The technology behind zinc carbon batteries dates back to 1866 and the invention of a wet cell by Georges Leclanche. This makes it one of the oldest types of battery still in general use. The contemporary version is a single-use, non-rechargeable dry battery which delivers 1.5 volts per cell.
How are they made?
The structure is straightforward. They are constructed from cylinders contained in a zinc can which acts as the anode. In the bottom and sides of the can, there is a paper separator layer treated with ammonium chloride and a thickening agent to from an electrolyte paste. The separator prevents short circuits by stopping the can from coming into contact with the cathode. Carbon is used as a conductor because it has strong resistance to the corrosion that can be caused by a salt-based electrolyte.
A huge range of everyday low-energy electronic items are powered by zinc carbon batteries, such as remote controls, radios, clocks, smoke detectors, torches and children’s toys.
Zinc carbon batteries pros and cons
- One of the reasons for the wide application and popularity of zinc carbon batteries is their low cost compared to other alternatives.
- The technology has been in use for decades so the production process is simple and reliable. Their universality is one of their greatest strengths.
- They are available in more standard sizes than any other battery, which means they are almost infinitely versatile.
- They have a much lower capacity than alkaline manganese dioxide cells, for example, which can out-perform zinc carbon by up to 8 times.
- There is always a risk that if batteries are left inside a device for long periods of disuse, caustic chemicals will leak and cause serious damage to the equipment.
- It’s not possible to recharge carbon zinc batteries which means always having to buy replacements, which can be costly over time and isn’t environmentally desirable.
Because they contain hazardous chemicals, zinc carbon batteries should not be disposed of in normal waste that goes into landfill, as this can contaminate the ground. Refuse centres and high street shops have designated bins for recycling batteries.