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

Abstract

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 Cu3[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 44mAhg−1 at a current density of 20mAg−1, and the capacity retention can be 57.1% after 50 cycles. The material can also deliver a specific capacity of 37mAhg−1 and 25mAhg−1 at a rate of 50mAg−1 and 100mAg−1, respectively. Furthermore, the material exhibits a high reduction peak at 3.32V 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 Fe3+/Fe2+. All of the findings suggest a possible use of Cu3[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.