Method of increasing the useful life of rechargeable lithium batteries

• US 4,736,150 A
• Filed: 07/09/1986
• Issued: 04/05/1988
• Est. Priority Date: 07/09/1986
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Wagner, Otto C.
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): Ault, Anita M.
• Application Number:
  US06/887,142
• Time in Patent Office: 636 Days
• Field of Search: 320/2, 320/3, 320/4, 320/21
• US Class Current: 320/139
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The cycle life of rechargeable lithium batteries is significantly prolongedy applying to the battery as a charging mode a current interrupted at intervals of 1 milliseconds to 9 seconds in a frequency range of about 0.1 to about 10 Hertz.

Claims

1. Method of significantly prolonging the cycle life of rechargeable lithium batteries comprising applying to the battery as a charging mode a current interrupted at intervals of 1 millisecond to 9 seconds in a frequency range of about 0.1 to Hertz, said batteries being charged to a safe voltage limit.

2. Method according to claim 1 wherein the rechargeable lithium battery is a rechargeable lithium-molybdenum disulfide battery.

3. Method according to claim 2 wherein the interrupted current is applied at a frequency of about 5 Hertz at a duty cycle of 100 milliseconds pulse, 100 milliseconds rest.

4. Method according to claim 2 wherein the interrupted current is applied at a frequency of about 2 Hertz at a duty cycle of 250 milliseconds pulse 250 milliseconds rest.

5. Method according to claim 2 wherein the interrupted current charging mode is superimposed on a constant potential that does not exceed the safe voltage limit for charging the battery.

6. Method according to claim 1 wherein the rechargeable lithium battery is a rechargeable lithium-titanium disulfide battery.

7. Method according to claim 6 wherein the interrupted current is applied at a frequency of about 5 Hertz at a duty cycle of 100 millimeters pulse, 100 milliseconds rest.

8. Method according to claim 6 wherein the interrupted current is applied at a frequency of about 2 Hertz at a duty cycle of 250 milliseconds pulse, 250 milliseconds rest.

9. Method according to claim 6 wherein the interrupted current charging mode is superimposed on a constant potential that does not exceed the safe voltage limit for charging the battery.

10. Method of significantly prolonging the cycle life of a rechargeable lithium-molybdenum disulfide battery comprising applying to the battery as a charging mode a current interrupted at intervals of 1 millisecond to 9 seconds in a frequency range of about 0.1 to about 10 Hertz wherein the interrupted current charging mode is superimposed on a DC current.

11. Method of significantly prolonging the cycle life of a rechargeable lithium-titanium disulfide battery comprising applying to the battery as a charging mode a current interrupted at intervals of 1 millisecond to 9 seconds in a frequency range of about 0.1 to about 10 Hertz wherein the interrupted current charging mode is superimposed on a DC current.