Charging lithium-ion batteries at high currents just before they leave the factory is 30 times faster and increases battery lifespans by 50%, according to a study at the SLAC-Stanford Battery Center Menlo Park, Calif. — A lithium-ion battery’s very first charge is more momentous than it sounds. It determines how well and how long the battery will work from then on – in particular, how many cycles of charging and discharging it can handle before deteriorating.
This is not about charging day-to-day, it’s specifically the very first charge in the factory.
This first charge is called formation and is extremely important. It sacrifices some capacity to build up a protective layer on the anode active material (negative side of the battery). If not done right, the battery will degrade after only a handful of cycles.
If you simply take any 18650 and charge it really fast, you will likely build up metallic lithium near the end of the charge, especially at low temperatures. This will lead to a lot of degradation and it’s a safety risk.
If you hook up your smartphone to a powerful wall plug, the actual charging unit that controls the speed is still inside the phone. It will have a temperature-dependent mathematical model of the battery that tells it how fast to go and still be on the safe side.
I read the article and it states that the new method results in batteries with ~25% lower capacity (batteries treated with the new method lose 30% of their active lithium vs. 9% loss with traditional formation).
So not quite a silver bullet
In fact, losing 25% capacity effectively means 33% higher cell cost for an equivalent-energy battery pack, because you need to use more cells. That’s a lot more additional cost compared to what is saved with the much shorter process.
