Neutron diffraction analysis of structural transformations in lithium-ion batteries

Abstract

The possibilities of using neutron diffraction in real-time studies of structural transformations occurring in crystalline functional materials during the action of external factors are discussed. As an example, the diffraction patterns are directly collected with 5-min resolution in the course of three charge–discharge cycles of a commercial lithium-ion battery (operando mode). It is shown that the analysis of spectrum evolution allows the main processes occurring in electrode materials to be characterized, namely, to identify the structural transformations, assess the fraction of material involved in the process, follow the kinetics and the degree of symmetry of charge–discharge processes, compare the structural transformations with the charge–discharge characteristic of the battery. The high-resolution neutron diffraction in combination with X-ray diffraction and X-ray spectral elemental analysis makes it possible to elucidate the structural type and composition of the working electrode and determine its microsctructural characteristics. Neutron diffraction is shown to be a powerful method often sufficient for studying structural transformations in complex multi-component objects.