|U.S. researchers say they've developed a new lithium-ion battery that can heal itself, last longer and provide more safety in today's electronics.
Scientists at the University of Illinois looked at the chemistry of rechargeable lithium-ion batteries -- found in cellphones, laptop computers, digital cameras and other portable electronics -- and found that like all batteries they tend to break down over time, NewScientist.com reported Tuesday.
"There are many different types of degradation that happen, and fixing this degradation could help us make longer-lasting batteries," Scott White, a UI materials engineer, said.
One site of damage is the battery's negatively charged terminal, the anode, which swells and shrinks as the battery is charged and then discharges over time, eventually creating cracks that can interfere with the flow of current and, ultimately, kill the battery.
White embedded tiny microspheres in the anode that would tear open as the anode began cracking, releasing a liquid metal alloy, indium gallium arsenide, that fills the cracks in the anode and restores the flow of electricity.
White also developed a system to keep batteries from overheating and catching fire in the event of a short circuit within the battery.
"It's not a common occurrence, but when it happens, the consequences are severe," White said.
White developed a second kind of microsphere made of solid polyethylene, embedded in the anode and other battery components.
If the temperature inside the battery rises above 221 degrees Fahrenheit, the spheres melt into a thin layer of insulating material that shuts off the flow of electricity, preventing a fire.
"We've tested this in real batteries," said White, whose research is funded by the U.S. Department of Energy. "It works beautifully."