Novel Nb26Mo4O77 rod-like nanoparticles anode with enhanced electrochemical performances for lithium-ion batteries

Abstract

As a branch of intercalation type niobium-based anodes for lithium-ion batteries, Nb26Mo4O77 samples are synthesized by hydrothermal and solid-state method, respectively, while the structure and lithium-ion storage characteristics are studied in depth. Nb26Mo4O77 belongs to a monoclinic phase with ordered intergrowth ReO3 structure, which is constructed by a mixture of (Nb/Mo)O6 octahedra blocks of 3 × 4 × ∞ and 4 × 4 × ∞ occurring in alternate sequence and linked by MoO4 tetrahedra, favoring to the structural stability during the rapid lithium-ion deintercalation. Compared to agglomerated Nb26Mo4O77 microparticles synthesized via solid-state process, rod-like nanoparticles synthesized by hydrothermal method with the high specific surface area and reaction reactivity exhibit an improved initial coulombic efficiency (89.3%), notable cyclability (203 mAh g−1 after 503 cycles at 0.5 C), significant intercalation pseudocapacitive contribution (82.2% at 0.9 mV s−1) and increased rate capability (107 mAh g−1 at 10 C). These results provide some new supplements for the improvement of niobium-based anodes.