Nanospace confined N,P co-doped carbon foams as anode for highly reversible and high capacity sodium ions batteries

Non-graphitic carbons have shown great potential in sodium ions batteries, however, major hurdle to address is the poor capacity performance. Herein, a facile strategy combining supramolecular chemistry polymerization and nanospace confinement carbonization is proposed to construct interconnected carbon foams with N,P co-doping (MNNPCs) to improve sodium storage performance. Electrochemical impedance spectroscopy (EIS) measurements demonstrate that defined MNNPCs display fast charge transfer at the electrode electrolyte interface. And the Na+ diffusion coefficient in the MNNPCs electrodes (1.2 x 10(-10) cm(2) s(-1)) is about 22 times than that of reference electrode, suggesting excellent sodium ions diffusion kinetics in MNNPCs electrodes. In particular, MNNPCs are capable of delivering superior specific capacity of 394.5 mAh g(-1) at 50 mA g(-1) after 100 cycles with an initial coulombic efficiency of 58.7%. Such architecture provides a promising structural platform for the preparation of carbon anode materials for high reversible and high capacity sodium ions batteries.