Recently, we patented a disruptive concept of hybrid membranes able to fulfill the specific requirements for Proton Exchange Membrane Fuel Cells. The disruptive idea is based on the improvement of all the properties of actual commercial polymer electrolyte membrane via a versatile approach based on Sol-Gel (SG) chemistry. The nature of the SG precursors and their content can be adjusted so that sacrificial groups remain available to protect the ionomer, during the lifetime of the hybrid membrane. The aim of the proposal is (i) to determine the SG network structural features and in turn, ascertain its location with respect to the different phase of the membrane for different SG content, (ii) determine the reciprocal structural impact of both phases (matching of sPEEK or SG phases)