Electrochemistry Made Simple at the MINT Festiva Jena

At this year  MINT Festival, our team demonstrated the basics of electrochemistry, the science behind how batteries work. We started from introducing  simple experiments and moving toward modern battery technologies.

We began with the Finger Battery. In this experiment, copper was paired with metals such as zinc, aluminum, stainless steel, and connected to a voltmeter. When the kinds touched both metals, the moisture and salts in the skin acted as the electrolyte, producing a small but measurable voltage.

Next, we used the same idea but instead of touching the metals we used vinegar as the electrolyte. The audience compared how much voltage different metal pairs could produce. The copper–zinc combination showed the highest voltage, making it clear that both the choice of metals and the electrolyte are important in a battery.

After these hands-on activities, we introduced new concepts. We explained polymer-based batteries, which use redox molecules to store energy, and presented the idea of a redox flow battery (the Zn–TEMPO system). Unlike regular batteries, these store energy in liquids and are promising for large-scale renewable energy storage. The key message we shared was simple: all batteries, from a “finger-powered cell” to the most advanced designs, work on the same principle  a chemical reaction that moves electrons from one material to another.