High crystalline Na2Ni[Fe(CN)6] particles for a high-stability and low-temperature sodium-ion batteries cathode

High crystalline Na2Ni[Fe(CN)6] particles are synthesized by a new electrostatic spray assisted coprecipitation method. Their structures and electrochemical properties are analyzed by X-ray powder diffraction, scanning electron microscopy and galvanostatic cell cycling and so on. Given its highly stable structure, the optimized Na2Ni[Fe(CN)6] cathode shows impressive cycling performance with high retention capacity of 89% after 440 cycles at 1 C and excellent rate capability of 56 mAh g−1 at 25 C. In addition, the optimized Na2Ni[Fe(CN)6] cathode achieves superior low temperature performances with retains 87% capacity after 440 cycles at 0 °C and a stable capacity of 54 mAh g−1 can be delivered even at −25 °C after 440 cycles. Such a Na2Ni[Fe(CN)6] sample provides a promising cathode for sodium-ion batteries in large-scale storage systems.