Battery Lab: Light It Up!¶

Welcome to the Battery Lab, where you become an electrical engineer and materials scientist in one! In this hands-on demo, you'll use simple materials to build your own working battery — and understand the science behind every spark.

What You'll Learn¶

How batteries store and deliver energy
The role of materials in electrochemistry
How to measure and amplify voltage
How real MSE researchers at UM are improving battery tech

Supplies Checklist¶

Flexible ice cube tray
Salt (KCl or NaCl)
Water
Copper wire (cathode)
Aluminum wire (anode)
Multimeter + alligator clips
Beaker or mixing cup
Optional: LED

Materials overview — Your materials: common, cheap, and ready to shine.

Question

Why are we using copper and aluminum wires? What might they contribute to our battery?

⚡ What is a Battery?¶

A battery converts chemical energy into electrical energy through a redox reaction:

Oxidation: At the anode, metal atoms lose electrons
Reduction: At the cathode, metal ions gain electrons

Galvanic cell — Electrons flow from aluminum (anode) to copper (cathode) through the wire.

We use an electrolyte (salt water) to let ions move between electrodes and keep the charge balanced.

Question

What would happen if we didn’t include the electrolyte?

Step-by-Step Assembly¶

Step 1: Mix the Electrolyte¶

Stir 5 g of salt into 60 g of water
Use warm water for faster dissolving

Step 2: Fill and Insert Electrodes¶

Fill one well of the ice cube tray with solution
Insert Al wire (–) and Cu wire (+), not touching each other

Filled tray — A single-cell saltwater battery setup.

Step 3: Measure Voltage¶

Connect the multimeter using clips
Select DC Voltage (VDC)
Record your result (~0.8 V is typical!)

Multimeter reading — Voltage measurement with aluminum and copper.

Question

What happens if you swap the multimeter leads?

Switch It Up¶

Try different cathodes:¶

Graphite (from pencils)
Steel wire
Brass sheets

Electrode options — Explore how materials affect battery performance.

Build a Multi-Cell Battery¶

Use 3 + tray wells with electrodes
Connect them in series: Al→Cu, Al→Cu…

Multi-cell setup — Series connection boosts voltage. Each cell adds ~0.8 V.

Question

If 1 cell = 0.8 V, how many cells to power a red LED (2.0 V)? A blue LED (3.2 V)?

💡 Let’s Light It Up¶

Try powering:
- Red LED (~2 V)
- Green or blue LED (~3 V)
- Maybe even a motor if you’re ambitious!

LED lit up — Did your battery light an LED?

Challenge

Try powering a small DC motor. Can you design a battery strong enough?

Science Behind It¶

Half Reactions:¶

Anode: Al → Al³⁺ + 3 e⁻
Cathode: Cu²⁺ + 2 e⁻ → Cu

Activity series — The farther apart two metals are on this chart, the higher the voltage.

MSE Research at UM¶

Laser patterning — UM MSE researchers engineer faster-charging batteries using lasers!

Real Topics UM Students Explore:¶

Fast-charging battery electrodes (Dasgupta Group)
Single-particle battery analysis (Li Group)
Safer, more sustainable materials

Become an MSE Engineer¶

Classroom demo — Students testing their hand-built batteries in action.

Design Challenge:¶

Can you power a motor requiring ~4–6 V at 60 mA?

Try: - Larger electrodes (more surface area = more current)
- More cells in series
- Better conductive materials

Reflection

What factors limited your battery performance? How might a real engineer overcome those limits?

Summary¶

You built a real battery.
You experimented like a scientist.
You designed like an engineer.

What will you power next?

For more MSE demos, head back to the Outreach Homepage.