Summary

In this activity, young students will build a simplified model of a lithium ion battery. The model will include “lithium ions” that can be observed moving between the cathode and anode. During the activity students will learn the difference between energy storage and energy conversion, and that batteries are amazing because they do both.

Grade Level

Elementary School

NGSS Alignment

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

• 4-PS3-2: Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents.
  
• 4-PS3-4: Apply scientific ideas to design, test and refine a device that converts energy from one form to another.
• 5-PS1-1: Develop a model to describe that matter is made of particles too small to be seen.
• Scientific and Engineering Practices:
  • Developing and Using Models

Objectives

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

• Identify the basic parts of a lithium-ion battery, including the cathode, anode, electrolyte, electrolyte additives, lithium ions given a simple model.
• Distinguish between the positive and negative electrodes of a battery using the vocabulary words “cathode” and “anode.”
• Observe that lithium ions move back and forth between cathode and anode during charging and discharging processes.

Chemistry Topics

This activity supports students’ understanding of:

• Electrochemistry
• Electricity
• Cathode
• Anode
• Energy
• Law of Conservation of Energy

Time:

• Teacher Preparation: ~ 1 hour (including shopping for supplies)

Lesson: ~45-60 minutes

Materials

• Small plastic canister, rectangular or cylindrical (approx. 4-5” tall)
  • Ex: Containers designed for storing sprinkles or spices
  • One per pair of students
  • This will represent the battery cell
• Silver-white sugar pearls
  • 1 bottle (2.5 oz) per ~30 students
  • These will represent the lithium ions
• Amber-colored, water-soluble cake glitter or sanding sugar
  • 1 bottle (5 oz) per ~30 students
  • To visualize electrolyte additives (one category is sulfones, amber-colored compounds)
• Water
• Colored paper
  • 1 piece per student
  • Only 1 color is needed. Cut into the same shape as the bottom of the plastic canister, but a bit larger so that it can be easily seen underneath the canister.
  • 1 piece per student
• 1 tsp measuring spoon
• 1/8 tsp measuring spoon
• Scissors
• Scotch tape

*Tip: The baking section of arts and crafts stores usually have all of these materials.

Safety

• No safety precautions need to be observed for this activity.

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”.
• This activity can be easily adapted to grade level (K-2 or 3-5) by varying the level of detail and complexity of discussion about lithium ion battery structure. Some suggested strategies include:
  • Complete the “Warm-Up” and “Key Concept” sections of the student handout as a class.
  • When using this with younger students, create the model drawing and label it as you build the model, rather than at the end.
  • Complete the empty portions of the table as a class, or provide the answers to the column, “In my model this part is:” in advance to help students make the connection.
  • More examples are provided in the script outline below.
• The amount of time needed to complete this activity will vary depending on the students age and ability to work independently, as well as the level of detail/complexity of discussion.
• The activity is designed for students to work in pairs; however students could work independently as well.
• An Answer Key document is included for teacher reference.

Activity Overview:

• The primary activity is for each pair of students to build a simple model of a lithium ion battery cell.
• Warm-up Exercise (complete on student handout):
  • Partner-brainstorm all the ways students used energy this morning.
  • Define energy conversion vs. energy storage:
    • Energy conversion: energy cannot be created or destroyed (law of conservation of energy), but it can change between different forms. Energy conversion is the changing of energy between different form(s). E.g. fire: chemical energy --> light + heat energyPartner-brainstorm all the ways students used energy this morning.
    • Energy storage: capturing energy and “holding” it so that it can be used at a later time when we need it.
  • Transition to talking about batteries by saying they are special (have “superpowers”) because they can both convert and store energy.

• Engage/Context:
  • What is a battery?
    • A container in which chemical energy is converted to electrical energy (and vice versa). It is also a container for energy storage because the energy is held (“the battery is charged”) so it can be used at a later time.
  • Battery backup systems are coupled to solar or other renewable energy sources and are an alternative to generators (which use fossil fuels).
    • Short video of battery cell manufacturing at Tesla (1:38):Tesla 4680 battery cell structural pack production
  • (Optional Resource) How Lithium-ion Batteries Work | Department of Energy
    • This page from the Department of Energy has a great interactive diagram of a lithium ion battery’s parts and animation of charging and discharging.
• Hands-on activity:
  • The table below corresponds to the procedures on the student handout.
  • It is designed to support teachers during each step of the activity, including definitions to emphasize, corresponding model photos, and differentiation ideas for various grade levels.

Teacher’s Guide (and script suggestions), Step-by-Step Photos, and Videos:

Pre-activity:

• What is a scientific model?
• Shows the different parts of a thing in nature or a tool made by humans to help us learn about how that thing/tool works.
• In the battery model we are making today, each piece is pretending to be a piece of a real battery. It won’t be exactly the same as a real battery, but it will still help us understand batteries better.

Step 1:

• Definition:
  • “Battery cell” is an object/container that holds all the parts of the battery. (grades K-2)
  • “Battery cell” is an object/container that holds all the parts of a battery, and it is where the battery chemistry happens. (grades 3-5)

• Do:
  • Provide each student (or pair of students) with one plastic canister. Define this as the battery cell.

Step 2:

• Definition:
  • “Electrodes” the pieces that connect the chemistry happening inside the battery to electrical circuits outside the battery so that the energy stored in the battery can be used in our devices.
  • Electrodes in lithium ion batteries are usually made of graphite (like in your pencils) and metals, (ex: lithium, nickel, cobalt, manganese).
  • 2 types of electrodes:
    • Anode (negative electrode)
    • Cathode (positive electrode)

• The anode and cathode are on opposite ends of the battery. You’ve probably noticed that batteries at home have a (+) end and a (-) end. In your model, the cap/lid of the canister is the cathode. The bottom of the canister is the anode. We will color code our electrodes to help us tell them apart.

• Do:
  • For the anode color: use a small piece of tape folded double-sided (see first photo) to attach a rectangular piece of colored paper to the bottom of the canister (see second photo).
  • For the cathode color: If the canister lid is colored, simply use it to distinguish the cathode. If not, repeat the process for anode but with a different colored piece of paper.
  • If desired, you can also label the electrodes (+) and (-).

Step 3:

• Definition:
  • “Electrolyte” is the liquid inside the battery cell that allows the lithium ions to move (“swim”) back and forth between the anode and cathode. (grades K-2)
  • “Electrolyte” is the liquid inside the battery cell that allows the lithium ions to move (“swim”) back and forth between the anode and cathode. It also allows the other chemicals that do the battery’s chemistry to “swim” and interact with each other inside the battery cell. (grades 3-5)
  • Electrolytes are typically clear liquids. We will use water in our model because it is also a clear liquid. Water damages real batteries, so this is one way that our model is not exactly the same as a real battery. The model is still useful because the water will allow our lithium ions to move inside our battery, just like real electrolytes do.

• Do:
  • Fill the canister with water up to about ¼ inch below the bottom of the cap/lid so that the surface of the water can clearly be seen when the canister is closed (see photo).

• *Note: once the “batteries” are full of liquid, there will be a risk of spills because some students knock their battery over. Try:
  • Taping the canister closed once all components are added.
  • Prompting students to keep their hands clasped and/or in their laps when a question is being asked/answered and then cueing them when to touch their battery models to do the next step.

Step 4:

• Definition:
  • “Electrolyte additive” chemicals added to the electrolyte to help the battery chemistry work better.
  • One type of electrolyte additive is a group of chemicals called sulfones, which have an amber color.
  • We will use amber-colored “cake glitter" for the electrolyte additive in our model.

• Do:
  • Add ~1/8 tsp of amber cake glitter to your electrolyte. Gently stir an allow to mix.

• Do not create a saturated solution; just add enough glitter to give the liquid an amber color.

Step 5:

• Definition:
  • “Charge carriers” are chemicals that move charge from end to end of a battery cell so that the battery can work.
  • “Lithium ions” are positively charged lithium atom and the charge carriers in a lithium ion battery.
  • Lithium is a silvery-white metal. We will use these silvery-white “pearls” (show the bottle to the students) as the lithium ions in our model.
  • We expect to see some of our lithium ions at the cathode (top) and some at the anode (bottom). We also expect to see some of them move (slowly) between the cathode and anode, because this is what happens during the processes of charging and discharging the battery.

• Energy conversions:
  • Charging the battery (electrical energy to chemical energy) Energy is stored in between charging/discharging.
  • Discharging ("using”) the battery (chemical energy to electrical energy)

• Do:
  • Add ~1 tsp cake decorating "pearls" to your electrolyte.No need to mix. The pearls are sugar and wax so some will remain at the water's surface, some will sink to the bottom (see video), and some will move between the two.

• Explain that real lithium ions dissolve in the electrolyte, but that the model ions do not fully dissolve because that allows us to watch them move inside our battery cell. Remind students that not all parts of a model will be exactly like the real thing, but they can still help us learn about the real thing.

*Note: If the “lithium ions” do not oscillate between the surface and the bottom of the water, you can still talk about the ions’ role to move back and forth between the electrodes, as well as how when a battery is fully charged or discharged, the lithium ions will all be at the anode or cathode, respectively.

Step 6:

• Do:
  • Engage students in making observations, completing the “observations” and “making connections section of the student handout, and asking questions about structure and function, batteries, charging/discharging, etc.

*Note: the sugar component of the pearls will dissolve in the water, so the oscillating movement in the model will be time-limited (approx. 10-15 minutes).

Conclusion:

• Reflection prompt: What’s one way you now think differently about batteries compared to what you thought yesterday?
• (option) Short video from ReVision Energy featuring children (1:00) Electricians Will Save the World