Successive synthesis and electrochemical properties of Na3FeF6 and NaFeF3/C cathode materials for lithium-ion and sodium-ion batteries

A strategy for the successive synthesis of Na3FeF6 and NaFeF3/C cathode materials during the same procedure is firstly proposed and realized. The as-synthesized Na3FeF6 and NaFeF3/C powders possess submicrometric cubic morphology and good dispersity. Na3FeF6 for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) displays initial discharge capacities of 510.8 and 138.7 mAh-g(-1), with capacity retentions of 48.1% and 63.8% after 400 cycles, separately. The corresponding values of NaFeF3/C for LIBs and SIBs are 180.6 and 154.2 mAh.g(-1), 87.7% and 77.1%, respectively.