Operando small‐angle x‐ray scattering for battery research

With the rapid growth of secondary batteries used in various industries, methods for analyzing battery elements such as electrodes and electrolytes have also improved. In addition, as the utility of nano‐scaled electrode materials have attracted greater attention, it has become increasingly clear that conventional electrochemical analytic methods have limitations. Consequently, electron microscopy and even synchrotron x‐ray radiation techniques have been adopted and are now widely used. Among several advanced analytical techniques, synchrotron radiation‐based operando small‐angle x‐ray scattering (SAXS) enables real‐time analysis of changes in the ordering of nanostructures and in the electron densities of electrodes and solid electrolytes during electrochemical reactions. In this review, the principle and applications of operando SAXS are briefly introduced, to help in understanding the complex nanostructural behaviors of battery components used in secondary batteries, and furthermore, it is hoped to contribute to innovative materials design. Operando small‐angle x‐ray scattering (SAXS) for battery research is briefly reviewed, to help in understanding the complex behaviors of nano‐scaled electrochemical components such as electrodes and electrolytes in secondary batteries, where this advanced analysis method is expected to play a key role in providing useful information for the design and synthesis of prospective materials in energy‐storage fields.