MOF-derived porous Co3O4-NC nanoflake arrays on carbon fiber cloth as stable hosts for dendrite-free Li metal anodes

A highly stable and wettable host to confine molten Li for the Li metal composite anode has been successfully fabricated through in-situ growth of MOF-derived, Co3O4-embedded and nitrogen-doped porous carbon nanoflake arrays on the commercial carbon fiber cloth (CFC/Co3O4-NC). It is demonstrated that the chemical reaction of the embedded Co3O4 with molten Li, the lithiophilic nature of the nitrogen dopants and the capillary force of the porous structures contribute synergistically to the superior Li wettability of the CFC/Co3O4-NC host. Moreover, after the intense chemical lithiation and rapid melt-infusion of massive Li, the wettable, stable and conductive nanoflake array frameworks of the CFC/Co3O4-NC could be well maintained, providing the uniform distribution of deposited Li, the fast charge transfer for Li/Li+ redox reactions and the reduced local current density during cycling. Consequently, the resulting CFC/Co-NC@Li composite anodes could effectively alleviate the volume change and suppress the growth of Li dendrites, demonstrating an ultralong and stable lifetime for repeated Li stripping/plating of 500 cycles (1000 h) with low overpotential of 18 mV and negligible voltage fluctuation at 1 mA cm(-2) in symmetric cells. Furthermore, in full-cell configurations with LiFePO4 or sulfur cathodes, the CFC/Co-NC@Li anodes show greatly improved cycling stability and rate capability. These encouraging results suggest that the MOF-derived porous Co3O4-NC nanoflake arrays on the commercial carbon fiber cloth should be a promising host to construct dendrite-free lithium metal anodes for advanced lithium metal batteries.