Qiu Daping, Guan Jingyu, Li Min, Kang Cuihua, Wei Jinying, Wang Feng, Yang Ru
State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical Technology Beijing 100029 China.
Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing 100029 China.
Adv Sci (Weinh). 2020 Aug 26;7(20):2001681. doi: 10.1002/advs.202001681. eCollection 2020 Oct.
Potassium-ion hybrid capacitors (PIHCs) have attracted tremendous attention because their energy density is comparable to that of lithium-ion batteries, whose power density and cyclability are similar to those of supercapacitors. Herein, a pomegranate-like graphene-confined cucurbit[6]uril-derived nitrogen-doped carbon (CBC@G) with ultra-high nitrogen-doping level (15.5 at%) and unique supermesopore-macropores interconnected graphene network is synthesized. The carbonization mechanism of cucurbit[6]uril is verified by an in situ TG-IR technology. In a K half-cell configuration, CBC@G anode demonstrates a superior reversible capacity (349.1 mA h g at 0.1 C) as well as outstanding rate capability and cyclability. Moreover, systematic in situ/ex situ characterizations, and theory calculations are carried out to reveal the origin of the superior electrochemical performances of CBC@G. Consequently, PIHCs constructed with CBC@G anode and KOH-activated cucurbit[6]uril-derived nitrogen-doped carbon cathode demonstrate ultra-high energy/power density (172 Wh kg/22 kW kg) and extraordinary cyclability (81.5% capacity retention for 5000 cycles at 5 A g). This work opens up a new application field for cucurbit[6]uril and provides an alternative avenue for the exploitation of high-performance PIHCs.
钾离子混合电容器（PIHCs）因其能量密度与锂离子电池相当，功率密度和循环稳定性与超级电容器相似而备受关注。在此，合成了一种具有超高氮掺杂水平（15.5 at%）和独特的超介孔-大孔互连石墨烯网络的石榴状石墨烯限制的葫芦[6]脲衍生的氮掺杂碳（CBC@G）。通过原位TG-IR技术验证了葫芦[6]脲的碳化机理。在K半电池配置中，CBC@G阳极表现出优异的可逆容量（在0.1 C时为349.1 mA h g）以及出色的倍率性能和循环稳定性。此外，还进行了系统的原位/非原位表征和理论计算，以揭示CBC@G优异电化学性能的起源。因此，用CBC@G阳极和KOH活化的葫芦[6]脲衍生的氮掺杂碳阴极构建的PIHCs表现出超高的能量/功率密度（172 Wh kg/22 kW kg）和非凡的循环稳定性（在5 A g下5000次循环容量保持率为81.5%）。这项工作为葫芦[6]脲开辟了一个新的应用领域，并为开发高性能PIHCs提供了一条替代途径。
