Posted on 11/25/2008 8:12:11 PM PST by LibWhacker
In what could potentially be a revolutionary breakthrough for everything from laptops to electric cars, a South Korean team of researchers have made a major discovery in Lithium-Ion battery technology. A team of researchers at South Koreas Hanyung University, led by professor Cho Jaephil, has claimed a discovery that could extend lithium ion battery energy capacity by up to 1000% or more.
The key to Jaephils discovery was the application of a three-dimensional porous silicon graphite cathode, which has the ability of holding up to ten times the number of lithium ions as conventional graphite cathodes. Patents have already been applied for. from the press release:
Lithium ion accumulator batteries produce current by moving lithium ions. The battery usually contains a cathode (positive electrode) made of a mixed metal oxide, such as lithium cobalt oxide, and an anode (negative electrode) made of graphite. While the battery is being charged, lithium ions migrate into the anode, where they are stored between the graphite layers. When the battery is being discharged, these ions migrate back to the cathode.If this is for real, it could have a huge impact on the electric vehicle industry. For example, the Tesla Roadster currently gets about 150-200 miles per charge. Imagine having an electric car that gets 1600 miles per charge, with a full charge costing you less than a regular tank of gas. Youre getting more miles for less money, with no fossil fuel use - especially if your electrity comes from a renewable source.
It would be nice to have an anodic material that could store more lithium ions than graphite. Silicon presents an interesting alternative. The problem: silicon expands a great deal while absorbing lithium ions (charging) and shrinks when giving them up (discharging). After several cycles the required thin silicon layers are pulverized and can no longer be charged.
Chos team has now developed a new method for the production of a porous silicon anode that can withstand this strain. They annealed silicon dioxide nanoparticles with silicon particles whose outermost silicon atoms have short hydrocarbon chains attached to them at 900 °C under an argon atmosphere. The silicon dioxide particles were removed from the resulting mass by etching. What remained were carbon-coated silicon crystals in a continuous, three-dimensional, highly porous structure.
My thought exactly. We’re talking enormous energy densities here.
Very exciting, but if that energy gets loose suddenly life in the immediate vicinity will be even more exciting!
At least in theory this won’t require as much additional electrical generating capacity as many think. If cars are recharged during presently low-use periods, much of the capacity can come from the more efficient use of peak capacity. This can easily be encouraged by having considerably lower rates for off-peak electricity use.
I also wonder how much these batteries will cost and how long they will last.
The energy in a gallon of gas is 1.3x108 joules, which equals 36 Kwh. At a household cost of 12 cents/Kwh, that's $4.33 for an amount of electricity that would equal the energy of one gallon of gas.
Now, electric cars are much more energy efficient than the internal combustion engine, so the real cost will probably be closer to $1 - $2, but it's still not free.
We graduate engineers. They just can’t find decent jobs.
Is there a country on a planet that values education more than Korea does? A hat tip to them.
*the*
Cool.
Good idea - IF/WHEN it works.
(Now, about that messy little “dispose of the old battery” problem. Will the enviro’s let us throw away Lithium compounds? )
Nice.
For one thing, Li-Ion batteries are such a promising technology that lots of people are working with them all around the world. It's not surprising that other folks make discoveries, too.
More to the point, if you've been following the FR threads on the topic (there have been many), you'd know that there is a lot of Li-Ion battery research in the US, including a large number of significant breakthroughs.
There seems to be a lot of confusion here about whether the energy density is being increased or the number of cycles of discharge - recharge.
The objective is to do both of course.
Maybe because it's too dangerous?.....8^)
I wonder if the crystal arrangement is fractoid in nature. I wonder if anyone has applied the fractoid concept to the anodic material.
“The energy in a gallon of gas is 1.3x108 joules, which equals 36 Kwh. At a household cost of 12 cents/Kwh, that’s $4.33 for an amount of electricity that would equal the energy of one gallon of gas.
Now, electric cars are much more energy efficient than the internal combustion engine, so the real cost will probably be closer to $1 - $2, but it’s still not free.”
Here are some real world watt hour per mile figures.
“impact 130 w-Hr/mile, truck 350 W-Hr/mile, prius 250 w-hr/mile, GMVolt 200 w-wh/mile, BugE 170 w-hr/mile, Tesla 177 w-hr/mile, GM EV1 115 w-hr/mile. “
An electric vehicle is 3 times more efficient than internal combustion. For the stoichiometric OTTO cycle less than 13% of your energy per gallon reaches the pavement. While electric motors are over 98% efficient in converting electricity to mechanical motion. The GMvolt uses 200 watt hours a mile so at 12 cents a kilowatt thats .024 cents a mile in electricity costs. A similar sized Otto cycle car would get 30 mpg ruffy, or to equal .024 cents per mile gasoline would need to cost 75 cents per gallon. Giving that gas is selling for 1.55 a gallon locally a 30 mpg car costs .0511 cents per mile or twice as much as the GMvolt. At the summers peak of 3.89 a gallon the little 30 mpg car cost 12.93 cents per mile or 6 times as much. No electric cars are just waiting for battery tech to come online once the bat tech is there they kill combustion cars in economics.
Go to any university engineering department and see how many Asian students there are compared to Americans.
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