Yin Xuemin, Li Hejun, Yuan Ruimei, Lu Jinhua
State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China.
State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China.
J Colloid Interface Sci. 2021 Mar 15;586:219-232. doi: 10.1016/j.jcis.2020.10.086. Epub 2020 Oct 26.
Rational construction of hierarchical electrode materials has been a research hotspot in the field of energy storage. In this work, metal-organic framework (MOF) derived hollow NiCoO nanocages (NCs) were strung by interwoven SiC nanowires (NWs) network on carbon cloth (CC), forming a unique sugar gourd-like core-shell architecture, which were fabricated via a multi-step process containing of chemical vapor deposition, solution reaction of MOF templates, ion exchanging/etching and subsequent heat treatment. Benefiting from the unique structural advantages, such as hierarchical porous structure with abundant active sites for electrochemical reactions and interwoven conductive networks for electron transport, the formed core-shelled CC/SiC@NiCoO as a binder supercapacitor electrode exhibits excellent electrochemical performance with a large specific capacitance (1377.6F g at a current density of 1 A g), good rate capability (68.8% capacitance retention at 20 A g) and excellent cycling stability (88.3% capacitance retention after 6000 cycles). Furthermore, the hybrid supercapacitor based on CC/SiC@NiCoO and activated carbon, not only delivers a high energy density of 46.58 Wh kg at the power density of 800 W kg, but also possesses good flexibility with high capacitance retention, exhibiting the application potential in the field of flexible energy storage. More importantly, our work gives a new thinking for structural design of SiC-based and MOF-based electrode materials for high-performance flexible energy storage.
合理构建分级结构电极材料一直是储能领域的研究热点。在本工作中，金属有机框架（MOF）衍生的空心NiCoO纳米笼（NCs）通过交织的SiC纳米线（NWs）网络串连在碳布（CC）上，形成独特的糖葫芦状核壳结构，该结构通过包括化学气相沉积、MOF模板的溶液反应、离子交换/蚀刻以及后续热处理的多步工艺制备而成。得益于其独特的结构优势，如具有丰富电化学反应活性位点的分级多孔结构和用于电子传输的交织导电网络，所形成的核壳结构CC/SiC@NiCoO作为一种无粘结剂超级电容器电极表现出优异的电化学性能，具有大的比电容（在1 A g电流密度下为1377.6 F g）、良好的倍率性能（在20 A g下电容保持率为68.8%）和出色的循环稳定性（6000次循环后电容保持率为88.3%）。此外，基于CC/SiC@NiCoO和活性炭的混合超级电容器，不仅在800 W kg的功率密度下具有46.58 Wh kg的高能量密度，而且具有良好的柔韧性和高电容保持率，展现出在柔性储能领域的应用潜力。更重要的是，我们的工作为高性能柔性储能的SiC基和MOF基电极材料的结构设计提供了新的思路。
