Due to the outstanding electrochemical performance, high safety coefficient, controllable reaction system and low production cost, Zinc-ion hybrid capacitors (ZIHCs) is considered as a new generation of promising energy storage technology, which even seem as a suitable choice for Medical application. However, to produce ideal carbon-base cathode material with low cost and high electrochemical performance still face challenge. Here, we report a ZIHCs’ cathode based on Bougainvillea petal-derived porous carbon nanosheets (Carbonized Bougainvillea activated at 850 °C, CB-3-850). CB-3-850 derived from Bougainvillea petals exhibit extremely an ultrahigh discharge capacity of 239.1 mAh g at 0.5 A g (from 0 V to 1.8 V) and an excellent electrochemical stability at 20 A g (90 %, 10,000 cycles). In addition, ultrahigh energy density (213.4 Wh kg) and high power density (14.8 kW kg) are realized in CB-3-850. Special “pores-on-surface” structure and ultrathin nanosheet-like morphology of CB-3-850 not only provide a high specific surface area that for more Zn and SO absorbed on its surface but also enable ions across the one nanosheet directly to reach other carbon-sheets units, which realize a fast kinetic process of ions storage and higher capacity. The excellent performance of the Zinc-ion capacitor can be also attributed to N and O doping that strongly interacted with Zn during the charge/discharge process. Finally, natural Bougainvillea petal just contains simple non-metal elements like C, N and O, exhibit high biocompatibility.

中文翻译：

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源自九重葛花瓣的分层多孔碳纳米片，具有“表面孔隙”结构，可用于超高性能锌离子混合电容器


由于优异的电化学性能、高安全系数、可控的反应体系和低廉的生产成本，锌离子混合电容器（ZIHC）被认为是新一代有前景的储能技术，甚至似乎是医疗应用的合适选择。然而，制备低成本、高电化学性能的理想碳基正极材料仍面临挑战。在这里，我们报告了一种基于九重葛花瓣衍生的多孔碳纳米片的 ZIHC 阴极（在 850 °C 下活化的碳化九重葛，CB-3-850）。源自九重葛花瓣的 CB-3-850 在 0.5 A g（0 V 至 1.8 V）下表现出 239.1 mAh g 的超高放电容量，以及在 20 A g（90%，10,000 次循环）下优异的电化学稳定性。此外，CB-3-850还实现了超高能量密度（213.4 Wh kg）和高功率密度（14.8 kW kg）。 CB-3-850特殊的“表面孔隙”结构和超薄纳米片状形态不仅提供了高比表面积，可以让更多的Zn和SO吸附在其表面，而且可以使离子穿过单个纳米片直接到达其他碳片单元，实现离子存储的快速动力学过程和更高的容量。锌离子电容器的优异性能还可以归因于在充放电过程中与Zn发生强烈相互作用的N和O掺杂。最后，天然三角梅花瓣只含有简单的C、N、O等非金属元素，表现出很高的生物相容性。