Current Applied Physics, Vol.20, No.1, 106-113, 2020
Electrochemical properties of modified negative electrode for Ni-MH cell
This study discusses the influence of different composition of negative electrode material on the performance of Ni-MH cells. Two major groups of multicomponent alloys were used during the experiments: AB(5) and AB(2) types. The best capacity was observed for the AB(5)-type alloy with the highest content of Co in its structure. The presence of Co in the alloy increased the capacity of the negative electrode most likely as a result of hydriding/dehydriding processes or Faradaic reaction following the dissolution-precipitation mechanism. The influence of different amounts of nickel (0-20 wt %) was determined. The presence of nickel in the electrode materials increased the current density as well as the diffusion of hydrogen into the bulk of alloys. Moreover, the carbon materials have been used as an additive for negative electrode grains in order to increase the conductivity and hydrogen sorption properties.