5 thoughts on “Nuclear Batteries”

1. Both Ni-63 and C-14 are beta emitters, which is something simple and useful that could have been in the article. It does make me quite curious what they’ve done to the diamond. Is it a superconductor effect? A semiconductor-doping effect?

   I’d expect the plausible efficiency increases to be anemic once one is willing to use an RTG. The block-of-fuel portion should be basically a push. The Peltier widgets aren’t massive. So potential dramatic savings would be restricted to terms of shielding or safety device elimination? But are we anywhere near man-made single diamonds that size?

2. C-14 decays by emitting a beta particle, having an energy of 0.15647 MeV. With a halflife of 5,730 years, a mole of pure C-14 would emit 2.3E+12 Bq. It works out to be 4.27 mW/g, or 4.2 W/kg. The average residential consumption is 900 kW-hr per month. It would take 293 kg of diamond to produce that energy (with intermediate storage for surges), but it would be the last energy the house ever needed.

   One drawback – the video asserted that C-14 turns into “normal carbon” when it decays. It doesn’t. C-14 decays to nitrogen. It’s not clear to me what the effect on the battery would be over a long period of time.

   Synthetic diamond costs vary over a wide range. In 1997, it was anywhere from $0.40 to $3.50 per carat (1 ct = 0.2 g) for cutting and grinding applications. That would make the home batter cost a minimum of between $586,000 and $5,127,500. Let’s say it cost $5.2 million, but was installed in a home that went through 10 generations of owners (250 years). The battery would still be at 97% capacity, so that’s probably not an issue. The cost would then be $1,733 a month. That, of course, is without factoring in the time value of money. Reminds me of my electric bill from California.

   1. 156 kev is the MAX energy of the beta particle in 14C decay, but the weighted average energy is less than 50 kev. The antineutrino typically carries off more energy.

      This sounds like betavoltaics, where beta particles create hole/electron pairs in a semiconductor diode (in this case, using diamond as the semiconductor). I see a paper suggesting the maximum efficiency for such a system in diamond with 14C electrons would be less than 1%.

      https://www.researchgate.net/publication/235130192_DESIGNING_CVD_DIAMOND_BETAVOLTAIC_BATTERIES

      1. Ah, those pesky beta emitters, and their misleading decay energies. Better to use tritium in this application. The power output of a gram of pure tritium is an honest 0.327 W/g. I know a guy who makes tritium micro-batteries, and they work reasonably well. Plus the tritium could be in the form of a polymer overlaid with CVD diamond film.

      2. That article mentioned that SiC devices had efficiencies of 4.5 to 6%. It would probably be easier to work with, and the breakdown product should be SiN (hopefully) instead of nitrogen trapped in diamond.

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