Han Lijie, Luo Jie, Zhang Rongkang, Gong Wenbin, Chen Long, Liu Fan, Ling Ying, Dong Yihao, Yong Zhenzhong, Zhang Yongyi, Wei Lei, Zhang Xiaogang, Zhang Qichong, Li Qingwen
Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies, College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.
Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
ACS Nano. 2022 Sep 27;16(9):14951-14962. doi: 10.1021/acsnano.2c05905. Epub 2022 Aug 29.
Nonmetallic ammonium ions that feature high safety, low molar mass, and small hydrated radius properties have shown great advantages in wearable aqueous supercapacitors. The construction of high-energy-density flexible ammonium-ion asymmetric supercapacitors (AASCs) is promising but still challenging due to the lack of high-capacitance pseudocapacitive anodes. Herein, freestanding core-shell heterostructures supported on carbon nanotube fibers were designed by anchoring MoS nanosheets on nanowires (MoS@TiN/CNTF) as anodes for AASCs. With contributions of abundant active sites and conspicuous synergistic effects of multiple components for arrayed heterostructure engineering, the developed MoS@TiN/CNTF anodes exhibit a specific capacitance of 1102.5 mF cm at 2 mA cm. Theoretical calculations confirm the dramatic enhancement of the binding strength of ammonium ions on the MoS shell layer at the heterostructure, where a built-in electric field exists to accelerate the charge transfer. By utilizing a MnO/CNTF cathode and NHCl/poly(vinyl alcohol) (PVA) as a gel electrolyte, quasi-solid-state fiber-shaped AASCs were successfully constructed, achieving a specific capacitance of 351.2 mF cm and an energy density of 195.1 μWh cm, outperforming most recently reported fiber-shaped supercapacitors. This work provides a promising strategy to rationally design heterostructure engineering of MoS@TiN nanoarrays toward advanced anodes for application in next-generation AASCs.
具有高安全性、低摩尔质量和小水合半径特性的非金属铵离子在可穿戴水系超级电容器中显示出巨大优势。构建高能量密度的柔性铵离子不对称超级电容器（AASC）很有前景，但由于缺乏高电容赝电容阳极，仍然具有挑战性。在此，通过将MoS纳米片锚定在纳米线上（MoS@TiN/CNTF）设计了支撑在碳纳米管纤维上的独立核壳异质结构作为AASC的阳极。由于丰富的活性位点以及用于阵列异质结构工程的多种组分的显著协同效应，所开发的MoS@TiN/CNTF阳极在2 mA cm时表现出1102.5 mF cm的比电容。理论计算证实了异质结构处MoS壳层上铵离子结合强度的显著增强，其中存在一个内建电场来加速电荷转移。通过使用MnO/CNTF阴极和NHCl/聚乙烯醇（PVA）作为凝胶电解质，成功构建了准固态纤维状AASC，实现了351.2 mF cm的比电容和195.1 μWh cm的能量密度，优于最近报道的纤维状超级电容器。这项工作为合理设计MoS@TiN纳米阵列的异质结构工程以用于下一代AASC的先进阳极提供了一种有前景的策略。
