4 ms·
This is silly. It's not going to disrupt Li-ion. Power outputs are way too low. C14 has a half life of 5700 years. This isn't going to output Li-ion levels of p
by leplen 6y ago
This is silly. It's not going to disrupt Li-ion. Power outputs are way too low. C14 has a half life of 5700 years. This isn't going to output Li-ion levels of power/weight for 5 millennia. It looks like it might give you microwatts/gram, but this is much closer to existing nuclear tech like RTGs or beta voltaics than it is to Li-ion batteries.
- econcon 6y agowhat has half life to be with energy density?
- heisenzombie 6y agoThe half life tells you how fast you're using up your fuel. A long half life means you're using the nuclear potential energy in your "battery" very slowly.
- deleted 6y ago[deleted]
- heisenzombie 6y agoYeah, the way they're presenting it is silly. C-14 decays to N-14 with a mass defect of 156.5 keV/c^2. With a half life of 5730 years, 1 kg of carbon-14 will produce 1.6×10¹⁴ decay events per second. That's 3.8 W/kg specific power, which is roughly 1% of lithium ion -- assuming 100% conversion efficiency. HOWEVER, we know that only 31% of the decay energy is actually carried away by the beta particles, and the rest ends up as heat (which is not captured)[1]. On top of that, the efficiency of converting the beta particle's kinetic energy into electrical power is low. I found a paper citing a 26% conversion efficiency [2], which seems high but lets go with it. Finally, the mass of the battery obviously includes more than just the C-14. Lets assume that half the mass of the battery is C-14. That would bring us down to 300 microwatts per gram of C-14, and less than 0.05% of the specific power of a LiIon battery. [1] There's also a positron that shares half of this energy -- I don't know if these devices capture that, so I'm just leaving it in. [2] https://www.sciencedirect.com/science/article/pii/S016890022... https://www.sciencedirect.com/science/article/pii/S016890022...)