3D-porous β-LiVOPO4/C microspheres as a cathode material with enhanced performance for Li-ion batteries

Abstract

3D porous β-LiVOPO₄/C microspheres were synthesized through a solvothermal method followed by a post-heat treatment. TG-DSC and FTIR results illustrate crystal structure transformation from α→β-LiVOPO₄. XRD results reveal pristine and synthesized powders that were crystallized in the triclinic α-LiVOPO₄ and orthorhombic β-LiVOPO₄ phase, respectively. Scanning electron microscopy (SEM) and pore distribution results reveal that β-LiVOPO₄/C spheres were built from small nanoplates and pores with a wide diameter distribution. HRTEM results indicate encapsulation of β-LiVOPO₄/C particles with amorphous carbon shells. A porous β-LiVOPO₄/C cathode delivered 134 mA h g⁻¹ and 74 mA h g⁻¹ initial discharge capacities at 0.1 C and 1 C, respectively. The cell presented superior capacity retention attributed to the contributions of surface coating, high specific surface area, and porous architecture that serve as facile electrical conduits for ion/electron transport.