Abstract
Transition metal oxides such as Fe3O4 have been widely explored as the anode material for lithium-ion batteries (LIBs). The rational design of the architecture of active materials is highly desirable to advance their lithium-storage properties. Herein, we report the construction of pomegranate-like microscale superparticles with an average size of 450nm, comprising close-packed Fe3O4@C yolk-shell nanoparticles (NPs), by combining bottom-up assembly and top-down etching methods. Combining the merits of yolk-shell NPs, secondary particle configuration, and homogeneous carbon coating, such elaborately designed superparticles show great promise for LIB anodes. Moreover, the ability to fine tune the void space in individual yolk-shell NPs allows for the further improvement in lithium storage. A stabilized capacity as high as 1246mAhg−1 is achieved at 0.8Ag−1, and even cycled at an ultrahigh current density of 5Ag−1, our pomegranate-like Fe3O4 NP superparticles can still maintain a high capacity of 520mAhg−1 after 1000 cycles. This work establishes a generic strategy for producing pomegranate-like superparticles of transition metal oxides for high-rate and long-cycle lithium storage.
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