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Research Promises Drastically Increased LiOn Capacity
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."
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
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"graphene" is single-atom-thick carbon.
Having read the article (*gasp*) as well as a few others it seems these batteries do NOT hold 10x more power. They degrade 10x slower on on drain/recharge cycles and can be charged 10x faster. BUT this is not the same as having 10x more POWER per cycle. Gonna have to wait some more before you get an cheap electric car that can go 500 miles before charging (though charging 10x faster is nice).
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Although it is subtle, battery technology has improve energy density steadily over the years. For lithium-ion, the trend has been about 5-10% / year for over a decade now. The battery pack from my ten-year old laptop (yeah, it's sittin' in a box somewhere) has just over half the nominal capacity of a battery of similar volume today. It's not Moore's Law, but it is there.
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. 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.
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?
In Soviet Russia, articles before post read *you*!
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?
In Soviet Russia, articles before post read *you*!
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.
I don't need a million points of light, just two points of multi-mode fiber and a 10 Gig-E router.
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.)