Hybrid composite membranes possess the desired properties than that of the pristine polymeric membranes for fuel cell applications. Phase inversion method was used to entrap silicotungstic acid (STA) particles in Sulfonated Poly Ether Ether Ketone (SPEEK) membranes as a source of protons having a high protonic conductivity at room temperature (0.02-0.1 S/cm). The physico-chemical properties of the hybrid membranes were characterized by SEM-EDX, line scanning, 3D non-contact profilometer, FTIR and XRD techniques. These membranes showed better ion exchange, proton conductivity values and were tested in single chamber microbial fuel cell (SCMFC). In addition, these membranes show decreased oxygen crossover and transport of cations other than protons. Among the various weight percentage (2.5%, 5%, 7.5% and 10%) of STA prepared composite membranes, 7.5% STA + SPEEK showed the highest power density of 207 mWm(-2) compared to that of commercial Nafion 117 (47 mWm(-2)) in the same setup of SCMFC. Overall, the composite membranes proved to be excellent candidates as electrolytes for Microbial Fuel Cell (MFC) applications. (C) 2016 Elsevier Ltd. All rights reserved.