Thermal battery

• US 6,475,662 B1
• Filed: 06/05/2000
• Issued: 11/05/2002
• Est. Priority Date: 06/05/2000
• Status: Expired due to Term

• Current Assignee: Eagle-Picher Technologies, LLC
• Original Assignee: Eagle-Picher Technologies, LLC
• Inventors: Spencer, Richard D.
• Primary Examiner(s): Kalafut, Stephen
• Assistant Examiner(s): ANTHONY, JULIAN
• Application Number:
  US09/587,444
• Time in Patent Office: 883 Days
• Field of Search: 429/112, 429/102, 429/103, 429/104
• US Class Current: 429/112
• CPC Class Codes: H01M 6/30 Deferred-action cells
• CPC Class Codes: H01M 6/36 containing electrolyte and made operational by physical means, e.g. thermal cells

Abstract

An improved thermal battery with improved operating efficiency. The thermal battery utilizes both a first activatible heat source and a second independently activatible heat source. The second heat source is optionally activated under storage environment conditions, such as low temperature, which thereby allow battery operation of improved efficiency.

Claims

1. A thermal battery comprising:

at least one cell including a cathode, a node, and heat activatible electrolyte;

a first pyrotechnic heat source;

a second independently activatible pyrotechnic heat source; and

a control device which monitors thermal battery storage temperature and activates said first pyrotechnic heat source when said storage temperature is within a first range, and activates both said first and second pyrotechnic heat sources when said storage temperature is within a second range.

2. The thermal battery of claim 1 further comprising a battery case to enclose said at least one cell, said first pyrotechnic heat source, and said second pyrotechnic heat source.

3. The thermal battery of claim 1 wherein said second pyrotechnic heat source is the same type and sensitivity as said first pyrotechnic heat source.

4. The thermal battery of claim 1 wherein said first pyrotechnic heat source is a mixture of iron powder and potassium perchlorate.

5. The thermal battery of claim 1 wherein said second pyrotechnic heat source is a mixture of titanium and boron.

6. A thermal battery comprising:

at least one cell including a cathode, anode, and heat-activatible electrolyte;

a first pyrotechnic heat source; and

a second independently activatible pyrotechnic heat source, wherein said second pyrotechnic heat source is a different type and sensitivity than said first pyrotechnic heat source.

7. A method of supplying heat to a thermal battery to activate the electrolyte in the thermal battery, comprising:

activating a first pyrotechnic heat source in thermal contact with said thermal battery in response to a signal for initiating operation of said thermal battery;

measuring a temperature of a storage environment of said thermal battery;

comparing said temperature to a predetermined minimum temperature; and

activating a second pyrotechnic heat source in thermal contact with said thermal battery when said temperature is less than said predetermined minimum temperature.

8. The method of claim 7 wherein said temperature is measured in a core of said thermal battery.

9. The method of claim 7 wherein said temperature is measured adjacent to a core of said thermal battery.