High‐Performance Na3V2(PO4)3/C Cathode for Sodium‐Ion Batteries Prepared by a Ball‐Milling‐Assisted Method

Na 3 V 2 (PO 4 ) 3 /C samples are synthesized by a wet‐ball‐milling and in situ carbon‐compositing process. The structural and morphological characterization of the milled samples shows that they are highly pure and crystalline composites, in which the specific surface undergoes an effective increase. The sample prepared by milling for 24 h shows an excellent electrochemical behavior and reaches a capacity value as high as 108.5 mA h g –1 at 40 C and full capacity recovery when returned to a C/2 rate at the end of the cycling. Furthermore, this sample is able to maintain 111 mA h g –1 at 10 C after 100 cycles. This exceptional performance is correlated to the good kinetic response, as evidenced by impedance spectroscopy and the analysis of the cell polarization at the charge and discharge branches.