"Here we report lithium ion microbatteries having power densities up to 7.4mWcm2m1,which equals or exceeds that of the best supercapacitors, and which is 2,000 times higher than that of other microbatteries."
WTF more do you want? you can calculate almost everything from there.
For god's sake, if you're going to quote technical math, can't you at least get it transcribed right? 7.4mWcm2m1 is utter nonsense. I realize for reasons unknown slashdot does not implement even elementary HTML markup like Greek letters, superscript and subscript. Preview shows garbage from cut and paste, so just improvise.
The article says 7.4 mW cm^-2 micrometer^-1, which are pretty bizarre units, but readily convertinle to 74 GW/m^3, or 74 MW/liter. That gives us the power density in meaningful form, and it seems pretty damn impressive to me.
"74 MW/liter" would imply 3 litre sized batteries could power an Enterprise-class aircraft carrier. Impressive would be a slight understatement.
mW / cm^2 / micrometre = 10^-3 W / (10^-2 m)^2 . 10^-6 m = 10^-3 W / 10^-10 m^3 = 10 MW / m^3 aka 10 Megawatts per cubic metre.
So I think we're looking at 74 kW / litre. Which is still impressive. It also ties in with the A123 data point on Figure 3 of the Nature preview and this page http://www.a123systems.com/prismatic-cell-amp20.htm quoting "4,500 W/L" energy density.
Looking at Figure 3 on the Nature preview, they seem to be offering energy densities of 0.1 to 10 microwatt hours / cm^2 / micrometre, or 1 to 100 Wh per litre. This would imply that at full output these batteries discharge in seconds. Right now these seem to be top of the range* capacitors. James Pikul hints that there is more to come: "if you want high power it’s very difficult to get high energy. But for very interesting applications, especially modern applications, you really need both. That’s what our batteries are starting to do."
I'm hoping this means they can drive the performance into that upper right quadrant of figure 3.
* = I refuse to climb any further aboard the super/mega/ultra/mithril superlative escalator.
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For god's sake, if you're going to quote technical math, can't you at least get it transcribed right? 7.4mWcm2m1 is utter nonsense. I realize for reasons unknown slashdot does not implement even elementary HTML markup like Greek letters, superscript and subscript. Preview shows garbage from cut and paste, so just improvise.
The article says 7.4 mW cm^-2 micrometer^-1, which are pretty bizarre units, but readily convertinle to 74 GW/m^3, or 74 MW/liter. That gives us the power density in meaningful form, and it seems pretty damn impressive to me.
"74 MW/liter" would imply 3 litre sized batteries could power an Enterprise-class aircraft carrier. Impressive would be a slight understatement.
mW / cm^2 / micrometre = 10^-3 W / (10^-2 m)^2 . 10^-6 m = 10^-3 W / 10^-10 m^3 = 10 MW / m^3 aka 10 Megawatts per cubic metre.
So I think we're looking at 74 kW / litre. Which is still impressive. It also ties in with the A123 data point on Figure 3 of the Nature preview and this page http://www.a123systems.com/prismatic-cell-amp20.htm quoting "4,500 W/L" energy density.
Looking at Figure 3 on the Nature preview, they seem to be offering energy densities of 0.1 to 10 microwatt hours / cm^2 / micrometre, or 1 to 100 Wh per litre. This would imply that at full output these batteries discharge in seconds. Right now these seem to be top of the range* capacitors. James Pikul hints that there is more to come: "if you want high power it’s very difficult to get high energy. But for very interesting applications, especially modern applications, you really need both. That’s what our batteries are starting to do."
I'm hoping this means they can drive the performance into that upper right quadrant of figure 3.
* = I refuse to climb any further aboard the super/mega/ultra/mithril superlative escalator.