Nanotubes Extend Battery Life

nickynicky9doors writes: "University of North Carolina researchers have demonstrated they can extend battery life by replacing the usual graphite electrode in a common rechargeable battery with a nanotube. The TRN News article speaks to an increase in the amount of charge a battery can hold and so to an increase it's lifespan. Rolled-up sheets of carbon atoms, nanotubes ...'have twice the storage capacity [of] the graphite electrode...'. The timeline for production is put at 2 years."

Will these be expensive?

[mfarah]

It will be at least two years before carbon nanotubes can be used in lithium-ion batteries, Zhou said. "We show the potential but there are many practical issues that need to be solved," he said.

I can't help but think that manufacturing these batteries will cost more than twice than current ones, making them economically unviable.

Re:Will these be expensive?

[JanneM]

Not quite true. Even if they cost a lot more than ordinary batteries, there are a lot of applications where the benefits of extended life is just so great it's worth it. Just consider all the laptop-toting executive types out there in the world; they're likely to pay through the nose if it means the difference between being able to work during the whole flight or not.

What I'm trying to say is that there isn't a linear correlation between battery life and price.

/Janne

Lifespan, recyclability, pollution

[Spamalamadingdong]

I think we can take it for granted that we'll find easy ways of making carbon nanotubes in ton quantities. But their usefulness for making batteries depends on other factors:

• How many cycles can they take before they have degraded by, say, 50%?
• How difficult are they to recycle or destroy?
• If they are released into the environment, do they pose a pollution hazard akin to the fine asbestos fibers which are known to cause lung disease?

None of those things were covered in the article, and they'd be very nice to know. If the nanotubes don't offer as good a lifespan as the proton polymer battery, or you'd have a health hazard if the fibers were dispersed, these things are not going to be the panacea they appear from the article.

Re:Lifespan, recyclability, pollution

[logophage]

it seems to me that since carbon nanotubes are, well, pure carbon that pollution is a non-issue. carbon must be better than polymers. also, any work done on the effects of graphite/diamond dust would seem to apply equally well for nanotubes.

Heard of soot? It's a health threat

[Spamalamadingdong]

it seems to me that since carbon nanotubes are, well, pure carbon that pollution is a non-issue.

Diesel soot is nearly pure carbon, but the PM10 class of particles into which the finest soot falls is strongly associated with hospital admissions from respiratory problems, as well as spikes in deaths. 500-nanometer (.5 micron) nanotubes sound like they're right in the size range where they'd be a serious threat.

Somehow I don't think that a solid block or sheet of polymer presents anything like the same threat from the battery being broken open.

Re:Heard of soot? It's a health threat

[logophage]

fortunately, the proposed battery doesn't superheat nanotubes and spew them out the end of an exhaust pipe. also, i find it unlikely the nanotubes would be in powder form; most likely there would be a bonding agent to ensure a constant surface area. can we say red herring?

Re:Heard of soot? It's a health threat

[Associate]

Does that mean that carbon nano-tubes are a communist plot to poison our children?

Re:Lifespan, recyclability, pollution

[p3d0]

You can predict the harmful effects of a substance based solely on the elements it contains? Wow, that's news to me. I think I'll go eat a bowl full of diamond shards.

Re:Lifespan, recyclability, pollution

[logophage]

yes, actually. you can predict if it will be harmful based solely on its elements (e.g. plutonium is considered harmful). also, you can predict its harmful effects based solely on how the substance will be used (e.g. granola in a bowl is okay; two tons of granola on top of you is not okay). since carbon nanotubes are not going to be sprayed into your lungs at any point during the lifetime/trashtime of the battery and carbon sitting in a trashdump leaching into groundwater is not particularly bad, i would say that pollution due to these nanotubes will not be high on the list of polluting sources in the world.

Re:Lifespan, recyclability, pollution

[p3d0]

I think you just proved my point. You can prove that something is harmful based only on the elements it contains, but not that it is harmless, which is what you are claiming to do.

I'll bet you a shiny new nickel that nanotubes will be found to be harmful to the environment somehow.

Next

[4of12]

So I have to wonder whether carbon nanotubes might better be used as capacitors than as an electrode in a conventional battery?

Carbon-layering.

[Nyphur]

Well, with the carbon artificially layered like this, in concentric circles with tiny spaces between the layers, the constructions resulting from this would be an artificial circular graphite-type material. The extra electron storage would result from the sea of free-floating electrons between each layer, as in graphite.

Re:Carbon-layering.

[PhuCknuT]

Actually, the article says they used single walled nanotubes, bot multiwalled. So the electrodes aren't layered. The article doesn't mention the configuration, but the most likely way they are doing it is to have the nanotubes attached at one end to the electrode, making a sort of hairy electrode.

Re:Carbon-layering.

[Nyphur]

Ah, but the principle is the same. There would be a lot of free floating electrons between the strands, and also the electron flow is more coherent when flowing laterally along the tube compared to a solid mass of disorganised carbon molecules. No matter how much of a latice solid carbon may be, strands in a certain direction would allow for a much faster electron transmission. This could be used to make welectrical wiring more efficient but it would also make them more fragile.

Nanotube-sized batteries?

[SVDave]

So I guess a nanotube used as a battery would be an AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAA-sized battery?