Individuals increasingly depend on rechargeable batteries for a range of essential uses; from electric cars and mobile phones to electrical grid storage. This demand is presently taken up by lithium-ion batteries. New battery technologies will be needed for more efficient energy storage and new applications as individuals continue to transition from fossil fuels to low emission energy.
One approach to develop batteries capable of storing more energy is to make use of “multivalent” metals instead of using lithium. In lithium-ion batteries, lithium ions are transferred inside the battery by charging and discharging processes. In multivalent batteries, a different metal, capable of transferring more than one electron per ion, will replace the use of lithium. This would provide multivalent batteries better performance and energy storage capacity for batteries of equal size.
The team demonstrated the possibility of modifying titanium dioxide in order to allow it to be used as an electrode in multivalent batteries, offering a valuable proof of concept in their development.
The Scientists, an international team from the University of Bath, France, Germany, Holland and the USA, intentionally introduced defects in titanium dioxide to produce high concentrations of microscopic holes, and proved that these can be reversibly occupied by aluminum and magnesium; which is capable of carrying more than one electron per ion.
The team also describes a new chemical strategy, wherein this new strategy will be used for designing materials that can be employed in future multivalent batteries.
The research has been published in the journal Nature Materials.
Multivalent batteries are a really exciting direction for battery technology, potentially offering higher charge densities and better performance. New battery technologies are going to be more and more important as we wean ourselves off fossil fuels and adopt greener energy sources.
Dr Benjamin Morgan, the Department of Chemistry, the University of Bath
Dr Morgan added, “There are quite a few technical hurdles to overcome, including finding materials that are good electrodes for multivalent ions. We’ve shown a way to modify titanium dioxide to turn it into a multivalent electrode... In the long term, this proof of concept is a possible step towards 'beyond lithium' batteries with superior performance.”