We explore how nickel and cadmium made a remarkable battery in this article. By the end of the nineteenth century, lead-acid batteries had already proved their point. But they had limitations …
Lead-Acid Batteries Were Relatively Heavy
They were relatively heavy, with acidic electrolyte playing a part in the battery reaction. Moreover, their performance could be affected by demanding operating conditions.
Scientists Were Looking For Something Different.
Nickel and cadmium offered an intriguing combination. Nickel could form an active positive electrode material, while cadmium could serve as the negative electrode. A nickel-cadmium battery could use an alkaline electrolyte, typically potassium hydroxide, instead of sulfuric acid, .
This changed an important feature of the battery. The alkaline electrolyte provided a path for ions to move between the electrodes, rather than being gradually consumed in the overall battery reaction. These factors were how nickel and cadmium made a remarkable battery.
Nickel-Cadmium Cells Could Deliver Substantial Current
During charging and discharging, the active materials at the electrodes changed, but could return their original states.
The combination produced a cell with a nominal voltage of about 1.2 volts. Nickel-cadmium cells could thus deliver substantial current and withstand repeated charging and discharging.
That Did Not Mean The First Cells Were Perfect
That did not mean the first cells were perfect. Early electrodes had problems with capacity, and physical changes occurred during cycling. Manufacturing methods were primitive compared with those developed later. The materials were also relatively expensive.
Nevertheless, the basic chemistry was remarkably durable. Improvements to the electrodes and construction would eventually make nickel-cadmium batteries useful in portable equipment, industrial systems, emergency power and many other applications.
This crucial breakthrough was not simply finding two suitable metals. It was finding a combination in which their electrochemical reactions could work together repeatedly.
The person who demonstrated this combination was Swedish inventor and scientist Waldemar Jungner. In 1899, he produced the first practical nickel-cadmium battery, opening a new chapter in rechargeable battery history.
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