High-Voltage Cathode α-Fe(2)O(3) Nanoceramics for Rechargeable Sodium-Ion Batteries

[Image: see text] Previously, α-Fe(2)O(3) nanocrystals are recognized as anode materials owing to their high capacity and multiple properties. Now, this work provides high-voltage α-Fe(2)O(3) nanoceramics cathodes fabricated by the solvothermal and calcination processes for sodium-ion batteries (SIBs). Then, their structure and electrical conductivity were investigated by the first-principles calculations. Also, the SIB with the α-Fe(2)O(3) nanoceramics cathode exhibits a high initial charge-specific capacity of 692.5 mA h g(–1) from 2.0 to 4.5 V at a current density of 25 mA g(–1). After 800 cycles, the discharge capacity is still 201.8 mA h g(–1), well exceeding the one associated with the present-state high-voltage SIB. Furthermore, the effect of the porous structure of the α-Fe(2)O(3) nanoceramics on sodium ion transport and cyclability is investigated. This reveals that α-Fe(2)O(3) nanoceramics will be a remarkably promising low-cost and pollution-free high-voltage cathode candidate for high-voltage SIBs.