纤维素基生物质多孔炭的制备及其超级电容器性能研究

Preparation of cellulose-derived biomass porous carbon and its supercapacitor performance

以棉纤维素为原料,采用硝酸盐、尿素、纤维素共混后热裂解的方法制备分级多孔炭HPC样品,通过改变煅烧温度和KOH活化处理对多孔炭比表面积及孔结构进行调控。对比三个不同温度煅烧活化处理后样品的循环伏安曲线、恒电流充放电曲线、比容量等电化学参数,结果表明,4AC@HPC800样品作为超级电容器工作电极具有优良的电化学性能,其比表面积高达2433.8 m2·g^(-1),在1 A·g^(-1)的电流密度下比容量高达234.7 F·g^(-1),在大电流密度10 A·g^(-1)时依然有207.6 F·g^(-1)的比容量,具有良好的倍率性能;电极在2 A·g^(-1)的电流密度下循环10000次后依然有196.1 F·g^(-1)的比容量,表明其具有长时工作的特性。

Using cotton cellulose as raw material,the hierarchical porous carbon(HPC)samples were prepared by pyrolyzing the mixture of magnesium nitrate,urea and cellulose.The specific surface area and pore structure of porous carbon were regulated by changing the calcination temperature and KOH activation treatment.By comparing the cyclic voltammetry curve,galvanostatic charge-discharge curve,specific capacity and other electrochemical parameters of the activated samples which were pre-calcined at three different temperatures,the results showed that 4AC@HPC800 sample had excellent electrochemical performance as the working electrode of supercapacitor,and its specific surface area reached 2433.8 m2·g^(-1).The specific capacitance was as high as 234.7 F·g^(-1) at the current density of 1 A·g^(-1),and 207.6 F·g^(-1) at the high current density of 10 A·g^(-1),indicating that it had good rate performance.The electrode still presented a capacity of 196.1 F·g^(-1) after 10000 cycles at the current density of 2 A·g^(-1),indicating that it can work for a long time.