Fe2O3 embedded in the nitrogen-doped carbon matrix with strong C-O-Fe oxygen-bridge bonds for enhanced sodium storages

By reason of rich sodium resources, sodium-ion batteries have excited enormous consideration for adhibition in the developing energy-storage stations. And not surprisingly, the exploration of cost-effective anode materials for SIBs have been a conspicuous topic. Herein, iron trioxide embedded in the nitrogen-doped carbon matrix with strong oxygen-bridge bonds is synthesized by using the iron based metal organic framework as template. The obtained composite delivers excellent electrochemical properties, such as specific capacity of 473.7 mAh g−1 at the current density of 100 mA g−1 after 100 cycles. Besides, the reversible capacity still remains at 155.3 mAh g−1 at the high density of 4000 mA g−1. This remarkable sodium-ion storage capability could be attributed to the incorporation of nitrogen atoms into carbon matrix and the strong chemical bonds between iron trioxide and carbon matrix, which can restrain electrode pulverization and also retain an interparticle connection even after long cycling that could offer a good electronic conductive pathway. This engineer strategy for preparing iron trioxide possess strong interfacial interaction with nitrogen-doped carbon matrix can be applied to other metal phosphides and metal oxide materials. •Fe2O3 embedded in the nitrogen-doped carbon matrix with C-O-Fe oxygen-bridge bonds.•Fe2O3@NC delivers excellent electrochemical performances.•C-O-Fe oxygen-bridge bonds offer a good electronic conductive pathway.•Nitrogen-doped carbon matrix can promote the transfer of Na ion.