题目：What Can Ti₃C₂T_x MXene Do for Supercapacitors?

报告人：Dr. Zifeng LIN （Université Paul Sabatier）

时间：12月22日（周五）14:00-15:30

地点：李薰楼468会议室

What Can Ti₃C₂T_x MXene Do for Supercapacitors?

Zifeng LIN
Université Paul Sabatier, CIRIMAT UMR CNRS 5085, 118 route de Narbonne, 31062 Toulouse, France
Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, France

MXenes are two-dimensional (2D) early transition metal carbides and carbonitrides which are produced by selective etching of the A group element from MAX phases [1]. Thanks to their unique properties, MXenes have shown great potential as electrode materials for supercapacitors [2-4]. Recently, we developed new strategies to push the performance of MXenes to reach levels where MXenes can operate at ultra-high rates exceeding those of conventional EDLCs in sulfuric acid electrolyte, as well as higher volumetric and areal capacitance than carbons [5]. By designing macro-porous Ti₃C₂T_x MXene films, high capacitance of 210 Fg^-1 at scan rates of 10 Vs^-1 is obtained. Meanwhile, a volumetric capacitance of 1500 Fcm^-3 can be delivered by a Ti₃C₂T_x MXene hydrogel film electrode. Additionally, the operation potential window is extended up to 1 V by using glassy carbon current collectors. Such performance surpasses the best reported results including carbon and pseudocapacitive materials.

Ti₃C₂T_x MXene was further studied in non-aqueous electrolytes. Capacitance of 70 Fg^-1 (20 mVs^-1) within a large voltage window of 3 V was obtained in EMI-TFSI neat ionic liquid (IL) electrolyte [6]. In-situ XRD measurement as well as molecular dynamic modeling revealed intercalation/de-intercalation of IL cations and anions during the charge / discharge process [7,8]. Despite the large voltage window achieved in IL electrolytes, future work will be dedicated to boost up the capacitance in these non-aqueous electrolytes.

References
[1]. Alhabeb, M., Maleski, K., Anasori, B., Lelyukh, P., Clark, L., Sin, S., Gogotsi, Y., Guidelines for Synthesis and Processing of Two-Dimensional Titanium Carbide (Ti₃C₂T_x MXene), Chem. Mat. (2017) 29 (18), 7633-7644
[2]. Lukatskaya, M. R., Mashtalir, O., Ren, C. E., Dall’Agnese, Y., Rozier, P., Taberna, P. L., Naguib, M., Simon, P., Barsoum, M. W., Gogotsi, Y., Cation Intercalation and High Volumetric Capacitance of Two-Dimensional Titanium Carbide, Science (2013) 341 (6153), 1502-1505
[3]. Ghidiu, M., Lukatskaya, M. R., Zhao, M.-Q., Gogotsi, Y., Barsoum, M. W., Conductive two-dimensional titanium carbide `clay' with high volumetric capacitance, Nature (2014) 516 (7529), 78-81
[4]. Anasori, B., Lukatskaya, M. R., Gogotsi, Y., 2D metal carbides and nitrides (MXenes) for energy storage, Nature Reviews Materials (2017) 2 (2), Article number: 16098
[5]. Lukatskaya, M. R., Kota, S., Lin, Z., Zhao, M.-Q., Shpigel, N., Levi, M. D., Halim, J., Taberna, P.-L., Barsoum, M. W., Simon, P., Gogotsi, Y., Ultra-high-rate pseudocapacitive energy storage in two-dimensional transition metal carbides, Nature Energy (2017) 2 (8), Article number: 17105
[6]. Lin, Z., Barbara, D., Taberna, P.-L., Van Aken, K. L., Anasori, B., Gogotsi, Y., Simon, P., Capacitance of Ti3C2Tx MXene in ionic liquid electrolyte, Journal of Power Sources (2016) 326, 575-579
[7]. Lin, Z., Rozier, P., Duployer, B., Taberna, P.-L., Anasori, B., Gogotsi, Y., Simon, P., Electrochemical and in-situ X-ray diffraction studies of Ti3C2Tx MXene in ionic liquid electrolyte, Electrochem. Commun. (2016) 72, 50-53
[8]. Xu, K., Lin, Z., Merlet, C., Taberna, P.-L., Miao, L., Jiang, J., Simon, P., Tracking Ionic Rearrangements and Interpreting Dynamic Volumetric Changes in Two-Dimensional Metal Carbides Supercapacitors: A Molecular Dynamics Simulation Study, ChemSusChem (2017), 10.1002/cssc.201702068