What type of battery did Thomas Edison develop in the early 1900s?

Thomas Edison developed a nickel-iron battery, also called the Edison battery, in the early 1900s.

The rechargeable battery used nickel oxide-hydroxide at one electrode and iron at the other, with an alkaline electrolyte. Edison promoted it as a durable alternative to lead-acid batteries, especially for electric vehicles and industrial uses.

The battery was rugged and capable of tolerating rough treatment, but it was relatively expensive and had lower efficiency than competing designs. Those limitations restricted its commercial success during Edison’s lifetime.

Modern nickel-iron batteries remain known for long service life and resilience. They are sometimes confused with nickel-cadmium batteries, which use cadmium rather than iron and were developed by other inventors.