Characteristics of Mn-Co-Ni Oxide Powders Prepared By Chemical Reduction Method for a Supercapacitor Electrode

Supercapacitor is considered as a candidate for the promising energy storage device due to its permanent properties, high power density, and short charging time [1]. It can be used as a backup system, starting power of fuel cell , hybrid vehicle, or large industrial equipment [2].

 There are two typical types of supercapacitors. One is electrochemical double layer capacitors (EDLC) utilizing a polarization phenomenon occurring between the surface of electrode and electrolyte. And the other is pseudo-capacitors using high-speed redox reactions. Normally, transition metal oxide and conductive polymer are used as the electrode materials of pseudo-capacitors [3]. Ruthenium [4] and nickel [5] are often studied among various metal electrode. They exhibit excellent performance, but it is difficult to commercially used because of its high price and eco-unfriendly with strong acid or alkali electrolyte. Therefore, manganese has been studied as an alternative materials.

 Manganese is showing potential to be used as a supercapacitor electrode because of its low price and eco-friendly property. But, the mechanical strength of manganese is weak, so discharge cycle life is relatively short as compared with that of other electrode materials [6]. In addition, manganese oxide is limited used in conditions that require high power because the power density is reduced with increasing contact resistance [7].

 In this study, we fabricate alloy of cobalt, nickel, and manganese prepared by chemical reduction method using the reducing agent (N₂H₄) and the dispersant (C₆H₅Na₃O₇) [8]. The unique shape of Mn-Co-Ni oxide powder was formed by combing powder of Mn (plate like), Co (flower like), and Ni (sphere) (Figure. 1). The electrochemical performance of the Mn-Co-Ni oxide was measured with cyclic voltammetry and charge-discharge test.

Reference

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