Use an aluminum plate/salt water, and water to construct a portable power supply strong enough to power a small motor or light.
Tools and Materials
Aluminum plate/40gsalt
self-charging power devices
Stick
cup
Water 380ml
KOH powerder 1bag
Pour the electrolyte into the water and stir until the electrolyte is completely mixed. operation video:https://youtu.be/2qP16d4u7XY
What’s Going On?
Batteries convert chemical energy into electrical energy. They have two electrodes—called a cathode and an anode—where chemical reactions that either use or produce electrons take place. The electrodes are connected by a solution—called an electrolyte—through which ions can move, completing an electrical circuit. In this activity, the salt provides ions that can move through the wet paper towel and transfer charge.
The aluminum plate provides an affordable supply of aluminum.
Teaching Tips
The self-charging power devices are available at www.wehometool.com.
This activity demonstrates oxidation and reduction reactions—integral parts of battery chemistry. The use of atmospheric oxygen as the oxidizing agent has extensions to other redox reactions that occur in corrosion, metabolism, and combustion. In addition, the participation of oxygen as a reactant in the aluminum–air battery can be used to introduce the concepts of fuel cells and alternative energy sources.
Related equations
Magnesium-aluminum battery (negative electrode - AI, positive electrode - Mg electrolyte KOH)
Negative electrode (Al): 2AI+8OH-- 6e-= 2AIO2-+4H2O (oxidation reaction)
Positive electrode (Mg): 6H2O +6e- = 3H2↑+6OH- (reduction reaction)
Chemical equation: 2AI+2OH-+2H2O =2AIO2-+ 3H2