Batteries
X-rays provide critical insight into failure mechanisms and the lifetimes of energy materials by enabling non-destructive measurements of the structure, chemistry, and composition of batteries while they are operating (in operando) or over time. Because of this, synchrotron-based approaches have played a key role in improving existing lithium-ion batteries and developing novel energy storage technologies such as lithium-sulfur and lithium-air batteries.
Sigray’s portfolio of x-ray systems enables cutting-edge research in battery formulations and materials, including the study of chemical, compositional, and structural changes as a function of cycling.
Read our comprehensive technical note on the advantages of the approaches in the technical white paper linked below.
Battery Bond Lengths as a Function of Cycling
X-ray absorption spectroscopy (XAS) has become the gold standard approach for characterizing the structural and electronic properties of electrodes, providing insight into the electrochemical mechanisms governing a battery’s chemistry. Sigray’s QuantumLeap enables both ex-situ determination of electrocatalyst chemistry and in-situ cells studies of chemical changes in-operando.
Sigray’s applications note (linked below) details an evaluation of Mn, Co, and Ni bonds in a NMC LIB, revealing that the Ni-O suffers from Jahn-Teller distortion, whereas the local environment remains preserved.
Speciation of Co in NMC Batteries
Sigray’s applications note (linked below) demonstrate the synchrotron-like quality of Sigray’s data in enabling Co speciation of an NMC LIB, identifying three isosbestic points of Co XANES. PCA and ITTFA reconstruction of the XANES reveal two unique Co species present in four NMC samples.
Battery Chemistry through XAS
Customers around the world are using the QuantumLeap for the development of novel battery materials. Several research groups have now published high-quality XANES data (K=12 or greater). One example is a team at Shanghai Jiao Tong University (SJTU), which reported advances in promising Ni-Zn batteries by using carbon dot coatings on ZnO anode materials to extend their lifetime.
In Operando Pouch Cell Batteries
Pouch cell batteries are among the most challenging samples to image at submicron resolution. They are simply too large for even the leading microCTs and XRMs to achieve suitable acquisition rates at the high resolutions (0.5 µm) required for quantifying microstructural changes.
3D Battery Structural Defects
3D X-ray Microscopy has become the gold standard for investigating battery failures and the structural defects that cause them. Shown to the right are various failures analyzed using Sigray’s EclipseXRM in intact batteries. More details and figures can be found in the article below, published in Cell Reports, which features x-ray microscopy images captured with EclipseXRM (the previous generation was named PrismaXRM) and microXRF data obtained using AttoMap.
In Operando Growth of Dendrites
The formation of Zn dendrites jeopardize the cell cycle life in novel Zn-ion battery schemes. Sigray’s EclipseXRM provides the resolution and speed to observe the in-situ growth of dendrites.
3D Microstructural Evolution of Electrodes
The microstructure of electrodes is increasingly of interest, as it is now recognized that damage incurred and particle agglomeration from charging limit long-term reliability and lifetime. TriLambdaXRM provides the resolution needed to visualize these changes—and, due to the non-destructive nature of x-rays, can be used to monitor such changes over time or in-operando.
3D Imaging of Intact Batteries and Batteries in-operando
Sigray’s EclipseXRM delivers submicron high-resolution imaging, even for large samples and those placed within in-situ cells. The flexibility of the EclipseXRM in switching between multiple fields of view enables hierarchical characterization of batteries—from the full-field imagine to detailed region-of-interest analysis—without requiring battery de-packaging. This allows for the non-destructive identification of problems such as small defects (e.g., cracks, particles) and shorts.
Read the paper published at Journal of Materials Chemistry A.
Transition-metal Precipitation Mapping
High-nickel LiNixMnyCo1-x-yO2 (NMC) cathodes have emerged as a highly promising candidate for next-generation lithium-ion batteries (LIBs). Operating battery cell at a high cutoff voltage is another widely adopted approach to increasing energy and power density. Unfortunately, high-voltage cycling exacerbates the degradation of the NMC cathode, leading to surface lattice reconstruction and transition metal dissolution. Sigray’s AttoMap microXRF uncovers the diffused precipitation of Mn, Co, and Ni, as well as their spatial distributions on the lithium metal anode.
Read Paper in Materials Today
Contamination in Battery Manufacturing and Metal Migration
Thermal runaway is one of the primary concerns in lithium-ion batteries (LIBs) and is often caused by an internal short circuit. Such shorts can occur due to contaminants, such as iron particles introduced during the manufacturing process. Sigray’s AttoMap microXRF provides high sensitivity at rapid speeds (down to 2ms/point) to quickly screen for contaminants.
For R&D researchers, the AttoMap’s high spatial resolution and sensitivity enable imaging of trace-level metal migration in electrodes during battery cycling. The system complements XRD and XAS by providing elemental distribution at microns-scale resolution.
