Ultracapacitors Soon to Replace Many Batteries?

einhverfr writes "According to an article in the IEEE Spectrun, the synergy between batteries and capacitors — two of the sturdiest and oldest components of electrical engineering — has been growing, to the point where ultracapacitors may soon be almost as indispensable to portable electricity as batteries are now. Some researchers expect to soon create capacitors capable of storing 50% as much energy as a lithium ion battery of the same size. Such capacitors could revolutionize many areas possibly from mobile computing (no worries about battery memory), electricity-powered vehicles, and more."

Comments

Re:Myth

[puck01]

I believe it depends on the type of rechargeable. The nickel cadmium did. Lithium does not.

The problem I've had with all of them is their life span. After a year of regular use, they then to hold a fraction of their original charge. It appears ultracapacitors have a much longer life span. rock on

Re:Myth

[ChrisMaple]

Electrolytic capacitors will dry out unless they are very well sealed. Manufacturers specify a life for electrolytics at a certain temperature. At room temperature, they probably are not good for a century.

Plastic film capacitors will wear out if they are operated at excessive currents.

High-k ceramic capacitors degrade partially over time.

Re:Myth

[squeegee_boy]

>>As far as I'm concerned, if the battery loses the ability to store the same amount of power as it did when you first bought it, then it has a problem with battery memory.

Memory is a very specific occurrence in very specific conditions with a very specific type of cell (sintered plane nickel-cadmium). It exists. You've never seen it.

>>I have an 2 year old cell phone that doesn't hold a charge at all and it has a lithium battery.

It's not memory. It's worn out (too many cycles) or reached the end of its calendar life (since manufacturing, not since you bought it - newer-generation LiIon cells are much better at this aspect). Or both. All cells do this eventually. 2-3 years for a consumer grade cell is not at all unusual. Yes, there are exceptions; I own a few of them.

Capacitors have a lifespan of "functionally forever." You're right: perfected, they'll be a whole lot better than any type of cell we have now.

R

Re:Interesting - crashes?

[dgatwood]

In terms of dumping current, yeah, the capacitor is very dangerous. That said, the amount of current contained (per device) in the largest supercaps I've seen thus far is not significantly greater than what an automotive-grade lithium ion battery pack can dump in a fraction of a second. The difference is that when you short out the supercap, only the shorting material catches on fire instead of the battery and any combustible materials nearby.

Unlike lithium ion cells, supercapacitors don't spontaneously combust when exposed to oxygen, react badly to conventional fire suppression systems, and release a highly caustic smoke that can cause severe lung damage if you breathe it. They don't burst into flames when overcharged or shorted. They don't get so hot that they can ignite adjacent materials when shorted. And so on.