Facile synthesis of hierarchical porous Na3V2(PO4)3/C composites with high-performance Na storage properties

Porous Na3V2(PO4)3/C composites were prepared in situ via a simple solution method using various amounts of cetyltrimethylammonium bromide and glycine mixtures. Platelet particles with a thickness of ~150 nm were formed when 0.4 mmol cetyltrimethylammonium bromide and 0.4 mmol glycine were used, resulting in a high specific surface area (16 m2 g−1) and porosity (0.05 cm3 g−1) of the composites. In addition, the porous Na3V2(PO4)3/C composites presented good reversible cyclic voltammetry peaks with low hysteresis and delivered a high specific discharge capacity of 113 mA h g−1, which decreased to 99 mA h g−1 (capacity retention of 88.1%) after 200 cycles at the current rate of 1 C. The high rate capability (96 mA h g−1 at 10 C) of the composites was attributed to their unique foamy microstructure, plate-like particles, and high electronic conductivity.