Formation of Fe‐embedded graphitic carbon network composites as anode materials for rechargeable Fe‐air batteries

This study reports on a composite consisting of iron (Fe) particles embedded in graphitic carbon network, which was prepared using a facile chemical synthesis method. The Fe‐embedded carbon composite was used as the anode material for Fe‐air batteries whose electrochemical charge‐discharge performance was subsequently evaluated. The effect of adding 0.01M Na2S to the batteries' alkaline electrolyte on the electrochemical performances of the Fe‐embedded carbon composite was investigated. The addition of Na2S to the electrolyte resulted in a higher discharge capacity during the charge‐discharge characterization. A maximum discharge capacity of 486 mAh g−1(Fe) was obtained because sulfide ions present in the electrolyte inhibited Fe passivation, thus enabling a better redox reaction. Interestingly, after prolonged charge‐discharge cycling (100 cycles), the replenishment of the 0.01M Na2S in the electrolyte resulted in the recovery of a high initial discharge capacity. The facile synthesis process, effect of Na2S addition, and the feasibility of discharge capacity recovery after prolonged charge‐discharge cycling reported in this study should be beneficial toward the further development of rechargeable Fe‐air batteries.