State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, Fudan University , Shanghai 200433, China.
Inorganic Materials Chemistry, Ruhr-University Bochum , 44780 Bochum, Germany.
ACS Appl Mater Interfaces. 2018 Jan 10;10(1):468-476. doi: 10.1021/acsami.7b13392. Epub 2017 Dec 18.
A novel hybrid core-shell structure of ZnO nanowires (NWs)/Ni as a pseudocapacitor electrode was successfully fabricated by atomic layer deposition of a nickel shell, and its capacitive performance was systemically investigated. Transmission electron microscopy and X-ray photoelectron spectroscopy results indicated that the NiO was formed at the interface between ZnO and Ni where the Ni was oxidized by ZnO during the ALD of the Ni layer. Electrochemical measurement results revealed that the Ti/ZnO NWs/Ni (1500 cycles) electrode with a 30 nm thick Ni-NiO shell layer had the best supercapacitor properties including ultrahigh specific capacitance (∼2440 F g), good rate capability (80.5%) under high current charge-discharge conditions, and a relatively better cycling stability (86.7% of the initial value remained after 750 cycles at 10 A g). These attractive capacitive behaviors are mainly attributed to the unique core-shell structure and the combined effect of ZnO NW arrays as short charge transfer pathways for ion diffusion and electron transfer as well as conductive Ni serving as channel for the fast electron transport to Ti substrate. This high-performance Ti/ZnO NWs/Ni hybrid structure is expected to be one of a promising electrodes for high-performance supercapacitor applications.
一种新型的 ZnO 纳米线（NWs）/Ni 核壳结构杂化材料作为赝电容器电极通过原子层沉积 Ni 壳成功制备，并对其电容性能进行了系统研究。透射电子显微镜和 X 射线光电子能谱结果表明，在 ZnO 和 Ni 之间的界面处形成了 NiO，在 Ni 层的原子层沉积过程中，Ni 被 ZnO 氧化。电化学测量结果表明，具有 30nm 厚 Ni-NiO 壳层的 Ti/ZnO NWs/Ni（1500 次循环）电极具有最佳的超级电容器性能，包括超高的比电容（~2440 F g）、在高电流充放电条件下良好的倍率性能（80.5%），以及相对较好的循环稳定性（在 10 A g 下循环 750 次后仍保持初始值的 86.7%）。这些有吸引力的电容行为主要归因于独特的核壳结构以及 ZnO NW 阵列作为离子扩散和电子转移的短电荷转移途径以及导电 Ni 作为快速电子传输到 Ti 基底的通道的综合效应。这种高性能的 Ti/ZnO NWs/Ni 杂化结构有望成为高性能超级电容器应用的一种有前途的电极。
