Composites of boron-doped carbon nanosheets and iron oxide nanoneedles: fabrication and lithium ion storage performance

Abstract

Novel boron-doped carbon nanosheets were prepared through a facile hydrothermal method using glucose and sodium borohydride as precursors. Taking structural advantage of the as-prepared boron-doped carbon nanosheets, high density Fe₃O₄ nanoneedle arrays were generated on them, resulting in the composites of boron-doped carbon nanosheets/Fe₃O₄ nanoneedles. The nanoneedle-like morphology and the unique perpendicular orientation of the Fe₃O₄ nanoneedles largely suppressed the aggregation of the boron-doped carbon nanosheets in the composites. Therefore, as lithium ion battery anodes, the composites exhibited an excellent lithium ion storage capacity, high rate capability, and decent discharge/charge cycling stability. It was demonstrated that the reversible specific capacity can reach 1132 mA h g⁻¹ at the charge/discharge current density of 0.1 A g⁻¹, and it can be maintained at 980 mA h g⁻¹ after 400 cycles. Even at a high current density of 10 A g⁻¹, the reversible capacity was still retained above 350 mA h g⁻¹, which is much higher than that of other carbon and Fe₃O₄ composites reported so far. These results render the as-prepared composite as an ideal anode material for high performance lithium ion batteries.