Porous Na3V2(PO4)3 prepared by freeze-drying method as high performance cathode for sodium-ion batteries

Abstract Na 3 V 2 (PO 4 ) 3 has aroused extensive attention as next generation cathode material for sodium-ion batteries because of its abundance, good thermal stability and special 3D Na + channel. In the current work, porous Na 3 V 2 (PO 4 ) 3 material is prepared by a simple freeze drying method followed by calcinations. Inside the porous material, Na 3 V 2 (PO 4 ) 3 particles are embedded in carbon matrix, thus forming facial electron channels and reducing Na + ion diffusion distance at the same time. Benefiting from the special porous structure, this material displays excellent rate capability of 92.8 mA h g −1 at high rate of 20 C. Equally impressive is the long cycling stability. 90.2% of the initial capacity is retained after 2000 cycles at 5 C. This kind of feasible preparation method and beneficial design provide a good strategy for other materials to improve electric conductivity and cycling stability.