Ruthenium‐Modified Bimetallic Zeolitic‐Imidazolate Framework Derivative as a High‐Efficient Catalyst for Rechargeable Zinc‐Air Batteries

Znic‐air (Zn‐air) cell has gained lots of attention due to its high specific energy. High activity and good stability of bifunctional electrocatalysts are very critical for Zn‐air cell. Herein, Co particles embedded in highly porous N‐doping carbon nanocube (Co/HP‐NC) has been successfully fabricated by pyrolyzing bimetallic Co/Zn‐zeolitic‐imidazolate framework (ZIF) and further evenly loaded with metallic Ru nanoparticles to obtain Ru‐coated Co/HP‐NC (Ru@Co/HP‐NC). Benefiting from introduction of Zn, Ru@Co/HP‐NC shows the large pore volume, small Co particles, high surface contents of Co4N and pyridinic/graphitic N. Furthermore, theoretical and experimental results further demonstrate that synergy of Ru coating with Co/HP‐NC can greatly improve the oxygen reduction/evolution reaction (ORR/OER) property of Ru@Co/HP‐NC. Furthermore, Ru@Co/HP‐NC based Zn‐air batteries present the high open circuit potential of 1.4 V, large power density of ∼210 mW cm−2, high discharge capacity (791 mAh g−1) and super‐long cycling life (∼475 cycles) with small overpotantials (∼0.89 V). Notably, flexible Zn‐air cell with Ru@Co/HP‐NC cathode also displays excellent flexibility and superior cycling stability under different bending conditions. The work provides the simple and reliable way to prepare high‐efficient electrocatalysts for high‐performance metal‐air systems.