Environmentally and economical method for Na₂Fe(SO₄)₂ with a broken, hollow cuboid structure as high performance sodium battery electrode

Iron-based sulfate (Na2Fe(SO4)(2)) is receiving increasing attention because of its heat resistance, moisture resistance as well as low cost. Herein, Na2Fe(SO4)(2) (NFS/bc + s), which is modified by sucrose and carbon black, was synthesized by the method of environment-friendly and economic liquid phase without waste water and with similar to 100 % utilization of raw materials. NFS/bc + s has a special structure with broken, open, porous, hollow cuboid, which provide an excellent specific capacity of 90.64 mAh/g at 0.1C, additionally, NFS/bc + s also shows good stability in charge-discharge cycles (its discharge capacity remain 71 % of initial capacity after 100 cycles at 1C between the high voltage range from 2.75 to 4.5 V). The excellent electrochemical performance is due to the large number of electrochemical active sites provided by the broken hollow structure. Therefore, the prepared electrode material has a potential practical application prospect in the sodium ion battery system.