Summary

In this lesson, students will learn how oxidation and reduction reactions work in a rechargeable battery. They will then build a simple rechargeable battery and test it to determine the strength of the battery.

Grade Level

High School

NGSS Alignment

This lesson will help prepare your students to meet the performance expectations in the following standards:

• HS-PS2-6: Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.
• HS-PS3-3: Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy.
• Scientific and Engineering Practices:
  • Developing and Using Models
  • Analyzing and Interpreting Data
  • Planning and Carrying Out Investigations

Objectives

By the end of this lesson, students should be able to:

• Define reversible reactions.
• Understand the application of reversible reactions in rechargeable batteries.
• Apply their understanding of oxidation and reduction reactions to rechargeable batteries.
• Calculate the oxidation numbers for each atom in a given example.
• Build a simple rechargeable battery.

Chemistry Topics

This lesson supports students’ understanding of:

• Electrochemistry
• Redox Reactions
• Oxidation
• Reduction
• Reversible Reactions
• Batteries

Time:

Teacher Preparation: 30 minutes
Lesson: 60-90 minutes

Materials

• Student handout

Per lab group:

• 0.5 M sodium chloride solution
• polyurethane adhesive (i.e. Elmer’s glue)
• one 15 cm x 15 cm piece of aluminum foil
• one x 0.5-inch by 3-inch copper plate
• pre-cut PVC piping (1-inch wide, ~2inches in length)
• Paper towel
• Multimeter

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.
• Sodium chloride solution SDS.
• Use Caution! The rechargeable battery may generate 1-1.5V, please make sure to wrap the cylinder with PVC pipe to minimize risk of potential electrical shock.

Teacher Notes

• This activity was created to support the celebration of Chemists Celebrate Earth Week (CCEW), and the 2024 theme, “Batteries: Get a Charge out of Chemistry”.
• Teachers can prepare 0.5 M sodium chloride solution by mixing 29.22 g of sodium chloride solution in 1.0L water.
  • Note that teachers can modified the solution to instead use or test other salts such as potassium chloride, or calcium chloride.
• The PVC pipes should be precut, enough for one per group. Each PVC pipe should be 1-inch wide, cut to 1.5-2 inches long (note that a hardware store will typically cut the piping for you).
• Copper typically comes in large sheets and will need to be cut to 0.5-inch by 3-inch pieces (note that this can also be done at the hardware store).
• Refer to the Answer Key document for guidance.
• Timing is suggested but should be adjusted based on student ability and teacher schedule.

Lesson Overview:

• Introduction to reversible reactions (~5 minutes):
  • Teacher defines reversible reactions and asks students to identify a list of reversible and non-reversible reactions such as formation of water and breaking down of water.
• Review of oxidation and reduction reactions (~5 minutes):
  • Part 1 and 2 of student handout is completed by students, teacher helps students to review oxidation and reduction reactions (ex. “OIL RIG” or “LEO GER”) and provides a list of species in the student handout to ask students to identify which ones are redox, and which ones are not redox reactions.
  • Possible extension: teacher asks students to identify oxidizing and reducing agents from the chemical equations.
• Application of redox on cathodes and anodes of batteries (~10 minutes):
  • In Part 3 of the student handout, teacher provides students the structure of a battery. It consists of a cathode and anode; both typically are made of metals placed in a solution of ions. These free flowing ions allow electricity to be passed through.
• Reversible reactions in rechargeable battery (~5 minutes):
  • In Part 3 of the student handout, teacher connects reversible reactions with batteries, explaining that due to the nature of reversible reactions, reactions on cathode and anode must be reversible, that ensures electrons to be lost and gained over time, allowing “charge” to be built up and released over time.
  • Teachers can use the AACT Galvanic Cell Animation to illustrate oxidation and reduction reactions on anode and cathode respectively.
• Building the rechargeable battery (~25 minutes):
  • Teacher provides each group (2-3 students per group) with equipment to build the rechargeable battery. The full procedure steps can be found on the student handout. A sketch is also available on the student handout to help guide the students in their construction.
  • Be sure to use caution! The rechargeable battery may generate 1-1.5V, please make sure to wrap the cylinder with PVC pipe to minimize risk of potential electrical shock.
• Test the battery (~10 minutes):
  • Teacher provides students with a multimeter to test and record the strength of their batteries.
• Discussion questions (~10 minutes):
  • Teachers can ask groups of students to discuss the provided questions to extend students’ thinking on efficiency of a battery.
  • Additionally, it might be fun to track what makes a battery’s output stronger.
• Optional Extension (~10 minutes):
  • As an extension activity, you can recharge the battery by connecting the anode to the positive terminal of the battery pack and the cathode to the negative terminal of the battery pack. The battery pack should be set to 5A and 3V.