Strong metal oxide-support interaction in MoO/N-doped MCNTs heterostructure for boosting lithium storage performance.

The low-rate capability and fast capacity decaying of the molybdenum dioxide anode material have been a bottleneck for lithium-ion batteries (LIBs) due to low carrier transport, drastic volume expansion and inferior reversibility. Furthermore, the lithium-storage mechanism is still controversial at present. Herein, we fabricate a new kind of MoO nanoparticles with nitrogen-doped multiwalled carbon nanotubes (MoO/N-MCNTs) as anode for LIBs. The strong chemical bonding (MoOC) endows MoO/N-MCNTs a strong metal oxide-support interaction (SMSI), rendering electron/ion transfer and facilitate significant Li intercalation pseudocapacitance, which is evidenced by both theoretical computation and detailed experiments. Thus, the MoO/N-MCNTs exhibits high-rate performance (523.7 mAh/g at 3000 mA g) and long durability (507.8 mAh/g at 1000 mA g after 500 cycles). Furthermore, pouch-type full cell composed of MoO/N-MCNTs anodes and commercial LiNiCoMnO (NCM622) cathodes demonstrate impressive rate performance and cyclic life, which displays an unparalleled energy density of 553.0 Wh kg. Ex-situ X-ray absorption spectroscopy (XAS) indicates the enhanced lithium-storage mechanism is originated from a partially irreversible phase transition from LiMoO to LiMoO via delithiation. This work not only provides fresh insights into the enhanced lithium-storage mechanism but also proposes new design principles toward efficient LIBs.