Supporting Information to Surface Modified … Supporting Information to Surface Modified Nanocellulose Fibers Yield Conducting Polymer-Based Flexible Supercapacitors with Enhanced

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Supporting Information to

Surface Modified Nanocellulose Fibers Yield Conducting Polymer-Based

Flexible Supercapacitors with Enhanced Capacitances

Zhaohui Wang1*, Daniel O. Carlsson2, Petter Tammela2, Kai Hua2, Peng Zhang2, Leif

Nyholm1*, Maria Strømme2*

1Department of Chemistry-The Ångström Laboratory, Uppsala University, Box 538, SE-751

21 Uppsala, Sweden

2Nanotechnology and Functional Materials, Department of Engineering Sciences, The

Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden

Corresponding authors: [email protected], [email protected] and

[email protected]

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Figure S1. FTIR spectra of the various NCFs.

As shown in Figure S1 above, all spectra from the three cellulose types under study exhibited

strong and well-defined peaks. The peak at 1113 cm-1 is ascribed to -OH glucose ring

stretching, while the peaks at 1057 and 1033 cm-1 are assigned to C-OH stretching vibrations

of cellulose.S1 Compared to the spectrum recorded on u-NCFs, the a-NCFs spectrum shows

an additional peak at 1608 cm-1, which is ascribed to -COO- stretching.S2, S3 The c-NCFs

spectrum shows a new peak at 1731 cm-1, indicating the existence of quaternary ammonium

groups.S4

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Figure S2. TGA curves for the different nanocellulose composite papers.

Figure S3. Tensile stress-strain curves for the different types of nanocellulose composite

papers under study.

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Figure S4. N2 adsorption/desorption isotherms for the nanocellulose composite papers. The

surface areas, as obtained from a BET analysis of the adsorption isotherms, are also

displayed.

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Figure S5. Charge/discharge curves recorded at different current densities (1 mA cm-2, 2 mA

cm-2, 5 mA cm-2, 10 mA cm-2, 20 mA cm-2, 30 mA cm-2, 50 mA cm-2, 100 mA cm-2, 150 mA

cm-2, 200 mA cm-2, 250 mA cm-2, 300 mA cm-2) for a supercapacitor containing different

nanocellulose composite papers: (a) PPy@u-NCFs, (b) PPy@c-NCFs, (c) PPy@a-NCFs,

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Figure S6. Cyclic voltammograms recorded in 2 M NaCl for (a) u-NCFs, a-NCFs and

c-NCFs and (b) the PPy@c-NCFs composite paper. The voltammogram for the c-NCFs

sample has also been included in (b) for comparison.

Figure S7. (a) Gravimetric and (b) volumetric capacitances obtained from the galvanostatic

charge/discharge curves for the symmetrical devices when normalized with respect to mass or

volume of PPy.

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Figure S8. Ragone plots of the different nanocellulose composite papers.

Figure S9. Cyclic voltammograms for the in-series supercapacitor device under flat and bent

conditions.

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Table S1. Electrochemical performance of the flexible composite electrodes.

Materials Energy density

(mWh cm-3)

Power density

(W cm-3)

Ref.

Compressed APP 3.7 (stack) 0.7 (stack) S5

CCF-PPy 0.18 (electrode) 0.27 (electrode) S6

PNG 3.4 (electrode) 1.1 (electrode) S6

CC/GPs/PANI 3.4 (electrode) 3 (electrode) S7 PANI/graphite/paper 0.32 (stack) 0.08 (stack) S8

PEDOT/carbon 0.28 (stack) 0.27 (stack) S9

PANI/Au/paper 35 (electrode)

10 (stack)

100 (electrode)

3 (stack) S10

PPy paper 1 (stack) 0.46 (stack) S11 PEDOT/paper 1 (stack) 1 (stack) S12

PPy@c-NCFs 3.1 (stack) 3 (stack) Our

work

The literature values represent the highest values given in the references.

Supporting References:

S1. Morán, J.; Alvarez, V.; Cyras, V.; Vázquez, A. Extraction of Cellulose and Preparation of

Nanocellulose from Sisal Fibers. Cellulose 2008, 15, 149-159.

S2. Calvini, P.; Gorassini, A.; Luciano, G.; Franceschi, E. FTIR and WAXS Analysis of

Periodate Oxycellulose: Evidence for A Cluster Mechanism of Oxidation. Vib. spectrosc.

2006, 40, 177-183.

S3. Carlsson, D.; Lindh, J.; Nyholm, L.; Strømme, M.; Mihranyan, A. Cooxidant-Free

TEMPO-Mediated Oxidation of Highly Crystalline Nanocellulose in Water. RSC Adv. 2014,

4, 52289-52298.

S4. Salajková, M.; Berglund, L.; Zhou, Q. Hydrophobic Cellulose Nanocrystals Modified

with Quaternary Ammonium Salts. J. Mater. Chem. 2012, 22, 19798-19805.

S5. Wang, Z.; Tammela, P.; Zhang, P.; Strømme, M.; Nyholm, L. High Areal and

Volumetric Capacity Sustainable All-Polymer Paper-Based Supercapacitors. J. Mater. Chem.

A 2014, 2, 16761-16769.

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S6. Wang, Z.; Tammela, P.; Strømme, M.; Nyholm, L. Nanocellulose Coupled Flexible

Polypyrrole@Graphene Oxide Composite Paper Electrodes with High Volumetric

Capacitance. Nanoscale 2015, 7, 3418-3423.

S7. Xiong, G.; Meng, C.; Reifenberger, R. G.; Irazoqui, P. P.; Fisher, T. S. Graphitic Petal

Electrodes for All-Solid-State Flexible Supercapacitors. Adv. Energy Mater. 2014,

4,1300515.

S8. Yao, B.; Yuan, L.; Xiao, X.; Zhang, J.; Qi, Y.; Zhou, J.; Zhou, J.; Hu, B.; Chen, W.

Paper-Based Solid-State Supercapacitors with Pencil-Drawing Graphite/Polyaniline

Networks Hybrid Electrodes. Nano Energy 2013, 2, 1071-1078.

S9. Anothumakkool, B.; Torris A. T, A.; Bhange, S. N.; Badiger, M. V.; Kurungot, S.

Electrodeposited Polyethylenedioxythiophene with Infiltrated Gel Electrolyte Interface: A

Close Contest of An All-Solid-State Supercapacitor with Its Liquid-State Counterpart.

Nanoscale 2014, 6, 5944-5952.

S10. Yuan, L.; Xiao, X.; Ding, T.; Zhong, J.; Zhang, X.; Shen, Y.; Hu, B.; Huang, Y.;

Zhou, J.; Wang, Z. L. Paper-Based Supercapacitors for Self-Powered Nanosystems. Angew.

Chem. 2012, 124, 5018-5022.

S11. Yuan, L.; Yao, B.; Hu, B.; Huo, K.; Chen, W.; Zhou, J. Polypyrrole-Coated Paper

for Flexible Solid-State Energy Storage. Energy Environ. Sci. 2013, 6, 470-476.

S12. Anothumakkool, B.; Soni, R.; Bhange, S. N.; Kurungot, S. Novel Scalable Synthesis

of Highly Conducting and Robust PEDOT Paper for A High Performance Flexible Solid

Supercapacitor. Energy Environ. Sci. 2015, 8, 1339-1347.