Exploring highly efficient electrocatalysts toward oxygen reduction and evolution reactions are critical for the development of rechargeable zinc–air batteries. As a novel class of electrocatalyst, transition metal nanoparticles encapsulated within nitrogen-doped carbon have been regarded as competitive alternative to replace noble metal electrocatalysts. Herein, we report successful synthesis of high-density iron nanoparticles encapsulated within nitrogen-doped carbon nanoshell (Fe@N–C) by solid-phase precursor׳s pyrolysis of dicyandiamide and ammonium ferric citrate. The resulting Fe@N–C material shows excellent bifunctionality for ORR and OER in alkaline medium compared to state-of-the-art commercial Pt/C and IrO2, which demonstrates high performance and cycling durability in zinc–air battery as efficient oxygen electrocatalyst.