Electric current in a battery is produced through a chemical reaction known as an electrochemical reaction. Batteries are devices that store and convert chemical energy into electrical energy. They consist of two or more electrochemical cells connected in series or parallel, and each cell contains two electrodes (usually made of different materials) immersed in an electrolyte solution.
Here's a basic explanation of how electric current is produced in a battery:
Electrodes: The battery has two electrodes – a cathode (positive electrode) and an anode (negative electrode). These electrodes are typically made of different materials, with each having a specific role in the chemical reaction.
Electrolyte: The electrolyte is an ion-conducting medium that separates the two electrodes. It allows ions (charged particles) to move between the electrodes while preventing the direct contact of the cathode and anode.
Chemical Reaction: When the battery is connected to an external circuit (such as a device or an appliance), a chemical reaction occurs between the materials of the electrodes and the electrolyte.
Oxidation-Reduction (Redox) Reaction: At the anode, a process called oxidation occurs. Here, the anode material loses electrons and turns into positively charged ions. These ions then migrate into the electrolyte.
Flow of Electrons: Simultaneously, at the cathode, a reduction process takes place. The cathode material gains the electrons that traveled through the external circuit from the anode, creating negatively charged ions in the process.
Electron Flow in the Circuit: The flow of electrons from the anode to the cathode through the external circuit creates an electric current, which can be used to power various devices.
Ion Movement: Within the battery, ions from the anode and cathode move through the electrolyte to balance the charge. This ion movement within the battery is essential to maintain the flow of electrons in the external circuit.
This electrochemical reaction continues until one or both of the electrodes' active materials are depleted, at which point the battery will no longer produce an electric current and will need to be recharged or replaced. Recharging a battery reverses the chemical reactions, allowing the active materials to regain their original states and restoring the battery's ability to produce electric current again.