Li3V2(PO4)3/C microspheres with high tap density and high performance synthesized by a two-step ball milling combined with the spray drying method

• The Li3V2(PO4)3/C microspheres are composed of the nanosized primary particles.
• The nanoparticles are coated and inter-connected by nano carbon layers.
• The Li3V2(PO4)3/C microspheres exhibit a high tap density of 1.49 g cm−3.
• The Li3V2(PO4)3/C microspheres show excellent rate and cycling performances.

Li3V2(PO4)3/C microspheres are synthesized by a two-step ball milling combined with spray drying method. XRD results reveal that the sample exhibits a single monoclinic Li3V2(PO4)3 phase, and no impurity phases are detected. SEM and TEM results indicate that the Li3V2(PO4)3/C microspheres (diameter 1–3 μm) are composed of uniformly distributed nanoparticles (diameter 50–200 nm), and the nanoparticles are coated and inter-connected by nano carbon layers (1–2 nm thick). The tap density of the sample is as high as 1.49 g cm−3. In the potential range of 3.0–4.3 V, the sample exhibits specific discharge capacities of 124.4, 108.6 and 89.5 mAh g−1 at 1C, 10C and 20C rates, respectively, and shows excellent cycling performance.