A Bundle of Energy: Thermal Battery Technology

EaglePicher manufactures and develops the finest and highest quality thermal battery technology in the world. Our technical and manufacturing expertise allow us to develop new, advanced thermal battery systems. We work closely with each client to ensure that your design is technically sound, able to be produced cost-effectively, and functions well in its intended application.

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Thermal batteries offer relatively high energy density versus volume. They can be stored for up to 20+ years without performance degradation; they perform without preparation in the most external environments; and they begin providing power almost immediately. Thermal battery technology is comprised of stacked series cells. Each cell consists of a cathode, an electrolyte, an anode and a pyrotechnic thermal energy source. State-of-the-art thermal battery designs utilize lithium silicon/iron disulfide (LiSi/FeS2) couple, because it offers the following benefits:

  • The highest capacity per unit volume
  • Substantial power density
  • Low, uniform internal impedance while active
  • Adaptability to a broad array of environments

Based on power density and volume requirements, a thermal battery may consist of a single series stack of cells, or two or more parallel stacks of series cells. The cell stacks are thoroughly insulated and placed in a stainless steel container, which is hermetically sealed.


Typical applications for thermal batteries are:

Missiles • Guidance systems
• Bombs • Torpedoes
Munitions • Sonobuoys
• Seat ejections Launch vehicles
• Custom applications  


EaglePicher started development work on thermal battery technology way back in 1949. In 1974, our company was the first to begin work on large LiAl/FeS batteries for load leveling and electric vehicle application. By 1976, EaglePicher was the first in the world to adapt this rechargeable system to a primary LiAl/FeS2 thermal battery, improving thermal battery performance capability.

In 1982, EaglePicher became the first thermal battery manufacturer to produce LiSi/FeS2 thermal batteries for the U.S. Department of Energy on a production basis, and in 2007, our automated production facility in Pittsburg, KS was brought on-line to increase thermal battery production capability.

For over 70 years, EaglePicher has produced high-quality, reliable and cost-effective thermal battery systems, producing millions of batteries for a variety of defense markets, qualifying and manufacturing more than 750 unique thermal battery designs. EaglePicher is currently the leading thermal battery manufacturer for the Department of Defense's missile applications.

We have a rich history of supporting nearly every major ordnance program including, but not limited to, TOW, Patriot, JDAM, Tomahawk, Excalibur, Paveway, Laser Guided Bomb, Hellfire, Javelin, Small Diameter Bomb, Stinger, Maverick, ESSM/Sparrow, Standard Missile 3/6, Sonobuoy and AMRAAM.


EaglePicher continues to dedicate resources toward advancing thermal battery technology. These improvements span across materials, manufacturing processes and modeling. We are currently looking at alternative cathode formulations that lead to higher operating temperature, higher voltage, higher density, higher capacity and lower impedance. EaglePicher is also working on high-voltage cathodes to create higher output in the same volume and overall weight reduction.

What is thermal battery technology?

A thermal battery consist of a stack of cells each made from a cathode, an electrolyte separator, an anode and a pyrotechnic, thermal energy source. The battery can be activated at any time without preparation, and will begin supplying power almost immediately. Once activated, the battery functions until a critical active material is exhausted or until the battery cools below the electrolyte’s melting point.

What are thermal batteries used for?

Thermal batteries are primarily used in military and space applications requiring a one-time use power source. Thermal batteries are ideal suited for military application due to their maintenance-free, long shelf life and high power that can operate in extreme temperature ranges and climates. Thermal batteries are currently used in a wide variety of military applications including missiles, munitions, torpedoes, ejection seats, guidance systems, sonobuoys and launch vehicles.

Interested in learning more about our thermal battery technology? Contact our team of experts or request information below.

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