Yang Chunhai, Chen Hao, Guan Cao
School of Chemistry & Environment Engineering, Hubei University for Nationalities, Enshi 445000, China.
School of Engineering, Zhejiang A&F University, Hangzhou 311300, China.
Nanomaterials (Basel). 2019 Apr 9;9(4):586. doi: 10.3390/nano9040586.
Transition metal oxides with high theoretic capacities are promising materials as battery-type electrodes for hybrid supercapacitors, but their practical applications are limited by their poor electric conductivity and unsatisfied rate capability. In this work, a hybrid structure of CoO nanowires coated with conformal polypyrrole (Ppy) nanolayer is proposed, designed and fabricated on a flexible carbon substrate through a facile two-step method. In the first step, porous CoO nanowires are fabricated on flexible carbon substrate through a hydrothermal procedure combined with an annealing process. In the second step, a uniform nanolayer of Ppy is further coated on the surfaces of the CoO nanowires, resulting in a hybrid core-shell CoO@Ppy nanoarrays. The CoO@Ppy aligned on carbon support can be directly utilized as electrode material for hybrid supercapacitors. Since the conductive Ppy coating layer provides enhanced electric conductivity, the hybrid electrode demonstrates much higher capacity and superior rate capability than pure CoO nanowires. As a further demonstration, Ppy layer can also be realized on SnO₂ nanowires. Such facile conductive-layer coating method can be also applied to other types of conducting polymers (as the shell) and metal oxide materials (as the core) for various energy-related applications.
具有高理论容量的过渡金属氧化物作为混合超级电容器的电池型电极材料具有很大潜力，但其实际应用受到电导率差和倍率性能不理想的限制。在本工作中，通过一种简便的两步法，在柔性碳基底上设计并制备了一种由保形聚吡咯（Ppy）纳米层包覆的CoO纳米线的混合结构。第一步，通过水热法结合退火工艺在柔性碳基底上制备多孔CoO纳米线。第二步，在CoO纳米线表面进一步包覆一层均匀的Ppy纳米层，得到核壳结构的CoO@Ppy纳米阵列。排列在碳载体上的CoO@Ppy可直接用作混合超级电容器的电极材料。由于导电的Ppy包覆层提高了电导率，该混合电极比纯CoO纳米线表现出更高的容量和更优异的倍率性能。作为进一步的证明，Ppy层也可以在SnO₂纳米线上实现。这种简便的导电层包覆方法也可应用于其他类型的导电聚合物（作为壳层）和金属氧化物材料（作为核层），用于各种与能源相关的应用。
