Lithium Ion Batteries – Recycling (Science Box Experiment 7)

As part of CoCoMAD, Royal Society of Chemistry have funded science boxes which are being distributed to local school children - however - the experiments are available online for anyone to take part!

Below you’ll find the experiment introductions, equipment list, method, questions to explore and - very important - health and safety information.

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Introduction

Introduction

Lithium ion (Li-ion) batteries are a rechargeable-type of battery which have become a staple in modern-day life and are used in mobile phones, laptops and, in more recent times, electric vehicles.

However, recycling Li-ion batteries at the end of their lives, is a challenging problem as they contain lots of different materials. Because of this they are often shredded before recycling to help separate the different materials.

This activity builds on Experiment 6 (Separation Science – Recycling) by looking at the separation of materials in shredded Li-ion batteries by using their different material properties. Below is how materials in this experiment compare to those in Li-ion batteries:

Iron filings represent metal oxides used In the cathode - Cobalt has magnetic properties, and magnetic separation can potentially be used to separate different cathode chemistries based on their magnetic properties.
Aluminium foil represents electrode foils inside a battery - In reality both aluminium and copper are used as the electrode foils in Li-ion batteries.
Polystyrene beads represent separators in the packaging of cell pouches - Lightweight plastics are chosen for the activity as they will float in water allowing them to be separated
Sugar represents electrolytes - through which the electrons flow between electrodes - The sugar will dissolve in the water and represents the chemicals which may be used in as the electrolyte. This is left behind after all of the other components have been separated.

Equipment List

Iron filings
Aluminium Foil
Polystyrene beads (or shredded plastic recycling such as milk bottles
Sugar
1 x small sieve
1 x tall container / measuring jug
1 x magnet (e.g. fridge magnet)
Water

What to Do

IT IS IMPORTANT THAT YOU HAVE READ THE HEALTH AND SAFETY SECTION BEFORE CARRYING OUT THE ACTIVITY – THE ROYAL SOCIETY OF CHEMISTRY, FRIENDS OF COTTERIDGE PARK OR THE DEVELOPER DO NOT ACCEPT ANY LIABILITY

Mix the water, sugar, iron fillings and polystyrene beads in the tall container (you need to have room to sieve out of the less dense material) – How can you separate the different materials?
Using a small sieve or tea strainer it should be possible to fish the materials from the top leaving the metal the bottom of the container.
Now it is time to start separating the metals from the liquid – how might this be done?
Wrap a magnet in cling film (to make it easier to remove the iron fillings from the magnet) to separate the two metals.
Once the filings have been removed the remaining shreds of “electrode foil” can be separated from the electrolyte solution by passing the mixture through a sieve into a separate container.

Things to think about

Are all of the materials completely separated or is there still some unseparated material? What does this say about the recycling process (is the recycled material pure?)

How might we separate these materials more efficiently? Write down your ideas.

Repeating the recycling process will further refine the materials and improve the quality of the recycled material. Does this mean that companies keep repeating the separation cycle until they get a pure product?

Health and Safety
(remember to always use common sense)

Risk(s) & Precaution(s)

Cuts (due to sharp edges on metal foils)
Be careful when handling the tin foil.
Getting fine iron filings in the eyes or ingestion
Be careful when handling the iron filings, and wash your hands thoroughly before eating or drinking.
Slips on spilled water
Set the experiment up so that any spilt water will be contained (e.g. in a tray or sink).
Clean up spills immediately.

Where can I learn more?

For more about Lithium Ion Batteries, the Faraday Instiution’s “Fully Charged STEM Battery Box”: https://faraday.ac.uk/stem-battery-box/
Read more about recycling Lithium Ion Batteries: https://faraday.ac.uk/research/lithium-ion/recycle-reuse/
Duracell’s Big Battery Hunt (how to recycle different types of batteries):
http://nationalschoolspartnership.com/initiatives/bigbatteryhunt

Feedback

We really hope you enjoy the experiments and would love your feedback on the activities and on the science activities and talks at Virtual CoCoMAD (4th July).

To send feedback please use the QR code or the link below to get to the feedback form which will probably take about five minutes to complete. If you do you will be invited to leave your email address and you will be entered into a draw to win a pack of RSC Periodic Table Top Trumps.