Research Promises Drastically Increased LiOn Capacity 378
daem0n1x writes "Could this be the breakthrough we've all been expecting that will finally make the electric car a reality? Researchers of Northwestern University USA discovered a new way to build lithium-ion batteries that changes dramatically both the charge time and capacity [original paper, paywalled]. Guess what it involves? That's right, graphene."
Re:The magical ingredient (Score:5, Informative)
Actually, if you read the university press release, you'll see the magical ingredient is silicon. Current lithium-ion batteries already contain graphene sheets. What they did was
Re:The magical ingredient (Score:5, Informative)
"graphene" is single-atom-thick carbon.
Don't confuse Duration with Capacity (Score:5, Informative)
Re:Better Place (Score:2, Informative)
I'm pretty sure you can replace everything you've just typed there with respects to a battery and use the word petrol.
Please see webheaded's comment [slashdot.org].
Re:Don't confuse Duration with Capacity (Score:5, Informative)
They do have more capacity - this isn't the traditional carbon electrode, this is a graphene-stabilised silicon anode, and silicon holds more charge.
They also have more power, as well as more capacity. If the internal resistance is low enough to charge it in 15 minutes, it's low enough to discharge it that fast as well.
Alas, the missing bit is similar innovations in cathode technology.
Re:Don't confuse Duration with Capacity (Score:3, Informative)
Not to mention that Gasoline or Diesel contains ooo 45 MJ/KG while a LIon Battery stores ooo 1 MJ/KG ... http://en.wikipedia.org/wiki/File:Energy_density.svg [wikipedia.org]
Seems we have a 'little' ways to go before LIon can replace good ole hydrocarbon fuels.
-- kjh
Re:Better battery life is always a year away (Score:5, Informative)
On the other hand, with the exponential increase in transistor count / computing power has some a corollary effect of decreasing energy needed to do that computation: Koomey's Law [wikipedia.org]. So if I take a look at the battery pack from my 5-y.o. flip phone and compare it to what's in an iPhone, they are roughly the same volume. But the newer battery has more capacity, and the newer phone does jumping jacks around my old feature phone, and has about the same amount of talk time / standby time, if not more.
Call me an optimist, but I think that in this regard we're still coming out ahead.
Re:Where was this reasearch done? (Score:5, Informative)
The confusion is because the paper linked in the summary is incorrect.
The Northwestern paper is titled "In-Plane Vacancy-Enabled High-Power Si–Graphene Composite Electrode for Lithium-Ion Batteries (pages 1079–1084)" and the summary linked paper is titled "In Situ Generation of Few-Layer Graphene Coatings on SnO2-SiC Core-Shell Nanoparticles for High-Performance Lithium-Ion Storage".
Can people mod me up or have the summary corrected?
Wrong article linked in summary (Score:5, Informative)
The Northwestern paper is titled "In-Plane Vacancy-Enabled High-Power Si–Graphene Composite Electrode for Lithium-Ion Batteries (pages 1079–1084)". The article linked in the summary is titled "In Situ Generation of Few-Layer Graphene Coatings on SnO2-SiC Core-Shell Nanoparticles for High-Performance Lithium-Ion Storage".
Can people mod me up or have the summary corrected?
Re:Better battery life is always a year away (Score:5, Informative)
Still, the main use case they are touting in the summary is cars. Faster charging, higher storage density batteries are a huge deal in that space. One of the big complaints with electric cars is that they take much longer to charge than a gas powered car takes to fill up, so faster charging is a big deal. More power density means either a) you can store the same amount of power in fewer batteries (thus theoretically reducing the weight and cost) or b) can get much farther on the same sized battery.
Right now electric cars are right on the cusp of being really commercially viable. If they become a hair cheaper, a hair longer range, a hair quicker to charge... it could put them over the top. This has the potential to do all three, and if the research is accurate increase all of them by more than a hair.
Plus, you know, I wouldn't complain if my iPhone went 3 days without a charge.
Re:The magical ingredient (Score:5, Informative)
Actually, if you read the university press release, you'll see the magical ingredient is silicon. Current lithium-ion batteries already contain graphene sheets. What they did was
That's not quite the whole story: current lithium-ion battery designs have *graphite* in them, which is a bit disingenuous to describe merely as "many layers of graphene". The fact that in this design, they are in discrete multiple layers (with silicon and, as a result of this research, perforations) is what makes the difference. To my knowledge (correct me if I am wrong) no commercial battery has discrete graphene layers in it (graphene is a relatively new area of research, circa 2004, and conventional li-ion battery design has been relatively unchanged for about 20 years.)
Re:Better Place (Score:4, Informative)
yes, $50/ fillup. I'm Canadian and drive a small 4 cylinder. That's what it costs me to fill up.
Try running a business... any business.
But if it helps. Let's work through this example.
Let's suppose you run the gas station and want to keep enough reserves to service 1000 fill-ups.
Using gasoline (assuming $50/fill up), you need inventory worth 1000*50 = $50,000. Need more gas, you just have it delivered on demand. It's easy to manage supply and demand here given the low cost per fillup.
Using battery exchange, you would need 1000 battery packs. That's an inventory of 1000 * $5000/battery pack... that's $5,000,000. Not to mention the huge space this would take to store the batteries. Not to mention the complexity of the batteries (failure rates...).
Again, I'm not saying it's impossible. But it is significantly more difficult and requires significantly higher capital costs to have a battery exchange style system.
It's not something I'd put my money into. I'd put my money on new innovation on battery technology, hybrids, rapid charging...
Re:I though they were already a reality... (Score:4, Informative)
That seems like a problem in your argument. There is no electric car+battery combination which costs $16k. The figure you cite is less than half the actual retail cost of an electric car+battery. Even the prius plug-in, due next year, costs over $30k, and the battery pack only provides a 10 mile range.
Retail electricity for residential consumers in states which don't burn coal is about $0.14/KwH, not $0.10. If we burn coal to generate electricity, then we've negated any environmental benefit of electric cars, so we should use the $0.14/KwH price for electricity. Electricity from renewables would be at least 50% more expensive than even that.
Let's try a comparison with these figures. The Nissan Leaf costs $35,000, and an approximately equivalent Nissan Versa Hatchback costs $15,000. If we drive the versa for 150,000 miles with $4/gal fuel at 35 mpg, we pay $17,142 for fuel. If we drive the Leaf for 150,000 mi (which is the rated life of the battery pack), the fuel (electricity) would cost $8,400 (leaf has a 24 KwH battery pack which costs $3.36 to recharge at $0.14/KwH and takes us 60 mi on average, for a per-mile charge of $0.056, *100,000 = $8,400).
We must also include the cost of financing. Interest at 3% above inflation for 5 years would cost $2250 for the Versa and $5250 for the Leaf. Even if you pay using cash upfront, you are foregoing interest you could have earned by investing the same money, so it's an opportunity cost.
There will also be different insurance costs, for insuring a $15,000 car against theft vs. a $35,000 car. But let's ignore that now.
Of course the government will give you a $7,500 tax break right now if you buy an electric car, but will only do so for a small number of buyers until the incentive expires, so let's ignore that now because it's not generalizable.
The total cost of the Versa for 150k mi is $34,392, and the total cost of the Leaf for the same distance is $48,650. It costs about 41% more to drive a similar electric car at present, not counting insurance or limited-time government incentives. It is not cost-competitive.
It's possible that an electric car will become competitive if gasoline costs far more in the future and batteries cost less. If the Leaf costs $30k in the future and gasoline costs $7/gal (in 2011 dollars), then the Leaf would be approximately cost-competitive with a gasoline-powered car. This circumstance is definitely possible within the next 15 years.