This data set contains all the data presented in the main text figures (for the manuscript titled 'Operando monitoring of single-particle kinetic state-of-charge heterogeneities and cracking in high-rate Li-ion anodes'). The information on how the data was acquired and processed is detailed in the open access manuscript + SI. This data set also contains the MATLAB code used to conduct the phase field modelling in the same manuscript. Figure 1: (Panel b) Galvanostatic cycling data of NWO (voltage vs specific capacity) for five cycles cycles at 1C, 5C and 20C. (Panel c) Li-ion self-diffusion coefficient in NWO, as a function of temperature and Li-concentration. Figure 2: (Panel a) SEM image of NWO particles. (Panel c) Unprocessed optical images of a NWO particle during a galvanostatic cycle at 5C. (Panel d) Cell voltage, single particle scattering intensity, and single particle length change, during galvanostatic cycles at 1C, 5C and 20C. (Panel e) Change in the c-lattice parameter of NWO, measured by operando and ex situ XRD, as a function of Li-content. Optically-determined length change for multiple individual NWO particles. Figure 3: (Panel a&d) Cell voltage and applied current for two galvanostatic cycles at 5C, initially preceded by a 2.8V hold. (Panel b) Differential optical images showing a particle of NWO at the beginning of the first 5C cycle shown in a. (Panel c) Cell voltage for the first 50s of the first 5C cycle. Differential linecut along a NWO particle during this same time period. (Panel e) Differential optical images showing a particle of NWO at the beginning of the second 5C cycle shown in d. (Panel f) Cell voltage for the first 50s of the second 5C cycle. Differential linecut along a NWO particle during this same time period. (Panel g) Simulated change in Li-content along a NWO particle, during the first 30 s of lithiation from a starting composition of x=0.08. (Panel h) Simulated change in Li-content along a NWO particle, during the first 30 s of lithiation from a starting composition of x=0.14. (Panel i) Experimentally-determined and simulated lithiation front velocities at 1C, 5C and 20C. Figure 4: (Panels a,d,I,j) Unprocessed optical images of a NWO particle at various stages between cycles. (Panels b,c,g) Cell voltage during delithiation at C/2, 5C or 20C. Differential linecut along the NWO particle during the same time periods. (Panels e,f,h) Differential optical images showing the particle of NWO at the time-points indicated in panels c and g. Figure 5: (Panels a,b,c) Statistical data obtained from optical images of a consistent set of particles, between ‘cracking cycles’. See explanatory document. (Panel d) Unprocessed optical images of NWO particles after 20 cycles.