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Why are nickel-metal hydride batteries used in electric and hybrid-electric vehicles?

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Cross-section diagram of an alkaline-manganese dioxide battery showing labeled internal components, including the steel-plated covers, cathode, anode gel, current collector, separator, steel can, and brass rivet. — battery Cutaway view of an alkaline–manganese dioxide power cell.

Nickel-metal hydride (NiMH) batteries are utilized in electric and hybrid-electric vehicles primarily because they offer a significant performance advantage over traditional lead-acid battery systems. When NiMH batteries are substituted for lead-acid batteries in electric propulsion systems, the driving range of the vehicle is effectively doubled.1

These batteries serve as a critical component in hybrid technology, where they store energy captured through regenerative braking and the vehicle's generator. By providing a more efficient energy-to-weight ratio than conventional storage-battery systems, NiMH technology helps overcome limitations in range and power, supporting the vehicle's ability to switch between or blend electric and gasoline power for improved fuel efficiency and reduced emissions.21