School of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, People's Republic of China.
Nanotechnology. 2023 Mar 16;34(22). doi: 10.1088/1361-6528/acbfbc.
Niobium-tungsten bimetal oxides have received wide attention due to their excellent lattice properties. In this work, NbWO(NbWO) with a tetragonal tungsten bronze structure was synthesized by simple hydrothermal method. NbWO was modified to provide high specific surface area via combining with hollow carbon nanotubes. Meanwhile, NbWO grows along the tube wall of carbon nanotubes, thus buffering the volume effect of NbWO particles. Also, the migration distance of Li-ion is effectively shortened, as well as the improved ion transfer efficiency and the reaction kinetics. In addition, carbon tube can enhance conductivity of NbWO, contributing to outstanding charge storage capacity and rate energy. Precisely, NbWO@C as electrode possesses large specific capacity (249.6 F gat 0.5 A g) and good rate performance (55.9% capacity retention from 0.5 to 2 A g). The aqueous Li-ion capacitor presents the advantages of high safety, low cost and good environmental friendliness. An asymmetric aqueous capacitor AC//NbWO@C, based on 'water-in-salt' electrolyte with high concentration lithium acetate, exhibits a large energy density of 43.2 Wh kgand a power density of 9 kW kg. Generally, NbWO@C as anode materials shows superior application perspective.
铌钨双金属氧化物由于其优异的晶格性能而受到广泛关注。在这项工作中，采用简单的水热法合成了具有四方钨青铜结构的 NbWO(NbWO)。通过与中空碳纳米管结合，对 NbWO 进行了改性，以提供高比表面积。同时，NbWO 沿着碳纳米管的管壁生长，从而缓冲了 NbWO 颗粒的体积效应。此外，还有效缩短了锂离子的迁移距离，提高了离子转移效率和反应动力学。此外，碳管可以增强 NbWO 的导电性，有助于提高电荷存储容量和倍率能量。具体而言，NbWO@C 作为电极具有较大的比容量（在 0.5 A g 时为 249.6 F g）和良好的倍率性能（从 0.5 到 2 A g 时容量保持率为 55.9%）。水系锂离子电容器具有高安全性、低成本和良好的环境友好性等优点。基于高浓度乙酸锂的“盐包水”电解质的不对称水系电容器 AC//NbWO@C 表现出 43.2 Wh kg 的高能量密度和 9 kW kg 的功率密度。总的来说，NbWO@C 作为阳极材料具有优异的应用前景。
