical performance. This study provides a promising method to construct hierarchical structures with controllable transition-metal compositions for enhancing the electrochemical performance in hybrid supercapacitors.