High-Rate Lithium Cycling and Structure Evolution in Mo₄O₁₁

Shear-phase early transition metal oxides, mostly of Nb, and comprising edge- corner-shared metal–oxygen octahedra have seen a resurgence in recent years as fast-charging, low-voltage electrodes for Li+-ion batteries. Mo broadly, been less well studied fast-charging electrodes. Here we examine reduced oxide, Mo4O11, that has structure only corner-connected MoO4 tetrahedra MoO6 octahedra. We show an electrode formed using micrometer-sized particles Mo4O11 the active material can function high-rate against Li metal, with stable capacity over 200 mAh g–1 at high rate 5C. Operando X-ray diffraction (XRD), entropic potential measurements, ex situ Raman spectroscopy are employed to understand nature charge storage. The crystal dramatically changes upon first lithiation, subsequent cycling is completely reversible low fade. It newly potentially more layered demonstrates small voltage polarization. A space group unit cell new proposed. This finding expands scope candidate materials those beyond expected Nb-containing shear-phase oxide materials.