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Major breakthrough in understanding battery degradation could revolutionize the electric car industry

On July 5, 2024 , updated on July 5, 2024 — automobile industry, batteries, degradation, electric cars, understanding - 4 minutes to read

In the field of electric vehicles, an essential advance has just surfaced: a better understanding of battery degradation. This discovery promises to revolutionize the automotive industry by offering more sustainable and efficient solutions for electric cars.

Recent research conducted by Argonne National Laboratory, in collaboration with the United States Department of Energy, has identified why electric vehicle battery cathodes rapidly degrade. These discoveries could well pave the way for future innovations in the field.
Lithium-ion batteries are essential for electric vehicles, and their future performance depends greatly on improvements to the cathodes. Nickel-rich nickel manganese cobalt oxide (NMC) cathodes have high capacity potential. However, they degrade quickly after several charge and discharge cycles, a major problem for their durability.
Scientists have discovered that the degradation of nickel-rich NMC cathodes is due to the breakdown of bonds between the crystals during charging cycles. To solve this problem, monocrystalline cathodes have been tested. Theoretically, they should not encounter this problem. However, even these cathodes showed signs of premature failure.
To better understand this phenomenon, researchers have developed a revolutionary analysis method combining large-scale X-ray diffraction and high-resolution electron microscopy. This made it possible to observe changes in the structure of crystals at various stages of charge, revealing processes of expansion, rotation and contraction, thereby disrupting the initial atomic order.
The observations revealed by this analysis method have highlighted how the stresses induced by charge cycles irreversibly alter the structure of the cathodes, leading to a notable reduction in their performance. Rotations of crystal structures, initially small, become more severe over time, exacerbating degradation.
These findings are crucial for the future development of more durable and efficient cathodes. They pave the way for optimizing battery materials, with the potential to increase the range of electric vehicles while reducing costs. By identifying the root causes of degradation, researchers can now work on structural solutions to improve battery performance and lifespan.
This work, published in the journal Science, provides a valuable roadmap for overcoming the sustainability challenges of lithium-ion batteries, promising significant advances in the performance of battery technologies for electric vehicles in the future.

Recent research conducted by Argonne National Laboratory, in collaboration with the United States Department of Energy, has identified the reasons why the cathodes of electric vehicle batteries deteriorate quickly. These discoveries could well pave the way for future innovations in the field.

The Promise and Challenges of Nickel-Rich Cathodes

Lithium-ion batteries are essential for electric vehicles, and their future performance depends greatly on improvements in cathodes. Nickel-rich nickel manganese cobalt oxide (NMC) cathodes have high capacity potential. However, they degrade quickly after several charge and discharge cycles, a major problem for their durability.

The Microstructure Problem

Scientists have discovered that the degradation of nickel-rich NMC cathodes is due to the breaking of the bonds between the crystals during charge cycles. To solve this problem, monocrystalline cathodes have been tested. Theoretically, they should not encounter this problem. However, even these cathodes showed signs of premature failure.

An Innovative Diagnostic Method

To better understand this phenomenon, researchers have developed a revolutionary analysis method combining large-scale X-ray diffraction and high-resolution electron microscopy. This made it possible to observe changes in the structure of crystals at various stages of charge, revealing processes of expansion, rotation and contraction, thereby disrupting the initial atomic order.

The Consequences of the Discoveries

The observations revealed by this analysis method have highlighted how the stresses induced by charge cycles irreversibly alter the structure of the cathodes, leading to a notable reduction in their performance. Rotations of crystal structures, initially small, become more severe over time, exacerbating degradation.

Towards More Durable Batteries

These findings are crucial for the future development of cathodes more durable and efficient. They pave the way for optimizing battery materials, with the potential to increase the range of electric vehicles while reducing costs. By identifying the root causes of degradation, researchers can now work on structural solutions to improve battery performance and lifespan.

This work, published in the journal Science, provides a valuable roadmap for overcoming the sustainability challenges of lithium-ion batteries, promising significant advances in the performance of battery technologies for electric vehicles in the future.