Researchers from Kansas State University are currently developing new materials to be used in future lithium-ion batteries that will dramatically improve their storage capacity, potentially allowing the batteries of electric cars, laptops, cellphones, and various other mobile devices to last much longer between charges.
The researchers are also working on lithium-ion batteries that can store energy and deliver power more rapidly, which they believe will be a more appropriate alternative power source for electric vehicles and machines that are powered by alternative energy. As an example, “solar- and wind-powered technologies could switch to the battery in the evening when there is a lack of wind or sunlight to produce energy,” says Steven Arnold Klankowski, a doctoral candidate in chemistry who is working under Jun Li, professor of chemistry, at Kansas State University.
“The battery market is moving very fast these days as everyone is trying to get an advantage for their electric vehicles and cellphones,” said Klankowski, who also has a background in materials engineering. “As our devices get smarter, so must our methods to supply greater amounts of portable electrical energy to power these devices.”
In the new research, Klankowski has been “developing and testing a high-performance nanostructure of silicon coated onto carbon nanofibers for the use as an electrode in lithium-ion batteries.” The electrodes resemble a dense brush. This allows the battery a greater charge capacity and charging rate. This technology is expected to replace the currently used commercial electrodes, made just from simple carbon-based materials.
These new materials that are being developed and improved by the researchers allows the electrode to store “roughly 10 times the amount of energy as current electrodes — giving the batteries a 10-15 percent improvement in current battery technology.”
“We’re trying to go for higher energy capacity,” Klankowski said. “To do that we’re looking at if we can store more energy per the electrode’s size or mass, and if we can use that energy more quickly to make the battery like a capacitor. Batteries and capacitors are on opposite sides of the energy storage field. We’d like to move them both closer together.”
For the lab work, he has been looking at how the lithium-silicon-alloy material’s characteristics vary with every production cycle, and also how those varied characteristics can be modified to allow lithium-ion batteries to become closer to capacitors.
This material is also of interest for its energy storing ability. Simulated battery operation tests have shown that it can repeatedly be charged and discharged with energy.
As per the current requirements of the U.S. Department of Energy, a battery needs to maintain at least an 80 percent charge capacity after being put though ’300 charge-discharge cycles.’
“A battery today tends to die after 400-500 cycles or three years,” Klankowski said. “One of the things we’ll want to improve on is that lasting performance. It won’t be much of an advantage if your phone’s battery can last for 36 hours for the first few months but then only two hours after that. With the progress we are seeing, I hope one day to drive from Manhattan to my folks’ house in Minnesota on a single battery change.”