Hello,
I am a graduate student studying in the NC state. For my research, I need to open a 18650 LiFePO4 commercialized batter as below.
I already open the top cap. But I don’t know how to open the cylinder case to pull out the rolled material.
Could someone having experince on this give me some advice?
Is there anything I need to be careful for not causing fire?
Thank you for your help.
Well, I hope you discharged the cell before that?
If you cant pull it out already, you could try removing the bottom too. Should be easier than opening up the whole case if you have a Dremel or similar (be careful with heat though).
Thank you. The battery is fully discharged (0~0.5 V) before I open it. Do you mean it will be easier to pull it out from the bottom? The clearance b/w the case and rolled material is very small.
In what case there will be sparks and causing fire?
At this point it would be very hard to cause a fire since it is fully discharged. :) As for how to get the roll out, you would most likely need to pull off both ends of the battery. Be careful with this thing though.
Oh wow, this should be fun. Lithium really really doesn't like water, water makes it very angry. Moisture in the air is enough to get it going. When it starts getting hot and you panic, DO NOT toss it into a bucket of water or the toilet. I'd recommend only doing this outdoors.
Oh, and I suggest having a video camera running when you unroll it. For, uh, science. Yeah, purely for the science. Most definitely not for the entertainment value.
The cathod is not pure Lithium metal. It’s LiFePO4. So it should be much more stable.
But thanks for your reminding, I will keep it away from contacting water. I will see if I can have my friend help video the whole process.
Anyone knows what is the material of the green part (out most layer) as shown in the picture and what’s its purpose?
If you charge up the cell to around 10 volts, it will probably open itself up… very spectacularly! J)
And rechargeable lithium cells do not contain metallic lithium (unless they have been damaged). The lithium is usually in the form of lithium carbonate.
Interesting!
+1 for a video
The roll is atteched at both ends, so you need to cut off the other end too. Dremel around the end lightly until the cap comes off, then the roll should slide out. When you have it out, can you post another pic or two? I’d be interested in seeing the roll and I don’t want to tear one apart. 