Left: Detector for synchrotron tomography at the BAMline at BESSY II, right: Formed copper crystallite in a copper sulfide particle. Volume expansion causes cracks to form in the surrounding solid.
Source: Henning Markötter, Kang Dong.
Solid-state batteries (SSBs) are considered a promising future battery technology. Compared with the lithium-ion batteries currently used in mobile devices and electric vehicles, SSBs promise even higher energy density and, above all, greater safety. This is because highly flammable liquid electrolytes are substituted with a solid, so that the entire battery consists only of "solid materials." To produce such a battery, the anode, cathode and solid electrolyte must be pressed together under high pressure.
Now, a team led by Prof. Philipp Adelhelm and Dr. Ingo Manke as well as Dr. Henning Markötter has succeeded in creating high-resolution 3D images at BAMline during the charging and discharging of a solid-state battery. This showed that cracking can be counteracted by applying high pressure to the materials. Researchers from Helmholtz-Zentrum Berlin, Humboldt-University Berlin, the Bundesanstalt für Materialforschung und -Prüfung and Helmholtz-Zentrum Hereon observed the processes within such a solid-state battery during charging and discharging. The working groups investigated the behavior of copper sulfide as a cathode in a solid-state battery. Lithium was used as the anode. During discharge, large copper crystallites form in the copper sulfide particles. Using high-resolution synchrotron X-ray tomography at BAMline, this crystallite formation was studied in detail. There, it is possible to image the charging and discharging reaction in 3D and to follow the changes of the cathode particles within the battery for the first time. It was shown that the volume expansion induces cracks in surrounding areas, but these are effectively reduced by higher pressure.
These complex measurements have been made possible not least by a detector upgrade at BAMline, which enables complete 3D scans to be recorded in just a few minutes. This means that processes can also be investigated in 3D with time resolution. This is also interesting for many in-situ tensile and compression tests or high temperature experiments. The work was recently published in "Advanced Energy Materials", a renowned journal in the field of energy-related materials.
Phase Transformation and Microstructural Evolution of CuS Electrodes in Solid-State Batteries Probed by in-situ 3D X-ray Tomography
Zhenggang Zhang, Kang Dong, Katherine A. Mazzio, André Hilger, Henning Markötter, Fabian Wilde, Tobias Heinemann, Ingo Manke, Philipp Adelhelm
published in Advanced Energy Materials (2022), DOI: 10.1002/aenm.202203143.
BAM Department Non-destructive Testing
BAM Division Micro Non-Destructive Testing