Anodes and cathodes in batteries have different roles, although these reverse depending on whether they are charging or discharging. This can cause confusion among our readers, and so we decided to write this article. Batteries are becoming so very, very important, and this makes it essential that everybody understands how they work. Especially as there are inferior, counterfeit products on the market that we need to avoid.
Seven Things to Know About Anodes and Cathodes
- Oxidation reactions occur at anode electrodes, whereby they release their charged electrons.
- Reduction reactions occur at cathode electrons, whereby they receive those charged electrons.
- However, both these reactions occur at anodes and cathodes, depending on the mode the battery is in.
- Therefore, some battery scientists prefer to speak of positive and negative electrodes instead.
- In terms of this latter approach, the positive electrode has the higher potential of the two.
- When we discharge a battery the cathode is the positive electrode, while the anode is the negative.
- Whereas when we charge a battery, the anode becomes the positive while the cathode is the negative.
A Shallow Dive Into Oxidation and Reduction Reactions
An exchange of electrons between electrodes must occur for a battery to function. The oxidation and reduction are physically separate, unlike the process when iron metal rusts. If we insert an electrical device between those two reactions, then the electrons energize the device and it works.
We can reverse this process and charge a battery, by inserting a charger between the two electrodes, and sending electrons in the opposite direction. The two electrodes then reverse roles, as the electron transmitter becomes the electron receiver, and vice versa.
Cathodes and Anodes Open Pathways to Opportunity
We used batteries in flashlights at night in summer camps, when we were kids,. We also knew dad had a battery in his auto under the hood, but we were not allowed to touch it. Nowadays, of course, batteries are everywhere, including in kids’ toys for Christmas.
While we remember, may we remind you to be careful about giving toys to small kids with penny button batteries inside them. You know, those shiny discs like small silver coins. Small kids can mistake them for candy, pop them in their mouths, and swallow them while they are talking and laughing.
More Information
Standard Potentials for Half Reactions
How A Gain in Electrons is a Reduction
