Redox flow batteries have gained renewed interest for grid storage applications. This work focuses on the effect of various chemical/physical parameters on the performance of the LiFePO4/LiPF6 EC-DMC/Li redox flow system. A methodical study of the influence of the content of active material and of the flow rate, coupled with electrochemical and hydrodynamic characterizations, have been carried out in order to better understand the various 'migration' and 'diffusion' limitations, as well as to try to overcome their effects. As a result, power density performances higher than 328 mW.cm(-2) at 104 mA.cm(-2) were achieved and the feasibility of reaching energy density of 50 Wh.kg(-1) demonstrated. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.071208jes] All rights reserved.