A Binder-Free Snowflake Grown Microcube Prussian Blue Particles As Possible Electrode for Supercapacitor and Sodium Ion Battery Applications

For constructing high energy storage devices, designing of electrode materials with high performance is a great challenge for the past decades. So far, various materials were employed as suitable electrode for supercapacitor and sodium ion batteries. Such as nickel, cobalt, tin, vanadium, ferrite and bismuth oxides/hydroxides/sulfides/phosphide/nitrides, conducting polymers, 2D-materials and its composites are subjected as possible electrode materials. However, limited reports are available for anode materials for energy storage applications. Recently, the Prussian Blue has received more attention because of its wide applications in various fields. Herein, a binder-free Prussian blue is synthesized by a facile hydrothermal method and employed as anode, for the first time to our knowledge. The x-ray diffraction and Fourier transform infrared spectroscopy results reveals that the single and phase purity of the sample. The microscopic image reveals that the snowflake grows from microcupe, which more favor for large energy storage. The Prussian Blue exhibited the maximum specific capacitance (166 mF cm -2 at 5 mV s -1 ) and good lifespan over 5000 cycles in 1MKOH electrolyte. Likewise, the Prussian Blue tested as anode for sodium ion battery and delivered the specific capacity of 250 mAh g -1 (first cycle) at a current of 1 mA. Our results suggest the novel design of materials holds a great promise for potential application toward next-generation energy storage. Figs. 1 represent the FESEM images of Prussian Blue at different magnifications. Figure 1