Military looking at 25 year batteries

Technology Review:

Batteries that harvest energy from the nuclear decay of isotopes can produce very low levels of current and last for decades without needing to be replaced. A new version of the batteries, called betavoltaics, is being developed by an Ithaca, NY-based company and tested by Lockheed Martin. The batteries could potentially power electrical circuits that protect military planes and missiles from tampering by destroying information stored in the systems, or by sending out a warning signal to a military center. The batteries are expected to last for 25 years. The company, called Widetronix, is also working with medical-device makers to develop batteries that could last decades for implantable medical devices.

Widetronix's batteries are powered by the decay of a hydrogen isotope called tritium into high-energy electrons. While solar cells use semiconductors such as silicon to capture energy from the photons in sunlight, betavoltaic cells use a semiconductor to capture the energy in electrons produced during the nuclear decay of isotopes. This type of nuclear decay is called "beta decay," for the high-energy electrons, called beta particles, that it produces. The lifetimes of betavoltaic devices depend on the half-lives, ranging from a few years to 100 years, of the radioisotopes that power them. To make a battery that lasts 25 years from tritium, which has a half-life of 12.3 years, Widetronix loads the package with twice as much tritium as is initially required. These devices can withstand much harsher conditions than chemical batteries. This, and their long lifetimes, is what makes betavoltaics attractive as a power source for medical implants and for remote military sensing in extremely hot and cold environments.

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If these batteries could be adapted to the many uses troops need for batteries it could save significant weight that they have to carry. Batteries are apparently needed for night vision goggles and other applications.

The military needs this kind of high tech gear much more than the civilian market does because of the logistics of getting things to remote places like Afghanistan.