Co3O4 nanoparticles@MOF-5-derived porous carbon composites as anode materials with superior lithium storage performance

Abstract

A new route to load Co3O4 nanoparticles (NPs) on MOF-5 (MOF-5 was composed of 1,4-benzenedicarboxylate (BDC) and Zn2+ via coordination bond (Zn4O(BDC)3·(DMF)8(C6H5Cl)), where MOF indicates metal-organic framework) derived hierarchically porous carbon (MDPC) was proposed. Various techniques including scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis and electrochemical methods were used to characterize the Co3O4NPs@MDPC. The results showed that the MDPC contained mesopores obtained by vaporizing ZnONPs and micropores came from MOF-5 self. Lots of nano-sized Co3O4NPs formed in MDPC's mesopores. The vast micropores of MDPC provided an effective channel for the transport of Li+ when it was used as anode materials for lithium ion batteries (LIBs). The MDPC prevented Co3O4NPs from agglomerating effectively, which remained robust for superior rate capability during repeated lithiation/delithiation process. And the as-prepared Co3O4NPs@MDPC composites remained 94% reversible capacity from the second cycle. Furthermore, the as-prepared Co3O4NPs@MDPC anode manifested outstanding capability of 587.2 mA h g-1 at 2000 mA g−1 after 200 cycles, apparently superior to that of other Co3O4NPs@PC. The high capacity especially at high current density and exceptional rate capability of Co3O4NPs@MDPC manifested it is a promising anode material for LIBs.