Hollow Fe3O4/C spheres as superior lithium storage materials

► The self-assembled hollow Fe3O4/C spheres favor a fast kinetic with facilitating the electron transportation, the lithium ions insertion/deinsertion and less volume expansion during cycling. ► Hollow Fe3O4/C spheres was first reported as anode material with excellent cycling and rate performance. ► Lithium insertion mechanisms are also proposed systematically based on the ex situ XRD analysis. ► This simple, inexpensive synthesis approach can be scale-up easily and used for producing of other hollow spherical materials for high power LIBs.