In-situ and Operando Characterization of Battery Materials using X-rays

Abstract

X-ray diffraction, scattering and imaging are powerful tools for the study of battery materials [1, 2]. In this work we describe several X-ray methods, which can provide a wealth of information about new materials used in battery applications. By using X-ray diffraction (XRD) it is possible to identify the different crystallographic phases, and with the Rietveld method [3] it is possible to refine the crystallographic structures of the different materials and quantify the amount of each phase in the bulk material. It is also possible to perform in situ and operando XRD measurements of the complete battery cells. This can be done either in reflection or in transmission geometry [4-6]. In order to perform the measurements in transmission geometry, radiation with higher energy is required, e.g. Mo or Ag X-ray anodes. A newly developed Malvern Panalytical X-ray detector (GaliPIX3D) allows for shorter measurement time and/or better data quality thanks to the higher efficiency of the CdTe sensor material [7]. In addition, the short-range structure of crystalline, nano-crystalline and amorphous materials can be studied with the Pair Distribution Function method (PDF), based on a total scattering approach. Also for this technique, hard X-ray radiation (Mo or Ag anodes) is required. Imaging is also a very useful technique, enabling detailed view of the interior structure of the battery in a non-destructive way. All X-ray scattering and imaging experiments can be performed on a single X-ray instrument, such as a Malvern Panalytical Empyrean multipurpose diffractometer.[1] E. Talaie et al., Energy & Environmental Science 8, 2512-2523 (2015)[2] Z. Liu et al., Chemistry of Materials 26(8), 2513-2521 (2014).[3] H.M. Rietveld, J. Appl. Cryst. 2, 65 (1969).[4] I. Buchberger et al., Journal of The Electrochemical Society 162(14), A2737-A2746 (2015).[5] N. Sharma et al., ChemSusChem, 8, 2826-2853 (2015).[6] E. Talaie et al., Chemistry of Materials, DOI: 10.1021/acs.chemmater.6b02726 (2016).[7] G. Confalonieri et al., Powder Diffraction Journal, 30(2), Supp. 1, S65 (2015).