Simple and efficient fabrication of pomegranate-like Fe2O3@C on carbon cloth as an anode for lithium-ion batteries

Pomegranate-like Fe2O3@C nanoparticles on carbon cloth (CC) as an anode for lithium-ion batteries are synthesized via a combination of dip-coating and hydrothermal synthesis. The spontaneous crosslinking reaction between sodium alginate (SA) and Fe3+ first creates a chelate compound, and then the SA-Fe3+ chelate is converted to Fe2O3@C nanoparticles after a simple hydrothermal treatment. The Fe2O3@C nanoparticles exhibit pomegranate-like morphology with an average diameter of 118 nm and are composed of smaller Fe2O3@C secondary nanoparticles of 13.7 nm. Such a hierarchical nanostructure can increase the accessible surface area of the Fe2O3@C/CC electrode, leading to enhanced electrochemical efficiency for the Li+ insertion/deinsertion reaction. Furthermore, by carefully controlling dip-coating time, the Fe2O3@C nanoparticles are individually and uniformly distributed on the CC surface, which supplies expansion space for Li+ insertion and protects the electrode from structural cracks. Owing to these structural characteristics, the Fe2O3@C/CC anode material shows superior electrochemical properties for lithium-ion batteries. The first discharge capacity is as high as 1006 mAh g−1 at the current density of 0.2 A g−1, and it remains up to 1091 mAh g−1 after 100 charge/discharge cycles, implying a stable cycling ability.