The evolution of battery technology

In 1780, Italian physicist Luigi Galvani accidentally discovered that muscles contract when touched by two different metals. Dubbed his ‘frog leg experiment’, this discovery formed the basis of the ‘galvanic cell’, where two different electrodes (the two metals) and an electrolyte (the water in the frog’s legs) produce a circuit.

Building on Galvani’s discovery, Italian physicist Alessandro Volta invented the Voltaic Pile in 1799. Several ‘galvanic cells’ were layered on top of each other, each cell consisting of a copper and zinc sheet, and a cardboard disc soaked in salt water, with the top and bottom cells connected by a wire to create a continuously flowing electric circuit.

Volta’s invention demonstrated that the more cells the column had, the higher the electrical voltage, laying the groundwork for modern-day batteries. His invention also disproved the common theory that electricity could only be created via living beings.

In 1859, French physicist Gaston Planté invented the lead-acid battery, which is considered the first rechargeable battery. This invention paved the way for low cost and high surge current in batteries, and the overall construction and cell arrangement can still be found in lead-acid batteries today.

In 1899, Waldemar Jungner invented Nickel cadmium (NiCd) batteries. Similar to lead-acid batteries, the prototypes contained ‘wet cells’ – using a liquid electrolyte instead of acid. This design could be used continuously and was extremely durable. Working independently from Jungner, Thomas Edison developed the same technology in 1901, using alkaline electrolytes instead of acid.

Despite the technology being invented half a century earlier, Jungner and Edison’s designs didn’t take off on a large scale until the 1950s, when Canadian engineer Lewis Urry invented the zinc-manganese dioxide battery. 

Urry discovered that manganese oxide and powdered zinc mixed with an alkaline substance could greatly increase the shelf life of batteries. This modern alkaline battery was snapped up by American consumers looking for longer-life batteries to power the fad of the time: transistor radios.