A team of scientists say magnesium batteries offer "high-energy density" at safe levels by using the readily available magnesium metalanode.
Dr Yan Yao, associate professor of electrical and computer engineering at the University of Houston and lead author of the study, said: "We are combining a nanostructured cathode and a new understanding of the magnesium electrolyte. That's new."
Whilst postdoctoral fellow Dr Hyun Yoo, first author on the study, added: "Magnesium ions are known to be hard to insert into a host. First of all, it is very difficult to break magnesium-chloride bonds. More than that, magnesium ions produced in that way move extremely slowly in the host. That altogether lowers the battery's efficiency ...
"The large capacity accompanies excellent rate and cycling performances even at room temperature, opening up possibilities for a variety of effective intercalation hosts for multivalent-ion batteries. We hope this is a general strategy. 'Inserting various polyatomic ions in higher voltage hosts, we eventually aim to create higher-energy batteries at a lower price, especially for electric vehicles."
Magnesium batteries - which are thought to be safer than traditional lithium ones - can be used as such thanks to a process called "intercalation".
The US-based team wrote in the Nature Communications journal: "Magnesium rechargeable batteries potentially offer high-energy density, safety, and low costdue to the ability to employ divalent, dendrite-free, and earth-abundant magnesium metalanode.
"Despite recent progress, further development remains stagnated mainly due to thesluggish scission of magnesium-chloride bond and slow diffusion of divalent magnesiumcations in cathodes. Here we report a battery chemistry that utilizes magnesium mono-chloride cations in expanded titanium disulﬁde.
"Combined theoretical modeling, spectro-scopic analysis, and electrochemical study reveal fast diffusion kinetics of magnesiummonochloride cations without scission of magnesium-chloride bond
"The battery demonstrates the reversible intercalation of 1 and 1.7 magnesium monochloride cations per titaniumat 25 and 60 °C, respectively, corresponding to up to 400 mAh g−1 capacity based on themass of titanium disulﬁde. The large capacity accompanies with excellent rate and cyclingperformances even at room temperature, opening up possibilities for a variety of effectiveintercalation hosts for multivalent-ion batteries."