NMR study aids battery safety

By helping them understand how these batteries behave under different conditions, the method could help researchers solve the fire-safety problems that have dogged the development of such batteries.

Lithium-ion batteries have enabled the development of many electronic devices, such as laptop computers and mobile phones. However, the batteries have one serious disadvantage: over several charge and discharge cycles, particularly if the batteries are charged quickly, minute fibres of lithium, known as dendrites, can form on the carbon anodes. These lithium fibres can cause short circuits, causing the battery to rapidly overheat and catch fire.

Prof Clare Grey of Cambridge University’s Department of Chemistry said: ’These dead lithium fibres 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.’

Previously, scientists have used theoretical models and optical and scanning electron microscopes to study dendrite formation, but finding a way of quantifying the amount of dendrites formed has proved elusive.