Hierarchical NiMoO₄ nanowire arrays supported on macroporous graphene foam as binder-free 3D anodes for high-performance lithium storage

Novel three-dimensional (3D) NiMoO₄ nanowire arrays (NWAs) grown directly onto the surface of macroporous graphene foams (GF) with robust adhesion were synthesized via a facile chemical vapor deposition (CVD) and subsequent hydrothermal route. The as-prepared NiMoO₄ nanowires are composed of ultra-small nanoparticles (∼5 nm) with a diameter of 70-150 nm and are several micrometers in length. Such as-grown NiMoO₄ NWA/3DGF composites are then evaluated as monolithic electrodes for lithium-ion batteries (LIBs) without the need of binders or metal-based current collectors. Benefitting from the unique three-dimensional arrayed architecture and characteristics with a high specific surface area and more active sites which facilitate fast electron and ionic transport within the electrode, the NiMoO₄ NWA/GF composites deliver a high reversible specific capacity of 1088.02 mA h g^-1 at a current density of 200 mA g^-1 and 867.86 mA h g^-1 after 150 cycles (79.77% retention of the second cycle), and excellent rate capability. With the advantages of excellent electrochemical performance and a facile synthesis method, the NiMoO₄ nanowire arrays supported on 3DGF exhibit great potential as anode materials for LIBs.