Abstract：In order to study the electrochemical hydrogen storage characteristics of the Mg3MnNi2 alloy, the Mg3MnNi2-xCox(x=0~0. 2) hydrogen storage alloys were synthesized by sinering method, in which Ni was partially substituted by Co in the alloys. The phase structure was analysed, and the electrochemical performance and dynamics performance were tested. The results show that the principal phase of alloys has not changed after the substituting Ni with Co. The substitution of Co for Ni clearly improves the discharge capacity, cycling stability, dynamics performance and so on. As Co content increase from 0 to 0. 2, the maximum discharge capacity (Cmax) of the alloy increases to 282. 36 mA·h/g, the retention capacity still has 68. 4% after 20 times cycle. And the dynamics performance is optimal, the high- rate discharge ability increases from 66. 4% to 73. 3%. This is mainly due to the substitution of Co for Ni reduces the stability of the hydride, increases the anti- pulverization ability of alloys, and reduces the polarization resistance.
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2016, Vol. 23 
