Monodisperse mesoporous Li9V3(P2O7)3(PO4)2 microspheres prepared via a hydrothermal method as cathode material for lithium-ion batteries

A hydrothermal approach was developed to synthesize monodisperse Li9V3(P2O7)3(PO4)2 microspheres consisting of nanoplates arranged in an open three-dimensional mesoporous structure. Conductive polyaniline (PANI) was deposited onto the Li9V3(P2O7)3(PO4)2 microspheres to increase their rate capability. The samples were investigated using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N2 adsorption–desorption, tap density, Fourier transform infrared spectroscopy, and electrochemical methods. The Li9V3(P2O7)3(PO4)2/PANI microspheres were found to have excellent rate capability and cycle stability, exhibiting a discharge capacity of 139 mAh g−1 at 0.1 C, which remained approximately 110 mAh g−1 at 5 C and 94 mAh g−1 at 10 C for a total of 500 cycles at 2.5–4.6 V.

► Monodisperse mesoporous Li9V3(P2O7)3(PO4)2 microspheres were prepared. ► The microspheres have a high tap density of 1.8 g cm−3. ► Li9V3(P2O7)3(PO4)2/PANI has excellent rate capability and cycle stability.