Pyro-synthesis of Na2FeP2O7 Nano-plates as Cathode for Sodium-ion Batteries with Long Cycle Stability

Carbon-coated sodium iron pyrophosphate (Na₂FeP₂O 7 ) was prepared by a simple and low-cost pyro-synthesis route for further use as the cathode for Na-ion batteries. The X-ray diffraction (XRD) pattern of the sample annealed at 650℃ confirmed the pure triclinic phase of Na₂FeP₂O 7 . Electron microscopy studies revealed a cross linked plate shape morphology of the Na₂FeP₂O 7 sample. When tested for application in Na-ion battery, the Na₂FeP₂O 7 cathode showed two redox pairs in the potential window of 2.0-4.0 V. The cathode registered initial discharge and charge capacities of 80.85 and 90 mAh/g, respectively, with good cycling performance.