A 50% performance improvement of Li1.1V3O8 electrodes is achieved with the poly(methyl methacrylate) (PMMA)/ethylene carbonate (EC) + propylene carbonate (PC) combination. However, EC + PC must be adjusted to a critical optimal quantity to be effective. EC + PC acts as a high permittivity co-solvent and strongly modifies the solid/liquid electrode dispersion, which has two opposite effects with respect to the electrochemical performance. EC + PC leads to better Li1.1V3O8 and carbon black (CB) distribution within the dried electrode, but it degrades indirectly the electrical resistivity of the CB/CB and CB/Li1.1V3O8 contacts. This study shows that designing efficient composite electrodes needs a perfect tuning of the solvent properties to tailor the interactions between the constituents during the processing. (c) 2007 The Electrochemical Society.