Kinetic and electrochemical properties of icosahedral quasicrystalline [formula omitted] powder

Abstract

Kinetic and electrochemical properties of icosahedral quasicrystalline Ti 45 Zr 35 Ni 17 Cu 3 alloy powder as negative electrode material of Ni–MH battery have been investigated at different temperatures. The calculated results show that the apparent activation enthalpy of the charge-transfer reaction is 43.89 kJ mol - 1 , and the activation energy of hydrogen diffusion is 21.03 kJ mol - 1 . The exchange current density and the diffusion coefficient of hydrogen in the bulky electrode increase with increasing temperature, indicating that increasing temperature is beneficial to charge-transfer reaction and hydrogen diffusion. As a result, the maximum discharge capacity, activation property and high-rate dischargeability are greatly improved with increasing temperature. However, the charge retention and the cycling stability degrade with the increase of the temperature.