P-doped Hard Carbon as Anode Material for Sodium-ion Batteries

The P-doped hard carbon was synthesized using carboxymethyl cellulose and phosphoric acid as the carbon and phosphorus precursors, respectively. The X-ray photoelectron spectroscopy (XPS) analysis reveals that the doped phosphorus atoms can incorporate into the carbon framework and most of them are connecting with carbon atoms to form P-C bonds. When used as anodes in sodium ion batteries, the obtained un-doped and P-doped hard carbon show poor electrochemical performances. The results indicate further optimization of the synthesis process is required. However, this approach opens up new possibilities to improve electrochemical performance of hard carbon anodes.