Green synthesis of N-doped carbon modified iron oxides (N-Fe2O3@Carbon) using sustainable gelatin cross-linker for high performance Li-ion batteries

Gelatin-tethered iron oxide composites are facilely prepared as high-performance anode materials for Li-ion batteries (LIBs). The synthetic procedures are simple, eco-friendly, and reproducible in that gelatin-linked Fe3O4 is directly converted into nitrogen (N)-doped carbon modified iron oxides (N-Fe2O3@Carbon) at 400 °C. The N-Fe2O3@Carbon exhibits an improved capacity retention and good rate capability. At a current density of 0.1C after 30 cycles, the N-Fe2O3@Carbon (400 °C) shows a high capacity of ∼800 mAh g−1 with a columbic efficiency of >99.5%. The excellent performance of N-Fe2O3@Carbon is mainly attributed to the conductive nitrogen and strong cross-linking force of gelatin, consequently leading to durable structural integrity of Li-storage iron oxides during charge/discharge processes. Since a small amount of gelatin with multiple amine groups delivers a high impact on the performance of Li-storage metal oxides, this chemical strategy is very useful to prepare cost-effective and environmentally benign electrode materials in the field of sustainable energy conversion and storage.