- Carbon rods are commonly used as the positive electrode (cathode) in dry cell batteries.
- The carbon rod is surrounded by a mixture of manganese dioxide (MnO2), carbon black, and other conductive materials to enhance its surface area and conductivity.
2. Current Collector:
- The carbon rod serves as a current collector, allowing electrons to flow from the manganese dioxide mixture to the external circuit when the battery is connected to a load.
3. Depolarizer:
- In dry cell batteries, the manganese dioxide surrounding the carbon rod acts as a depolarizer.
- When the battery discharges, the manganese dioxide reacts with hydrogen ions (H+) produced during electrochemical reactions, preventing the buildup of hydrogen gas and maintaining the battery's voltage.
4. Electrical Connection:
- The carbon rod provides an electrical connection between the internal components of the battery and the external circuit.
5. Structural Support:
- The carbon rod helps to maintain the structural integrity of the dry cell battery by providing support to the internal components.
6. Long Shelf Life:
- Carbon rods contribute to the long shelf life of dry cell batteries by preventing self-discharge and maintaining their voltage over extended periods of time.
Overall, carbon rods play a crucial role in dry cell batteries as cathodes, current collectors, depolarizers, electrical connectors, and structural support elements, ensuring efficient electrical energy generation and long-term battery performance.
