The effects of surface coating on electrode properties of LiMn2O4 in a sulfide solid electrolyte were investigated. The surface coating with LiNbO3 reduced the electrode resistance by two orders of magnitude. Changes in the electrode properties were very similar to those observed for the corresponding LiCoO2 electrodes, which strongly suggest that the space-charge layer formed at the high-voltage cathode/sulfide electrolyte interface is rate-determining and must be controlled to improve the rate capability. (c) 2012 Elsevier B.V. All rights reserved.