Na3V2(PO4)3/C cathode material with three-dimensional interconnected porous structure constructed using cotton soft tissue as carbon source

Abstract

• Na 3 V 2 (PO 4 ) 3 /C was successfully synthesized by a facile impregnation approach. • Cotton soft tissue was used as a novel carbon source to construct 3D structure. • Na 3 V 2 (PO 4 ) 3 nanoparticles are evenly distributed in porous carbon matrix. • Na 3 V 2 (PO 4 ) 3 /C shows a high first discharge capacity of 106.4 mAh g −1 at 0.1 C. • Na 3 V 2 (PO 4 ) 3 /C cathode can still remain stable after 2000 cycles at 2 C and 5 C. Sodium-ion batteries have significant advantages in the field of large-scale energy storage due to their low cost, abundant sodium resources, and appropriate redox potential. Na 3 V 2 (PO 4 ) 3 with a unique NASICON structure demonstrates a high voltage platform and high capacity. However, the low electronic conductivity of Na 3 V 2 (PO 4 ) 3 causes it to have poor cycling stability and rate capability. High-conductivity carbon materials can enhance the Na 3 V 2 (PO 4 ) 3 ’s poor electronic conductivity. In this study, Na 3 V 2 (PO 4 ) 3 nanoparticles were evenly distributed in the carbon skeleton’s porous structure by a simple impregnation approach using daily necessities cotton soft tissue as a new carbon source. The prepared Na 3 V 2 (PO 4 ) 3 /C cathode material with a three-dimensional (3D) interconnected porous structure shows better electrochemical properties than pure Na 3 V 2 (PO 4 ) 3 . The first discharge specific capacity of Na 3 V 2 (PO 4 ) 3 /C material at 0.1 C is 106.4 mAh g −1 in the voltage range of 2–4.0 V. The material’s capacity can still remain stable after 2000 cycles at 2 C and 5 C rates. The presence of 3D interconnected porous carbon significantly enhances the electronic conductivity of Na 3 V 2 (PO 4 ) 3 material, shortens the ion diffusion path, speeds up the electron transfer, and inhibits electrode/electrolyte interface side reactions. Several common carbon sources in everyday life are promising auxiliary materials for enhancing the electrochemical properties of electrode materials used in secondary batteries.