I came across the regime they put cells through which I’d never seen before.
What current would “ ~15 mA cm−2 ” be for an 18650 or 26650?
Or is it just the heat that is the healer and could externally heat them?
I came across the regime they put cells through which I’d never seen before.
What current would “ ~15 mA cm−2 ” be for an 18650 or 26650?
Or is it just the heat that is the healer and could externally heat them?
Unfortunately, we can’t use these research results.
That paper is about lithium-metal sulfur cells, not the lithium-ion graphite cells we use.
Never heat a cell!
I’ve read of similar methods with other lithium chemistry
Lithium-ion or lithium-metal?
People heat lipos often just before using them for better performance
Done with different lithium battery chems:
The heating of LiPo’s (or any other types of li-ion cells) lowers the internal resistance and can give you better performance. Though probably at the expense of cycle life. We can do the same for our cells too.
That is different from the topics of these papers though.
Those other papers also talk about li-metal anode cells and not the li-ion graphite anode cells we use. Dendrite formation is a big issue with li-metal cells. It’s just not much of an issue for us unless the cells are spectacularly abused.
There’s no metallic lithium in our li-ion cells to start dendrites. Any dendrites in our cells has to come from LOTS of abuse that causes lithium to plate out and then to eventually grow dendrites.
They’re talking about lithium ion cells.
Re-read the first few paragraphs of your third paper.
There’s many papers out there where they use ion cells.
I’d love to read a few if you had the time to post those links.
Please don’t think I’m putting down your post! It’s just that we can’t use that method for the cells we use. Those experiments used li-li (lithium metal) cells and li-sulfur cells which are very different from the cells we use.
I would LOVE to be able to use high charge rates to suppress dendrite formation. Unfortunately, with our cells, high rate charging can cause dendrites to form.
So it seems my mistake. I assumed they meant all lithium chemistries
Thanks for posting those papers though! I’m always interested in stuff like this.
While we are on this subject…is there any way to bring a liion cell back to life from 0 or close to 0 volts? I have a dead 12s4p pack on my bench, I was able to revive one pgroup from 0ish to 3v and started working on the others, but my charger is refusing to charge the other groups lol
Nah those just need to be recycled. Damage is irreversible and safety is key.
I see
Yeah you can, I trickle charge dead cells as lead acid with low current until they hit 3v then I switch it back to lithium. I’ve used this to revive a dead tablet battery with mutimeter probes. Careful the battery might blow up but also never be the same again. I’ve only had good results revivng dead cells though.
Also kind if related is you can recover lead acid batteries with overcharging and high current, desulphating is the term I think
The cells are never the same again either, much lower capacity
Can it be done? Often, yes.
Should it be done? That’s a whole ‘nother question.
Some cells can actually start dissolving their copper negative electrode when below about 2.0V or so. The lower the voltage and the longer it goes on the more copper that is dissolved. When the cell is recharged this copper plates itself out onto places it’s not supposed to be inside the cell. This can eventually lead to an internal short-circuit.
These short circuits can just slowly discharge the cell or they can lead to thermal runaway, fire, explosion, and the end of life in this galaxy.
So, you might be able to revive a dead cell but it can be damaged and it could be dangerous. It’s your call whether to try it or not.