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| BATTERY F.A.Q. |
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| How does a battery work? |
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When you switch on a device like a flashlight, the electric circuit completes and electric currents in the form of electrons power the bulb. That happens because the anode material, zinc (Zn) gives up two electrons (e-) per atom in a process called oxidation. This process leaves unstable zinc ions (Zn2+) behind. (An ion is an atom that has gained or lost electron(s) so it has a positive or negative charge.)
After the electrons do their stuff and power the light bulb, they re-enter the battery at the cathode. There they combine with the active material, manganese dioxide (MnO2), in a process called reduction.
Oxidation and reduction could not occur in a battery without a way to carry electrons back to the anode after they enter the cathode. Here's where the electrolyte comes in.
After each electron enters the cathode, it reacts with the manganese dioxide to form MnOO-. Then the MnOO- reacts with water in the electrolyte solution. The water splits to hydroxide ions (OH-) and hydrogen ions (H+) that combine with MnOO- to form MnOOH. The hydroxide ions flow to the anode in the form of an ionic current.
There, they combine with unstable zinc ions which had given up their electrons to power the light bulb. The reaction produces zinc oxide (ZnO) and water (H2O). This completes the circuit (which is necessary to have a constant flow of electricity) and powers your flashlight.
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