Inserting quantum dots made from iron pyrite, more commonly known as fool’s gold, into conventional lithium-ion batteries drastically reduces the time it takes to charge.
Researchers from Vanderbilt University in Nashville, Tennessee, found that if iron pyrite nanocrystals, which are 10,000 times smaller than the width of a human, were inserted into the batteries, they could achieve a full charge in as short a time as 30 seconds.
The team added millions of iron pyrite quantum dots of different sizes to standard lithium button batteries like those that are used to power watches, automobile key remotes and LED flashlights.
"Researchers have demonstrated that nanoscale materials can significantly improve batteries, but there is a limit," said Professor Cary Pint.
"When the particles get very small, generally meaning below 10 nanometres (40 to 50 atoms wide), the nanoparticles begin to chemically react with the electrolytes and so can only charge and discharge a few times. So this size regime is forbidden in commercial lithium-ion batteries."
However, they found that crystals that were 4.5nm in size were the most effective and substantially improved both the batteries' cycling and rate capabilities.
The researchers believe that the improvements were due to the unique way in which iron pyrite changes form into an iron and a lithium-sulphur or sodium-sulphur compound to store energy.
"The batteries of tomorrow that can charge in seconds and discharge in days will not just use nanotechnology, they will benefit from the development of new tools that will allow us to design nanostructures that can stand up to tens of thousands of cycles and possess energy storage capacities rivalling that of gasoline," said Pint. "Our research is a major step in this direction."
Californian researchers recently discovered that graphene treated with hydrogen can boost the capacity of traditional lithium-ion batteries.
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