×

Lithium ion rapid charging system and method

  • US 7,227,336 B1
  • Filed: 04/01/2003
  • Issued: 06/05/2007
  • Est. Priority Date: 04/02/2002
  • Status: Active Grant
First Claim
Patent Images

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 valueb) 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;

    thenc) 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.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×