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Samsung Nanotech Breakthrough Nearly Doubles Li-Ion Battery Capacity
The Korea Times reports that Samsung researchers have published in Nature Communications the results of research (here's the abstract) that could lead to vastly greater storage capacity for lithium-ion batteries. The researchers, by growing graphene on silicon anodes, were able to preserve the shape of the anodes, an outcome which has formerly eluded battery designers: silicon tends to deform over numerous charging cycles. From the linked abstract: Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700Whl1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries.
Also at ZDNet.
And battery capacity just doubled last week! It's amazing that they can keep releasing breakthrough after breakthrough!
How can I believe you when you tell me what I don't want to hear?
For those cozy nights by the fire.
to make half as thick phones, instead of phones that last twice as long...
The Cloud - because you don't care if your apps and data are up in the air.
I suppose it depends on the definition of "supercar."
However, I hope this means my android phones will start to get better battery life. Half the life of an iOS device would be a huge win.
Mod me down, my New Earth Global Warmingist friends!
There have been scores of purported breakthroughs in this subject over the last ten years, but nothing dramatic has as yet hit the market. There have of course been noticeable improvements - but I still have to recharge my phone every night, and a decent range in an electric car will still set you back to the tune of nearly $100K. We'll see whether this is really becomes a breakthrough, or whether it is just another incremental step forward.
That's not what it says. It says that the capacity at 200 cycles is 1.5x a current cell. No mention is made of the point at which the capacity of these cells drops below the capacity of regular cells, if indeed such a point even exists: it's entirely possible these cells have roughly the same performance vs cycle curve as current cells after 200 cycles, just with a generally higher capacity.
I suppose you might raise the question of why they limited their testing to 200 cycles rather than more, but I note that if each charge/discharge cycle takes 4 hours then 2000 cycles would take almost a year to complete.
The value of 1.5 is equal to 2 for small values of 2.0
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Any theories for why Tesla's stock price didn't pop on this news?
Musk already had one big pop today.
There's news like this every week. None of these is clearly better cheaper or faster to market than any other breakthrough like it at this early stage. It all evens out to a fairly steady improvement over time. Battery weight and prices still keep halving every five years or so and that's already factored into stock prices, minus some risk.
Top commercial li-ion capacities are about 30% more than they were 5 years ago. And today's batteries include some of the "advances" you were reading about 5 years ago.
I'm sorry if technology doesn't move forward at the pace you want. But it does move forward when you're not looking. Remember the size of cell phone batteries back in the day?
Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
On the other hand, if they're doubling capacity, then you only need half the number of cycles (it actually even works *better* than that, as li-ion cells prefer shallow charges and discharges rather than deep ones - but yes, fractional charge cycles do add up as fractional charge cycles, not whole cycles). If you have a 200km-range EV and you drive 20 kilometers a day, you're using 10% of a cycle per day. If you have a 400km-range EV and you drive 20 kilometers a day, you're using 5% of a cycle per day.
Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
Keep in mind that for widgets like phones and tablets that they are not always cycling fully on a daily basis. Lithium Ion batteries degrade much faster being deep cycled from 100% to near 0% than if you are only going 80% to 20%, like an order of magnitude longer. Most applications do not ever fuly charge the cells, and shut down before hitting zero to trade off a little capacity for vastly longer useful lifetimes.
On the other hand, if they're doubling capacity, then you only need half the number of cycles
I'm pretty sure I saw an episode of Red Dwarf where they made a similar trade off... It ended up with Lister playing pool with planets.
Don't be like Lister.
#DeleteChrome
What's the power density? (Amount of energy delivered over time)
That's not power density. That's just power. Power density is how much power (energy delivered over time) it can deliver per unit volume of battery. That's really only of concern for high power applications such as an electric race car. For most usages, energy density is far more valuable.
Problem with lithium based batteries, in general, are two things:
1: Puncture them, they go boom unless engineering is done to prevent this.
2: If they are not discharged and charged correctly, they go boom.
One place where lithium batteries are starting to make an impact (namely LiFePO4 batteries) is RV-ing. However, Silverleaf controllers tend to be expensive, so if you want this and you like off-grid camping, expect to pay upwards of $120,000 just to play in this ballgame. More useful setups (800-1200 ampere-hours) are available (Advanced RV comes to mind as well as Roadtrek), but expect to pay dearly for those.
What really is needed is a charge/discharge controller that can take a bank of lithium cells and make it appear to existing chargers and electrical loads like the battery is a flooded lead-acid or AGM battery. This would allow retrofitting without having to do major re-engineering of the rest of the electrical system. However, in reality, it will take a re-engineering of charging and discharging eventually because of lithium's different charging/discharging curves.
Remember the size of cell phone batteries back in the day?
Back when they lasted a week on a charge? Yes, they were larger. And lasted longer. Much longer. Of course the phones were lower-draw (though not as low as you'd think, as the radios were more power hungry).
Learn to love Alaska
By definition.
They may be expecting an advantage to 1000 cycles, but have only tested to 200 because of the time involved, and released with 200, and are halfway to 1000 by now.
It's only your assumption that they aren't testing to 1000.
Learn to love Alaska
Plus of course, 1.8x at brand new means that all other things being equal, you'll have many fewer charge cycles.
Would be interesting to see someone do the math, but the battery decay curve on these should be much shallower overall (until some doofus uses it to make a smaller phone - which isn't really very likely, they're already reaching the limits of what you can do in terms of structural strength if you can bend them by sitting on them...)
Without even reading the article, I can guess what they did from my own experience: use a hole punch and flip the battery over.
-Dave