A report by Pohang University of Science and Technology in South Korea, confirms their researchers made a break-through. This step concerns stabilizing high-nickel cathodes in lithium-ion batteries by applying single-element doping. This novel technique could contribute to next-gen batteries, in urgent need to meet growing demand for electric vehicles and storage.
Why The Focus On Stabilizing High-Nickel Cathodes?
The current generation of lithium-ion batteries plays a vital role in the drive for longer-range electric cars. The next generation will require even higher-capacity cathodes to cope with the volume.
Nickel metal is a popular choice for these cathodes, because it offers superior density after blending with other materials. But there’s a catch to increasing the nickel concentration, as often occurs in our world of batteries.
As the concentration increases, more nickel ions infiltrate the lithium layer by exchanging positions with their lithium counterparts. This diminishes battery performance as it partly negates the objective of the exercise.
The break-through involved using metal ions as dopant additives within the transition metal, or lithium layers of high-nickel cathode materials.
How the Team Turned Theory Into Practice
The key to effectively stabilizing high-nickel cathodes lay in precisely knowing where to place these metal ions in the structure. Previous researchers were baffled how to pinpoint the small number of locations.
The team developed a deep learning AI technique, to quantitatively analyze cation mixing using atomic structure images. Then they teamed this with atomic-scale electron microscopy.
They were then were able to observe how the dopants affected the surface structure, and electro-chemical properties of the cathode material. Just 3 metal ion cations was all that they needed to curb nickel infiltration, and enhance structural stability.
More Information
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Preview Image: Doping Layer on Nickel Cathode