An In Situ Multiscale Study of Ion and Electron Motion in a Lithium‐Ion Battery Composite Electrode

This work reveals the great potential of in situ dielectric spectroscopy for deciphering the motion of ions and electrons on different scales in lithium‐ion battery electrodes. One of the main bottlenecks limiting composite electrode kinetics and energy density, is a critical lack of fundamental understanding with respect to the electronic and the ionic transport within the electrode architecture. The latter is a granular material made up of clusters of particles, in which the particles are separated by boundaries that limit the electronic transport. The ionic transport is also severely restricted due to its tortuous porosity. Here, in situ dielectric spectroscopy is used to study the lithium‐ion battery LiNi 1/3 Co 1/3 Mn 1/3 O 2 composite electrodes. Short‐ and long‐range motions of ions are evident in the low‐frequency region. At higher frequencies, the influence of the adsorbed electrolyte ions on the electronic transfer at the micrometer scale is shown.