adminPRIMARY BATTERIES
Primary batteries also known as disposable batteries are non-rechargeable batteries. In primary batteries the electrode reactions are not reversible i.e. applying the external electric energy will not reconstruct the electrodes hence the cells are not rechargeable.
There are several types of primary batteries and they are as follows; alkaline, zinc carbon, lithium and mercury primary batteries.
Alkaline batteries use a chemical reaction between zinc and manganese dioxide to generate electricity.
Zinc-carbon batteries use a chemical reaction between zinc and carbon to generate electricity.
Lithium batteries use a chemical reaction between lithium and other materials to generate electricity.
Mercury batteries use a chemical reaction between mercury and other materials to generate electricity.
The components of a primary battery are as follows; anode (negative terminal), cathode (positive terminal), electrolyte, separator, current collectors, terminals and jacket or casing.
The anode is the negative terminal of the battery. It is typically made of zinc (Zn) or lithium (Li). It is the site where chemical reactions occur releasing electrons.
The cathode is the positive terminals of the battery. It is typically made of manganese dioxide (Mno2) or other materials. It is the site where chemical reactions occur absorbing electrons.
The electrolyte is a chemical substance that facilitates the flow of ions between the anode and cathode. It is typically liquid or gel like substance such as potassium hydroxide (KOH) or ammonium chloride (NH4Cl).
The separator is a thin porous material that separates the anode and cathode preventing electrical shorts and ensuring the battery operates safely.
The current collectors are conductive materials that collect electrons from the anode and cathode allowing them to flow through the external circuit.
The terminals are the metal contacts on the battery that connect to the external device allowing the battery to power the device.
The jacket or casing is the outer casing of the battery. It is typically made of metal or plastic which protects the internal components and provide structural strength and integrity.
The advantages of primary batteries are as follows; primary batteries are widely available and easy to use. Primary batteries are often less expensive than rechargeable batteries. Primary batteries are reliable and provide consistent voltage. Primary batteries have a long shelf life and can be stored for extended periods.
The disadvantages of primary batteries are as follows; primary batteries contribute significantly to waste and pollution. Primary batteries have limited energy density which means they may not provide enough power for high drain devices. Primary batteries are disposable and cannot be recharged.
Primary batteries find extensive applications in the following; primary batteries are used in flash lights, toys, remote controls and other household devices. Primary batteries are used in medical devices such as pacemakers, hearing aids and insulin pumps. Primary batteries are used in industrial applications such as sensors, alarms and emergency lighting. Primary batteries are used in military applications such as communication devices and navigational systems.
The future of primary batteries is based on the advances and development of the following technologies; the development of mercury free batteries is becoming the norm to reduce environmental pollution. Lithium iron disulfate batteries are being developed as a more environmental friendly alternative to lithium batteries. Advances in the use of sustainable materials in primary batteries are ongoing such as biodegradable electrolytes and recyclable components. Development work is ongoing to increase the energy density of primary batteries to make them suitable for high drain devices.
SOURCES:
- Batteries in a portable world: A handbook of batteries by Isidor Buchmann.
- Hand book of batteries by David Linden and Thomas Reddy.
- Primary batteries by C.A Vincent and B, Scrosati.
- Batteries and energy storage: Technology and applications by Paul T. Moseley and J. Garche.
- Electrochemical power sources: primary and secondary batteries by S.S. Dhere and S, M. Joshi.
