N-doped porous carbon wrapped FeSe2 nanoframework prepared by spray drying: A potential large-scale production technique for high-performance anode materials of sodium ion batteries

Transition metal selenides are promising anode materials for sodium ion batteries. However, large-scale production of these materials still challenges their practical applications. Herein, a facile and scalable strategy is developed to construct N-doped porous carbon framework wrapped FeSe2 composite (P-FeSe2/NCF) through an industrially established spray-drying process and salt-template method, which not only facilitates ion/electron transport, but also alleviates large volume variation. As anode material of sodium ion batteries (SIBs), P-FeSe2/NCF composite displays a reversible capacity of 507 mA h g(-1) after 200 cycles at 2 A g(-1) and 386.7 mA h g(-1) at 10 A g(-1) after 500 cycles. The galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) reveals that the remarkable performance of FeSe2/NCF composite is attributed to the homogeneous holes and conductive channels, which reduces sodium ion diffusion resistance and charge transfer resistance. This work demonstrates the successful preparation of FeSe2/NCF composite by using industrially established protocol, which sheds light on the massive production of high-performance anode materials of sodium ion batteries and their industrial application.