蔗渣基活性炭孔结构的调控及其对超级电容器电化学性能的影响研究

Regulation of the Pore Structure of Bagasse-based Activated Carbon and Its Effect on the Electrochemical Properties of Supercapacitor

中文关键词:  蔗渣  活性炭  孔结构调控  超级电容器  电化学性能

Key Words:bagasse  activated carbon  pore structure regulation  supercapacitor  electrochemical performance

中文摘要:

      采用KOH、ZnCl₂、H₃PO₄ 3种活化剂活化蔗渣，制得了微孔型活性炭KAC、微介孔型活性炭ZAC和兼具微介大孔型活性炭PAC，并对这3种活性炭进行理化性能分析。结果表明，3种活化剂处理可实现蔗渣基活性炭孔结构的调控；3种活性炭主要含有C、H、N和O元素，其中C和O元素含量最多，且均含有不同量的C=C、C—C和C=O官能团；3种活性炭中，ZAC孔体积最大，达0.65 cm³/g，其石墨化程度也最高；ZAC在三电极体系的双层电容中具有比电容高（282 F/g）、倍率性能出色（212 F/g，保持在10 A/g）和循环稳定性良好（在1000次循环后保持98.5%的比电容）等性能，组装的ZAC//ZAC对称超级电容器的能量密度为39.2 Wh/kg，优于一般的商用电极材料（<10 Wh/kg）。因此，ZAC具有成为超级电容器电极材料的潜力。

Abstract:

      Three activators （KOH， ZnCl₂， H₃PO₄） were respectively used to activate bagasse and three kinds of activated carbons， i.e.， microporous activated carbon KAC， micro mesoporous activated carbon ZAC， and micro meso-macroporous activated carbon PAC were successfully prepared. The results showed that the abovementioned three activators were capable of regulating the pore structures of bagasse-based activated carbons. The chemical analysis showed that the as-prepared activated carbons mainly contained C， H， N， and O elements， and the contents of C and O were the largest. All of them contained different amounts of C=C， C—C， and C=O functional groups. Physical analysis presented that ZAC had the largest pore volume of 0.65 cm³/g and the highest graphitization degree among the three activated carbons. ZAC exhibited high specific capacitance （282 F/g）， excellent rate performance （212 F/g， stablizing at 10 A/g） as well as good cycle stability （maintaining a specific capacitance of 98.5% during 1000 cycles） in a double-layer capacitor of the three-electrode system. The energy density of the double-assembled ZAC/ZAC symmetrical supercapacitor was 39.2 Wh/kg， higher than that of the general commercial electrodes （<10 Wh/kg）， which endowed it great potential as a supercapacitor electrode material.