Hao Pin, Zhao Zhenhuan, Tian Jian, Li Haidong, Sang Yuanhua, Yu Guangwei, Cai Huaqiang, Liu Hong, Wong C P, Umar Ahmad
State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China.
Nanoscale. 2014 Oct 21;6(20):12120-9. doi: 10.1039/c4nr03574g. Epub 2014 Sep 9.
Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.
可再生、具有成本效益且环保的电极材料在能量转换和存储领域备受关注。甘蔗渣是甘蔗的废弃物，主要含有纤维素衍生物，有望成为制造超级电容器电极材料的候选原料。本研究展示了以甘蔗渣为原料制备高孔隙率碳气凝胶及其表征。首先通过对冷冻干燥的甘蔗渣气凝胶进行碳化制备出大孔和中孔碳；随后通过化学活化在中孔碳的壁上形成微孔结构。有趣的是，观察到分级多孔碳的比表面积、孔径和分布受活化温度的影响。为了评估分级多孔碳作为超级电容器电极的性能，组装了固态对称超级电容器，在放电电流密度为0.5 A g(-1)时展示出了142.1 F g(-1)的可比高比电容。所制备的固态超级电容器在5000次循环中表现出93.9%的优异电容保持率。分级多孔碳的高储能能力归因于其特殊设计的孔结构，即微孔和中孔共存。这项研究表明，利用可持续生物聚合物作为高性能超级电容器电极材料的原料是制造低成本储能装置的有效途径。
