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."

Comments

Re:The magical ingredient

[Halo1]

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

• sandwich silicon between the graphene sheets, because silicon can bind many more ions than carbon (the downside is that it fragments, and that's what they addressed with their sandwiching process) -> more capacity
• make minuscule holes in the graphene sheets to offer shortcuts to ions traveling from one side of the sheet to the other side (-> faster charging)

Re:The magical ingredient

[timmy.cl]

"graphene" is single-atom-thick carbon.

Don't confuse Duration with Capacity

[DumbSwede]

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).

Re:Don't confuse Duration with Capacity

[Dr_Barnowl]

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:Better battery life is always a year away

[necro81]

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.

Re:Where was this reasearch done?

[dokebi]

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

[dokebi]

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?