Re:Solar-driven water splitting at 13.8% solar-to-hydrogen e...
by rektide on Thursday November 18, 2021 @10:40PM
(#29273546)
meta-note: this post has bounced up and down, 1, 2, 1, 2, 3, 1, 2. something like that. i just find that weird. hn has some weird downvoting behaviors that i really don't understand at all. maybe there's something legit downvotable or that people don't like? this seems like an innocuous post to me. i don't see the reason for it to keep getting negged.
apologies. i know discussing meta-topics is against the rules. i just really dont understand why there's an ongoing basis against this content becoming popular. it's so weird to me. i want to believe there's genuine real authentic behavior behind the votes happening here & elsewhere, but it feels so so weird to see this kind of straightforward telling constantly bounded, rising, then flattened back down, again and again. it instills a larger sense of disbelief, feels like there are vulgar reactionary forces about, which is not at all a conspiracy mindset i want to fall into.
Relatedly, LFP are just rugged as heck batteries. They tend to have double or more the life-cycle count. 5000 cycle count before getting down to 80% capacity? In many cases yes. That's pretty impressive, and a great boon to overall lifecycle/long-term costs. Even if you're getting less energy-density, or even less energy-store/$, that battery is going to live at least 2x the effective lifespan (barring accidents, major defects, &c).
In general, anything built for high current tends but lower energy density tends to have much more ruggedness. Sanyo’s UR18650E is Li(NiMnCo)O2, for example, but in one paper shows 4X the lifecycle count of the extremely well regarded O.G. of LFP, the A123 ANR26650M1-A[1]. Even though it's considered a "lithium ion". And uses some of the rarer/more expensive materials. (Edit: re-reading the paper more closely, I'm less willing to embrace this conclusion. The A123 remains around 2000 cycle count regardless of depth of discharge pattern, while the li-ion drops to 1000 around 50% DoD.)
Not that phosphorous (The P in LFP) is projected to remain cheap/available forever. 2 days ago, talking more about phosphor's availability specifically with regard to agriculture (and rather alarmistly), "Phosphorus is essential to life and the world is running out of it"[2].
[1] http://www.jocet.org/vol7/511-C0056.pdf
[2] https://medium.com/climate-conscious/peak-phosphorus-may-be-... https://news.ycombinator.com/item?id=29244529 (2 days ago, 2 comments)