自组装杂原子掺杂碳纳米带作为超快充电锌离子混合超级电容器阴极

Self-assembled carbon nanoribbons with the heteroatom doping used as ultrafast charging cathodes in zinc-ion hybrid supercapacitors

锌离子混合超级电容器(ZHSs)由于其具有较高安全性,较低成本和超长寿命等优点,适合应用于大型储能设备.然而,目前阴极材料的倍率性能较差,严重阻碍了ZHSs的发展.基于此,本文设计合成了一系列自组装杂原子掺杂(B,N,O)碳纳米带CPTHB-Bx,作为ZHSs的阴极材料.杂原子掺杂可以显著改善碳骨架的化学特性,产生更多的活性位点,并加速电荷传输.除此之外,本文还证明了B–N基团是快速吸附和脱附锌离子的主要活性位点.以CPTHB-B2作为阴极的ZHSs表现出最优异的电化学性能,在0.5 A g^(−1)电流密度下,比电容高达415.3 F g^(−1),当电流密度从0.5增大到100 A g^(−1)时,比电容保留率高达81%,能量密度为131.9 W h kg^(−1),功率密度为42.1 kW kg^(−1).此研究为超快速锌离子存储材料提供了新的设计思路.

Zinc-ion hybrid supercapacitors(ZHSs)are highly desirable for large-scale energy storage applications owing to the merits of high safety,low cost and ultra-long cycle life.The poor rate performance of cathodes,however,severely hinders their application.Herein,aqueous ZHSs with superior performance were fabricated by employing a series of ultrathin carbon nanobelts modified with B,N,O(CPTHBBx).The heteroatom doping can significantly modify the chemical behaviors of carbon frameworks,which could generate numerous active sites and accelerate the charge transport.The systematic investigation reveals that the B-N groups are active species for fast Zn-ion adsorption and desorption.As a result,the best-performed CPTHB-B2 exhibits an excellent electrochemical performance as cathodes in ZHSs,delivering a high specific capacitance of 415.3 F g^(−1) at 0.5 A g^(−1),a record high capacitance retention of 81%when increasing the current densities from 0.5 to 100 A g^(−1),an outstanding energy density of 131.9 W h kg^(−1) and an exceptionally high power density of 42.1 kW kg^(−1).Our work provides a new cathode design for ultrafast charging Zn-ion storage devices.