Polyacrylamide-assisted freeze drying synthesis of hierarchical plate-arrayed LiV3O8 for high-rate lithium-ion batteries

Hierarchical plate-arrayed LiV3O8 is synthesized by freeze drying method with polyacrylamide (PAM) as surfactant followed by calcination at 500 °C. As a cathode material for lithium-ion batteries, the plate-arrayed LiV3O8 delivers an initial discharge capacity of 255.2 mAh g−1 between 2.0 and 4.0 V at the current density of 50 mA g−1, and possesses a capacity retention of 88.7% after 60 cycles. Moreover, high discharge capacities of 145.2, 133.7 and 111.8 mAh g−1 can still be obtained after the 200th cycle at current densities of 600, 1500 and 3000 mA g−1, respectively. Electrochemical impedance spectroscopy (EIS) test indicates that the LiV3O8 electrode always has very low impedance during the 3rd to 180th cycles. The improved electrochemical performance is attributed to the high crystallinity and uniform arrayed structure of LiV3O8, which can facilitate the fast electron transport and Li ion diffusion in the electrode.

► We synthesize hierarchical LiV3O8 via polyacrylamide-assisted freeze drying method. ► The cyclic stability and rate capability are improved due to the special structure. ► This structure can facilitate the fast electron transport and Li ion diffusion.