Preparation and sodium storage properties of CuFeSe2@C nanorods

The large radius of sodium ions induces significant volume expansion in the anode during charging and discharging, potentially damaging the electrode structure and leading to the deterioration of the battery's cyclic performance. In this work, Cu/Fe bimetallic oxalate nanorod precursors were prepared via a liquid-phase precipitation process and subsequently calcined in air to form bimetallic oxides. These oxides were then coated with resorcinol-formaldehyde resin and subjected to carbonization and selenization process to fabricate porous carbon-coated CuFeSe 2 (CuFeSe 2 @C) nanorod composite materials. Electrochemical studies confirmed that the CuFeSe 2 @C electrode represented stable cycling performance as an anode for Na + battery. Notably, this electrode had a reversible capacity of 295.8 mAh g −1 after 3500 cycles at a current density of 10.0 A g −1 . The interstitial space between the conductive carbon layer and the active material mitigates volume expansion, reduces fragmentation or detachment of the active material, enhances the stability of the cycling and service life of battery.