Spatially resolved in operando neutron scattering studies on Li-ion batteries

Spatially-resolved neutron diffraction has been applied to probe the lithium distribution in radial direction of a commercial Li-ion cell of 18650-type. The spatial evolution of selected Bragg reflections for LiCoO2 (positive electrode, cathode) and graphite and lithium intercalated graphite (negative electrode, anode) was observed and evaluated by taking beam attenuation and cell geometry effects into account. No evidences for lithium inhomogeneities have been found for the investigated set of cells. Computed neutron tomography using a monochromatic neutron beam confirmed the homogeneous lithium distribution. The relevance of the monochromatic beam to neutron imaging studies of Li-ion cells is discussed. (C) 2013 Elsevier B.V. All rights reserved.