The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution: Selection of electrolyte and effect of weight ratio

The supercapacitive performances of Co(OH)(2)/Ni(OH)(2) composites in lithium hydroxide solution are investigated in detail. Cyclic voltammetries and galvanostatic charge/discharge measurements reveal that LiOH is the most suitable electrolyte for the composite electrodes among MOH (M = Li, Na and K). The redox behavior of the Co(OH)(2)/Ni(OH)(2) composites different to that of the pure components shows that weight ratio of Co(OH)(2)/Ni(OH)(2) exerts a great influence on the capacitive performances. After 1000 continuous charge/discharge cycles, the capacitance retention ratio for the composite electrode with the weight ratio of 2/3 is elevated from 41.6% to 88.2% compared with pure Ni(OH)(2) electrode, exhibiting improved long-life cyclability. (C) 2012 Elsevier B.V. All rights reserved.