Effect of mechanical milling on the structure and electrochemical properties of Ti₂Ni alloy in an alkaline battery

Mechanical milling (MM) has been used to treat the crystalline Ti ₂Ni alloy prepared by solid-state intering. Changes of the structure, morphology, and electrochemical properties were investigated. The particle size of the alloy decreases first and then increases after the milling. Moreover,MMcontributes to a decrease in grain size and the formation and increase of the amorphous phase by increasing the milling time, resulting in improvements of the antipulverization ability and cycle life after the milling. The result of linear polarization indicates that the exchange current density, determined by the competition between the specific surface area and amorphous phase, increases first and then decreases. The amorphous phase is beneficial to hydrogen diffusion according to the result of potential-step measurement. The electrochemical properties of Ti₂Ni alloy are significantly improved by the non-equilibrium processing technology.