Structural Analysis of Na-ion Cathode Material
High-Resolution Characterization of Inorganic Materials with the D8 ADVANCE HE
High‑energy X‑ray diffraction is a powerful tool for correlating atomic‑scale structure with material properties.
The D8 ADVANCE HE, equipped with a Mo X‑ray source and the high‑efficiency LYNXEYE HE detector, provides an ideal platform for detailed crystallographic analysis of inorganic materials, combining extended reciprocal‑space access with excellent data quality.
Investigating Sodium Cathode Material using an Mo X-ray Source
Sodium-ion batteries have emerged as a promising alternative to traditional lithium-ion batteries, offering advantages in terms of resource abundance, cost efficiency, and environmental sustainability. One key factor to optimizing performance of Na-ion batteries is a detailed understanding of how subtle structural features influence electrochemical behavior. In this report, we demonstrate the capabilities of the D8 ADVANCE HE for structural analysis of the Na-ion battery cathode material NaNi₀.₃Mn₀.₃Fe₀.₄O₂ using a Mo X-ray source.
Mo radiation offers several advantages for crystallographic investigations of inorganic materials. The short wavelength (0.71 Å) enables access to smaller d-spacings and larger Q-range, allowing finer structural details to be resolved. In addition, reduced sample absorption and fluorescence effects lead to lower background levels and improved overall signal-to-noise ratios, particularly at high diffraction angles.
Method, Results & Discussion
NaNi₀.₃Mn₀.₃Fe₀.₄O₂ powder was prepared in a 0.7 mm Kapton capillary, and data was collected with a D8 ADVANCE HE diffractometer equipped with a Mo sealed tube, focusing Goebel mirror optic, capillary stage, and LYNXEYE HE detector. High‑quality diffraction data suitable for structure solution and refinement were collected in just two hours, highlighting the high efficiency of the experimental setup.
Like widely used Li-ion cathode materials such as NMC, NaNi₀.₃Mn₀.₃Fe₀.₄O₂ adopts an O3-type layered structure where Na⁺ ions occupy octahedral sites between 2D layers of edge-sharing MO₆ octahedra (Figure 2). This layered arrangement provides accessible diffusion pathways for Na⁺ ions, making it particularly well-suited for battery applications.
Figure 3 shows the result of a Rietveld structure refinement using the DIFFRAC.TOPAS software package. Owing to the high efficiency and low noise of the CdTe sensor in the LYNXEYE HE detector, peaks in the high-angle region can be easily resolved even with short measurement times. Additionally, a small amount of NiO impurity (less than 1%) could be detected and quantified. Selected structural parameters of the Rietveld refinement can be found in Table 1; the Na-site occupancy as well as the atomic displacement parameters of all crystallographic sites were refined.
High‑energy X‑ray diffraction on the D8 ADVANCE HE enables rapid, high‑precision structural analysis of complex battery materials. This capability makes the D8 ADVANCE HE a powerful tool for advancing the structural understanding and optimization of next‑generation functional materials.
References & Further Information
- K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data” J. Appl. Crystallogr., 44, 1272–1276 (2011).
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