MOF-Templated sword-like Co3O4@NiCo2O4 sheet arrays on carbon cloth as highly efficient Li–O2 battery cathode.

Highly effective cathode materials are critical to improve existing Li–O 2 batteries. In this paper, we report a free-standing Co 3 O 4 @NiCo 2 O 4 sheet array cathode, which is prepared by in-situ growing an array of sword-like cobalt-based metal-organic framework (Co-MOF) sheets on a carbon cloth (CC) substrate, followed by impregnated with nickel nitrate solution and pyrolyzed in air flow. The Co 3 O 4 @NiCo 2 O 4 /CC cathode exhibits excellent ORR/OER bifunctional activity and high cathodic performance in a Li–O 2 battery, achieving a specific capacity of 10645 mAh g−1 and a stability of 225 cycles. We suggest the high performance of our cathode can be ascribed to its well-defined 3D sheet array structure, which can facilitate O 2 diffusion and electrolyte impregnation, provide sufficient space for the discharge products, and the synergistic effect between Co 3 O 4 and NiCo 2 O 4. This work provides an effective method for the rational design of electrode composition and structure. Image 1 • A sword-like Co 3 O 4 @NiCo 2 O 4 nanosheet array cathode for Li–O 2 battery is prepared. • The cathode exhibited enhanced bifunctional OER/ORR activities in Li–O 2 batteries. • The high performance can be ascribed to its hybrid and array structure. • A high specific capacity of 10645 mAh g−1 with stability of 225 cycles is achieved. [ABSTRACT FROM AUTHOR]