RECHARGEABLE BATTERY CELL WITH ULTRA THIN SEPARATOR

Rechargeable battery cells and methods for extreme fast charging are disclosed. For example, such a rechargeable battery cell might be chargeable to at least 70% of usable capacity within 15 minutes. Such a rechargeable battery cell may include an anode having a conductive current collector coated with a composite containing a carbon-based material, a cathode configured as a source of Li ions, an electrolyte capable of carrying Li-ions between the anode and the cathode, and a separator between the anode and the cathode, the separator having a thickness of less than 20 microns. Methods of charging the rechargeable battery cells are also disclosed.