Tritium batteries are now available commercially and can have a life exceeding 20 years (Tritium has a half-life of 12.3 years). These thumb-size batteries can produce enough nanowatt (1 nW = 10−9 watt) power to keep micro-electronics going. An 8-bit PIC microcontroller chip when in “sleep” mode consumes around 10 nW. The cost is still in thousands of Dollars but should come down fast. It appears that they could be scaled up to the microwatt (1 µW = 10−6 watt) range which would be enough to power a wristwatch.
Tritium (symbol T or 3H, also known as hydrogen-3) is a radioactive isotope of hydrogen. The nucleusof tritium (sometimes called a triton) contains one proton and two neutrons, whereas the nucleus of protium (by far the most abundant hydrogen isotope) contains one proton and no neutrons. Naturally occurring tritium is extremely rare on Earth, where trace amounts are formed by the interaction of the atmosphere with cosmic rays. The name of this isotope is formed from the Greek word “tritos” meaning “third”.
Tritium is produced in nuclear reactors by neutron activation of lithium-6. This is possible with neutrons of any energy, and is an exothermic reaction yielding 4.8 MeV. In comparison, the fusion of deuterium with tritium releases about 17.6 MeV of energy. High-energy neutrons can also produce tritium from lithium-7 in an endothermic reaction, consuming 2.466 MeV. This was discovered when the 1954 Castle Bravo nuclear test produced an unexpectedly high yield.
(Tritium) although occurring naturally in the upper atmosphere, it’s also produced commercially in nuclear reactors and used in such self-luminescent products as aircraft dials, gauges, luminous paints, exit signs in buildings and wristwatches. It’s also considered a relatively benign betavoltaic, providing a continuous flow of low-powered electrons for a good many years.
According to the Environmental Protection Agency, tritium has a half-life of 12.3 years and the Model P100a NanoTritium betavoltaic power source from Toronto’s City Labs is claimed to be capable of providing juice to low-power micro-electronic and sensor applications for over 20 years. It’s described as robust and hermetically sealed, and the tritium is incorporated in solid form.
Independent testing undertaken by Lockheed Martin during an industry-wide survey also found the technology to be resistant to broad temperature extremes (-50° C to 150° C/-58° F to 302° F), as well as extreme vibration and altitude.
Examples of possible applications for the technology offered by City Labs include environmental pressure/temperature sensors, intelligence sensors, medical implants, trickle charging lithium batteries, semi-passive and active RFID tags, deep space probes, silicon clocks, SRAM memory backup, deep-sea oil well electronics, and lower power processors.
It is still a long way from microwatts to the kilowatts needed to power a home or to drive electric vehicles and the Megawatts needed for small scale power generation. Central power generation requires Gigawatts.
It is easier to convert nuclear radiation into heat and only some materials are betavoltaics which generate current. If only all low-grade radioactive waste from nuclear plants could be converted into batteries! Perhaps nuclear batteries are the breakthrough that electric cars are waiting for!! With current battery technology they are not going anywhere very fast.