We all know Li-ion batteries decay, and this is a problem that most EV detractors raise when speaking about the future of electric cars. A group of DOE and Stanford scientists has found a clever way to extend Li-Ion batteries’ life, which involves nothing more than a software redesign for the charging circuits.
Li-Ion batteries are so popular because they pack an incredible amount of energy in a small volume that also weighs very little. This could also become a problem, as the more energy is crammed into a Li-Ion battery, the more unstable it gets. This and manufacturing mistakes could lead to fires like the ones that consumed more than a few electric cars
in the past.
Another big problem with Li-Ion batteries is the inevitable loss of capacity while they’re being used – that is getting charged, discharged, and recharged. This happens because small bits of lithium become loose from the battery’s electrodes with every charging and discharging cycle. Now, a team of DOE and Stanford scientists announced they’ve been able to make these “dead” lithium bits “reconnect” with the battery’s negative electrode.
“I always thought of isolated lithium as bad since it causes batteries to decay and even catch on fire. We have discovered how to electrically reconnect this ‘dead’ lithium with the negative electrode to reactivate it,” said Yi Cui, a professor at Stanford and SLAC and investigator with the Stanford Institute for Materials and Energy Research (SIMES), in an interview with Science Daily.
The method for reactivating the lithium anode involves providing a big surge in discharging current at the end of a charge cycle. This moves the isolated lithium ions toward the anode. The higher the discharging current, the faster they move and the more efficient the process is. The results of the study have been validated with multiple test batteries and through computer simulations.
The study showed the lithium ions in a real battery could be recovered by simply changing the charging protocol. This should be enough to extend a battery’s life by as much as 30%. Recycling the lost lithium ions also lowers the risk of the battery catching on fire. This could be a real boon for second-life batteries used in residential energy storage systems.