响应面法优化双电层电极槐木炭的制备

Optimization of Preparation Process of Locust Carbon as Electrical Double-layer Electrode Using Response Surface Methodology

以刺槐树枝为原料,采用水蒸气活化法,以电流密度1 A/g下的比电容为指标,响应面法优化双电层电极活性炭的活化工艺,并利用恒电流充/放电、循环伏安曲线和交流阻抗方法对所制得的双电层电极槐木炭的电化学性能进行研究。实验结果表明:活化条件对活性炭比电容影响的显著性大小为活化温度>水蒸气流量>活化时间。制备双电层电极槐木炭的最佳工艺为1 g槐木炭,活化温度674.85℃、活化时间82.42 min、水蒸气流量0.92 g/min,模型预测比电容为133.2 F/g(电流密度1 A/g);优化条件下制备的双电层电极槐木炭,电阻较小,导电性强,其孔结构有利于离子的电极表面迁移,在10~50 mV/s扫速范围内保持较好的双电层特性和倍率性能。

Using Robinia pseudoacacia branches as raw materials,the activation process of activated carbon with double-layer electrode was optimized by response surface method using water vapor activation method and the mass specific capacitance at current density of 1A/g as the index.The electrochemical properties of the prepared double-layer electrode Robinia pseudoacacia carbon were studied by constant current charge/discharge,cyclic voltammetry curve and AC impedance methods.The experimental results showed that the best process for preparing the double-layer electrode Robinia pseudoacacia charcoal was that the activation temperature of 1 g charcoal was 674.85℃,the activation time was 82.42 min,the water vapor flow rate was 0.92 g/min,and the specific capacitance predicted by the model was 133.2 F/g.The significance of the activation conditions on the specific capacitance of activated carbon was:activation temperature>water vapor flow rate>activation time.The double-layer electrode prepared under the optimized conditions had low resistance and strong conductivity.Its pore structure was conducive to the migration of ions on the electrode surface,and maintains good double-layer characteristics and magnification performance in the range of 10-50 mV/s.