Researchers from ETH Zurich and Swiss materials science institute Empa have produced uniformly sized antimony nanocrystals and believe these may find applications as an anode material in high energy density batteries.
Antimony has been regarded as a promising anode material for high performance lithium-ion batteries because it exhibits a charging capacity twice that of graphite. The crystals are also seen to have the potential to enable the creation of sodium-ion batteries. Sodium is being seen as a possible replacement for lithium because it is more naturally abundant and more evenly distributed around the globe. However, antimony only has this high storage capability when produced in a special form. In their work, the team, led by Professor Maksym Kovalenko, synthesised 'monodisperse' antimony nanocrystals ranging in size from 10 to 20nm. Production of a sufficient number of high quality uniform antimony nanocrystals is still too expensive. "Development of cost effective synthesis is the next step," said Prof Kovalenko, "together with our industrial partner. Batteries with sodium ions and antimony nanocrystals as anodes will only constitute a highly promising alternative to today's lithium-ion batteries if the costs of producing the batteries will be comparable." In Prof Kovalenko's opinion, it will be at least a decade before a sodium-ion battery with antimony electrodes is launched.