Kinetic and electrochemical properties of icosahedral quasicrystalline Ti_(45)Zr_(35)Ni_(17)Cu_3 powder

摘要

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 kJmol~(-1), and the activation energy of hydrogen diffusion is 21.03 kJmol~(-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.