Built-in electrical field enhanced ionic transport kinetics in T−Nb2O5@MoO2 heterostructure

Mg2+/Li+ hybrid ion battery (MLIB) is regarded as an engaging candidate of next generation rechargeable batteries. However, realizing superior high-rate performance is still an unremitting challenge for further development of MLIB. Herein, a rational design of T−Nb2O5@MoO2 nanorod array heterostructure is presented as the cathode of MLIB. The resulted heterostructure reinforces structural stability and induces the generation of built−in electrical field, which facilitates ionic transport kinetics, as verified by reaction kinetics analysis, ex-situ characterization technique and density functional theory calculations. As expected, the T−Nb2O5@MoO2 heterostructure delivers a reversible capacity of 250.3 mA h g−1 at 0.5C, excellent rate performance (68.8 mA h g−1 at 10C) and long cycling life (capacity retention of 76.0% at 5C after 1500 cycles). Thus, this strategy paves a way for designing the advanced electrode materials with excellent electrochemical performance.