Electrochemical and electronic properties of nanocrystalline TiNi1 − xMx (M = Mg, Mn, Zr; x = 0, 0.125, 0.25) ternary alloys

Nanocrystalline TiNi1 − xMx (M = Mg, Mn, Zr; x = 0, 0.125, 0.25) ternary alloys were prepared by mechanical alloying (MA) followed by annealing. The effect of Mg, Mn and Zr on the structure and electrochemical properties of nanocrystalline TiNi-type alloys was studied. It was found that the respective replacement of Ni in TiNi by Mg, Mn or Zr improved not only the discharge capacity but also the cycle life of these electrodes. In the nanocrystalline TiNi0.875Mn0.125 powder the discharge capacity up to 151 mA h g−1 on the 10th cycle was measured (at 40 mA g−1 discharge current). The studies show, that the electrochemical properties of nanocrystalline MH electrodes are a function of the chemical composition of the used materials. The band structure has been studied by the Tight Binding version of the Linear Muffin-Tin orbitals method in the Atomic Sphere Approximation (TB LMTO ASA).