Wu Qiong, Wang Yihao, Li Pengfei, Chen Shunhua, Wu Fufa
School of Material Science and Engineering, Liaoning University of Technology, Jinzhou, 121001, China.
School of Mechanical Engineering, Hefei University of Technology, Hefei, 230009, China.
Dalton Trans. 2022 Feb 22;51(8):3263-3274. doi: 10.1039/d1dt02543k.
The electrochemical properties of the MXene titanium carbide, TiC, which has received much attention in the application of electrode materials for supercapacitors, are affected by the different morphologies of its precursor. In particular, the increase of layer spacing and specific capacitance, as well as the decrease of impedance and the dynamics analysis of TiC etched from hexagonal TiAlC precursors, are still not clear, and need to be further studied and explored. In this work, MXene TiC was synthesized efficiently in 2 hours by microwave assisted selective etching with hexagonal TiAlC as the precursor material. The specific capacitance of the TiC electrode is up to 357.85 F g, while the ohmic resistance of the whole electrochemical energy storage system is 0.234 ohm and the charge transfer resistance is 0.875 ohm. By analyzing the structural evolution and electrochemical properties from hexagonal TiAlC to TiC, it is revealed that TiC prepared with hexagonal TiAlC as the precursor material has larger atomic layer spacing, more active sites, smaller diffusion impedance and higher energy storage efficiency than that prepared with ordinary TiAlC. These lay a structural foundation for improving the energy storage performance of TiC supercapacitor electrodes.
MXene碳化钛TiC在超级电容器电极材料应用中备受关注，其电化学性能受前驱体不同形貌的影响。特别是，从六方TiAlC前驱体蚀刻得到的TiC，其层间距和比电容的增加、阻抗的降低以及动力学分析仍不明确，需要进一步研究和探索。在这项工作中，以六方TiAlC为前驱体材料，通过微波辅助选择性蚀刻在2小时内高效合成了MXene TiC。TiC电极的比电容高达357.85 F/g，而整个电化学储能系统的欧姆电阻为0.234欧姆，电荷转移电阻为0.875欧姆。通过分析从六方TiAlC到TiC的结构演变和电化学性能，发现以六方TiAlC为前驱体材料制备的TiC比用普通TiAlC制备的TiC具有更大的原子层间距、更多的活性位点、更小的扩散阻抗和更高的储能效率。这些为提高TiC超级电容器电极的储能性能奠定了结构基础。
