Poly(vinylidene fluoridePoly(vinylidene fluoride)) (PVDF) membranes were synthesized through non-solvent-induced phase separation and modified with styrene–butadiene rubber (SBR) and graphene nanosheets (Gn) to adjust electroactive properties. FTIR data show a shift from the non-polar α phase (764, 976 cm⁻1) to the electroactive β phase (840 cm⁻1), with the β-phase content increasing from 51.38% (neat PVDF) to 81.84% at 1 wt% Gn, consistent with heterogeneous nucleation and better dipole alignment. DSC indicates improved crystallization, with crystallinity rising from 53.6% (PVDF0) to 77.0% (PVDF–SBR/Gn, 2 wt%), reflecting Gn-induced chain ordering and β-phase stabilization. ElectricalElectrical four-point-probe measurements reveal a significant increase in DC conductivityConductivity, from 1.26 × 10⁻13 to 1.51 × 10⁻⁶ S cm⁻1 at 3 wt% Gn (approximately 10⁷-fold increase), in a regime where charge transport and trap filling during poling are facilitated while field penetration is maintained. Mechanical testing reveals that 1 wt% Gn enhances both stiffness and ductility, with Young’s modulus at 211.7 MPa and yield strain at 8.58%. A structure–property map highlights an optimal range at 1–2 wt% Gn, where β-phase enrichment and crystallinity are maximized with minimal leakage; at 3 wt%, partial agglomeration increases supercooling and reduces Xc, though conductivityConductivity remains adequate. Overall, SBR flexibility, Gn-driven heterogeneous nucleation and interfacial dipole alignment, along with water-induced phase inversion, produce a β-rich, polarizable structure with tunable electronic conductivityConductivity, making these membranes suitable for next-generation piezoelectricPiezoelectric sensors, energy harvesters, and smart filtration.