Guo Zihan, Wang Zhiwei, Wang Dong, Gao Yanfang, Liu Jinrong
School of Chemical Engineering, Inner Mongolia University of Technology Hohhot 010051 P. R. China
Engineering Management Department, Inner Mongolia University of Finance and Economics Hohhot 010070 P. R. China.
RSC Adv. 2022 May 5;12(22):13653-13659. doi: 10.1039/d2ra00496h.
The Li-ion hybrid capacitor (LIHC) is considered as a promising candidate for electrochemical energy storage owing to the high energy and power density. However, the sluggish anodic reaction kinetics and high reaction voltage greatly hinder the overall performance of LIHCs. Herein, a free-standing VN/MXene composite anode with high specific capacity and low reaction voltage was prepared by a simple vacuum filtration method. The obtained VN/MXene composite anode shows a high discharge specific capacity of 501.7 mA h g at 0.1 A g and excellent rate capability (191.8 mA h g at 5 A g), as well as much extended cycling stability (1500 cycles at 2 A g). When combined with an egg white-derived activated carbon (E-AC) cathode, the assembled LIHC delivers a high specific capacity of 59.1 F g and a high energy density of 129.3 W h kg with a power density of 449.7 W kg. Even at a high current density of 5 A g, the LIHC still maintains an exciting energy density of 42.81 W h kg at 11 249 W kg. Meanwhile, the cycling life can be extended to 5000 cycles with a high capacity retention of 98% at 1 A g. We believe that this work opens up new possibilities for developing advanced free-standing MXene-based electrodes for Li-ion storage.
锂离子混合电容器（LIHC）因其高能量和功率密度而被认为是电化学储能的一个有前途的候选者。然而，缓慢的阳极反应动力学和高反应电压极大地阻碍了LIHC的整体性能。在此，通过简单的真空过滤法制备了具有高比容量和低反应电压的独立式VN/MXene复合阳极。所制备的VN/MXene复合阳极在0.1 A g下显示出501.7 mA h g的高放电比容量和优异的倍率性能（在5 A g下为191.8 mA h g），以及大大延长的循环稳定性（在2 A g下循环1500次）。当与蛋清衍生的活性炭（E-AC）阴极结合时，组装的LIHC具有59.1 F g的高比容量和129.3 W h kg的高能量密度，功率密度为449.7 W kg。即使在5 A g的高电流密度下，LIHC在11249 W kg时仍保持令人兴奋的42.81 W h kg的能量密度。同时，循环寿命可以延长到5000次循环，在1 A g下具有98%的高容量保持率。我们相信这项工作为开发用于锂离子存储的先进独立式基于MXene的电极开辟了新的可能性。
