Synthesis and electrochemical properties of ordered macroporous Li3V2(PO4)3 cathode materials for lithium ion batteries

A series of ordered macroporous Li3V2(PO4)3 (LVP) cathode materials with three different pore sizes (65 nm, 120 nm and 210 nm) are prepared via a templating method using poly(methyl methacrylate) (PMMA) colloidal crystals as templates. The structure, morphology and electrochemical properties of the as-prepared LVP samples are characterized by SEM, TEM, XRD, BET, galvanostatic charge–discharge tests, cyclic voltammograms and electrochemical impedance spectroscopy measurements. The three LVP samples all show pure monoclinic structure and ordered macroporous morphology. The LVP sample with pore size of 210 nm shows the best electrochemical performance. In the potential range of 3.0–4.8 V, it delivers a high initial discharge capacity of 189.4 mAh g−1 at 0.1 C, which is close to the theoretical capacity (197 mAh g−1). Moreover, at 0.5 C, 1 C and 5 C, it exhibits initial discharge capacities of 170.5, 166.0 and 145.9 mAh g−1, and can still retain 77.3%, 71.2% and 77.1% of the initial discharge capacity after 100 cycles, respectively.