Energy

Lifetime of lithium-ion batteries boosted by new cathode coating

Lifetime of lithium-ion batter...
The new coating, called PEDOT, covers every individual particle of the cathode in a lithium-ion battery, extending its useful life
The new coating, called PEDOT, covers every individual particle of the cathode in a lithium-ion battery, extending its useful life
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The new coating, called PEDOT, covers every individual particle of the cathode in a lithium-ion battery, extending its useful life
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The new coating, called PEDOT, covers every individual particle of the cathode in a lithium-ion battery, extending its useful life

Despite seemingly-endless advances in experimental battery designs, good old lithium-ion batteries continue to be the frontrunner. There’s still plenty of room for improvement though, and now researchers have identified a new cathode coating that could make them safer and longer lasting.

Ubiquitous as they may be, lithium-ion batteries are known to have some problems. One such issue is that the cathode in these batteries can generate excess oxygen, which reacts with the electrolyte. That forms a film on the cathode surface, which reduces the amount of energy that can be passed between the two, in turn reducing the performance of the whole battery.

To counter that problem, the cathodes in most lithium-ion batteries have special coatings that reduce the effect. Unfortunately, this slows down lithium ions passing in and out, decreasing efficiency. Plus, because the coating doesn’t cover the entire surface, the degradation can still occur when the battery is operating at a higher temperature or voltage.

For the new study, researchers at Argonne National Laboratory and Hong Kong University of Science and Technology (HKUST) investigated alternative coatings, to help these batteries last longer.

The team settled on a conducting polymer called PEDOT. This stuff, they found, protected the cathode while still allowing lithium ions and electrons to pass through. And because it’s applied from a gas, using an oxidative chemical vapor deposition technique, it covers every individual particle of the cathode. That makes it far more comprehensive than the usual coatings, which are only partial.

The new coating was able to boost the operating voltage of the battery to 4.6 V, up from 4.2 V on existing lithium-ion batteries. The team says that this would reduce the cost of battery packs, and extend the battery life of devices.

“This is an incredibly exciting advancement,” says Khalil Amine, an author of the study. “This could significantly improve our experience with the devices we’ve come to rely on.”

The research was published in two papers, one appearing in Advanced Energy Materials and the other in Nature.

Source: Argonne National Laboratory

5 comments
PAV
Yet another discovery in batteries. When will they be offered up and combined to get past the energy density that hasn't changed?
Username
How many millions of article have we seen here about battery breakthroughs ? How many have been implemented?
Kpar
What about dendrite formation? Does this coating inhibit those?

Username, these things improve incrementally. Many small improvements have been implemented and rechargeable batteries have shown significant improvement over the last fifteen years, but we are certainly in agreement about all these claims of "dramatic breakthroughs".
Rob Andrews
The increase to 4.6 volts is a 10% increase in effective density if the new coating is not significantly larger than previous coatings. Increase battery life is less important because other companies have already announced million mile batteries. Battery density improves slowly, this may well take years to get out of the lab so have very little impact short term. Long term every bit helps. If we double density in 10 years, it will be a huge success.
WB
all the amazing discoveries over the past decades that I have been reading.. and pretty much non ever make it through ...still the same old lithium ion batteries everywhere...