Cambridge University researchers developed a new technique that could fully charge most smartphones and laptops in as little as five minutes. (Image Credit: Pixabay)
Researchers at the University of Cambridge developed a low-cost lab-based technique that could fully charge most laptops and smartphones in just five minutes. The key advancement may lead to better battery materials and progress toward next-gen battery development, allowing a greater shift to a fossil-fuel-free world.
Although Li-ion batteries provide high energy density and longevity compared to other batteries, they can overheat and explode and are costly to produce. Additionally, their energy density isn’t on the same level as petrol. Therefore, it’s not ideal for electric cars and grid-scale storage for solar power.
“A better battery is one that can store a lot more energy or one that can charge much faster – ideally both,” said co-author Dr. Christoph Schnedermann, from Cambridge’s Cavendish Laboratory. “But to make better batteries out of new materials and to improve the batteries we’re already using, we need to understand what’s going on inside them.”
However, if researchers want to improve li-ion batteries and speed up charging times, they need to study and understand their real-time processes in the active materials. This requires using synchrotron X-ray or electron microscopy techniques, which are costly and time-consuming.
“To really study what’s happening inside a battery, you essentially have to get the microscope to do two things at once: it needs to observe batteries charging and discharging over a period of several hours, but at the same time, it needs to capture very fast processes happening inside the battery,” said first author Alice Merryweather, a Ph.D. student at Cambridge’s Cavendish Laboratory.
To observe these processes, the team developed an optical microscopy technique called interferometric scattering microscopy. By using this method, they observed individual lithium cobalt oxide (LCO) particles as they charged and discharged, which was achieved through scattered light measurements. The team noticed that the LCO underwent a series of phase transitions during its charge-discharge cycle. The phase boundaries in the LCO particles moved and transitioned while the lithium ions entered and exited. They also discovered that the moving boundary’s mechanism differs based on whether or not the battery charges or discharges.
“We found that there are different speed limits for lithium-ion batteries, depending on whether it’s charging or discharging,” said Dr. Akshay Rao from the Cavendish Laboratory, who led the research. “When charging, the speed depends on how fast the lithium ions can pass through the particles of active material. When discharging, the speed depends on how fast the ions are inserted at the edges. If we can control these two mechanisms, it would enable lithium-ion batteries to charge much faster.”
“Given that lithium-ion batteries have been in use for decades, you’d think we know everything there is to know about them, but that’s not the case,” said Schnedermann. “This technique lets us see just how fast it might be able to go through a charge-discharge cycle. What we’re really looking forward to is using the technique to study next-generation battery materials – we can use what we learned about LCO to develop new materials.”
The technique’s high throughput means that many particles can be sampled across the electrode. Additionally, it presents new opportunities to observe and prevent a battery’s failure process.
“This lab-based technique we’ve developed offers a huge change in technology speed so that we can actually see these phase boundaries changing in real time was really surprising. This technique could be an important piece of the puzzle in the development of next-generation batteries.”
Have a story tip? Message me at: http://twitter.com/Cabe_Atwell
