How to Make an Alkaline Battery
An alkaline battery is so named because it uses an alkaline electrolyte of potassium hydroxide and electrodes composed of zinc and manganese oxide. This is in contrast to zinc-carbon batteries, which use an acidic electrolyte. An alkaline battery is the familiar commercial battery that comes in both disposable and rechargeable forms. These batteries have a good energy density and therefore are used in many portable applications.
Things You'll Need
- Brass nail
- Gasket
- Metal cap
- Metal lid
- Steel can
- Manganese dioxide
- Potassium hydroxide
- Washer
- Zinc
Instructions
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Create the cathode (negative electrode). The cathode of an alkaline battery is composed of a mixture of manganese dioxide, potassium hydroxide and graphite. The potassium hydroxide is the electrolyte in an alkaline battery.
Granulate this mixture into a fine powder and press it into tablets. Insert the tablets into a steel can so that the combination of the tablet and steel form the battery's cathode.
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Soak a tube of paper in an electrolyte and insert it into the steel can. The paper will prevent the anode (positive electrode) and cathode from coming in contact with each other, while the electrolyte will allow the zinc and manganese dioxide ions to pass through the paper.
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Insert the anode into the steel can. The anode in alkaline batteries is a gel that consists primarily of powdered zinc. The battery now has an anode and cathode separated by a physical barrier that contains an electrolyte. This is the basic arrangement common to all batteries.
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Seal the battery. The seal consists of a brass nail, a gasket, a washer and a cap. Insert this assembly into the middle of the battery to collect the current from the cathode. Weld a metal lid to the other end of the battery to create an electrical contact to the anode.
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