Rechargeable battery diagram convention

 

Battery_Charge_Discharge

Battery Diagram Convention

This diagram of a battery is an approach for a widely used battery diagram convention. During previous literature research, I couldn’t find a valid accessible version of a battery diagram and after comparing various articles and talking to other scientists, I developed the diagram above as a visual convention. I hope it helps others to grasp the convention more easily.

Discharge

In this diagram, for the discharge, the anode material is oxidized whereas the cathode material is reduced (obeying the definition for anodes and cathodes in a galvanic cell). Following to this, the electrons flow from anode (-) to cathode (+). I am personally remembering this case by the mnemonic “OMA” (Dutch and German for grandmother / granny; my grandmothers are really active and give off a lot of energy as it do galvanic cells / batteries). As the anode is loosing its electrons, it is attracting anions and other way round for the cathode.

Charge

During the process of charging, a voltage is applied and the electrons move in the other direction (but be careful that (-) and (+) stay at the same sides because the electrons move now in the direction they left from before). Although now the left electrode is reduced and the right electrode oxidized, what would also require a switch of anode and cathode, anode and cathode stay for the convention the same. If one would change the sides, as a scientist one could not easily talk about anodes and cathodes anymore because they would depend on the state of the battery (charge vs. discharge)! Because primary batteries (cannot be recharged) were discovered before secondary batteries (rechargeable), one keeps the anode and cathode definition for the discharge (and inverses it for the charge).

Usage

Please feel free to use this battery convention (including the battery convention diagram illustration) if it is helpful for you and I would be thankful for a notification  where you used it.  If you want to use this text or illustration in a commercial manner, please contact Storage4 in beforehand.

Remarks – This article only reflects the authors opinion. Please give feedback through comments or mail how to improve / make it easier understandable, spelling, content, other errors etc. This is part of Storage4′s initiaive to create a dialogue on the fascinating field of batteries.

Author – Simon Engelke, MaastrichtScience Programme, Maastricht University, Maastricht, Netherlands, Email: s.engelke@student.maastrichtuniversity.nl