FeSe₂ Graphite Intercalation Compound as Anode Materials for Sodium Ion Batteries

Based on theoretical calculations, the molecule predominantly generated by the combination of sodium with graphite is identified as NaC 186 . Consequently, this compound has a relatively limited capacity for sodium storage, amounting to only 36 mA h g –1 . In this study, we construct FeSe 2 graphite intercalation compounds (FeSe 2 -GIC) by in situ inserting FeSe 2 between the graphite interlayers by a hydrothermal process. The resulting FeSe 2 -GIC material is then subjected to ball milling to form the FeSe 2 -GIC-BM. The FeSe 2 material was found to be tightly intercalated within the graphite layers, resulting in a limited volume expansion and improved electrical conductivity. The electrochemical test results indicate that the FeSe 2 -GIC-BM anode exhibits a remarkable electrochemical performance. It exhibits an initial specific discharge capacity of 676.2 mA h g –1 at a current density of 0.1 A g –1 and a specific discharge capacity of 425.0 mA h g –1 at a current density of 5 A g –1 . After 1200 cycles, the observed reversible capacity remains at 182.9 mA h g –1 . The exceptional storage and cycling characteristics can be attributed to the distinctive layered structure.