Tuesday, May 18, 2010

Cambridge Scientists Solve Mystery of Flammable Laptop Batteries

Telegraph U.K.

Researchers at Cambridge University believe metal fibres, known as dendrites, are one of the main reasons why lithium batteries in phones, laptops and other devices overheat and catch fire.

There have been several high-profile stories in recent years of iPods, laptop computers and phones spontaneously combusting, sometimes when they're in the owner's pocket or handbag, or when left unattended at home.

Batteries in discount laptops and phones are designed to charge quickly, but this can cause dendrites to form on the battery's carbon anodes, said the team of scientists. These fibres are one of the main causes of short circuits, which can, in turn, cause laptop computer batteries to overheat and even catch fire.

Now, the team is hoping to get a better understanding of how dendrites form, and how their development can be halted, but using nuclear magnetic resonance spectroscopy to trace their development. It is hoped that this information will help consumer electronics manufacturers improve the safety of lithium batteries.

"These dead lithium fibres have been a significant impediment to the commercialisation of new generations of higher capacity laptop batteries," Professor Clare Grey, one of the researchers from Cambridge University's chemistry department, told the BBC.

"Fire safety must be solved before we can get to the next generation of lithium-ion batteries and before we can safely use these batteries in a wider range of transport applications. Now that we can monitor dendrite formation inside batteries, we can identify when they are formed and under what conditions.

"Our new method should allow researchers to identify which conditions lead to dendrite formation and to rapidly screen potential fixes to prevent the problem."