Technology

Electrify ship you say?

We’ve seen so many battery breakthroughs in academia in the past decade, it’s about time some of them start to transition into production.

For ships they are rediscoverings sails so that might be enough

CRI is defined as how closely a light source matches the spectral emission of a thing glowing at a specific temperature. So, for a light source with a 4000 k color temperature its CRI describes how closely its emission matches that of an object that's been heated to 4000 k.

Because incandescent bulbs emit light by heating a filament by definition they will have 100 CRI and its impossible to get any better than that. But the emission curve of incandescent lights doesn't actually resemble that of sunlight at all (sorry for the reddit link). The sun is much hotter than any incandescent bulb and it's light is filtered by our atmosphere, resulting in a much flatter more gently sloping emission curve vs the incandescent curve which is extremely lopsided towards the red.

As you can see in the above link, there are certain high end LED bulbs that do a much better job replicating noon day sunlight than incandescents. And that flatter emissions profile probably provides better color rendering (in terms of being able to distinguish one color from another) than the incandescent ramp.

Now, whether or not you want your bulbs to look like the noon day sun is another matter. Maybe you don't want to disrupt your sleep schedule and you'd much rather their emissions resemble the sunset or a campfire (though in that case many halogen and high output incandescent lamps don't do a great job either). Or maybe you're trying to treat seasonal depression and extra sunlight is exactly what you want. But in any case I think CRI isn't a very useful unit (another reddit link).

You can buy high (97-99) CRI LEDs for things like the film industry, where it really does matter. They are very expensive, but can pay for themselves with longer service life, and lower power draw for long term installations.

The CRI on regular LED bulbs was climbing for a long time, but it seems as though 90ish is "good enough" most of the time.

And early LEDs had flickering issues w/ dimmers. And somehow they're still way more expensive than incandescent bulbs (not sure about per hour of use, but certainly by unit, which matters when renting).

I feel the same way when I read these articles. They make it seem like everything is an earth shattering breakthrough when in reality, they're making a small (albeit worthwhile) contribution towards solving a problem that already has 20 other solutions with other trade-offs.

But I like it when I read about any new battery tech being scaled up do industrial scale, like the article here. That's the hard part.

I don't see the point of nanoelectrofuel flow batteries. I'm sure there are niche applications that I can't see. But not anywhere near what that author is describing.

Flow batteries are good because they're so cheap per mAh and W, and if you're using them for grid scale storage, size and weight doesn't matter. The energy density is greatly increased when you add nanoparticles, to the point where it competes with EV batteries. This includes the extra weight of pumps and membranes. I think the addition of pumps and membranes make it really unfit for personal vehicles, even if it increases the energy density. The article talks about military applications, but doesn't really explain what it could do better that Li-ion except for fire safety. And they'd be dependent on the fuel of this one company.

I think its major selling point is that it's cheap and very modular, so you can easily choose what capacity/power your grid scale facility should store/output, and change it after the fact. But if your building a facility, then the weight doesn't matter as much and you might as well skip the nanoparticles.

As a technology I think it's really clever. It's not a very well studied idea. They're tight lipped and I assumed it was some sort of Vanadium flow battery, but judging by the articles they're citing in their patent and their conference talk abstract I'd speculate the cathode nanoelectrofuel is a water based slurry with lithium iron phosphate nanoparticles and carbon powder. The particles discharge like they would in a conventional Li-ion battery. But then instead of charging them you pump the slurry to your big tank, replacing them with charged particles. You need the carbon to conduct the electrons from the suspended particles to the current collector plate.