Electrochemical Hydrogen Storage in Ti1.6V0.4Ni1−xCox Icosahedral Quasicrystalline Alloys

The discovery of the icosahedral phase (i‐phase) in rapidly quenched Ti_1.6V_0.4Ni_1?xCo_x (x=0.02–0.1) alloys is described herein. The i‐phase occurs in a similar amount relative to the coexisting β‐Ti phase. The electron diffraction patterns show the distinct spot anisotropy, indicating that the i‐phase is metastable. The electrochemical hydrogen storage performances of these five alloy electrodes are also reported herein. The hydrogen desorption of nonelectrochemical recombination in the cyclic voltammetric (CV) response exhibits the demand for electrocatalytic activity improvement. A discharge capacity of 261.5 mA h g^?1 was measured in a Ti_1.6V_0.4Ni_0.96Co_0.04 alloy electrode at 30 mA g^?1 and 303 K and it is shown that an appropriate amount of Co element addition would enhance the cycling stability at the expense of high‐rate discharging ability.