Dell Battery Blowups

Just how should you react to Dell Computer's recent recall of 4.1 million lithium-ion laptop batteries as potential fire hazards?

A selfish reaction always works for me. "Is my personal computer going to go up in flames?" And that question, at least, is easily satisfied with a visit to Dell's battery recall page. It details all the models affected by the recall. A link at the bottom of the page will even take you to photos of the affected batteries.

Even more information about the recall can be found at the U.S. Consumer Product Safety Commission's page on the recall. It turns out Dell received six complaints of overheating in batteries made by Japan's Sony Energy Corp.

Fortunately, no injuries were reported. But Dell's battery blowup raises more serious questions about the potential hazards and utility of lithium-ion batteries. Most of the blame lies with the commonly used cathode materials - such as lithium cobalt - that have relatively poor thermal stability. In the worst cases, short circuits in the battery electronics, overcharge conditions, or even manufacturing defects in the battery cells can result in a nasty exothermic reaction known as thermal runaway.

Though the biggest recall of its type, Dell is by no means alone in its recent battery woes.A long list of CPSC battery recalls since 1997 can be found on Valence Technology's website. The company also offers battery safety white papers and technical presentations on different pages within the same site. And check out the video for a detailed explanation of why lithium-ion batteries can spontaneously combust.

Valence developed and recently patented an alternative to conventional lithium-ion batteries. It relies on lithium-phosphate cathodes rather than the more popular - though less thermally stable - lithium cobalt.

Other alternative lithium-ion technologies are available too. A123 Systems has used nanoscale electrode materials to improve overall battery performance and safety. From a safety standpoint, the company claims these nanoscale electrode materials do not release oxygen at higher temperatures and thus head off the risk of thermal runaway. Altair Nanotechnologies Inc. likewise developed nanoscale materials, including Li4Ti5O12, for use as battery electrodes.

Finally, if you'd like to brush up on battery technology, it may be time to go back to school - sort of. Battery University is an online guide to battery basics - including some charging strategies. It also contains links to a free, 300-page online book about battery technology called "Batteries In A Portable World." It's written by Isidor Buchmann, founder of Cadex Electronics, a specialist in battery analysis systems. Though he pitches the book as a guide for non-engineers, it nonetheless contains more than its share of technical data on the various battery chemistries in use today.