The arrangement of carbon black around active particles in LiMn2O4 composite cathodes is studied by using EDS analysis, scanning electron microscopy (SEM) and microelectrode impedance spectroscopy. It is shown that a uniform carbon black distribution around the active particles is reflected in a normal-like distribution of locally probed resistances around the active particles. If the carbon black is non-uniformly arranged (that is, it tends to form agglomerates within the composite), then a bi-modal distribution of local resistances is obtained. The normal-distribution case leads to considerably lower polarization of cathodes and, consequently, to higher cathode capacities at given current densities. (C) 2004 Elsevier B.V. All rights reserved.