Battery: Mystery Layer Passivation Discovered, KIT researchers have defined the chemical structure and electrodes of lithium-ion batteries.
In our daily life, lithium-ion batteries have become an important thing. They work only through the layer of passivation that develops during their first cycle. As researchers at the Karlsruhe Institute of Technology (KIT) discovered through simulations, this solid electrolyte interphase does not grow directly on the electrode but aggregates in the solution.
The scientists report their story in the journal Advanced Energy Materials. Their findings make it possible to improve the performance and life of batteries in the future.
From smartphones to electric cars – wherever a mobile power source is needed, almost always lithium-ion batteries do the job. The solid electrolyte interphase (SEI) is an important part of the reliable operation of this battery and other liquid electrolyte batteries.
This passivation layer forms when the voltage is first applied. Electrolyte decomposes near the surface. Until now, it is not known how the particles of electrolytes form a layer that can reach 100 nanometers thick on the surface of the electrode since the decomposition reaction is possible only a few nanometers from n ‘ up.
The pass layer above the anode is critical to the electrochemical potential and life of the lithium-ion battery because it is subjected to severe stress during each charge cycle. When the SEI breaks down during this process, the electrolyte breaks down further and reduces the battery’s capacity – a process that determines the battery’s life.
With accurate knowledge of SEI growth and composition, the characteristics of batteries can be controlled. And now, no computer or computer system is sufficient to explain a complex plan that takes place in a dimensional and different parts.
Study as part of 2030+ batteries of EU plan
Researchers from Institute of Nanotechnology Institute (Ins) now now is successful in making a scale. “This solves one of the biggest mysteries about the important aspects of all electrolyte batteries – especially the lithium-ion batteries we use every day,” said Professor Wolfgang Wenzel, head of the research group “Multiscale Materials Modeling and Virtual Design ” said INT, which participates in the large European research project BATTERY 2030+ which aims to create better, cheaper, sustainable and sustainable batteries for the future. KIT researchers report their findings in the journal Advanced Energy Materials.
More than 50,000 simulations for different reaction conditions
To analyze the growth and formation of the passivation layer at the anode of liquid electrolyte batteries, INT researchers created more than 50,000 simulations representing different reaction conditions.
They found that the growth of organic SEI follows a solution process: first, SEI precursors that form directly on the surface are assembled from the electrode surface through a nucleation process. The rapid increase in the velocity of the nuclei leads to the formation of a layer that eventually covers the surface of the electrode.
These findings provide a solution to the puzzling situation that SEI producers can create only on the surface, where the electrons are, but their growth will stop when this narrow area is covered. “We were able to identify the key reaction parameters that determine the thickness of the SEI,” explains Dr. Saibal Jana, postdoctoral fellow at INT and one of the authors of the study.
“This will enable the future development of appropriate electrolytes and additives that control the properties of SEI and optimize battery performance and life.”
Source: Karlsruhe Institute of Technology
