Everybody knows that in 1492 Columbus sailed the ocean blue. But did you know that in 1866 Georges Leclanché invented the battery for your favorite gadgets?
While that rhyme probably won't make its way into history books, the invention of the Leclanché cell by the French engineer of the same name certainly did. This device, with only minor changes to its original design, evolved into modern alkaline batteries and the most popular household battery to date.
Born in Parmain, France, in 1839, Leclanché began his career as an electrical engineer in 1860. At the time, several varieties of batteries were in use or under experimentation, but they all stemmed from Alessandro Volta’s invention of the voltaic pile in 1800 and followed (as most batteries still do) the same principle. Technically, a battery is a combination of electrical "cells" that generates an electric charge through a chemical reaction between an anode (negatively charged electrode) and a cathode (positively charged electrode). These two electrodes are kept separate, but both are in contact with an electrolyte (a solution capable of conducting electricity) that facilitates the chemical reaction and movement of charge. This charge can then be transferred to an outside circuit, where it powers a device such as a toy. As Leclanché was beginning his career, the most common form of battery was the Planté lead-acid battery. These batteries, because they were capable of generating high surges of electrical activity, remained a popular design for automobiles, but their weight, toxicity and intensity made them impractical for household use.
Leclanché's battery, also called a zinc-carbon battery, contained a different kind of cell than its predecessors. Instead of lead, he used zinc and a carbon-manganese dioxide mixture for his electrodes. He also replaced the sulfuric acid that had been in use as an electrolyte with ammonium chloride. These changes made the cell less toxic and lighter than the Planté model. The battery generated electricity as the zinc anode began to lose electrons in a chemical process called oxidation. If the battery was connected to an outside circuit, the electrical charge created by these excess electrons would be conducted by the electrolyte toward the carbon-manganese dioxide cathode. From there, the electrons were transferred externally, powering whatever device was connected to the battery. The design of Leclanché’s cell, termed a wet cell, packed the cathode inside a porous pot, which was then submerged, along with the anode, in the ammonium chloride solution. The electrolyte could easily seep through the pot and connect the anode to the cathode electrically while keeping them physically separate.
Though non-rechargeable and incapable of supplying sustained electricity, these 1.5 V "wet" cell batteries seemed ideal for applications involving short bursts of current or requiring little maintenance. Nobody believed more in their promise than Leclanché himself. In 1867, just a year after patenting his Leclanché cell, the engineer quit his job to devote himself to the production of the battery. His efforts paid off, as the design was adopted by Belgium’s telegraph service the following year, and Leclanché opened a factory to meet the growing demand for his invention.
One of only a few but important changes to Leclanché’s original design came from German chemist Carl Gassner, who incorporated a low-moisture paste electrolyte into the cell. These new batteries, called “dry” cells, eliminated the risk of spilling a liquid electrolyte and greatly broadened the range of both the Leclanché cell and battery power in general. Meanwhile, the popularization of flashlights, radios and other electronics was pushing the demand for practical, reliable batteries, and removing heavy metals like mercury from the zinc alloy anode helped answer that call safely. It was a switch to an electrolyte of potassium hydroxide in the 1950s, however, that fixed the Leclanché cell firmly in the hearts – and gadgets – of consumers forever (or at least until now). Because the electrolyte in these new longer-lasting cells was a base, rather than an acid, they were termed alkaline. Thus, the most widely used household battery was born of Leclanché's original design, now immortalized in everything from our spinning CD players to dancing Santa Claus dolls.
