Researchers at Ohio State University had been trying to study why batteries lose their ability to hold a charge as they age — specifically lithium-ion batteries, which have generated a lot of buzz for their potential to power the electric cars of the future.
Yann Guezennec and Giorgio Rizzoni of OSU developed new experimental facilities and procedures to charge and discharge commercially available Li-ion batteries thousands of times over many months in a variety of conditions designed to mimic how these batteries are actually used by hybrid and all-electric vehicles.
When the batteries died, the scientists dissected them and used a technique called infrared thermal imaging to search for problem areas in each electrode, a 1.5-metre-long strip of metal tape coated with oxide and rolled up like a jelly roll.
Additional studies of the aged batteries, using neutron depth profiling, revealed that a fraction of the lithium that is responsible, in ion form, for shuttling electric charge between electrodes during charging and discharging, was no longer available for charge transfer, but was irreversibly lost from the cathode to the anode. “An aged sample versus and unaged sample has much lower lithium concentration in cathode,” said Rizzoni.
Smaller than a grain of salt
Batteries smaller than a grain of salt may soon become a reality, as scientists are trying to create some of the tiniest batteries on Earth, ANI reports. These tiny devices could be used to power the electronics and mechanical components of tiny micro to nano-scale devices. Jane Chang, an engineer at the University of California, said: “We’re trying to achieve the same power densities as traditional lithium ion batteries, but we need to make the footprint much smaller.”