Low-Co rare-earth-based hydrogen storage alloy①
(Department of Metal Materials, Sichuan University, Chengdu 610065, P.R.China)
Abstract:On the basis of typical high-Co MI(Lanthanum-rich mischmetal)-based hydrogen storage alloy, a series oflow-Co or Co-free alloys have been prepared by means of partial or full replacement of Co by a combination of other elements. The microstructures,p-c-T(pressure-concentration-temperature) characteristics and electrochemical propertiesunder different charge-discharge conditions of the alloys have been investigated. Compared with the high-Co alloy, thelow-Co or Co-free alloys have the lower hydrogen equilibrium pressure and discharge capacity, but have the nearly samehigh-rate and high temperature discharge capability, and better charge-discharge cycling stability. The reason is revealedby SEM, XPS and XRD results.)
Abstract:On the basis of typical high-Co MI(Lanthanum-rich mischmetal)-based hydrogen storage alloy, a series oflow-Co or Co-free alloys have been prepared by means of partial or full replacement of Co by a combination of other elements. The microstructures,p-c-T(pressure-concentration-temperature) characteristics and electrochemical propertiesunder different charge-discharge conditions of the alloys have been investigated. Compared with the high-Co alloy, thelow-Co or Co-free alloys have the lower hydrogen equilibrium pressure and discharge capacity, but have the nearly samehigh-rate and high temperature discharge capability, and better charge-discharge cycling stability. The reason is revealedby SEM, XPS and XRD results.)
Abstract: On the basis of typical high-Co MI(Lanthanum-rich mischmetal)-based hydrogen storage alloy, a series oflow-Co or Co-free alloys have been prepared by means of partial or full replacement of Co by a combination of other elements. The microstructures,p-c-T(pressure-concentration-temperature) characteristics and electrochemical propertiesunder different charge-discharge conditions of the alloys have been investigated. Compared with the high-Co alloy, thelow-Co or Co-free alloys have the lower hydrogen equilibrium pressure and discharge capacity, but have the nearly samehigh-rate and high temperature discharge capability, and better charge-discharge cycling stability. The reason is revealedby SEM, XPS and XRD results.
Key words: low-Co hydrogen storage alloy; metal hydride electrode; rare-earth alloy; electrochemical property; Ni—MH battery