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Beta-voltaic and other nuclear batteries have been around for a long time. The issue, at least so far, isn’t technology, it’s mostly just cost and safety. These

by zakary 3y ago

Beta-voltaic and other nuclear batteries have been around for a long time. The issue, at least so far, isn’t technology, it’s mostly just cost and safety. These things cost hundreds and into the thousands per battery last time I checked. And for that they put out less power than a coin cell. Outside of pacemakers and space probes where a battery change is difficult to impossible, there aren’t a lot of use cases where the cost is justified. There actually are other isotopes such as Hafnium 178m2 which have the potential to make much more energy and power dense nuclear batteries, but due to safety concerns haven’t been developed yet. Checkout: https://en.m.wikipedia.org/wiki/Hafnium_controversy https://en.m.wikipedia.org/wiki/Hafnium_controversy > 178m2Hf has the highest excitation energy of any comparably long-lived isomer. One gram of pure 178m2Hf contains approximately 1330 megajoules of energy, the equivalent in about 300 kilograms (660 pounds) of the explosive TNT. The half-life of 178m2Hf is 31 years

phkahler 3y ago
What is the decay chain? For the one in the article (And I'm sceptical) they say "After the decay period, the 63 isotopes turn into a stable isotope of copper, which is non-radioactive and does not pose any threat or pollution to the environment." How long does that take and what other things are produced? What if someone throws one into a campfire?
- p1mrx 3y ago
  It's a single isotope, nickel-63, which decays into regular copper-63. The amount of nickel halves every 96 years. If you throw it in a fire, you'll disperse nickel-63 into the environment, which isn't good, but the decay process is unaffected.
  - Fatnino 3y ago
    I've seen it said that it takes 10 halflives for something to decay all the way away. So like 1000 years for this to flush itself.
    - jbboehr 3y ago
      > I've seen it said You can estimate it yourself: 0.5 ^ 10 = 0.0009765625 (~0.1%) https://en.wikipedia.org/wiki/Half-life#Probabilistic_nature https://en.wikipedia.org/wiki/Half-life#Probabilistic_nature > When there are many identical atoms decaying, the law of large numbers suggests that it is a very good approximation to say that half of the atoms remain after one half-life
- nine_k 3y ago
  Beta decay is emission of electrons. They quickly slow down in the air. A beta emitter can only burn you if you literally pick it with you fingers, or maybe swallow it. Throwing it in a campfire is not a great idea, but nickel is not going to burn or melt in a campfire, so it won't become a dangerous pollutant. Nickel is also chemically pretty stable, so underground waters are not going to carry around any significant amounts of it after you have extinguished the campfire and put some soil on its site. 172m2 Hafnium decays into regular 178 Hafnium, but it readily burns in the air, so if you throw a battery with in into a campfire, chances are you'll add some beta radioactivity to the environment nearby, or inhale part of it yourself.
- mikhailfranco 3y ago
  The battery contains 50 curie (Ci). This radionuclide safety sheet says that anything more than 1 Ci of Ni-63 is a high-level (A) hazard. https://ehs.stanford.edu/wp-content/uploads/Ni-63-RSDS.pdf https://ehs.stanford.edu/wp-content/uploads/Ni-63-RSDS.pdf It also gives the annual limit on inhalation as 800 µCi and ingestion as 9 mCi. So the battery contains more than 60,000 max annual inhalation doses, if it was all vaporized, and more than 5,000 max ingestion doses, if it found its way into the water/food supply.
moffkalast 3y ago
> 1330 megajoules of energy Which would be about 370 kWh, at 8% efficiency at best that would be 30kWh, or about a kWh a year. The average phone uses about 2 kWh per year, so 2 grams + a suitably sized battery for spike draws could potentially hack it. Of course the suggested smartphone use case is probably the single worst possible application for these things. We literally carry them on ourselves constantly, trash them every few years at most and usually keep them within range of a power outlet. Outer solar system cubesats, underwater gliders, arctic weather stations, etc. may be better ideas. Places where solar isn't viable.
- yterdy 3y ago
  There are also probably ethical concerns wrt devices that can run a human lifetime without intervention. You gonna put weapons on any of those? (Someone wants to.)
  - lazide 3y ago
    Anyone who wants to won’t care about ethics. And anyone who wants to make money wouldn’t bother to consider someone repurposing an existing one for that purpose until it made such a big mess the gov’t got involved (generally). That said, ITAR is a huge hassle, and threatening to put something on it would get a manufacturers attention.
  - moffkalast 3y ago
    > You gonna put weapons on any of those? Quite right Mr. Bond, a fleet of wake homing betavoltaic glider torpedoes that once launched will disperse into the world's oceans and make them an unsailable for the next 50 years. People will have no choice but to move the world's freight with my heavy lift zeppelins or suffer the consequences. And speaking of consequences Mr. Bond... it seems your luck has run out for the last time.
- vlovich123 3y ago
  > We literally carry them on ourselves constantly, trash them every few years at most and usually keep them within range of a power outlet. I mean if we’re legit trashing the phone, is that radioactive material actually worse than all the other toxic materials in a phone including the lithium ion battery? Saying “nuclear radiation scary” and leaving it at that doesn’t actually tell us as the radioactive material matters a lot (eg plutonium is chemically toxic separate from its radioactivity and while short half life radiation is more dangerous than long in the abstract, the specific decay products matter a lot). Besides, the battery could easily retain its value well beyond the use of the phone which would encourage harvesting rather than trashing (if you force a standard battery connection there would probably be a large thriving secondary market).

by zakary 3y ago

phkahler 3y ago

What is the decay chain? For the one in the article (And I'm sceptical) they say "After the decay period, the 63 isotopes turn into a stable isotope of copper, which is non-radioactive and does not pose any threat or pollution to the environment." How long does that take and what other things are produced? What if someone throws one into a campfire?

p1mrx 3y ago
It's a single isotope, nickel-63, which decays into regular copper-63. The amount of nickel halves every 96 years. If you throw it in a fire, you'll disperse nickel-63 into the environment, which isn't good, but the decay process is unaffected.
- Fatnino 3y ago
  I've seen it said that it takes 10 halflives for something to decay all the way away. So like 1000 years for this to flush itself.
  - jbboehr 3y ago
    > I've seen it said You can estimate it yourself: 0.5 ^ 10 = 0.0009765625 (~0.1%) https://en.wikipedia.org/wiki/Half-life#Probabilistic_nature https://en.wikipedia.org/wiki/Half-life#Probabilistic_nature > When there are many identical atoms decaying, the law of large numbers suggests that it is a very good approximation to say that half of the atoms remain after one half-life
nine_k 3y ago
Beta decay is emission of electrons. They quickly slow down in the air. A beta emitter can only burn you if you literally pick it with you fingers, or maybe swallow it. Throwing it in a campfire is not a great idea, but nickel is not going to burn or melt in a campfire, so it won't become a dangerous pollutant. Nickel is also chemically pretty stable, so underground waters are not going to carry around any significant amounts of it after you have extinguished the campfire and put some soil on its site. 172m2 Hafnium decays into regular 178 Hafnium, but it readily burns in the air, so if you throw a battery with in into a campfire, chances are you'll add some beta radioactivity to the environment nearby, or inhale part of it yourself.
mikhailfranco 3y ago
The battery contains 50 curie (Ci). This radionuclide safety sheet says that anything more than 1 Ci of Ni-63 is a high-level (A) hazard. https://ehs.stanford.edu/wp-content/uploads/Ni-63-RSDS.pdf https://ehs.stanford.edu/wp-content/uploads/Ni-63-RSDS.pdf It also gives the annual limit on inhalation as 800 µCi and ingestion as 9 mCi. So the battery contains more than 60,000 max annual inhalation doses, if it was all vaporized, and more than 5,000 max ingestion doses, if it found its way into the water/food supply.

moffkalast 3y ago

> 1330 megajoules of energy Which would be about 370 kWh, at 8% efficiency at best that would be 30kWh, or about a kWh a year. The average phone uses about 2 kWh per year, so 2 grams + a suitably sized battery for spike draws could potentially hack it. Of course the suggested smartphone use case is probably the single worst possible application for these things. We literally carry them on ourselves constantly, trash them every few years at most and usually keep them within range of a power outlet. Outer solar system cubesats, underwater gliders, arctic weather stations, etc. may be better ideas. Places where solar isn't viable.

yterdy 3y ago
There are also probably ethical concerns wrt devices that can run a human lifetime without intervention. You gonna put weapons on any of those? (Someone wants to.)
- lazide 3y ago
  Anyone who wants to won’t care about ethics. And anyone who wants to make money wouldn’t bother to consider someone repurposing an existing one for that purpose until it made such a big mess the gov’t got involved (generally). That said, ITAR is a huge hassle, and threatening to put something on it would get a manufacturers attention.
- moffkalast 3y ago
  > You gonna put weapons on any of those? Quite right Mr. Bond, a fleet of wake homing betavoltaic glider torpedoes that once launched will disperse into the world's oceans and make them an unsailable for the next 50 years. People will have no choice but to move the world's freight with my heavy lift zeppelins or suffer the consequences. And speaking of consequences Mr. Bond... it seems your luck has run out for the last time.
vlovich123 3y ago
> We literally carry them on ourselves constantly, trash them every few years at most and usually keep them within range of a power outlet. I mean if we’re legit trashing the phone, is that radioactive material actually worse than all the other toxic materials in a phone including the lithium ion battery? Saying “nuclear radiation scary” and leaving it at that doesn’t actually tell us as the radioactive material matters a lot (eg plutonium is chemically toxic separate from its radioactivity and while short half life radiation is more dangerous than long in the abstract, the specific decay products matter a lot). Besides, the battery could easily retain its value well beyond the use of the phone which would encourage harvesting rather than trashing (if you force a standard battery connection there would probably be a large thriving secondary market).