Charge-discharge Performance and Energy Density of MH/Air Secondary Battery using A₂B₇ Type Hydrogen Storage Alloys

Abstract

The charge-discharge performance and the energy density of a metal hydride/air secondary battery using A 2 B 7 type hydrogen storage alloys were studied. The MH/air secondary battery showed a high energy density more than 750 Wh/L or 100 Wh/kg, which is higher than the theoretical energy density of lithium ion secondary batteries. A high current discharge up to 1100 mA (83 mA cm −2 ) was demonstrated with no plugging of the positive electrode by discharge products. The results indicated that the MH/air secondary battery is one of the most promising candidates for next generation of energy storage devices to a wide range of applications such as electric vehicles and home energy storage systems.