We've all heard stories about. A person is just walking down the street with his phone in his pocket and next thing he know his pants are ablaze.
The specific culprit batteries that cause such fiery incidents are lithium-ion batteries, which are known to have issues with heat. So, why can't there be chargeable batteries that are immune to overheating? There may be.
The Department of Energy's Oak Ridge National Laboratory (ORNL) has been working on new technology that looks to replace lithium-ion batteries. The lab has designed and tested a small all-solid sulfur-based battery that it says outperforms lithium-ion tech on energy density, cost, and flammability.
"Our approach is a complete change from the current battery concept of two electrodes joined by a liquid electrolyte, which has been used over the last 150 to 200 years," said Chengdu Liang, lead author on an ORNL lithium-sulfur battery study published Tuesday. "This game-changing shift from liquid to solid electrolytes eliminates the problem of sulfur dissolution and enables us to deliver on the promise of lithium-sulfur batteries."
Lithium-sulfur batteries have four times the energy density of lithium-ion batteries, according to ORNL, which means they should be able to hold a charge for much longer. Also, the material used in the lithium-sulfur battery doesn't have the same reaction to heat and therefore shouldn't be able to catch someone's pants on fire.
Currently, lithium-ion batteries are used in the majority of consumer electronics, from tablets to cell phones to laptops. They're also used in electric and hybrid cars and even in the Boeing Dreamliner airplanesbecause of on-board battery fires.
Though scientists have been working for decades on a fix for lithium-ion battery debacles, it wasn't until recently that ORNL was able to figure out how to create an all-solid battery that combines a sulfur-rich cathode, lithium anode, and solid electrolyte material. Lithium-ion batteries use liquid electrolytes, which are what cause the flammability issues.
According to ORNL, another positive for lithium-sulfur batteries is the cost. Sulfur is an abundant and cheap material -- it's the industrial byproduct of petroleum processing.
"Sulfur is practically free," Liang said. "Not only does sulfur store much more energy than the transition metal compounds used in lithium-ion battery cathodes, but a lithium-sulfur device could help recycle a waste product into a useful technology."
Lithium-sulfur batteries are still in the demonstration stage, but ORNL plans to keep the process moving and have the batteries put to use in commercial products in the near future.