• @wahming
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    910 months ago

    Yes, let’s put a piece of radioactive waste into every pocket. What could go wrong?

    • hallettj
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      310 months ago

      I’d sure want to be very careful with health-risk assessments. But nickel-63 is pretty low-energy. According to this fact sheet absorbed radiation from exposure to skin is negligible without shielding. And that level of radiation is easy to shield so the battery casing presumably blocks all of it. (Tbf I believe fact sheets like that assume that your dead layer of surface skin cells has a small shielding effect, so the calculation is different if it gets in your body.)

      The article also mentioned a possible variation with strontium-90 which is stronger stuff. It’s emissions are 8 times more energetic than Ni-63, and instead of decaying to stable copper, strontium-90 decays to yttrium-90 which emits radiation several times again more energetic than strontium-90. Here’s another fact sheet. (Sorry about using two different sources for fact sheets. I had a hard time finding one source with facts on both isotopes.)

      The term “radioactive waste” suggests products from uranium fission, and the isotopes they decay to which can have extremely high-energy emissions, and decay through chains of several radioactive isotopes before finally decaying to stable elements which means extremely long half-lives overall. IMO the comparison is misleading. It’s kinda like comparing one “moderate” air quality day to many days inside a smoke stack.

    • @PaddleMaster@beehaw.org
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      210 months ago

      With the exception of the listed medical devices, all the other use cases point to military, and it would make sense to have such a battery in that environment.

      Medical devices definitely make me ask your question.

      • @wahming
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        510 months ago

        They do mention smart phones as an application they’re targeting though, which is where I get the ‘every pocket’ image from

        • @PaddleMaster@beehaw.org
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          210 months ago

          Yeah, very stupid, unless it’s for military applications where there’s no guarantee of power to recharge a phone everyday. I doubt this would be used for the everyday person. But if it is, I’m real curious to see the impact, especially for the people who store their phone in a pocket.

    • @wahming
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      610 months ago

      This is multiple degrees of magnitude smaller than conventional RTGs

      • @CJOtheReal@ani.social
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        210 months ago

        But nothing actually new, just downscaled. This was possible before, but not done because we don’t want to give people the ability to get radioactive material, even in small quantities.

        • @wahming
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          10 months ago

          It is new. Traditional RTGs rely on heat differentials. This converts the energetic particles directly to electricity without the intermediate step. That’s a very significant technical difference. Assuming what the article attests is true, of course

  • @TheWonderfool@lemmy.world
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    310 months ago

    Ok so maybe my calculation is off, but based on the specs in the article the battery on my phone would become 225x225x5 mm in size to be equivalent on the LiPo it currently has.

    That seems way too big to be usable, and contrary to what the article says about this battery being more energy dense…

    (Calculation is - 4385mAh x 5V = 21925mWh, so around 220 batteries as they output 100mW, and as they are 15x15x5 it becomes ✓220*15=~225 so 225x225x5)

    Please someone smarter help me!

    • @wahming
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      1610 months ago

      It’s more energy dense because it carries 50 years of power within it. It’s not a rechargeable battery. They’re discussing the energy density, you’re measuring the energy output per cubic mm per second.

      That said, this reads like a fluff piece so I wouldn’t overthink it.