Zhao Xueyan, Bi Qiong, Yang Cui, Tao Kai, Han Lei
School of Materials Science & Chemical Engineering, Ningbo University, Ningbo, Zhejiang 315211, China.
Institute of Drug Discovery Technology, Ningbo University, Ningbo, Zhejiang 315211, China.
Dalton Trans. 2021 Nov 2;50(42):15260-15266. doi: 10.1039/d1dt02819g.
Transition metal sulfides (TMSs) are the most used electrode materials for supercapacitors (SCs). However, they still suffer from unsatisfactory electrochemical properties. Designing a hollow mixed TMS nanostructure with a well-defined chemical composition and shape is an effective strategy to tackle this issue, yet remains challenging. Herein, using a bimetallic zeolitic imidazolate framework (Zn-Co-ZIF) with various Zn/Co ratios as the template, a series of trimetallic sulfide (Ni-Zn-Co-S) hollow nanocages were successfully prepared by sequential nickel nitrate etching, co-precipitation and vulcanization. As an electrode material for a three-electrode SC in an aqueous alkaline electrolyte, the Ni-Zn-Co-S-0.25 electrode achieves an ultra-high specific capacitance of 1930.9 at 1 A g with a good rate performance (64.5% at 10 A g). In order to further prove the advantage of the as-prepared Ni-Zn-Co-S-0.25 material, it was assembled into an asymmetric energy storage device using an activated carbon (AC) anode. The Ni-Zn-Co-S-0.25//AC cell exhibits an outstanding energy storage capability (32.8 W h kg at 864.8 W kg) with a splendid cyclic life (retaining ∼92.2% of the initial capacitance after 10 000 cycles). The excellent electrochemical performance of Ni-Zn-Co-S-0.25 is ascribed to the merits of the trimetallic sulfide hollow nanocage , good electronic conductivity, a large active surface area, fast charge transfer, rich redox reactions and the synergic effect of different metal ions.
过渡金属硫化物（TMSs）是超级电容器（SCs）中使用最多的电极材料。然而，它们的电化学性能仍不尽人意。设计具有明确化学成分和形状的中空混合TMS纳米结构是解决这一问题的有效策略，但仍具有挑战性。在此，以具有不同Zn/Co比的双金属沸石咪唑框架（Zn-Co-ZIF）为模板，通过依次进行硝酸镍蚀刻、共沉淀和硫化，成功制备了一系列三金属硫化物（Ni-Zn-Co-S）中空纳米笼。作为碱性水电解质中三电极SC的电极材料，Ni-Zn-Co-S-0.25电极在1 A g时实现了1930.9的超高比电容，具有良好的倍率性能（在10 A g时为64.5%）。为了进一步证明所制备的Ni-Zn-Co-S-0.25材料的优势，将其与活性炭（AC）负极组装成不对称储能装置。Ni-Zn-Co-S-0.25//AC电池表现出出色的储能能力（在864.8 W kg时为32.8 W h kg），具有出色的循环寿命（10000次循环后保留约92.2%的初始电容）。Ni-Zn-Co-S-0.25优异的电化学性能归因于三金属硫化物中空纳米笼的优点、良好的电子导电性、大的活性表面积、快速的电荷转移、丰富的氧化还原反应以及不同金属离子的协同效应。
