College of Chemistry and Materials Engineering, Anhui Science and Technology University, Bengbu, 233030, P. R. China.
Chem Commun (Camb). 2019 Apr 2;55(28):4083-4086. doi: 10.1039/c9cc01277j.
3D hierarchical nanocomposites always lead to excellent electrochemical properties. In this research, we have successfully designed and synthesized a hierarchical three-dimensional cobalt sulfide encapsulated carbon nanotube/carbon nanofiber (Co9S8@CNT/CNF) composite, resulting in a high-performance supercapacitor with an unrivalled capacitance of ≈1580 F g-1 at a current density of 1 A g-1. An asymmetric supercapacitor (ASC) based on these 3D hierarchical Co9S8@CNT/CNF composites exhibits a maximum energy density of 58 W h kg-1 at a power density of 1000 W kg-1 and maintains it at 38 W h kg-1 at a higher power density of 16.7 kW kg-1. Even after 10 000 charge/discharge cycles, the ASC still retains 93% of the initial capacitance at a current density of 5 A g-1. A large number of aligned CNF nanochannels combined with the synergistic effects of cobalt sulfide nanowires encapsulated in CNTs obviously accelerates the ion transfer speed and shortens the ion transfer distance, thereby boosting both power density and energy density.
3D 分层纳米复合材料通常会带来优异的电化学性能。在这项研究中，我们成功设计并合成了一种分层的三维硫化钴包裹碳纳米管/碳纳米纤维（Co9S8@CNT/CNF）复合材料，由此构建的高性能超级电容器在 1 A g-1 的电流密度下具有高达 ≈1580 F g-1 的电容。基于这些 3D 分层 Co9S8@CNT/CNF 复合材料的非对称超级电容器（ASC）在 1000 W kg-1 的功率密度下具有 58 W h kg-1 的最大能量密度，并在 16.7 kW kg-1 的更高功率密度下保持 38 W h kg-1。即使经过 10000 次充放电循环，在 5 A g-1 的电流密度下，ASC 仍保持初始电容的 93%。大量对齐的 CNF 纳米通道与包裹在 CNT 中的硫化钴纳米线的协同作用明显加快了离子转移速度并缩短了离子转移距离，从而提高了功率密度和能量密度。
