Supporting Information

Transcription

1 Supporting Information Two-dimensional titanium carbide/rgo composite for high-performance supercapacitors Chongjun Zhao a *, Qian Wang a, Huang Zhang b,c **, Stefano Passerini b,c, Xiuzhen Qian a a School of Materials Science and Engineering, East China University of Science and Technology, Shanghai , P.R. China. b Helmholtz Institute Ulm, Helmholtzstrasse 11, D Ulm, Germany. c Karlsruhe Institute of Technology, PO Box 3640, D Karlsruhe, Germany. Corresponding author *Tel: ; chongjunzhao@ecust.edu.cn **Tel: +49 (0) ; huang.zhang@outlook.com S-1

2 Materials and reagents Pristine graphite powder (325 mesh), hydrogen chloride (HCl, wt.%), hydrogen peroxide (H 2 O 2, 30.0wt.%), sulfuric acid (H 2 SO 4, 98.0wt.%), potassium permanganate (KMnO 4 ), phosphorus pentoxide (P 2 O 5 ), potassium persulfate (K 2 S 2 O 8 ), ethanol (C 2 H 5 OH), were purchased from Sinopharm Chemical Reagent Company, China. All reagents were used as received without any further purification. Synthesis of graphene oxides Graphene oxides (GO) were synthesized via a modified Hummers method using pristine graphite powders as raw materials. In a typical procedure, pristine graphite powers (3 g, 325 mesh) was put into an 80 C solution of concentrated H 2 SO 4 (12 ml), K 2 S 2 O 8 (2.5 g), and P 2 O 5 (2.5 g). The mixture was kept at 80 C for 4.5 h. Then, the mixture was diluted with 500 ml of de-ionized (DI) water and left overnight. The mixture was filtered and washed with water to remove the residual acid. The product was dried under ambient conditions overnight. Pre-oxidized graphite powder was added into cold (0 C) concentrated H 2 SO 4 (120 ml). Then, KMnO 4 (15 g) was slowly added, with the temperature of mixture kept below 20 C. After addition of 250 ml of water, the mixture was stirred for 2 h, and then an additional 700 ml of water was added. After that, 20 ml of 30% H 2 O 2 was added into the mixture, and the solution changed into brilliant yellow, accompanied by the generation of bubbles. The mixture was filtered and washed with diluted HCl aqueous solution (10 wt.%, 1 L) to remove metal ions. The brownish yellow solution was centrifuged at 10,000 rpm, the supernatant solution was decanted away, and the resulting material was subjected to multiple washings with water until the ph was 7. S-2

3 Figure S1. CV curves for Ti 3 C 2 T x /RGO-7, Ti 3 C 2 T x /RGO-7-grind and Ti 3 C 2 T x electrodes at 20 mv/s S-3

4 Figure S2. Cycling performance of Ti 3 C 2 T x /RGO-7 and Ti 3 C 2 T x /RGO-7-no immersion S-4

5 Figure S3. Phase angle Bode plot of all electrodes S-5

6 Table S1. ESR values from Nyquist plots and IR drop of all the electrodes Samples Nyquist plots ESR value IR drop Ti 3 C 2 T x /RGO Ti 3 C 2 T x /RGO Ti 3 C 2 T x /RGO Ti 3 C 2 T x /RGO Ti 3 C 2 T x RGO S-6

7 Table S2. Performance comparisons with other work MXene-based Materials sweep rate or current density Electrolyte Capacity Ref. Ti 3 C 2 T x /PVA-KOH 2 mv/s 1 M KOH 528 F/cm 3 S1 Ti 3 C 2 T x /PDDA 2 mv/s 1 M KOH 296 F/cm 3 S1 Ti 3 C 2 T x /PPy 5 mv/s 1 M H 2 SO F/g S2 CNT-Ti 3 C 2 T x 2 mv/s 1M EMITFSI 85 F/g S3 Ti 3 C 2 T x /MWCNT 2 mv/s 1 M H 2 SO F/g S4 d-ti 3 C 2 /CNT 5 mv/s 6 M KOH 393 F/cm 3 S5 Ti 3 C 2 T x /RGO-7 2 A/g 2 M KOH F/g Our work S-7

8 REFERENCES [S1] Ling, Z.; Ren, C. E.; Zhao, M. Q.; Yang, J.; Giammarco, J. M.; Qiu, J.; Barsoum, M. W.; Gogotsi, Y. Flexible and Conductive MXene Films and Nanocomposites with High Capacitance. PNAS 2014, 111, [S2] Boota, M.; Anasori,.; Voigt, C.; Zhao, M. Q.; Barsoum, M. W.; Gogotsi, Y. Pseudocapacitive Electrodes Produced by Oxidant-Free Polymerization of Pyrrole between the Layers of 2D Titanium Carbide (MXene). Adv. Mater. 2015, 28, [S3] Dall Agnese, Y.; Rozier, P.; Taberna, P. L.; Gogotsi, Y.; Simon, P. Capacitance of Two- Dimensional Titanium carbide (MXene) and MXene/Carbon Nanotube Composites in Organic Electrolytes. J. Power Sources 2016, 306, [S4] Zhao, M. Q.; Ren, C. E.; Ling, Z.; Lukatskaya, M. R.; Zhang, C.; Van Aken, K. L.; Barsoum, M. W.; Gogotsi, Y. Flexible Mxene/Carbon Nanotube Composite Paper with High Volumetric Capacitance. Adv. Mater. 2015, 27, [S5] Yan, P. T.; Zhang, R. J.; Jia, J.; Wu, C.; Zhou, A.; Xu, J.; Zhang, X. S. Enhanced Supercapacitive Performance of Delaminated Two-Dimensional Titanium Carbide/Carbon Nanotube Composites in Alkaline Electrolyte. J. Power Sources 2015, 284, S-8