Gd substituted 0.94(Na0.5Bi0.5-xGdxTiO3) – 0.06 BaTiO3 (x = 0.00, 0.01, 0.02 and 0.03) lead free ferroelectric ceramics were synthesized by a conventional solid-state synthesis. Room temperature XRD reveals the formation of perovskite structure without secondary impurity peaks. Rietveld refinement pattern confirms the coexistence of dual phase i.e., major monoclinic (Cc) and minor tetragonal (P4mm). More tetragonality and slim ferroelectric properties were noted with increasing Gd content in NBT-BT solid solutions. A collective Gd substitution stimulates the transition of PE loop shape from square to slim with slanted leads to suit for high energy density storage applications. The optimum energy storage properties can be achieved for x = 0.03 ceramic showed a recoverable energy density 1.59 J/cm3 and a remarkably best energy efficiency of 67% under 65 kV/cm at room temperature.