[Article] Partially Reverse Battery Degradation in NMC Li-ion Batteries

[Infinion]

Did anyone catch this article in '22? I'd lost the article and was only just now able to type in the right keywords to uncover it again.
Article
https://www6.slac.stanford.edu/news...ing-batteries-bringing-dead-lithium-back-life
and the paper
https://www.nature.com/articles/s41586-021-04168-w

The article is a quick read and you'll get a gist of what might be going on under your seats and what you could do to maintain the health of the Spark's cells.

Spoiler: tldr

Some capacity loss comes from a quantity of lithium that has precipitated in an inactive region of the cell where it shouldn't be, and no longer participates in the electrochemical activity that gives the Li-ion cell its capacity.
These researchers suggest that a brief rapid discharge step after charging will be an opportune time to induce forces on those disconnected islands of lithium that will nudge them toward the anode where they're supposed to be. Once they are close enough, the lost lithium will dissolve and reconstitute itself on the anode and shuffle between the anode and cathode once again, allegedly recovering as much as 30% of the cell's life.

From what I gather, results probably won't manifest themselves right away and depend on the size of the dendrite, its shape and orientation, and how far away it is from the anode (it's a big shot in the dark). The best you could do if you're interested in trying to recover capacity is to just do it consistently. Use departure charging and pull a 100kW discharge shortly after unplugging. I imagine itll be hard to measure success, but I suppose if you do a capacity test every once in a while you might be able to catch something.

This paper was specifically discussing NMC chemistries, so I can't say it would work on 2014s that have A123's LFP makeup, but it could be worth a shot if that chemistry suffers from isolated lithium as well.

 

[TomK]

I realize this is an older post but someone just pointed me to this. Just curious if anyone has actually tried to implement this strategy and what if any results they have seen.

If i understand the above correctly (unfortunately the article didn't seem to offer much more detail either), you should try to have a high energy discharge right after finishing charging. Few questions this brings up

Do you charge to 100% to get the most benefit from the high discharge rate?
How long do you need keep up the high discharge rate?
Can you do multiple cycles in one go (e.g. step on the accelerator for a couple of seconds, break then step back on etc)?
What is a safe discharge rate for this?
Is there a way to force a dicharge other than using the car acceleration?

Lastly, this sounds like a fun experiment, however, being i am on about 2 miles of dirt road before i get on a paved street, i think it would not be advised to pull 100kw from a stand still. That's a lot of rocks being shot at the underside of the vehicle.

 

[Randy960]

Reading through this, it seems like your best bet would be to go to a fast charger, 100% charge, then go full throttle to the next charger, and repeat. It would certainly be an interesting experiment.