ALL ABOUT BATTERIES

Wondering what's up with all those battery recalls? Here's a little info:
All charged up
Damon Darlinand & Barnaby J. Feder, 8/20/2006 (NYTimes via StL Post-Dispatch)
- In the information age, people want their electronics everywhere they go…But they rely on batteries that have not improved as rapidly as the devices they power. Moore's Law, which offers a yardstick for the exponential advances in computer chips, has no counterpart in the world of batteries…Researchers are trying to improve the situation…

-Portable rechargeable batteries are expected to be a $6.2-billion market this year, and more than 1 billion batteries will be made by some of the largest electronics companies in the world: Sony, Sanyo, Matsushita, and Samsung…But scientists are running into some basic hurdles of chemistry and physics. The more energy they store in a small package, the more volatile and dangerous that package becomes…Though the chance of a flaming notebook is small, the number of incidents involving burning batteries is rising each year because there are so many more devices using small and powerful power sources…
- There is another pressing reason for the quest for improvements: battery-powered cars. An electric car needs a power source that is 2,000 times as powerful as a laptop battery…
- The potential for fire in a lithium-ion battery is a result of its chemical composition. Contained in that small package are all the elements needed for a fierce blaze: carbon, oxygen, and a flammable fluid…The battery is made of a thin layer of lithium cobalt oxide, which serves as the cathode, and a strip of graphite, the anode. These are separated by a porous insulator and surrounded by fluid, a lithium salt electrolyte that happens to be highly flammable…When the battery is charged, lithium ions on the cathode migrate to the anode. As the battery is used, the ions migrate back to provide the energy. In the charged state, the cathode without most of its ions is highly unstable. If a spark occurs, the temperature of the cathode can exceed 275 degrees…That is hot enough to cause the cathode to decompose and release oxygen. A fire starts, and as heat builds the battery begins what scientists call a "thermal runaway."
- Scientists are looking for new battery chemistry that does not involve carbon, oxygen, and fuel…much of the work is concentrated on replacing the cobalt-based cathode with magnesium. Others want to get the carbon out of the system. Sony, for instance, has a new generation of batteries that use tin…Valence Technology, a maker of alternatives to lithium-ion batteries in Austin, Texas, uses a phosphate-based cathode…

- As consumers demand more from notebooks and cell phones, the electronics industry may need a whole new way of thinking about power supplies…The most likely candidates are miniaturized versions of the fuel cells that are being developed for cars. Fuel cells use hydrogen, but because hydrogen is hard to store and handle, many microcells get hydrogen from fuels like methanol…Methanol-based microcells, for instance, have roughly 10 times the energy density, creating the prospect of wireless laptops that could run all day without recharging…The tweaking of materials and chemicals in the lithium-ion battery will extend its usefulness for at least another decade or more, said Gao Liu, a scientist at Lawrence Berkeley National Laboratory…The best bet for the future probably is fuel cells, he said, but it may be more than a decade before they start appearing in mass-market portable devices…Pulling together all of the components has proved more challenging than fuel cell advocates predicted…