This looks promising:

The researchers are working on a new device that uses carbon nanotubes to store and release electrical energy in a system that could carry as much power as today's lead or lithium batteries.

But unlike the rechargeable batteries used on today's cellphones and laptop computers, these devices could be recharged hundreds of thousands of times before wearing out.

There are the skeptics, of course:

Andrew Burke, research engineer at the Institute of Transportation Studies at the University of California at Davis, said that the new capacitors would have to be many times more powerful than any previously created. "I have a lot of respect for those guys, but I have not seen any data," Burke said. "Until I see the data, I'm inclined to be skeptical."

Even if Schindall's capacitors work, he doubts they'll transform the electronics industry overnight. Companies have too much invested in today's battery systems, and it would take years before carbon nanotube capacitors could be mass-produced.

A classic innovator's dilemma.

I've never been a big battery fan. Chemical energy storage always seemed very crude to me.

I think this is old news; I'm pretty sure you covered it months ago.

After we got to discussing it in the comments, somebody with a better understanding than I went through the white paper and determined that the energy density just wasn't there for it to be an effective battery replacement. Efficient charging, ultra-fast release, but not enough gas in the tank.

Which doesn't mean that it can't be used for things like the regenerative braking system on a car, or to serve as a temporary battery/buffer for a fuel-driven engine to allow it to operate on a more efficient, less demand-sensitive level.

Burke is right, to an extent.

But if even one company begins to offer a new cell phone, PDA, laptop with a new long life battery EVEN if the cost is high, the competitors will follow. Think how any of the technologies we now have, have dropped in price and have subsequenty taken off in the market after the first high dollar models got out to the consumers.

Personally, I'd pay high dollar for a laptop battery that would last more than 18 months, and would stiil take a decent charge. My laptop is old, IBM 600X, but it does what I need from a laptop, at a speed I can live with. I've spent $300 on replacement batteries over the life of the machine. I'd pay that once for a battery that didn't wear out until the laptop died. I know this probably puts me in the minority, but it's how many people do things. That $300 is still cheaper than a new machine.

My cell phone is the same way for me. It's so old it just takes and makes a phone call!! But I've spent $100 for batteries for our phones over the last 4 years.

If someone makes them, we will buy!!

I wouldn't say the end of the battery, but as you put it later, the end of electro-chemical batteries. As others have stated though, there no need for nostalgia yet. I recall first hearing this at a nano-conference in 2000.

There is this one:
http://www.europositron.com/en/index.html

I think a rechargeable aluminium air battery with which they are promising 1.3kW/kg, about eight times that of Li-polymer. It smells a bit like a scam but I do not know enough to be sure - the theoretical energy storage potential is there.

Chemical energy storage always seemed very crude to me.

Well...any power storage device other than a big spring or a nuclear pile stores energy in chemical bonds. What you maybe want to focus on is the folly of insisting on a storage device that can release and take up energy directly as electricity, which seems to intrinsically require macroscopic hunks of material with zero band gap, i.e. metals.

The theoretical power-storage density of chemical fuels is actually very high, and it is possible to get the energy out directly as electricity, so as not to need to run a heat engine. Our own metabolism does just that, which is how a 95 kg man "operating" at 37°C can run 10 km on the energy in 3 ounces of stored fat. Fuel cells strike me as a crude mimicry of natural energy metabolism. The fact that a superior natural model exists may mean they'll get a lot better, in time.

Actually a big spring also stores it's energy in the chemical bonds that are distorted when the spring is bent.

You can calculate the storage capacity of a spring from it's chemical bonds if you want.