Pressure-based battery charging

• US 6,437,542 B1
• Filed: 10/13/2001
• Issued: 08/20/2002
• Est. Priority Date: 10/13/2000
• Status: Expired due to Fees

• Current Assignee: Battery Tech Hawaii, LLC
• Original Assignee: Bor Yann Liaw, Xiao-Guang Yang
• Inventors: Liaw, Bor Yann, Yang, Xiao-Guang
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/976,779
• Time in Patent Office: 311 Days
• Field of Search: 320/127, 320/128, 320/135, 320/137, 320/147, 320/DIG.17, 324/426, 324/435, 324/437
• US Class Current: 320/147
• CPC Class Codes: H01M 10/30 Nickel accumulators H01M10/34 takes precedence
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/445 in response to gas pressure
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• CPC Class Codes: H01M 2200/20 Pressure-sensitive devices
• CPC Class Codes: H02J 7/00719 in response to degree of gas development in the battery
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Battery charge control protocols and methodologies to use pressure-based controls and algorithms to properly terminate battery charging processes.

Claims

1. A method of battery charging control, the method comprising the steps of:

providing a pressure probe,

measuring pressure change inside a battery via the pressure probe,

characterizing pressure profile and its change,

employing the characterization as a primary protocol to control battery charging processes.

2. The method of claim 1 wherein the measuring step comprises measuring internal battery gas pressure.

3. The method of claim 1 additionally comprising the step of employing as a secondary protocol to control battery charging processes one or more of the parameters from the group consisting of time, operating temperature range, ambient pressure in an operating environment, voltage range, change of voltage range, current level, change of current level, charge inputs, charge outputs, age of battery, and state of charge or battery.

4. The method of claim 1 wherein in the measuring step the battery has a battery chemistry that has one or more side reactions that generate gas species.

5. The method of claim 4 wherein the employing step minimizes side reactions that generate gas species.

6. The method of claim 1 wherein in the measuring step the battery comprises aqueous electrolytes and/or organic electrolytes that have reactions selected from the group consisting of gas reactions and gas generating side reactions.

7. The method of claim 6 wherein the employing step minimizes side reactions that generate gas species.

8. The method of claim 1 wherein in the measuring step the battery comprises nickel-based chemistries.

9. The method of claim 8 wherein the employing step results in a charging rate higher than 3C rate without causing battery degradation from high rate charging.

10. The method of claim 8 wherein in the measuring step the battery comprises a nickel-based aqueous battery chemistry.

11. The method of claim 10 wherein in the measuring step the battery comprises a nickel-based aqueous battery chemistry selected from the group consisting of Ni—

Cd and Ni—

MH.

12. The method of claim 1 wherein in the employing step a higher pressure excursion results in better sensitivity of control.

13. The method of claim 1 wherein in the employing step the battery is substantially protected from degradation caused by gas generating reactions.

14. The method of claim 1 wherein in the employing step pressure limits are based on mechanical integrity of the battery'"'"'s containment.

15. The method of claim 1 wherein in the employing step the primary protocol minimizes one or more battery characteristics selected from the group consisting of thermal excursions and temperature changes.

16. The method of claim 1 wherein in the measuring step the pressure probe accesses a headspace of the battery.

17. The method of claim 1 wherein in the employing step termination conditions for the battery charging process are controlled.

18. The method of claim 1 wherein the employing step employs one or more means selected from the group consisting of physical control devices, computer software, and signaling means.