School of Materials Science & Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
Nanoscale. 2018 Feb 8;10(6):2735-2741. doi: 10.1039/c7nr07931a.
Porous nanosheet-structured electrode materials are very attractive for the high efficiency storage of electrochemical energy. Herein, a porous cobalt sulfide nanosheet array on Ni foam (CoS-NSA/NF) is successfully fabricated by a facile method, which involves the uniform growth of 2D Co-based leaf-like zeolitic imidazole frameworks (Co-ZIF-L) on Ni foam followed by subsequent sulfurization with thioacetamide (TAA). Benefiting from the unique porous nanosheet array architecture and conductive substrate, the CoS-NSA/NF exhibits excellent electrochemical performance with a high capacitance (1098.8 F g at 0.5 A g), good rate capacity (54.6% retention at 10 A g) and long-term stability (87.4% retention over 1000 cycles), when acted as a binder-free electrode for supercapacitors. Furthermore, an assembled asymmetric supercapacitor device using the as-fabricated CoS-NSA as the positive electrode and activated carbon (AC) as the negative electrode also exhibits a high energy density of 20.0 W h kg at a high power density of 828.5 W kg. The method developed here can be extended to the construction of other structured metal (mono or mixed) sulfide electrode materials for more efficient energy storage.
多孔纳米片结构的电极材料对于高效存储电化学能量非常有吸引力。在此，通过一种简便的方法成功制备了泡沫镍上的多孔硫化钴纳米片阵列（CoS-NSA/NF），该方法包括在泡沫镍上均匀生长二维钴基沸石咪唑骨架（Co-ZIF-L），随后用硫代乙酰胺（TAA）进行硫化。得益于独特的多孔纳米片阵列结构和导电基底，CoS-NSA/NF 作为无粘结剂超级电容器电极表现出优异的电化学性能，具有高电容（在 0.5 A g 时为 1098.8 F g）、良好的倍率性能（在 10 A g 时保持 54.6%）和长期稳定性（在 1000 次循环后保持 87.4%）。此外，使用所制备的 CoS-NSA 作为正极和活性炭（AC）作为负极组装的非对称超级电容器装置在 828.5 W kg 的高功率密度下也表现出 20.0 W h kg 的高能量密度。这里开发的方法可以扩展到构建其他结构化金属（单或混合）硫化物电极材料，以实现更高效的能量存储。
