Scientists claim battery safety breakthrough

 

Gallery

By Stewart Mitchell

Posted on 17 May 2010 at 11:33

Scientists at Cambridge University believe a breakthrough technique for monitoring the chemistry taking place inside a lithium-ion cell could lead to safer laptop batteries and improved performance.

Lithium batteries are found in the vast majority of portable electronic devices, but they are highly volatile. As the battery is charged and discharged, tiny fibres of lithium form on the carbon anodes, causing short circuits that can lead to overheating and the battery catching fire. HP, Packard Bell, Dell and Sony have all had to recall laptop batteries over the past few years.

"These dead lithium fibres (or dendrites) have been a significant impediment to the commercialisation of new generations of higher capacity batteries that use lithium metal as the anode instead of the carbons used today," said professor Clare Grey in a research paper published in Nature Materials

Researchers had previously used theoretical models and electron microscopes to study lithium fibre formation, but progress using these methods has been slow. The scientists claim their technique, which uses Nuclear Magnetic Resonance imaging to study the way batteries behave, could lead to less flammable power packs.

“Our new method should allow researchers to identify which conditions lead to dendrite formation and to rapidly screen potential fixes to prevent the problem,” said Grey.

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