The trickiest part looks like the chemical vapor deposition of graphene onto SiO2 nanoparticles. CVD is a slow growth process that I normally see applied to creating precise, thin layers on flat substrates. I think it would be hard to scale this up to industrial (tonne per day) quantities of coated particles. Is it possible to replace that process with something like a fluidized bed reactor? I'm out of my depth here regarding paths to scale-up -- I have a chemistry background, but I'm not qualified to comment on most chemical engineering.
Wow, this might be one of those rare instances where new research is gonna proceed rapidly into industry. The paper[1] isn't shy about it either. This is great on all fronts: increases cycle life, charge speed, and even marginally increases capacity. They're very optimistic about integrating it into production lines and it seems cost-effective. Cheap, even. The inputs are methane and fumed silica into a 1000 C furnace- you can practically buy those at a hardware store and then it just gets mixed into the r2r slurry.
I think it's pretty likely that charge speeds are about to increase handily. Fig. 4 shows the battery with additives charging at 5 C compared to virgin chemistry at 1 C. That's about 5 minutes to charge the middle 50% of a battery- incredible. Still remains to be seen if this is compatible with standard additives and SEI conditioning, but I'd be surprised if it didn't work out fine.
I feel the same about the CVD but it looks like it was fast and easy from the paper (as much as I recall right now). Certainly way less exotic than most CVD.
Could have fooled me.
I applaud you, sir, on your awareness of self and awareness of scale. If only all programmers were as self aware and aware of the difference between a background in programming and software engineering at scale, I'd smile a little more.
For reference, I used to see ~4 hour cycle times for growing graphene on copper sheets. I think most of that was in the heat up and cool down, maybe order of 30min actual growth time. These numbers might be off by a factor of 2-5, it's been a few years since that job, and I was a equipment design engineer not a process guy as such.
Compared to other Battery tech advance from University Research and Startup which are trying to hype and gain new funding, Samsung doesn't need that. And my guess it is at least small scale production ready before they make such announcement. ( Or they knew a competitor which has a similar product announcement soon and step up ahead of them )
Hopefully we see this in shipping product by 2020.
800 / 2.5 would be 320 Wh/kg.
800 / 3.0 would be 267 Wh/kg.
Both numbers are quite good, as batteries go, but not an order of magnitude higher than what's available now.
I thought I was watching an episode of Flash for a moment.
10 years ago PERC cells weren't available on an industrial scale, even though the technological basics were discovered, explored at the lab scale, and published in the 1980s. It took a lot of manufacturing advances and market evolution before PERC technology was both practical and profitable to manufacture for large scale use.
http://www.aleo-solar.com/perc-cell-technology-explained/
Likewise, I expect that some battery ideas that are published and "go nowhere" will eventually reach industrial scale, but only much later.
We have been spoiled by the web to expect a whole other time scale, but physical technology still takes the time it has to take.
My - not very informed - impression is that battery technology actually is moving very fast, considering the timescale constraints.
That's precisely the sort of thing that most manufacturers don't want, because a battery designed to last effectively forever means less recurring revenue on replacements.
"100% recyclable" is good for them (and "biodegradable" even better), because they can act "green" while continuously making products that don't last and have to be recycled, expending even more energy and creating profit in the process. "The best kind of planned obolescence is environmentally friendly planned obolescence."
That's ridiculous, tinfoil hat thinking. Longer cycle life = cheaper battery = higher profit + happier consumer.
Those breakthroughs, when applied to scaled up battery manufacturing give us the 5%-10% compounding annual improvement we see. A doubling at least every 15 years is pretty good!
Experts were skeptical[1] that their recharge rates and capacity were possible with current gen tech...unless Elon knew something they didn't.
[1] https://www.bloomberg.com/news/articles/2017-11-24/tesla-s-n...
Isn't this only necessary because Lithium-Ion batteries need it to maintain efficiency and longevity? Is this also an issue with graphene?
Edit: better source here https://www.nature.com/articles/s41467-017-01823-7
The growth process is the only remaining question, but it seems very tame. Methane is the carbon feedstock, and the furnace is only 1000 C. It doesnt have the pitfalls of normal graphene production because they arent concerned about monolayers etc- I would say their product has a lot more in common with expanded graphite than graphene. Because of that I expect its similar in cost to synthetic graphite, which is roughly equal to natural graphite.
Observe the noticeable lack of any mention of how many cycles a cell will last at this charge rate. It is well known that ordinary li-ion cell can be charged extremely fast too, as long as you don't charge so fast it heats up rapidly and goes into explosive thermal runaway, but it shortens the lifetime considerably.
> A full-cell incorporating graphene balls increases the volumetric energy density by 27.6% compared to a control cell without graphene balls, showing the possibility of achieving 800 Wh L−1 in a commercial cell setting, along with a high cyclability of 78.6% capacity retention after 500 cycles at 5C and 60 °C.
In your other comment you write:
>the standard is 80% capacity after 500 cycles at the normally specified (1C) charge rate
So I'd say that's pretty good.
Does that mean 5C Charge rate and > 5C Discharge? Because in the EV Market 5C discharge would be borderline enough (I think Teslas 18650 discharge at a peak of 20A per ~3,5Ah Cell so 5C Discharge would be cutting it very close.)
If it's 5C Charge and getting to 500 cycles with higher discharge then...woah.
Heres an "entry" article: https://kabru.eecs.umich.edu/wordpress/wp-content/uploads/St...
and you can follow the references from there (into SciHub etc. if need be.)
Problem is that this graphene layer is extremely thin, one atom. Mass-production, what they claim to do, would be a killer app for much more than just batteries, but for batteries it's the easiest win.
For cars, having twice the capacity with the same charge speed would be enough, since you can charge slowly when you sleep, what matters is that the car can handle the distance you can travel in a day.
