Synthesis Of Niobium Nitride Materials Via Reduction Nitridation Reaction And Their Properties

Niobium nitride has a potential application in the field of electrochemical energy storage due to its electrical conductivity and electrochemical performance.The niobium nitride powder,fiber and nanotube arrays was preparated.The structure and properties of the materials were adjusted by optimizing the process parameters,and tested by XRD,XPS,SEM,TEM,BET,CV and GCD.The results show that:1)The Nb₄N₅powder was prepared by solvothermal method combined with reduction-nitridation technology,and the pore structure was modulated by adding P123.When the dosage of P123 is 0.2 g,the powder is nearly spherical shape and is composed of crystal grains with a diameter of 20 to 40 nm.Its specific surface area is 39 m²/g,the average pore size and pore volume is 16 nm and 0.16 cm³·g^-1.The specific capacitance is90 F/g and energy density is 7.2 Wh/kg when power density is 480 W/kg.2)The porous Nb₄N₅fiber was prepared by electrospinning combined with reduction nitridation process.The optimal parameters is as follow:the dosage of Nb Cl₅was 1.0 g,electrospinning voltage and flow rate was 25 k V and 1 m L/h,and reduction nitridation temperature was 800℃.The of porous Nb₄N₅fiber obtained has large length-diameter and good continuity,which specific surface area is 72 m²·g^-1,and it average pore size and pore volume is 17 nm,and 0.3 cc/g.The specific capacitance of the sample is 187.43 F/g,energy density is 10.74 Wh/kg when the power density is 537 W/kg.The specific capacitance is above 80%after 1000 cycles.3)The Nb₄N₅nanotubes were prepared by anodic oxidation combined with reduction nitridation method.The preferable oxidation time voltage and temperature was15 min,20 k V,180℃,respectively.A highly ordered niobium nitride nanotube array was fabricated after reduction nitridation 700℃.The diameter and wall thickness of the tube is about 35 nm and about 12 nm,and the length is about 1.5μm.The sample has a good charge-fast transfer characteristic and an electric double-layer energy storage characteristic.The specific capacitance is 400μF/cm²at current density of 0.1 m A/cm².Figure 91,Table 30,Reference 84.