Chemical Engineering Journal ( IF 13.3 ) Pub Date : 2022-08-30 , DOI: 10.1016/j.cej.2022.138877 Yinying Long , Xingye An , Hao Zhang , Jian Yang , Liqin Liu , Zhongjian Tian , Guihua Yang , Zhengbai Cheng , Haibing Cao , Hongbin Liu , Yonghao Ni
Porous carbon nanoparticles have been widely utilized as electrode materials for electric double-layer capacitors (EDLCs) owing to their rich microporous and mesoporous structures. Herein, we successfully prepared lignin@ZIF-8 based carbon with hierarchical porous “core-shell” graphitized superstructure (KGC-EHL@ZIF-8) fabricated by carbonized ZIF-8 NPs as “core” and lignin derived graphitized porous carbon layer as “shell” via a two-stage carbonization-graphitization process for advanced supercapacitor performance. The prepared KGC-EHL@ZIF-8 NPs possess a high graphitization degree, high porosity with micro/meso porous hierarchical structure and high content of N/O co-dopants induced by the synergistic effects of ZIF-8 NPs coupling potassium hydroxide (KOH) activation treatment, thus guaranteeing excellent electrochemical performance. As a result, the graphitization degree of lignin-derived porous carbon “shell” structure increased with KOH ratio, and the maximum specific surface area of 2307.3 m2·g−1 was successfully obtained at a mass ratio (KOH/C-EHL@ZIF-8 NPs) of 1:1. The maximum specific capacitance within three-electrode system was 462.6 F·g−1 at 0.5 A·g−1 with a porous carbon “shell” thickness of around 75.25 nm. Moreover, the areal energy density of assembled supercapacitor can reach to 1.95 mWh·cm−2 at a power density of 27.44 mW·cm−2. This study put forward a novel strategy to efficiently harness lignin combined with a metal–organic framework for the construction of porous electrodes with hierarchical nanostructure for high-performance supercapacitors.
中文翻译:
高度石墨化的木质素衍生多孔碳,具有由金属有机框架支持的分级 N/O 共掺杂“核壳”超结构,用于先进的超级电容器性能
多孔碳纳米粒子因其丰富的微孔和介孔结构而被广泛用作双电层电容器(EDLCs)的电极材料。在此,我们成功地制备了木质素@ZIF-8 基碳,其具有分层多孔“核壳”石墨化超结构(KGC-EHL@ZIF-8),由碳化 ZIF-8 NPs 作为“核”,木质素衍生的石墨化多孔碳层作为通过两阶段碳化-石墨化工艺“壳”,以获得先进的超级电容器性能。所制备的 KGC-EHL@ZIF-8 NPs 具有高石墨化程度、高孔隙率和微/中观ZIF-8 NPs耦合氢氧化钾(KOH)活化处理的协同作用诱导了多孔分层结构和高含量的N / O共掺杂剂,从而保证了优异的电化学性能。结果,木质素衍生的多孔碳“壳”结构的石墨化程度随着KOH比的增加而增加,在质量比( KOH / C- EHL @ ZIF-8 NPs) 为 1:1。三电极系统内的最大比电容在 0.5 A·g -1时为 462.6 F·g -1,多孔碳“壳”厚度约为 75.25 nm。此外,组装的超级电容器的面能量密度可以达到1.95 mWh·cm -2功率密度为 27.44 mW·cm -2。本研究提出了一种有效利用木质素与金属有机框架相结合的新策略,用于构建用于高性能超级电容器的具有分层纳米结构的多孔电极。