We came across some thought-provoking research by Walker Department of Mechanical Engineering, at University of Texas in Austin. Their study explores cathode deformation from internal strain in lithium-ion batteries, and reaches some interesting conclusions.
We are already aware of how strain inside batteries is a major cause of electrode deformation. However, to date, exactly how this happens in lithium-ion batteries has not been abundantly clear. The Texas study helps us understand how local strain forms, and evolves during battery operation.
Strain Dynamics In Lithium-Ion Battery Cathodes
Cathode electrodes receive the energy in batteries, and pass it on to the user’s chosen device. University of Texas in Austin scientists, explored strain dynamics in lithium-ion batteries.
They discovered what they refer to as ‘substantial heterogeneity in the states of charge, among electrode particles at the onset of operation’. And they conclude that this induces ‘local strain’.
But how does this connect to cathode deformation from internal strain, the team wondered? They used optical flow mapping and grain-resolved synchrotron x-ray diffraction technologies to drill down deeper.
Particle Behavior and Internal Strain
The Austin, Texas team discovered ‘an intriguing coupling between charge transfer and particle motion’. In practical terms, Interesting Engineering explains, this leads to some internal materials becoming displaced.
This discovery challenges traditional thinking that although battery materials do degrade, they generally remain in the same place. In contrast, this new finding indicates that some particles move around repeatedly during battery operation.
These particles settle elsewhere each time, in a process that speeds up battery degradation. This constant activity is what causes cracks in lithium-ion battery cathodes, leading to eventual failure.
So what does this mean to us as consumers? We now have a glimpse of a fascinating world of cathode deformation from internal strain. We also have a better idea of how batteries degrade faster, when we push them to their limits and why longer battery life is so elusive.
More Information
Thorny Dendrites in Lithium-Ion Batteries
When Lithium-Ion Batteries Fail
Preview Image: Cathode Particles Collide
