Preparation And Electrochemical Performances Of Activated Carbon Electrodes From Bamboo

The supercapacitor is a new kind of reversible electrochemical energy storage device with the advantages of high charge-discharge power density, long cycle life, no pollution, et al, which has been widely used in many fields such as memory back-up devices and electric vehicles. However, along with modernized science and technology rapid development, electrode materials of supercapacitors are endowed with higher demands, from the persistence and cleanness of raw materials to high stability and energy density of end products.In this work, electrode materials of supercapacitors, high specific surface activated carbon, were prepared from biomaterial bamboo, with the process of carbonization, and activation by water steam and KOH. The basic properties of bamboo and bamboo charcoal were analyzed by ways of thermogravimetric analysis, nitrogen adsorption-desorption test, XRD and so on. The relationships between different factors and the specific capacitance were investigated through galvanostatic charge-discharge test, cycle voltammetry, etc.The main results are as follows:The accumulation mechanism of bamboo charcoal used as the electrode of supercapacitors is based upon double-electrode-layer theory. The activation is an effectual way of increasing the specific surface of bamboo charcoal, reaching 2365 m~2/g; pore sizes are mainly within the range of 1.8nm,2.4nm and 3-4nm. The specific capacitance of bamboo charcoal used as electrode for supercapacitor is influenced by microelements remained in bamboo charcoal, carbonization temperatures, types of activating agents, and activating temperatures; the specific capacitance of the bamboo charcoal activated by KOH at 800℃is as high as 205F/g, showing a good performance under macrocurrent charge-discharge.