Effect of hot pressing on the electrochemical properties of Ti-Ni alloy

Abstract

Ti 2 Ni alloy pellets were produced by mechanical alloying and hot pressing at 750°C for 0.5 h in vacuum. X-ray diffraction analysis showed that, after 8 h of milling, a starting mixture of elements mostly decomposed into an amorphous phase. Obtained powders and flakes have cleavage fracture morphology with huge number of dimples with different sizes. Hot pressing of materials caused formation of Ti 2 Ni main phase. Porosity of pellets strongly depended on size of agglomerates and pressure of pressing. Ti 2 Ni pellets were used as negative electrodes for Ni-MHx batteries. Maximum measured discharge capacity of studied materials was 220 mAh/g. Electrochemical properties resulted from size of agglomerates, degree of oxidation and pressure of pressing.