A technique developed by Australian researchers that adds an extremely thin protective layer – just one atom thick – on battery cathodes could see lithium-ion batteries with extremely high energy density become viable for use in electric vehicles.
EV batteries in use today generally give between 200-400km driving range depending on the size of the battery, and the car. It’s proving to be enough for mane people to start switching to EVs, but the cost to manufacture them, combined with degradation of driving range over time still has many drivers worried.
Researchers from the University of Queensland (UQ) say the new findings could double the life of high energy density batteries to the point they become viable for use as they no longer degrade within a few hundred cycles.
The upshot of the research is that once commercialised, we could be seeing EVs with much longer driving range and batteries that last a lot longer.
The energy capacity of lithium-ion batteries, particularly in those with chemistries that have a much higher energy density than ones used today in electric cars, degrade over time because of the formation of lithium dendrites caused by the energy transfer when charging and discharging.
In the new research outlined in a recent paper in Nature Communications last Wednesday, researchers described how adding a layer that is just one atom-wide, which significantly reduces the degradation caused at high voltage.
Instead of lasting just a few hundred cycles, batteries using the atom-wide anti-corrosive layer could be charged and discharged more than 1,000 times, said Professor Lianzhou Wang who leads the team from the School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN) at UQ.
In a statement Wang said that, “Our process will increase the life-span of batteries in many things from smart phones and laptops, to power tools and electric vehicles,” Professor Wang said.
“This new approach features a minimal protective coating at a scalable process, paving the way for the deployment of these abundant high-voltage materials for next generation high energy batteries.”
Research conducted by the team found that after 1,000 cycles, capacity retention remained at 77%.
For context, according to a 2020 paper from the Journal of the Electrochemical Society, lithium-iron-phosphate (LFP) batteries that avoid the use of rare earths including cobalt such as those used in the standard range Tesla Model 3 can cycle up to 4,000 times before capacity dips below 80%.
However, current LFP chemistries have a much lower energy density compared to nickel-based chemistries, meaning EV makers must use larger and heavier batteries which contributes to poorer vehicle energy efficiency.
But Wang says the new technology could be used on higher energy density versions of LFP batteries. In a note to The Driven, Wang said that, “Some advantages of the new material include … cobalt-free and low-cost materials, high voltage of the single cell, and more than 1000-cycle stability,” and that the new technology offers “at least 20% more energy” than the LFP batteries currently used by Tesla.
Wang says he believes the team’s new research could have a significant impact on sectors that rely on rechargable batteries such as in computing and transport.
“We’re confident the nanotechnology will have widespread applications across industry, including in consumer electronics, electric vehicles and the energy storage sector,” he said.
Citation:
Title: Epitaxial growth of an atom-thin layer on a LiNi0.5Mn1.5O4 cathode for stable Li-ion battery cycling
Published in: Nature Communications volume 13, Article number: 1565 (2022)
Date: DOI: https://doi.org/10.1038/s41467-022-28963-9
This article has been updated with quotes from Professor Wang regarding potential battery chemistries and cycles.
Bridie Schmidt is associate editor for The Driven, sister site of Renew Economy. She has been writing about electric vehicles since 2018, and has a keen interest in the role that zero-emissions transport has to play in sustainability. She has participated in podcasts such as Download This Show with Marc Fennell and Shirtloads of Science with Karl Kruszelnicki and is co-organiser of the Northern Rivers Electric Vehicle Forum. Bridie also owns a Tesla Model Y and has it available for hire on evee.com.au.