Lithium Batteries Get Longer Lives, Faster Charging Through Ultrasound

Researchers from the University of California San Diego have made a breakthrough in boosting the speed at which lithium batteries can be charged and how long they live — by bombarding them with ultrasound using a tiny additional component.

The team's work concentrated on lithium metal batteries (LMBs), long considered as a successor to lithium-ion batteries owing to having roughly twice the energy density. Unfortunately, the road from the lab to the shelves has been slow: LMBs may store more energy, but they have a very low lifespan and need correspondingly slow and careful charging.

That drawback may be a thing of the past, however, thanks to work on preventing the dendrite growth — needle-like deposits of lithium which stretch from the anode to the cathode and eventually short-circuit the battery — using ultrasound waves to "flow" the electrolyte and refresh the battery.

"This work allows for fast-charging and high energy batteries all in one," claims Ping Liu, co-senior author on the paper detailing the work. "It is exciting and effective."

In testing, the ultrasonic emitter was found to allow a lithium metal battery to charge for 250 full charge-discharge cycles — each charge lasting ten minutes and taking the battery from completely empty to completely full — without degradation. Interestingly, the same technique appears to apply to other battery types regardless of chemistry: A lithium-ion battery exposed to the same ultrasound went through over 2,000 of the same rapid charge-discharge cycles.

The team has confirmed it is working on integrating the technology into commercial lithium-ion batteries, and has licensed its work to Matter Labs on a non-exclusive basis. More information is available from the paper, published under closed access terms in the journal Advanced Materials.