3D porous Li3V2(PO4)3/hard carbon composites for improving the rate performance of lithium ion batteries

Abstract

In this paper, three dimensional (3D) porous Li₃V₂(PO₄)₃ (LVP)/hard carbon (HC) composites have been synthesized via a simple method at 800 °C. The XRD, SEM, HRTEM, XPS, Raman spectra, TG, and BET show that the 3D LVP/HC composite is composed of monoclinic LVP nanocrystals (50–100 nm in size) and 3D HC (about 9 wt%) with a pore size range of 2–200 nm. The LVP nanoparticles were conglutinated and uniformly coated by HC. We have clarified the formation mechanism of the nanocomposite structure and the influences of the calcination temperature on the structure and electrochemical properties of 3D porous LVP/HC composites. As a novel cathode for lithium ion batteries, the 3D LVP/HC composites exhibit desired electrochemical performances with a discharge capacity of 143 mA h g⁻¹ at the rate of 0.1C and excellent cycle stability at high rate (the retention capacity is about 92 mA h g⁻¹ after 1000 cycles at 10C).