Lithium-sulfur batteries have a higher potential for energy storage than lithium-ion batteries, but they have a shorter life. The main performance bottlenecks have now been identified by scientists from Uppsala University in Sweden.
The figure above shows how different reaction products form depending on how fast the battery is charged, and thus how various bottlenecks arise that change their efficiency. This information guides the way to make better batteries. Image Credit: Chien, et al.
Lithium-sulfur batteries, which are made from less expensive and environmentally friendly materials compared to lithium-ion batteries, are high on the wish list for future batteries. They also have a higher energy storage capacity and can operate at significantly lower temperatures. They do, however, have short lifespans and energy losses.
A research group from Uppsala University identified the processes that limit the performance of sulfur electrodes, reducing the current that can be delivered. During the discharge/charge cycles, a variety of materials are formed, each of which causes its own set of issues. A bottleneck is frequently caused by a localized lithium shortage. The study was published in the journal Chem.
Learning about problems allows us to develop new strategies and materials to improve battery performance. Identifying the real bottlenecks is needed to take the next steps. This is big research challenge in a system as complex as lithium-sulfur.
Daniel Brandell, Professor, Materials Chemistry, Uppsala University
Daniel Brandell works at the Ångström Advanced Battery Centre.
The research used different radiation scattering techniques. X-Ray analyses were carried out in Uppsala, Sweden, and neutron results were obtained from a large research facility — the Institut Laue Langevin in Grenoble, France.
The study demonstrates the importance of using these infrastructures to tackle problems in materials science. These instruments are expensive but are necessary to understand such complex systems as these batteries. Many different reactions happen at the same time and materials are formed and can disappear quickly during operation.
Adrian Rennie, Professor, Uppsala University
The research was carried out in collaboration with Scania CV AB.
Electric power is needed for the heavy truck business and not just personal vehicles. They must keep up with developments of a range of different batteries that may soon become highly relevant.
Daniel Brandell, Professor, Materials Chemistry, Uppsala University
Journal Reference:
Chien, Y.-C., et al. (2022) Correlations between precipitation reactions and electrochemical performance of lithium-sulfur batteries probed by operando scattering techniques. Chem. doi.org/10.1016/j.chempr.2022.03.001.