High-power nickel/metal-hydride battery using new micronetwork substrate: Discharge rate capability and cycle-life performance

A new positive substrate for high-power nickel/metal-hydride (Ni/MH) battery was designed and prepared based on a nonwoven cloth technique. For the substrate, the amount of plated nickel was reduced to less than half compared with the conventional foam-type substrate, and the manufacturing process was simplified, which lowers the manufacturing cost of the substrate. The sub-C size cylindrical sealed cell using the developed substrate exhibited superior high-rate discharging capability to the cell using the foam-type one in spite of the reduction in the amount of plated nickel due to the characteristic three-dimensional micronetwork structure of the developed substrate. In addition, the prepared cell exhibited a long cycle-life of more than 2000 cycles at 25 °C. A hybrid electric vehicle (HEV) mode cycle test consisting of multiple pulse patterns was also performed on the cell at 45 °C, and the cell remained more than 85% power of the initial value even after 100,000 cycles (driving distance: ca. 300,000 km). The developed micronetwork substrate was revealed to satisfy both high-power output and long cycle-life.