An alkaline battery is a type of primary battery (non-rechargeable) that uses an alkaline electrolyte, typically potassium hydroxide.
Alkaline Battery
Composition:
Anode: The anode (negative electrode) of an alkaline battery is typically made of zinc powder, which reacts with the hydroxide ions (OH⁻) in the electrolyte.
Cathode: The cathode (positive electrode) is made of manganese dioxide (MnO₂) mixed with graphite and an electrolyte paste. This mixture facilitates the reduction reaction during discharge.
Electrolyte: Alkaline batteries use a potassium hydroxide (KOH) electrolyte, which is a strong alkaline solution. This electrolyte facilitates ion transport and the chemical reactions within the battery.
Operating Principle:
During discharge, zinc at the anode oxidizes to zinc ions (Zn²⁺) and releases electrons.
Electrons flow through the external circuit to the cathode, where manganese dioxide is reduced by gaining electrons and reacting with the hydroxide ions from the electrolyte to form water and manganese oxide.
The overall chemical reaction is:
Advantages:
Higher Energy Density: Alkaline batteries typically have a higher energy density compared to zinc-carbon batteries, providing longer-lasting power.
Longer Shelf Life: They have a longer shelf life and better performance in high-drain devices compared to zinc-carbon batteries.
Environmentally Friendly: They are less harmful to the environment compared to some other battery chemistries.
Applications:
Alkaline batteries are commonly used in various consumer electronics such as remote controls, flashlights, portable radios, toys, and digital cameras.
They are also used in medical devices, portable tools, and other applications where a reliable and long-lasting power source is required.
Disposal:
Alkaline batteries are considered safe for disposal in most jurisdictions because they do not contain heavy metals like mercury or cadmium (unlike some older battery types).
Recycling programs exist for alkaline batteries to recover materials like zinc, manganese dioxide, and steel casing.
Alkaline batteries are widely used due to their reliable performance, long shelf life, and versatility in powering various electronic devices. They are a popular choice for both household and industrial applications where a cost-effective and efficient power source is needed.
