Breaking Down Lithium Battery Aging: Innovative X-ray Study Unveils Cathode Changes

**Lithium-ion batteries** are on the cusp of a performance leap with the introduction of _lithium-rich transition metal oxides_ (LRTMOs) for cathodes, promising higher energy density. However, these materials face rapid degradation due to structural and chemical changes over multiple charging cycles. A collaborative study from several Chinese research institutions used the unique capabilities of the **BESSY II X-ray microscope** to investigate these changes at the nanoscale. Embedded instruments like **3D tomography and nanospectroscopy** provided unprecedented insights into the morphology and structure of the cathode material and the chemical processes during battery discharge. Dr. Peter Guttmann's team, having performed these measurements in 2019, shed light on local lattice distortions from phase transitions and nanopore formations, alongside variations in oxidation states. **The speed of charging significantly influences these effects**; slow charging supports phase transitions, while fast charging can lead to inhomogeneous lithium diffusion. These results are crucial for designing cathodes that withstand cycling better. TXM's capacity for energy-resolved X-ray tomography allows for detailed 3D imaging, representing a significant leap forward in understanding and improving battery materials.