Making a Battery Author(s): Mark Walsh, Kevin Kimura, Albert Park Date Created: June, 2014 Subject: Chemistry Grade Level: 6­12 Standards: ​
Next Generation Science Standards (w
​ww.nextgenscience.org)​
MS­ETS1­4. ​
Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved. HS­PS3­3. ​
Design, build and refine a device that works within given constraints to convert one form of energy into another form of energy. Schedule: 2 to 3 ­ 40 minute lessons CCMR Lending Library Connected Activities: Forms of Energy Electroplating Electromagnets - 1 – Objectives: Students will learn about chemical reactions and how they can create an electrical current. They will construct a battery and test to see how variables affect its strength. Students Will: * Observe the anatomy of dry cell battery and learn how it works. * Make a wet cell battery. * Experiment to find out which combination of electrodes or which type of electrolyte produces the most voltage. * Learn how to measure voltage with a multimeter. *Learn about the changes in energy. Safety Vocabulary: Battery Dry Cell Wet Cell Electrode Anode Cathode Electrolyte Voltage Circuit Materials: For Class: 1 Dry cell battery (cut open) For Each Group: 1 Plastic cup 2 Wires w/alligator clips 1 multimeter Electrolyte solutions Electrodes Do not let students touch the electrolyte in the dry cell battery. Be careful if using hydrochloric or sulfuric acid. Science Content for the Teacher​
: How do batteries work? Electricity, as you probably already know, is the flow of electrons through a conductive path like a wire. This path is called a ​
circuit​
. Batteries have three parts, an ​
anode​
(­), a ​
cathode​
(+), and the ​
electrolyte​
. The cathode and anode (the positive and negative sides at either end of a traditional battery) are hooked up to an electrical circuit. The chemical reactions in the battery causes a build up of electrons at the anode. This - 2 – results in an electrical difference between the anode and the cathode. You can think of this difference as an unstable build­up of the electrons. The electrons wants to rearrange themselves to get rid of this difference. But they do this in a certain way. Electrons repel each other and try to go to a place with fewer electrons. In a battery, the only place to go is to the cathode. But, the electrolyte keeps the electrons from going straight from the anode to the cathode within the battery. When the circuit is closed (a wire connects the cathode and the anode) the electrons will be able to get to the cathode. In the picture above, the electrons go through the wire, lighting the light bulb along the way. This is one way of describing how electrical potential causes electrons to flow through the circuit. However, these electrochemical processes change the chemicals in anode and cathode to make them stop supplying electrons. So there is a limited amount of power available in a battery. When you ​
recharge​
a battery, you change the direction of the flow of electrons using another power source, such as solar panels. The electrochemical processes happen in reverse, and the anode and cathode are restored to their original state and can again provide full power.1 Batteries that you use are called dry cell batteries. This is because the electrolyte is a paste. You are going to make a wet cell battery, which means that the electrolyte is a liquid. 1
"How do batteries work?." 2005. 4 Jun. 2014 <​
http://www.qrg.northwestern.edu/projects/vss/docs/power/2­how­do­batteries­work.html​
> - 3 – Classroom Procedure​
: Formative: Have the students follow​
Activity Sheet 1​
to build a wet cell battery and do some testing about the electrolyte and electrodes. ● Note ­ There will not be much difference in voltage between the saltwater and distilled water. This is because the distilled water has ions in it. To show the class a difference, use an organic solvent, such as acetone, to test. It is recommended that you do this only as a class demo. Have students visit the following website to watch the video and/or read about how a battery works: ​
http://mocomi.com/how­do­batteries­work Show the students a dissected dry cell battery and talk about how it works. Have students follow ​
Activity Sheet 2​
to plan, perform, and evaluate an experiment looking at how a variable affects the strength (voltage) of a wet cell battery. Have them make a list of variables (type of electrodes, type of electrolyte, concentration of electrolyte, distance between electrodes), then discuss as a class before having them choose one. They will then plan and run their experiment. Summative: Have a competition to see who can build the strongest (voltage) wet cell battery. They will then answer some questions about their battery and batteries in general on ​
Activity Sheet 3​
. - 4 – Assessment​
: The following rubric can be used to assess students during each part of the activity. The term “expectations” here refers to the content, process and attitudinal goals for this activity. Evidence for understanding may be in the form of oral as well as written communication, both with the teacher as well as observed communication with other students. Specifics are listed in the table below. 1= exceeds expectations 2= meets expectations consistently 3= meets expectations occasionally 4= not meeting expectations Engage Explore Explain 1 Shows leadership in the discussion and activity, displays good understanding of how a battery works. Completes work accurately while providing an explanation for what is observed. Works very well with partners. Provides an in­depth explanation of findings. Makes excellent and thoughtful comparisons to everyday life. Completes activity sheet and lab report. 2 Participates in the discussion and activity; shows an understanding of how a battery works.. Completes work accurately and works cooperatively with partners. Provides clear explanation of findings. Notes good correlations to everyday life. Completes activity sheet and lab report. 3 Contributes to the discussion and activity, but shows little understanding of how a battery works. Works cooperatively with partners, but makes some mistakes with the procedure. Provides a limited explanation of findings. Struggles to make comparisons to everyday life. Completes some of the activity sheet and lab report. 4 Does not participate in discussion or activity. Shows no understanding of how a battery works.. Has trouble working cooperatively. Work is not completed.. Provides no explanation of findings and does not make comparisons to everyday life. Does not complete activity sheet or lab report. Other Resources: "How do batteries work?." 2005. 4 Jun. 2014 - 5 – <​
http://www.qrg.northwestern.edu/projects/vss/docs/power/2­how­do­batteries­work.html​
> Other Activities: "Wet Cell Battery out of Food ­ Instructables." 2013. 4 Jun. 2014 <​
http://www.instructables.com/id/Wet­Cell­Battery­out­of­Food/​
> "Penny and Nickel Battery ­ Instructables." 2007. 4 Jun. 2014 <​
http://www.instructables.com/id/Penny­and­Nickel­Battery/​
> - 6 –