贮氢合金/石墨烯复合材料的电化学性能

Electrochemical performance of hydrogen absorbing alloy/graphene composite

用改进的Hummers法制备了石墨氧化物,用化学还原法制得石墨烯聚集物;用研磨法制备了贮氢合金/石墨烯复合材料。循环伏安、线性极化法及模拟电池充放电实验结果表明:与未复合的贮氢合金相比,贮氢合金/石墨烯复合材料降低了电极的极化,改善了大电流放电性能及循环性能。在实验条件下,3.0C放电比容量达225 mAh/g,提高了64%,平台电压提高了70 mV,5.0C放电比容量达200 mAh/g,提高了220%,平台电压提高了120 mV。

Graphite oxide was prepared by modified Hummers＇ method and then the graphene accumulation was prepared by a chemical reducing method. The graphene accumulation and hydrogen absorbing alloy were groud together to obtain a composite. The results of cyclic vohammetry,linear polarization and galvanostatic charge-discharge tests showed that compared to hydrogen absorbing alloy, the charge-discharge polarization of the composite electrode was decreased;its high-power and cyclic performance were improved. The discharge capacity of the electrode was 225 mAh/g at 3.0 C and 200 mAh/g at 5.0 C, which was increased by 64% and 220% respectively. The discharge voltage plateau of the electrodes was increased by 70 mV at 3.0 C and 120 mV at 5.0 G, respectively.