Plastic Batteries Coming Soon?

Roland Piquepaille writes "Engineers at Brown University have built a prototype of a hybrid plastic battery that uses a conductive polymer. The system, which marries the power of a capacitor with the storage capacity of a battery, can store and deliver power efficiently. For example, during performance testing, 'it delivered more than 100 times the power of a standard alkaline battery.' Still, it's unlikely that such a device can appear on the market before several years."

Comments

CAPACITY, not power, is important...

[dpbsmith]

...for most of the things I care about. And this device only had double thecapacity of an an alkaline battery. Capacity is mAh. Power is watts.

An alkaline battery might have a capacity of (say) 2000 mAh, meaning that it could power a three-watt bulb for about an hour. This device, if it lives up to the claims, could do so for about two hours.

An alkaline battery couldn't power a 100-watt bulb at all, because it can't deliver more than a few amps. This device apparently _could_ power a 100-watt bulb... but only for about four minutes.

The ability to deliver power, that is to deliver energy in a short, intense burst, might be very useful for some applications. But it wouldn't let you recharge your laptop once a week or anything like that.

(There's another question I have. A battery hold an almost steady voltage for a long time, then declines fairly rapidly. Almost a square wave. This is one reason why it's hard to measure discharge state. Presumably these ultracapacitors have a smooth, exponential voltage decline, like radioactive decay. That probably means that you need tricky circuitry to exploit them... and there is probably always a significant amount of power in the device that you can't use, because the voltage has dropped too low).