Facile synthesis of urchin-like MoNb12O33 microspheres with a superior performance as an anode material for lithium-ion half/full batteries

Monoclinic MoNb ₁₂O ₃₃ is a promising material for the anode of lithium-ion batteries (LIBs) owing to its high safety, long-term cyclability, and large capacity. However, its practical use is limited by its poor electrical conductivity and sluggish Li-ion diffusion kinetics. Constructing three-dimensional MoNb ₁₂O ₃₃ micro-/nano structures can be used to overcome these drawbacks. Herein, we report a new simple hydrothermal method for synthesizing urchin-like MoNb ₁₂O ₃₃ (U-MoNb ₁₂O ₃₃ ) microspheres with a 3D hierarchical structure and comprising of one-dimensional radially oriented nanorods. This unique structure of U-MoNb ₁₂O ₃₃ not only exhibited fast ion/electron transport kinetics but also had structural stability and high tap density, which significantly improved the Li ⁺ storage properties. When used as the anode for LIBs, the U-MoNb ₁₂O ₃₃ microspheres exhibited high practical capacity (298 mA h g ⁻¹ at 0.5 C), superior rate capability (168 mA h g ⁻¹ at 20 C), and excellent cyclability (capacity retention of 90 % over 500 cycles at 10 C). Furthermore, an LiNi _0.5Mn _0.3Co _0.2O ₂ ||U-MoNb ₁₂O ₃₃ full cell exhibited outstanding electrochemical performance, including a large capacity, good rate performance, and especially ultra-long cyclability (capacity retention of 77 % after 2500 cycles at 10 C). These results indicate that U-MoNb ₁₂O ₃₃ is a promising anode material for next-generation high-rate LIBs.