Studies Of Bismuth Oxychloride/Activated Carbon Asymmetric Supercapacitor

With the development of science and technology, the more requirements about energy storage devices was brought forward. Asymmetric supercapacitor,which has a higher energy density than conventional capacitors, and a higher power density than batteries displayed great potentials. In this paper, porous activated carbons were prepared from sweet potato as the positive electrode material, BiOCl nanosheet was prepared from BiCl3 and Bi2O3 as the negative electrode material,an asymmetric supercapacitor was assembled by BiOCl and actived carbon above-mentioned.The electrochemical properties.of the asymmetric supercapacitor was studied,so were the morphology and structure of materials.The main contents of this paper are as follows:1. Translucence colloform was prepared by gelatinizing the sweet potato powder firstly.Then we prepared a uniform dispersive hydrothermal carbon coke precursor. Uniformly dispersed microsphere actived carbon with a predominant dispersibility was prepared by further carbonizated and activation. the diameter of which is about 0.9 ?m,and the specific surface area was 1527 m2 g-1. It also exhibited an excellent performance in supercapacitor, The specific capacitance was 208 F g-1 at 1 A g-1,While the power density was 998.6 W Kg-1 and the energy density is 28.8 Wh Kg-1.2. The BiCl3 was dissoloved in diluted hydrochloric acid solution,acting as the bismuth solution, then an appropriate amount of CH3 COONa solution was dropped into the mentioned bismuth solution to prepare BiOCl material,which was named sample B. We found that Sample B was flower-like microspheres with average diameter of about 5 ?m, which were assembled by the BiOCl nanosheets with a thickness of about 50 nm. The experimental conditions were changed to prepare BiOCl named sample B0. The microstructure and morphology of Sample B and sample B0 were compared.The electrochemical properties of an asymmetric supercapacitor assembled by BiOCl electrodes and activated carbon electrodes were studied study,The results showed that the specific capacitances of sample B and sample B0 were 819 F g-1 and 926 F g-1 respectively at 1A g-1.3. A series of BiOCl materials were prepared by Bi2O3 and dilute hydrochloric acid in a novel one-pot method. Then we analyzed the electrochemical properties of BiOCl materials and Bi2O3 by assembling asymmetric supercapacitors. The results showed that the performance of the BiOCl material was improved,comparing with Bi2O3, the specific capacitance of which was 681 F g-1 at 0.5 A g-1.We also found that the BiOCl material could achieved a best spcific capacitance 993 F g-1at 0.5 A g-1,when the ratio of the amount of hydrochloric acid and Bi2O3 was 1.3:1.