Chinese Journal of Applied Chemistry ›› 2020, Vol. 37 ›› Issue (5): 579-586.DOI: 10.11944/j.issn.1000-0518.2020.05.190315

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Synthesis of Nickel Cobalt Hydroxide and Its Electrochemical Properties

AN Lulu,MI Jie()   

  1. State Key Laboratory of Coal Science and Technology, Taiyuan University of Technology,Taiyuan 030024,China
  • Received:2019-11-25 Accepted:2020-03-11 Published:2020-05-01 Online:2020-04-29
  • Contact: MI Jie
  • Supported by:
    Supported by the Major Projects of Shanxi Province(No.MC2015-04)

Abstract:

In this work, the flake nickel cobalt hydroxide was successfully prepared by the chemical co-precipitation method, and the effect of nickel to cobalt molar ratios on the morphologies and electrochemical properties were explored. The structures and morphologies of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscope (XPS) and specific surface area and pore size analyzer (BET). The electrochemical properties were analyzed by cyclic voltammetry, galvanostatic charge/discharge, etc. The results show that when nickel cobalt hydroxide (n(Ni):n(Co)=4:1) is directly used as electrode material, it has a high specific capacitance of 1852 F/g at a current density of 0.5 A/g. When the current density is increased by 20 times, it still has a high specific capacitance of 1330 F/g. The asymmetric supercapacitor is assembled with nickel cobalt hydroxide as the positive electrode material and active carbon as the negative electrode material. The asymmetric cell possesses a high energy density of 52 Wh/kg at a power density of 346 W/kg, and superior cycle stability (the capacitance retention of 92% after 10000 cycles). Excellent electrochemical properties indicate that flake nickel cobalt hydroxide is one of the most promising electrode materials.

Key words: nickel cobalt hydroxide, supercapacitors, cycle stability