An international team of researchers have used neutron and X-ray tomography to investigate the processes that leads to electrode capacity degradation in lithium batteries.
Researchers from the Helmholtz-Zentrum Berlin (HZB) and University College London investigated degradation on electrode surfaces during cycling using a combination of the two tomography methods.
Scientists found the inner windings of the cell exhibited completely different electrochemical activity (and lithium capacity) than the outer windings. They also discovered the upper and lower parts of the battery behaved differently.
The neutron data showed areas where a lack of electrolyte developed, and the anode was not equally well-loaded and unloaded with lithium.
The study to observe the migration of lithium ions and determine how the distribution of the electrolyte in the battery cell changes over time was published in industry journal Nature Communications.
The team was able to analyse the microstructure of the electrodes and detect deformations and discontinuities that develop during cycling using data from HZB and Institut Laue-Langevin at the European Synchrotron Radiation Facility in Grenoble, France.
Alessandro Tengattini, instrument scientist at NeXT-Grenoble, a novel imaging station at Institut Laue-Langevin (ILL) said: “We’re demanding more power from our consumer electronics all the time. To make them more efficient, and also safe, we need to understand the minor fluctuations occurring inside the batteries throughout their lifetime.
“It’s hard to analyse lithium with x-rays because it is a light-weight element, but in combination with high-flux neutrons provided at the ILL we have been able to learn about the electro-chemical and mechanical properties at play simultaneously while these lithium-ion batteries are in use.”
It is the first time an algorithm, which was modified and improved in feedback steps in collaboration with computer scientists of the Zuse-Institut, has been applied to a typical commercially available lithium battery.