Abstract:In order to improve the electrochemical properties of La-Mg-Ni system hydrogen storage alloy, graphene was synthesized and added into the hydrogen storage alloy La0.73Ce0.18Mg0.09Ni3.20Al0.21Mn0.10Co0.60. It was found that the alloy still retained the phase structure. Electrochemical studies showed that the maximum discharge capacity of these electrodes decreased slightly. After adding 1%, 2% and 5% grapheme, the cyclic capacity retention rate after 50 charge-discharge cycles was significantly enhanced from 63% of original alloy to 75%, 78% and 73%. As the graphene content was 2%, the high rate dischargeability (HRD) at the discharge current density of 900 mA/g increased from 79.8% to 83.9%, and the exchange current density I0 and the limiting current density IL improved from original 54 mA/g and 512 mA/g to 281 mA/g and 1537 mA/g, respectively. Furthermore, the addition of graphene had a positive effect on the anti-corrosion capability of electrodes.