Hierarchical MOF-derived layered Fe3O4 QDs@C imbedded on graphene sheets as a high-performance anode for Lithium-ion storage

Herein, a double-buffering strategy is presented to boost the lithium storage potential of Fe 3 O 4 . Firstly, the skeleton of MIL-100 (Fe) MOF is grown on graphene oxide, as a self-assembled template via in-situ solvothermal approach, which transform into ultrafine, well-dispersed and mesoporous carbon coated Fe 3 O 4 QDs (4 nm) imbedded on reduced graphene oxide (Fe 3 O 4 QDs@C/rGO), by pyrolysis. Each component in such a well-designed porous hierarchical structure significantly contributes to the remarkable enhancement of lithium ion storage performance, leading to high reversible capability with excellent prolonged cyclic stability after 2000 cycles (505 mAh g −1 at 2.0 A g −1 ). Both, Graphene sheets and mesoporous carbon act as conductive support for anchoring uniform Fe 3 O 4 QDs with confined double buffering for cyclic volume flux. Multi-channels with uniform mesopores in the self-assembled array and 4 nm QDs of Fe 3 O 4 confined in conductive carbon shells were favorable to enhance the interfacial electron/ion transfer, leading to the excellent rate and cycling performance with released volume changes upon Li + insertion/extraction. The present research work provides a promising outset design and synthesis strategies for metal oxide QDs based nanocomposites, which may also be extended to the other electrode material system.