图6.5为不同乳化装置下MnO2/PPy复合材料的比容量对比图。图6.

Figure 6.5 is a different emulsification device MnO2 / PPy specific capacity of Comparative Composite FIG. FIG. 6.5 (a) of MnO2 / PPy composite scan rate of 10 mV s-1 cyclic voltammogram of comparison rules are rectangular-like shape, prepared miniemulsion IS-RPB synthesized MnO2 / PPy Composite substantially close to the current area of ​​the ultrasonic crusher cells, greater than a high-speed disperser; Figure 6.5 (b) MnO2 prepared different emulsification device / PPy composite current density constant current 0.5 a g-1 of the charge-discharge curve also shows that the ultrasonic cells crusher discharge time> iS-RPB> high speed disperser, i.e., the specific capacity of MnO2 / PPy composite mechanism of cell sonication prepared> iS-RPB> high speed disperser. With the specific capacity curve of current density can be visually seen from Figure 6.5 (c), three kinds of the emulsifying device IS-RPB, ultrasonic cell crusher and high-speed disperser specific capacity at a current density of 0.5 A g-1 is the maximum, respectively, to 241.3 F g-1,231.9 F g-1 and 216.9 F g-1. With increasing current density, apparent specific capacity is decreasing. This is because the storage MnO2 / PPy composite mainly through the Faraday pseudo capacitance generated when the charge and discharge current density is small, slow changes in the voltage window, longer charge and discharge, the electrolyte ions into the pore size through the composite material mesoporous bulk phase, this time, not only in the surface of the electrolyte ion desorption reaction occurring materials, but highly reversible phase oxidation also occurs in vivo - reduction reaction pseudocapacitance, high utilization of active material at this time, than the capacity reaches a maximum value; when the enlargement of a large current density, rapid changes in the voltage window, charge and discharge time shorter, most of the electrolyte ion desorption reaction occurs only at the surface of the electrode material, the active material into the electrolyte ionic phase is decreased, the activity of material utilization is reduced, resulting in reduced specific capacity. (C) found from FIG. 6.5, sonicated cells prepared miniemulsion mechanism synthesized MnO2 / PPy composite after the current density exceeds 10 A g-1, a large specific capacity decreased, because the cells prepared by ultrasonic crushing mechanism miniemulsion droplets smaller size, small nuclei formed composite, thus smaller average pore size of the particles, and the smaller pore size of a certain extent, also hinder the diffusion rate of charge, causing the electrode material at high magnification ratio capacity decreased rapidly in Chapter 4 of this inference can be verified.

Figure 6.5 is a comparison of the ratio capacity of MnO2/PPy composites under different emulsifiers. Figure 6.5(a) For MnO2/PPy composites in the scanning rate of 10 mV s-1 cycle volt-amp curve, are more regular class rectangular shape, IS-RPB prepared fine emulsion synthesis MnO2/PPy composite current area and ultrasonic cell machine crushing area is basically close to, larger than the high-speed disperser; Figure 6.5(b) MnO2/PPy composite materials prepared by different emulsifiers at a current density of 0.5 A g-1 constant current charge and discharge curve also indicate the discharge time of ultrasonic cell crushers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IS-RPB- High-speed disperser. From the graph 6.5(c) ratio capacity changes with the current density curve, it can be seen that IS-RPB, ultrasonic cell crusher and high-speed disperser three emulsifiers have the largest ratio capacity of 0.5 A g-1 at current density, 241.3 F g-1, 231.9 F g-1 and 216.9 F g-1, respectively. As the current density increases, there is a significant decrease in ratio capacity. This is because the energy storage capacity of MnO2/PPy composite materials is mainly generated by the Faraday capacitor, when the charge and discharge current density is small, the voltage window changes slowly, charge and discharge time is longer, the electrolyte ions through the material meso-porous diameter into the composite material phase, at this time, the electrolyte ions not only absorb the material surface Reaction, and in the body phase also occurs a highly reversible oxidation-reduction reaction to produce a capacitor, at which time the utilization rate of the active substance is high, the ratio capacity also reached the maximum, and when the current density is large, the voltage window changes rapidly, the charge and discharge time is short, most electrolyte ions only absorb the echo reaction on the surface of the electrode material, The electrolyte ions entering the body phase of the active substance are reduced and the utilization rate of the active substance is reduced, resulting in a decrease in ratio capacity. From Figure 6.5(c), it was found that MnO2/PPy composites synthesized by fine emulsions with ultrasonic cell fragmentation mechanism were larger than the decrease in capacity after the current density exceeded 10 A g-1, because of the fine emulsion prepared by the ultrasonic cell fragmentation mechanism. The droplet size is small, the resulting composite material has a smaller core, so the average aperture of the particles is smaller, and the smaller aperture also hinders the diffusion rate of the charge to some extent, resulting in the electrode material at a high magnifying rate than the volume decline faster, in this chapter 4 inference can be verified.

Figure 6.5 shows the comparison of specific capacity of MnO2 / PPy composite under different emulsification devices. Fig. 6.5 (a) is the cyclic voltammetric curve of MnO2/PPy composite material at a scanning rate of 10 mV s-1, which is a regular rectangular shape. The area of the current area of the MnO2/PPy composite made by IS-RPB is basically closer to that of the ultrasonic cell breaker than that of the high-speed dispersive device. Fig. 6.5 (B) MnO2/PPy composite material prepared by different emulsification devices has a current density of 0.5 A. The constant current charge discharge curve of g-1 also shows that the discharge time of ultrasonic cell breaker is more than IS-RPB > high-speed disperser, that is, the specific capacity of MnO2 / PPy composite prepared by ultrasonic cell breaker is more than IS-RPB > high-speed disperser. From the curve of specific capacity with current density in Fig. 6.5 (c), it can be seen that the specific capacity of IS-RPB, ultrasonic cell breaker and high-speed disperser is the largest when the current density is 0.5A g-1, 241.3fg-1231.9f g-1 and 216.9f g-1 respectively. With the increase of current density, the specific capacity decreases obviously. This is because the energy storage of MnO2 / PPy composite is mainly generated by Faraday pseudocapacitance. When the current density of charge and discharge is small, the voltage window changes slowly, and the charge and discharge time is long, and the electrolyte ions enter the composite phase through the mesoporous aperture of the material, at this time, the electrodialysis liquid ions not only take place the adsorption and desorption reaction on the surface of the material, but also take place in the bulk phase The reverse oxidation-reduction reaction produces pseudo capacitance, at this time, the utilization rate of active substances is high, and the specific capacity reaches the maximum value; however, when the current density increases, the voltage window changes rapidly, and the charge and discharge time is short. Most of the electrolyte ions only have adsorption and desorption reaction on the surface of electrode materials, and the electrolyte ions entering into the active substances are reduced, so the utilization rate of active substances is reduced Results in a reduction in specific capacity. From figure 6.5 (c), it is found that the miniemulsion synthesized MnO2/PPy composite prepared by ultrasonic cell breakage has a current density of more than 10 A. After g-1, the trend of specific capacity descends. This is because the size of microemulsion droplets prepared by ultrasonic cell breakage mechanism is small, and the nucleation of composite materials is small. Therefore, the average pore size of particles is small, and the smaller pore diameter will also impede the diffusion rate of charge to a certain extent, which leads to a faster decrease of specific capacity of electrode materials at high magnification. The inference in the fourth chapter is verified.