Rechargeable nanoelectrofuel electrodes and devices for high energy density flow batteries

Nanoelectrofuel compositions include a plurality of electroactive surface-treated or surface modified nanoparticles dispersed in an electrolyte or self suspended and exhibit fluid characteristics are provided. A Redox flow cell may employ the nanoelectrofuels compositions, wherein the redox flow cell includes a first inlet and a first outlet in fluid communication with a first half-cell body, a second inlet and a second outlet in fluid communication with a second half-cell body, a third cell body, and an ion-conductive membrane separating the first half-cell body from the second half-cell body and defining the second half-cell body.