The electrochemical performance of Cu3[Fe(CN)6]2 as a cathode material for sodium-ion batteries

Prussian blue analogues (PBAs) have recently attracted extensive interests as a new class of cathode materials for rechargeable batteries. Copper hexacyanoferrate, a typical Prussian blue analogue with the chemical formula Cu 3 [Fe(CN) 6 ] 2 , has been synthesized by solution precipitation method and investigated as a cathode material for sodium-ion batteries. The galvanostatic cycling tests show a specific capacity of 44   mA   h   g −1 at a current density of 20   mA   g −1 , and the capacity retention can be 57.1% after 50 cycles. The material can also deliver a specific capacity of 37   mA   h   g −1 and 25   mA   h   g −1 at a rate of 50   mA   g −1 and 100   mA   g −1 , respectively. Furthermore, the material exhibits a high reduction peak at 3.32   V vs. Na + /Na, which brings more power to sodium-ion batteries. The data indicate the as-prepared material is capable of realizing the single electron redox capacity due to the reduction of Fe 3+ /Fe 2+ . All of the findings suggest a possible use of Cu 3 [Fe(CN) 6 ] 2 nanoparticles as environmental friendly and cost-effective cathode material, which also open new perspectives to develop cathode materials for sodium-ion batteries.