Large‐Area Carbon Nanosheets Doped with Phosphorus: A High‐Performance Anode Material for Sodium‐Ion Batteries

Large‐area phosphorus‐doped carbon nanosheets (P‐CNSs) are first obtained from carbon dots (CDs) through self‐assembly driving from thermal treatment with Na catalysis. This is the first time to realize the conversion from 0D CDs to 2D nanosheets doped with phosphorus. The sodium storage behavior of phosphorus‐doped carbon material is also investigated for the first time. As anode material for sodium‐ion batteries (SIBs), P‐CNSs exhibit superb performances for electrochemical storage of sodium. When cycled at 0.1 A g(−1), the P‐CNSs electrode delivers a high reversible capacity of 328 mAh g(−1), even at a high current density of 20 A g(−1), a considerable capacity of 108 mAh g(−1) can still be maintained. Besides, this material also shows excellent cycling stability, at a current density of 5 A g(−1), the reversible capacity can still reach 149 mAh g(−1) after 5000 cycles. This work will provide significant value for the development of both carbon materials and SIBs anode materials.