| Ni/MH batteries as efficient secondary storage batteries have wide range of applications. The hydrogen storage alloy as the anode material of the Ni/MH battery, its performance will largely limit the merits of nickel-metal hydride battery performance. Therefore, it has great significance to understand and develop the hydrogen storage alloy at theoretical and practical.So in this paper, we do some relevant research to improve the electrochemical properties of the anode alloy material to, namely surface modification of the alloy, doping metal oxide and changing the electrolyte formula.Firstly, adding different qualities Cu2O powder to the alloy powder, it can be proved to improve the stability of charge-discharge cycle and the discharge capacity of the negative electrode which maybe the alloy powders cause itself to expand chalking, CU2O may become Cu, CuO material, to fill the lattice defects or play the role of a conductive network in series alloy at the charging and discharging process.Secondly, we studied a new approach to modified the surface of LaNis alloy:the first step is the alloy treated with an aqueous solution of HF and KF2H2O, then the as-obtained product reacts with CuCl in aqueous media at 30 ℃,50℃ and 70℃. XRD and SEM show that the samples obtained at 50℃ and 70℃ contain Cu and Cu2O, and their particles are evenly distributed on the alloy surface. The electrochemical properties of the alloy treated with 12.5wt.% of the alloy at 50℃ is the best, which discharges 285 mAh·g-1 at the current density of 800 mA-g-1.Finally, adding different molar amounts of Cu (OH)2 into the KOH electrolyte, the effect was examined during charging and discharging process, and found that, the Cu2+ in the electrolyte will reduce to Cu plated on the surface of alloy at each cycle of charging, which can protect and inhibit oxidation of the alloy powder, thereby enhancing the discharge capacity and cycle stability of alloy electrodes. |
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