Synthesis and characterizations of structural and electrochemical properties of CeTi2Ni4.5Al0.2Mn0.3Cr4 AB3 type compound

Abstract The structural and hydrogen absorption/desorption properties of the new AB3- type compound CeTi2Ni4.5Al0.2Mn0.3Cr4 used as material for negative electrode in Ni – MH batteries were investigated. The elaboration of the CeTi2Ni4.5Al0.2Mn0.3Cr4 was carried by mechanical alloying process starting from CeNi4.5Al0.2Mn0.3 and TiCr2 compounds. The abundance of the CeTi2Ni4.5Al0.2Mn0.3Cr4 phase increases with the milling duration and reaches its maximum of 61 wt% after 8 h and then undergoes a decrease to 40 wt% after 20 h. The electrochemical characterization shows that the discharge capacity reaches a maximum of 138 mAh g−1 and remains stable at an average value of 130 mAh g−1 after 30 cycles. The values of the hydrogen diffusion coefficient DH and the charge transfer coefficient α of CeTi2Ni4.5Al0.2Mn0.3Cr4 –based alloy show that the electrochemical reaction has good kinetics in terms of diffusibility of hydrogen. The chronoamperometry shows that the material particles act in the electrochemical reaction as clusters of 1–2 µm size.