A study on anions intercalation into carbons for asymmetric supercapacitors

• Main Authors: Huang, MingGang, 黃銘鋼
• Other Authors: Hu, Chi-Chang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/14150214930583139006

碩士 === 國立清華大學 === 化學工程學系 === 103 === Abstract The thesis aims at studying the electrochemical behavior of anion intercalation into carbon materials and designing the asymmetric supercapacitors based on this energy storage mechanism. The first part introduces using carbon paper (GDL25BC), which is a gas diffusion layer in fuel cell, as an electrode for studying the electrochemical behavior of the anion intercalation. A three-electrode test system with electrolytes system was established and comparaed the electrochemical reaction on the carbon paper positive electrode with results of material analysis in this section. In conclusion: 1. Anion intercalation type carbon paper (GDL25BC) is a high specific capacity and good rate-performance electrode; 2.Carbon paper (GDL25BC) by the rolling process, can be made to flexible electrode. 3. It has a high rate performance and good cycling stability. The second part demonstrates comparing the electrochemical behavior of anion intercalation into commercial graphitic carbons. In summary: 1. Anion intercalation need occur at graphitic carbon materials with a high crystallinity degree, so that the soft carbon is not allowed; 2 Particle size affects on the electrode through charge transfer impedance (Rct) and Warburg diffusion impedance, a large particle size material greatly restricts its rate performance. 3. Mesosphere carbon microbeads (MCMB) has a high crystallinity degree, but also amorphous carbon peak. These amorphous carbon promote electrolyte diffusion transfer in the electrode, so that the electrode performance ratio has been greatly improved. In the third part, worms-like type expanded graphite was selected as new cathode based on the above conclusions. Modify expanded graphite by heat treatment, ultrasonic vibration, pitch carbon coated and phenolic resin coated. Get the best performance sample EG-600Up (expanded graphite treated treatment at 600 ℃, ultrasonic oscillation 4h, 75% pitch coated), it has a high rate capability (3A / g) and discharge stability (500cycle, retention 95.7%). Assembled asymmetric supercapcitors (AC /EG-600Up) which activated carbons as a negative electrode, EG-600Up as a positive electrode, measured in TEABF4 solving in propylene carbonate (PC). It has a good performance on energy density and power density: 51.47Wh / kg, 10.12kW / kg.