Harvesting honeycomb-like carbon nanosheets with tunable mesopores from mild-modified coal tar pitch for high-performance flexible all-solid-state supercapacitors
Harvesting honeycomb-like carbon nanosheets with tunable mesopores from mild-modified coal tar pitch for high-performance flexible all-solid-state supercapacitors
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从轻度改性煤焦油沥青中获取具有可调介孔的蜂窝状碳纳米片，用于高性能柔性全固态超级电容器
DOI：
10.1016/j.jpowsour.2019.227446
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发表时间：
2020
影响因子：
9.2
通讯作者：
Li Kaixi
中科院分区：
文献类型：
--
作者：
Zhang Guoli;Guan Taotao;Cheng Miao;Wang Yongxia;Xu Nengneng;Qiao Jinli;Xu Feifei;Wang Yuzi;Wang Jianlong;Li Kaixi
多功能拓扑结构和分级孔结构是超级电容碳非常需要的，但是通过高效和无模板的路线合成在两个方面同时工作的材料是一个艰巨的挑战。本文以煤焦油沥青为原料，采用溶剂萃取-温和改性-活化的方法，在不使用任何模板剂的情况下制备了具有可调介孔的蜂窝状多孔碳纳米片。通过在温和条件下在氧化多环芳烃的边缘接枝松香结构，实现了沥青分子间距的工程设计，避免了分子过度堆积，进一步促进了活化过程中K+的刻蚀和嵌入。所获得的碳纳米片显示出明确的蜂窝状纳米片特征以及丰富的可调介孔，具体尺寸为2-5 nm。得益于分层微架构的协同作用，优化的碳纳米片可提供411.2 F g− 1的超高比电容和出色的倍率性能。组装后的对称柔性全固态超级电容器具有PVA/KCl膜电解质，在249.5 W kg−1的功率密度下具有12.3 W h kg− 1的高能量密度，以及超过50，000次循环的上级长期耐久性。这项工作铺平了道路，从散装廉价前体高价值的碳纳米片从事高性能灵活的超级电容设备。
Versatile topology structures and hierarchical pore configuration are highly desired for supercapacitive carbons, but there is a daunting challenge to synthesize the material that works well on both fronts synchronouslyviaan efficient and template-free route. Herein, honeycomb-like porous carbon nanosheets with tunable mesopores are fabricated from coal tar pitch through a sequential solvent extraction-mild modification-activation process without any templates. Engineering design of molecular spacing of pitch is implemented by grafting rosin structures on the edge of oxidized polycyclic aromatic hydrocarbons under mild condition, which avoids molecular excessive stacking and further promotes K+etching and intercalation during activation. As-obtained carbon nanosheets show a well-defined honeycomb nanosheet features together with rich tunable mesopores specific in sizes of 2–5 nm. Benefiting from the synergy of hierarchical micro-architectures, the optimized carbon nanosheets deliver an ultra-high specific capacitance of 411.2 F g−1and an excellent rate performance. As-assembled symmetrical flexible all-solid-state supercapacitor with PVA/KCl membrane electrolyte exhibits a high energy density of 12.3 W h kg−1at a power density of 249.5 W kg−1, as well as a superior long-term durability over 50,000 cycles. This work paves the path from bulk cheap precursors to high-value carbon nanosheets engaged in high-performance flexible supercapacitive devices.