Hierarchical porous hollow FeFe(CN) nanospheres wrapped with I-doped graphene as anode materials for lithium-ion batteries.

Hierarchical porous hollow FeFe(CN)6 nanospheres were synthesized via a facile anisotropic chemical etching route at different temperatures. Herein, we integrated these FeFe(CN)6 nanospheres and conductive iodine-doped graphene (IG) into a lithium-ion battery (LIB) system, FeFe(CN)6@IG. The hollow Prussian-blue type FeFe(CN)6 nanospheres with an average particle size of 230 nm are uniformly and tightly encapsulated by IG sheets. As an anode material for LIBs, the fabricated FeFe(CN)6@IG exhibits high specific capacity, excellent rate properties, and superior cycling stability. A reversible capacity can be maintained at 709 mA h g-1 after 250 cycles at a current density of 1000 mA g-1. Even at a current rate of 2000 mA g-1, the capacity could reach 473 mA h g-1. This facile fabrication strategy may pave the way for constructing high performance Prussian blue-based anode materials for potential application in advanced lithium-ion batteries.