Construction of Co-NC@Mo2C hetero-interfaces for improving the performance of Li-O2 batteries

Abstract

Lithium-oxygen batteries (LOBs) are becoming the rising stars of a new generation of energy storage devices due to high theoretical energy density. The crucial factor of its high performance and stability is developing efficient cathode electro-catalysts. In this work, the Zn3[Co (CN)6]2 Prussian Blue analog (Zn-CoPBA) was used as the precursor, then ammonium molybdate tetrahydrate was incorporated by hydrothermal treatment, and finally Mo2C-modified Co-NC was prepared by one-step pyrolysis. The mesoporous hetero-interfaces of N-doped carbon matrix embedded by Mo2C/Co nano-heterostructures facilitate the transport of substances, provide more catalytic active sites and storage space for the discharge product Li2O2 due to the characteristic electronic structure and catalytic properties of Mo2C with d-orbital state distribution near the noble metal-like Fermi level. The composite Co-NC@Mo2C was used for LOBs cathode catalyst, it presents wonderful charge-discharge specific capacities (21,930 mA h g − 1), stable cycling performance.