添加不同生物质对无灰煤基活性炭结构及性能的影响

Effect of different biomass addition on structure and properties of hypercoal-based activated carbons

通过在无灰煤中添加不同生物质(玉米芯或松木屑),制备双电层电容器用活性炭电极材料,探究生物质对无灰煤基活性炭结构和电化学性能的影响。采用SEM、XRD、FTIR、N2吸脱附表征其结构和组成,通过循环伏安、恒流充放电及交流阻抗测试其电化学性能。从生物质组成成分来看,添加高纤维素含量的生物质更有利于中孔的发育,使活性炭的孔隙结构更加完善。高纤维素半纤维素含量能够有效降低碳材料的电荷转移电阻和物质扩散阻力,使离子在孔结构之间的传输更加迅速。向无灰煤中添加玉米芯时,比电容提升45%,电荷转移电阻降低65%;向无灰煤中添加松木屑,比电容提升30%,电荷转移电阻降低35%,证明添加高纤维素含量的生物质更有利于活性炭的结构完善和电化学性能提升。

By adding different biomass(corn cob or pine sawdust)to hypercoal,the activated carbon electrode materials for double electric layer capacitors were prepared.The effect of biomass on the structure and electrochemical performance of hypercoal-based activated carbon was explored.Its structure and composition were characterized by SEM,XRD,FTIR and N 2 desorption.Its electrochemical performance was tested by cyclic voltammetry,constant current charge-discharge and AC impedance.In terms of biomass composition,the addition of biomass with high cellulose content is beneficial to the development of mesopore and the pore structure is more perfect.High cellulose and hemicellulose content can effectively reduce the impedance of carbon materials,and make the ion transport between pore structures more rapid.When corn cob was added to hypercoal,the specific capacitance increased by 45%and the charge transfer resistance decreased by 65%.Adding pine sawdust to hypercoal can increase the specific capacitance by 30%and decrease the charge transfer resistance by 35%.It is proved that adding biomass with high cellulose content is more beneficial to improve the structure and electrochemical performance of activated carbon.