Quantifying the structural origin of the improved electrochemical performance of novel cathode materials for Li-ion batteries using XRD-CT

This proposal aims to observe and quantify the physicochemical characteristics of novel Li ion battery cathode materials (single crystal & concentration gradient) responsible for improved cycle retention and resistance to degradation versus current state of the art materials such as NMC811 (LiNi0.8Mn0.1Co0.1O2). To do this, we will study the materials in situ inside fresh and aged Li ion cells using X-ray diffraction computed tomography (XRD-CT) [1-4] at different length scales, spatially resolving the chemical structure as a function of depth within the cathode layer, down to single particle level. The improvements in performance are considered to relate to a reduction in side reactions and CEI formation, reduced strain and structural rearrangement, and reduced transition metal migration. Such processes are closely linked to the applied cut-off voltage and cycle number – this proposal seeks to directly quantify the structural origin of the improved electrochemical performance.