Construction of novel lithium-ion battery anode materials with superior rate performance through Fe/Li2O composite interface.

[Display omitted] • Two materials that are not electrochemically active towards lithium ions are compounded and the resulting Fe/Li 2 O composite has excellent rate performance. • The Fe/Li 2 O composites consisting of two non-electrochemically active materials have excellent rate performance. • Composite materials with a large number of heterogeneous interfaces are obtained after the compounding of Fe and Li 2 O by a facile balling method. • Composite materials with a large number of heterogeneous interfaces are obtained after a facile balling method. • The storage of lithium ions is controlled by a combination of capacitance and diffusion, in which the interface capacitance process dominates. • The kinetic properties of lithium-ion storage are mainly controlled by interfacial capacitance processes. Based on the "job-sharing" mechanism, we have designed novel anode materials for LIBs, consisting of nano-transition metal and lithium oxide particles. The composites exhibit excellent rate performance, maintaining a specific capacity of 29% of the stabilized capacity at 6 A g−1. Since neither metallic iron nor lithium oxide has lithium storage capacity, the lithium storage behavior of the composites is mainly related to the interface. Moreover, the interface facilitates the improvement of the ion diffusion ability and pseudocapacitance percentage of the composite material. This study provides new horizons for designing anode materials for high power density LIBs. [ABSTRACT FROM AUTHOR]