This is the accepted version of the following article: Rueda-Garcia D., Cabán-Huertas Z., Sánchez-Ribot S., Marchante C., Benages R., Dubal D.P., Ayyad O., Gómez-Romero P.. Battery and supercapacitor materials in flow cells. Electrochemical energy storage in a LiFePO4/reduced graphene oxide aqueous nanofluid. Electrochimica Acta, (2018). 281. : 594 - . 10.1016/j.electacta.2018.05.151, which has been published in final form at https://dx.doi.org/10.1016/j.electacta.2018.05.151 © https://dx.doi.org/10.1016/j.electacta.2018.05.151. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/