ニッケルカドミウム電池の発明は1899年らしい。ニッケル水素電池は1990年。


Nickel–cadmium battery
https://en.wikipedia.org/wiki/Nickel%E2%80%93cadmium_battery
Wet-cell nickel-cadmium batteries were invented in 1899. Among rechargeable battery technologies, NiCd rapidly lost market share in the 1990s, to NiMH and Li-ion batteries;
History
The first Ni–Cd battery was created by Waldemar Jungner of Sweden in 1899. At that time, the only direct competitor was the lead–acid battery, which was less physically and chemically robust.

Nickel–metal hydride battery
https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery
History
Work on NiMH batteries began at the Battelle-Geneva Research Center following the technology's invention in 1967.
Development was sponsored over nearly two decades by Daimler-Benz and by Volkswagen AG within Deutsche Automobilgesellschaft, now a subsidiary of Daimler AG.
The first consumer-grade NiMH cells became commercially available in 1989.
In 1998, Ovonic Battery Co. improved the Ti–Ni alloy structure and composition and patented its innovations.
In 2008, more than two million hybrid cars worldwide were manufactured with NiMH batteries.[
In the European Union and due to its Battery Directive, nickel metal hydride batteries replaced Ni–Cd batteries for portable consumer use.