Nickel–Cadmium and Nickel–Metal Hydride Battery Energy Storage

Since the invention of nickel–cadmium (Ni-Cd) battery technology more than a century ago, alkaline batteries have made their way into a variety of consumer and professional applications, developing different electrochemical couples (Ni-Cd, Ni–metal hydride (MH)) into essentially five distinctive electrode technologies. Variants in cylindrical and prismatic shape, as well as vented and sealed designs exist. Due to the stability of both the active materials and their support structure in alkaline electrolyte, alkaline batteries are characterized by very slow aging and a high level of robustness and reliability under harsh environmental conditions. Besides industrial standby, starting, and traction applications, alkaline batteries are playing a role in smart grid applications providing energy storage for dispatching, bridging and stabilization functions. The following chapter describes technical characteristics of Ni-Cd and Ni-MH batteries and their various design variants, analyzes its main performance parameters, including life time, and considers material and environmental aspects. Finally, different grid storage applications are described with specific emphasis on the specific advantages of alkaline batteries illustrated through a number of real life examples.