Synthesis of Co(OH)2/Ni(OH)2 nanomaterials with excellent pseudocapacitive behavior and high cycling stability for supercapacitors

Sheet-like Co(OH)2 or Co(OH)2/Ni(OH)2 nanomaterials has been synthesized on conducting carbon fiber paper (CFP) via a simple electrochemical deposition. The microstructural, chemical bonding and surface morphology of the nanomaterials were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). And the electrochemical properties of nanomaterials were investigated by cyclic voltammetry and galvanostatic charge-discharge. Compared to Co(OH)2, Co(OH)2/Ni(OH)2 nanomaterials exhibits not only a higher specific capacitance (1498 Fg− 1 than Co(OH)2 (709 Fg− 1) at a current density 2 Ag− 1) but also a higher cycling stability (92.4% specific capacitance remain over 20,000 charge-discharge cycles than Co(OH)2 (72.3% remains) at a high current density of 32 Ag− 1). The introduction of Ni(OH)2 brings a synergistic effect for the whole material.