Cycle life and utilization studies on cobalt microencapsulated AB5 type metal hydride

LaNi4.27Sn0.24 alloy was microencapsulated with cobalt by electroless deposition. The coated material has a higher capacity compared to the bare alloy due to the faradaic reaction of cobalt during discharge. This additional capacity has been studied using various material and electrochemical characterization techniques. The capacity due to cobalt varies depending on the amount of active material available for reaction. An increase in utilization is seen with decrease in thickness of the coating. Active surface area and the transport process within the film control the amount of cobalt utilized. Finally, cobalt coated alloys are seen to cycle ten times more than bare LaNi4.24Sn0.27 with constant capacity. (C) 1999 Elsevier Science S.A. All rights reserved.