The days of smartphones and laptops running out of battery after a few hours could be over thanks to a new breakthrough.
Scientists have at last created pure lithium batteries, which in time could last four times longer than those currently powering smartphones and other gadgets.
The ‘Holy Grail’ discovery could revolutionise technology from electric cars to consumer devices like MP3 players, which all demand power storage.
Currently, owners of gadgets using the lithium ion batteries face the constant frustration of having to frequently recharge devices to make sure they do not run out of battery after a matter of hours. This is because while small, the batteries are power-hungry.
But after years of research, engineers at Stanford University, California, believe they have worked out how to keep them the same size, while boosting their longevity.
To do this, they have made the battery’s anode out of lithium too, according to the research, which is published in the journal Nature Nanotechnology.
All batteries have three basic components: an electrolyte to provide electrons, an anode to discharge those electrons and a cathode to receive them.
Today, we have lithium ion batteries, but the lithium is in the electrolyte and not in the anode.
Scientists have been working for years to produce an anode of pure lithium, because it would be cheap, small and be a huge boost to battery efficiency. But many have failed because the lithium didn’t survive the process.
The engineers managed to create a lithium anode by inventing a film made from carbon nanospheres to protect the anode and stop it from cracking when it expands.
The nanospheres create a surface resembling a honeycomb to make a flexible, uniform and non-reactive film that protects the unstable lithium.
The carbon nanosphere wall is just 20 nanometres thick. It would take 5,000 layers stacked one on top of another to equal the width of single human hair.
‘The ideal protective layer for a lithium metal anode needs to be chemically stable to protect against the chemical reactions with the electrolyte and mechanically strong to withstand the expansion of the lithium during charge,’ said Yi Cui, Professor of Material Science and Engineering at the university.
The Stanford nanosphere layer is made of amorphous carbon, which is chemically stable, yet strong and flexible so it can move freely up and down with the lithium as it expands and contracts during the battery’s normal charge-discharge cycle.
‘Of all the materials that one might use in an anode, lithium has the greatest potential. Some might call it the Holy Grail,’ said Professor Cui.
‘It is very lightweight and it has the highest energy density. You get more power per volume and weight, leading to lighter, smaller batteries with more power.’
Fellow researcher Guangyuan Zheng added: ‘Many engineers had given up the search, but we found a way to protect the lithium from the problems that have plagued it for so long.’
Professor Cui said: ‘In practical terms, if we can improve the capacity of batteries to, say, four times today’s, that would be exciting.
‘You might be able to have cell phone with double or triple the battery life or an electric car with a range of 300 miles that costs only $25,000 (£14,700) – competitive with an internal combustion engine getting 40 mpg,’ Cui said.
The new invention could ‘power the next generation of rechargeable batteries,’ he said.