Lithium sulfur battery pulse charging method and pulse waveform

Patent metadata

Field	Value
Publication number	US-9331364-B2
Application number	US-201414171933-A
Country	US
Kind code	B2
Filing date	Feb 4, 2014
Priority date	Feb 4, 2014
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Provided are methods and apparatus for charging a lithium sulfur (Li—S) battery. The Li—S battery has at least one unit cell comprising a lithium-containing anode and a sulfur-containing cathode with an electrolyte layer there between. One method provides controlled application of voltage pulses at the beginning of the charging process. An application period is initiated after a discharge cycle of the Li—S battery is complete. During the application period, voltage pulses are provided to the Li—S battery. The voltage pulses are less than a constant current charging voltage. Constant current charging is initiated after the application period has elapsed.

First claim

What is claimed is:

1. A method of charging a lithium-sulfur battery having at least one unit cell comprising a lithium-containing anode and a sulfur-containing cathode with an electrolyte layer there between, the method comprising:
while cycling of the lithium-sulfur battery during normal use of the lithium sulfur battery, applying voltage pulses during an application period, the application period initiated when a battery charge cycle would be initiated, the application period delaying initiation of the battery charge cycle, wherein the voltage pulses are less than a constant current charging voltage and dissolve lithium sulfide formed on the sulfur-containing cathode of the battery; and
initiating constant current charging after the application period has elapsed.

2. The method of claim 1 , wherein application of the voltage pulses is configured to create surface defects on lithium sulfide particles.

3. The method of claim 1 , wherein application of the voltage pulses is configured to optimize coulombic efficiency of the battery.

4. The method of claim 1 , wherein applying the voltage pulses includes controlling pulse characteristics of each voltage pulse during the application period.

5. The method of claim 4 , wherein controlling pulse characteristics comprises gradually increasing, in succession, a peak voltage of each of the voltage pulses, each peak voltage being less than the constant current charging voltage.

6. The method of claim 4 , wherein controlling pulse characteristics comprises applying an extended peak voltage for each voltage pulse for a duration of time before the peak voltage is decreased.

7. The method of claim 4 , wherein controlling pulse characteristics comprises maintaining each valley between adjacent voltage pulses at an equal valley voltage.

8. The method of claim 4 , wherein controlling pulse characteristics comprises gradually increasing, in succession, a valley voltage of each valley between adjacent voltage pulses.

9. The method of claim 4 , wherein controlling pulse characteristics comprises maintaining each valley between adjacent voltage peaks at a constant voltage for a duration of time.

10. The method of claim 1 , wherein the application period is only initiated when a battery state of charge is at or below a predetermined threshold state of charge, and if the battery state of charge is not the predetermined threshold, the battery charge cycle is initiated.

11. The method of claim 10 , wherein the predetermined threshold state of charge is 20%.

12. The method of claim 1 , wherein a low voltage of the voltage pulses is greater than a discharge voltage.

Assignees

• Nissan North America Inc

Inventors

• Ramaswamy Nagappan
• Aurora Peter
• Dileo Gregory
• Hao Xiaoguang
• Han Taehee
• Yadav Rameshwar
• Niangar Ellazar
• Oshihara Kenzo

Classifications

• H02J7/927

  with introduction of pulses during the charging process · CPC title

• H02J7/875

  Charging or discharging for charge maintenance, battery initiation or rejuvenation · CPC title

• H01M10/46

  Accumulators structurally combined with charging apparatus (circuits for charging H02J7/00) · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title