PowerGenix Technology In-Depth

Comparing The Charge - Discharge Reactions

H2O + Zn + 2NiOOH = ZnO +2Ni(OH)2

H2O + Cd + 2NiOOH = CdO + 2Ni(OH)2

Nickel-zinc batteries are chemically very similar to nickel-cadmium. Both use an alkaline electrolyte and a nickel electrode but differ significantly in their voltage. The nickel-zinc cell delivers more than 0.4V of additional voltage both at open circuit and under load.

With the additional 0.4V per cell, an inherent value of the nickel-zinc cell lies in the reduced cell count required for a multi-cell battery.  For higher voltage applications the advantages associated with fewer cells are quickly apparent through a smaller footprint, lighter weight, and lower impedance battery.

Before PowerGenix was able to make available the advantages of the nickel-zinc battery chemistry they needed to solve the technical problems associated with the instability of the zinc electrode in a rechargeable cell. The cornerstone of this solution was found in a patented electrolyte formulation that reduces zinc solubility and prevents dendrite shorting problems.

The Makeup of a NiZn Cell

  • Zinc electrode kinetics are faster than cadmium
  • Zinc conductivity is 15% higher than cadmium
  • High negative zinc potential allows use of high conductivity copper current collector
  • Zinc passivation is not a problem
  • Patent pending "negative cap" design unique to NiZn technology

The capabilities of the cell were further enhanced with patented advancements in both the positive and negative electrode composition that are free of any heavy metal elements. Additionally, the company has a strong and broad intellectual property position that addresses all major aspects of the cell chemistry as well as engineering and construction details that enable the use of existing nickel-cadmium equipment manufacturing for production of the cells.