Lithium ion rapid charging system and method
View Patent ↗The present invention discloses a method and system for the rapid charging of a lithium-ion battery. A charging algorithm is applied to modify a charging pulses frequency, duty cycle and amplitude depending on the measurement of the battery temperature. The charging algorithm is based on the chemical Diffusion Coefficient of the battery, with this Diffusion Coefficient, in turn, dependent on the type of solvent system, the type of electrolyte, and the temperature of the battery.
1. A method for rapid charging of a lithium ion battery at a particular temperature, said battery with a negative and a positive electrode and said battery including a solvent system and an electrolyte, comprising:
a) measuring the diffusion coefficient of said battery at a series of battery temperatures prior to charging, applying a constant current charge to the lithium ion battery until a sum of a lithium ion battery voltage, said sum defined as an intrinsic free energy difference value as measured between said negative electrode and said positive electrode, and a concentration polarization value, reaches a first predetermined value; then upon reaching said predetermined value
b) applying a pulsed current charge to the lithium ion battery with a calculated frequency and a calculated duty cycle, said pulsed charge having a value dependent on a chemical diffusion coefficient of said battery, the chemical diffusion coefficient continually adjusted depending on actual battery temperature measured, with said chemical diffusion coefficient previously measured at a series of battery temperatures applied to the battery prior to charging; then
c) reducing the pulsed current charge value when a sum of a lithium ion battery voltage, said sum defined as an intrinsic free energy difference value as measured between said negative electrode and said positive electrode, and a concentration polarization value, reaches a third predetermined value.
2. The method of claim 1 further including discontinuing the pulsed current charge and applying a constant voltage charge to the lithium ion battery when the sum of the lithium ion battery voltage reaches a fourth predetermined value.