Energy

High-voltage electrolyte gives lithium-ion batteries a boost

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Scientists have developed a new electrolyte that enables lithium-ion batteries to tolerate higher voltages
Scientists have developed a new electrolyte that enables lithium-ion batteries to tolerate higher voltages
Scientists in Japan have developed a new high-performance battery electrolyte, which they say is a result of a new understanding of its molecular structures
Yamada et al.

Lithium-ion batteries power much of the modern world, so improvements in performance can benefit a wide range of devices. Scientists in Japan tinkering with battery components have come up with a new ingredient they say can offer greater safety and an ability to operate at higher voltages, raising the prospect of electric cars or smartphones that run longer on each charge.

The research was carried out by scientists at University of Tokyo (UT), who were focused on the part of the battery known as the electrolyte. This is a solution that carries the lithium ions back and forth between the battery’s electrodes as it is charged and discharged, and by experimenting with alternatives to the solvent typically used in today’s devices, the team believes it has found a superior option.

“A battery’s voltage is limited by its electrolyte material,” says (UT’s) Professor Atsuo Yamada. “The electrolyte solvent in lithium-ion batteries is the same now as it was when the batteries were commercialized in the early 1990s. We thought there was room for improvement, and we found it. Our new fluorinated cyclic phosphate solvent (TFEP) electrolyte greatly improves upon existing ethylene carbonate (EC), which is widely used in batteries today.”

According to the team, the EC solvent that features as the electrolyte in today’s batteries becomes both flammable and unstable above 4.3 V, while the TFEP electrolyte the team developed and tested can handle up to 4.9 V.

With further work, this additional voltage from a battery of the same size could mean electric vehicles that can travel further on each charge, without weighing any more. The same would apply to extending the battery life of smartphones, laptops, tablets, or anything else powered by lithium-ion batteries.

“Most research on electrolytes is a bit trial and error, with slight alterations to the basic chemistry rarely offering any advantage,” says Yamada. “Our approach came from a theoretical understanding of the underlying molecular structures. We predicted the safe, high-voltage properties before we experimentally verified them. So it was a very pleasant surprise indeed.”

You can hear from the researchers involved in the video below, while the study was published in the journal Nature Energy.

Source: University of Tokyo

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4 comments
paul314
Can it just be swapped into existing production lines? Because a 15% boost in battery capacity would be nice. (Albeit you would need to redesign all the power electronics that have been designed for 3.7v standard.)

Going to a fluorinated electrolyte would make recycling of lithium batteries even more of a priority. Random fluorine compounds out in the environment have never proved a good idea.
Username
When will any of these daily advancements go into production?
guzmanchinky
Anyone who thinks we won't have super batteries (that can hold as much energy as gasoline in the same space) in the next decade is denying the exponential pace of scientific progress.
Colton Rainey
Gasoline has about 50 times the specific energy (energy per weight) of current lithium ion technology. There is no chance of coming close to that anytime soon. Hopefully in 10 years gas will only be 25 times the specific energy. This poor ratio is offset by the much better efficiency of the electric motor. Also, even if the electrolyte allows a higher voltage, different electrode materials must be used to actually achieve that voltage so this won't go into production until new electrode materials are ready.