Performance as electrode of electrical double layer capacitor of activated carbon prepared from bamboo using guanidine phosphate and CO2 activation

摘要

The electrochemical performances of an electrical double layer capacitor were investigated regarding the activated carbon prepared from bamboo by a new approach, that is, the combination of delignification, addition of guanidine phosphate, and CO2 activation. In this study, a 1 M H2SO4 aqueous solution was used as the electrolyte of the capacitor. The physical properties, such as the BET specific surface area of the carbon material, depend on the preparation conditions of the activated carbon. A TEM image indicated that the addition of guanidine phosphate did not facilitate the graphitization and did not prevent activation by CO2. The apparent reaction equation for the CO2 activation was first-order, which is reasonable for physical activation. The electrochemical performances of the carbon material depended on the preparation conditions of the carbon material, such as the heat treatment temperature, amount of added guanidine phosphate, and CO2 activation time. The sample prepared under the following conditions (the amount of added guanidine phosphate: 9 wt%, the heat treatment temperature: 800 degrees C, CO2 activation time: 3 h) had the highest performance (153 F g(-1) at 1000 mA g(-1)) because the sample had the highest BET specific surface area (2001 m(2) g(-1)).