基于“蛋盒”结构高电化学性能活性炭的制备

Preparation of high performance activated carbon based on“egg-box”structure

与陆生植物不同,海藻中通常含有大量的海藻酸和海藻酸盐,其中海藻酸盐主要以海藻酸钙、海藻酸镁等形式存在于细胞壁中。本文利用海带中海藻酸钙的“蛋盒”式结构,对海带炭化产物进行盐酸酸洗处理,除去海藻酸钙中的钙离子,形成“蛋盒”式初始孔结构,然后采用KOH活化法制备海带基活性炭,研究海带基活性炭的孔结构特性以及电化学性能。实验结果表明:基于“蛋盒”结构制备的海带基活性炭拥有丰富的孔隙结构,其比表面积高达3027m^2/g,其中73.3%由中孔比表面积提供,且中孔孔径分布比较集中,几乎全部分布在2~10nm。海带基活性炭在碱性电解液中展现出优秀的电化学性能,当电流密度为0.1A/g时,其比电容高达366F/g,即使在电流密度为10A/g的条件下,活性炭比电容仍然高达329F/g,显示出良好的比电容性能和倍率性能。

Unlike terrestrial plants,algae usually contain a large amount of alginate,which mainly exist in the cell wall in the forms of calcium alginate and magnesium alginate.In order to maintain the“eggbox”structure of calcium alginate in kelp,the carbonized products of kelp were treated by hydrochloric acid pickling to remove calcium ions from calcium alginate and to form the initial“egg-box”pore structure.Then kelp-based activated carbon was prepared by KOH activation method.The pore structure and electrochemical properties of kelp-based activated carbon were investigated.The experimental results showed that the kelp-based activated carbon with“egg-box”structure had abundant pore structure,and its specific surface area was as high as 3027m^2/g,73.3%of which was from the mesopores with uniform pore size in the range of 2-10nm.The kelp-based activated carbon exhibited excellent electrochemical performance in alkaline electrolyte.When the current density was 0.1A/g,the specific capacitance of the kelp-based activated carbon reached 366F/g.Even when the current density was 10A/g,the specific capacitance still maintained 329F/g,showing good specific capacitance and rate performance.