A company called Widetronix has developed a 25-year battery. Reminiscent of Heinlein's micro-fission reactors that could be worn on a belt, beta voltaic battery cells last 25 years or more, using semiconductors to turn high energy electrons known as beta particles thrown off by radioactive decay into a usable current.
The technology is 50 years old, but semiconductors back in the day required more radioactive substances to achieve the same (tiny) power output. This made them more dangerous and bulkier once the necessary shielding was in place. Lithium-ion cells simply out competed beta voltaics. But now, with improved semiconductor technologies, Widetronix is hoping to make converting beta particles into usable current the next big thing in medical implants and military and infrastructure sensors.
Ithaca, N.Y.-based Widetronix is focusing on the use of a hydrogen isotope called Tritium. It is relatively benign and sourced as a waste product from Canadian fission reactors that produce “heavy water” -- water with two neutrons in the hydrogen atom (normally, hydrogen is a single proton and neutron). Tritium is super rare in the natural world and its other uses include painting watch hands and gun sights so that they glow in the dark.
In case you were already wondering, this technology won't be powering your cell phone or your laptop any time soon. Those aren't even on the list of potential uses; beta voltaics produce an extremely long-lived current but a very small one. So what is it good for?
They are extremely rugged -- to the extent that they are being considered for the next generation of military sensor use. For these applications, they will have to be able to withstand temperatures from -65 to 150 degrees Celsius, high humidity, long-term salt buildup and high-frequency vibrations. In short, these batteries will have to survive conditions you'd find on a jet aircraft going from rough seas to 50,000 feet in the South Pacific, with the possibility of being subjected to burning jet fuel. They'll also do just fine inside a human body, where they might power a pacemaker or other surgical implants.
Here's what a possible application would look like:
The military will probably use the batteries in anti-tamper devices that need to do nothing at all for years at a time but may suddenly be called upon to provide self-destruct power. Beta-batteries may also be useful in wireless sensors for perimeter security, flight recorders and remote missile monitoring when higher-powered units are developed. Sensors placed in buildings, bridges and other large infrastructure projects could also alert engineers to potential failures before visible cracks appear. The beta voltaics seem like they would be useful anywhere you never want to change a battery.
One of the biggest hurdles to commercialization at this point is that the nuclear materials supply infrastructure in the U.S. has fallen apart since the end of the Cold War. The availability of nuclear materials has fallen off sharply. While many people aren't heartbroken over this, it does make never-change battery development a bit more difficult: higher energy materials like nickel-63 must be bought from overseas and at high prices.
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