Rapid activation and enhanced cycling stability of Co3O4 microspheres decorated by N-doped amorphous carbon shell for advanced LIBs

Abstract

Co3O4 has been always highlighted as an anode material for lithium ion batteries (LIBs) due to its high theoretical capacity and low cost. However, its practical application is severely limited by the inherent structural pulverization and activation hysteresis during cycling. To overcome such limitation, in this work, a facile route of air-injection assisted soaking in dopamine-tris (DA-tris) solution followed by annealing in Ar atmosphere is successfully approached to decorate N-doped amorphous carbon (a-C) shells on surface of Co3O4 microspheres. The N-doped a-C shells are co-constructed by films and nanoparticles of N-doped a-C. The concentration of DA-tris plays significant roles to the structural nature of the N-doped a-C shells and the phase configuration of the Co3O4 microspheres. As an anode material for LIBs, the Co3O4 microspheres decorated by the N-doped a-C shells exhibit superior reversible capabilities of 1074 mA h g−1 under 500 mA g−1 and 830 mA h g−1 under 1000 mA g−1 after 500 cycles, respectively. Moreover, the rate capacity is impressive and the activation hysteresis is remitted effectively. Such an excellent lithium ions storage performance is firstly ascribed to the rapid activation of Co3O4 promoted by metallic Co, which is reduced by the N-doped a-C shells in situ. Secondly, the N-doped a-C shells effectively protect the structure from cracking and promote the electrochemical reactions of the Co3O4 microspheres. The present work provides an effective way to buffer the activation hysteresis of the transition metal oxides used for advanced LIBs application.