Electronic Supplementary Material

Engineering electrochemical actuators with large bending strainbased on 3D-structure titanium carbide MXene composites Tong Wang1,2, Tianjiao Wang1,2, Chuanxin Weng1, Luqi Liu1, Jun Zhao1,2 (), and Zhong Zhang1,2 ()

1 CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience

and Technology, Beijing 100190, China 2 University of Chinese Academy of Science, Beijing 100049, China Supporting information to https://doi.org/10.1007/s12274-020-3222-x

 Figure S1 The SEM image of Ti3C2Tx MXene flakes.

 Figure S2 XRD pattern of the Ti3C2Tx film.

 Figure S3 Mechanical properties of (a) electrode layers including MXene films and MXene/PS-MXene films and (b) electrolyte layers including EMIBF4/PVDF films and H2SO4/PVA films.

Address correspondence to Zhong Zhang, zhong.zhang@nanoctr.cn; Jun Zhao, zhaoj@nanoctr.cn

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 Figure S4 Surface SEM images of (a) the pure MXene electrode, (b) the MXene layer and (c) the MXene/PS layer of the MXene/PS-MXene electrode.

 Figure S5 Cross-sectional SEM images of the H2SO4/PVA actuator. The overall thickness of the H2SO4/PVA actuator is 49 m, in which the thickness of the MXene electrode layer is 2 m and the thickness of the H2SO4/PVA electrolyte layer is 45 m.

 Figure S6 SEM images of the interface between the electrode layer and the electrolyte layer in (a) MXene actuators, (b) H2SO4/PVA actuators and (c) MXene/PS-MXene actuators.

 Figure S7 The equivalent circuit model of electrochemical impedance spectroscopy (EIS) measurements.

 Figure S8 Galvanostatic charge-discharge profiles of EMIBF4/PVDF actuators and H2SO4/PVA actuators at the current density of 1 A g-1.

 Figure S9 Photographs of bending deformations of (a) MXene actuators and (b, c) MXene/PS-MXene actuators where the diameter of PS microspheres is 0.6 m and 1 m respectively under ±1.5 V, 0.1 Hz square wave voltage. Each small grid in the background for the scale is in 1 × 1 mm2.

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 Figure S10 Actuation performances of MXene actuators at different frequencies and voltages. (a) Bending displacement versus time under ±0.5 V square wave voltage at different frequencies. (b) Peak-to-peak strain and strain rate under ±0.5 V square wave voltage at different frequencies. (c) Bending displacement versus time under different voltage at the frequency of 2 Hz. (d) Peak-to-peak strain and strain rate under different voltage at the frequency of 2 Hz.

 Figure S11 Actuation performances of MXene/PS-MXene actuators where the diameter of PS microspheres is 0.6 m at different frequencies and voltages. (a) Bending displacement versus time under ±0.5 V square wave voltage at different frequencies. (b) Peak-to-peak displacement under ±0.5 V square wave voltage at different frequencies. (c) Bending displacement versus time under different voltage at the frequency of 2 Hz. (d) Peak-to-peak displacement under different voltage at the frequency of 2 Hz.

 Figure S12 Cross-sectional SEM images of (a) the MXene actuator and (b) the MXene/PS-MXene actuator after 10000 cycles of bending deformation under ±1.5 V, 2 Hz square wave voltage.

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Table S1 EIS molding data of EMIBF4/PVDF actuators and H2SO4/PVA actuators.

R0/ Q1/F sn-1 n R1/ Zw/ C1/F

EMIBF4/PVDF 2.69 0.00246 0.470 28.9 110 0.0189

H2SO4/PVA 0.262 0.0123 0.387 31.0 49.5 0.0224

Table S2 EIS molding data of MXene actuators and MXene/PS-MXene actuators.

R0/ Q1/F sn-1 n R1/ Zw/ C1/F

MXene 2.69 0.00246 0.470 28.9 110 0.0189

MXene-MXene/PS 9.00 0.00313 0.581 4.33 47.5 0.00795

Table S3 The performance comparison of different electrochemical actuators.

Electrode layer Electrolyte layer

Young’s modulus of

actutors (MPa)

Voltage (V)

Frequency(Hz)

Waveform Peak-to-peak displacement

(mm)

Peak-to-peak strain (%) References

Ti3C2Tx/PS-Ti3C2Tx EMIBF4/

PVDF 246.4 1.5 0.1 Square wave 35 1.18 This work

Ti3C2Tx EMIBF4/

PVDF 765.5 1.5 0.1 Square wave 18 0.68 This work

SWCNT EMIBF4/ Chitosan

1200 4 30 Square wave 4 0.75 S1

MWCNT BMIBF4/

PVDF - 2 0.1 Square wave 0.8 0.034 S2

rGO BMIBF4/

PVDF - 2 0.1 Square wave 4 0.17 S2

rGO/ MWCNT

BMIBF4/ PVDF

- 2 0.1 Square wave 3.4 0.14 S2

NiO/rGO/ MWCNT

EMIBF4/ TPU

146.33 2.5 1 Square wave 30 0.51 S3

BP-CNT/ CNT

EMIBF4/ PVDF-HFP

246.1 2.5 0.1 Square wave 21.4 1.04 S4

PANI/ VA-CNT

EMIBF4/ PVDF-HFP

- 3 0.1 Square wave 9.2 0.58 S5

MWCNT/ Chitosan

BMIBF4/ Chitosan

- 3 0.5 Square wave 2 0.3 S6

SWCNT/ EMITFSI

EMITFSI/ PVDF-HFP

143 2.5 1 Square wave 5 0.57 S7

SWCNT/ EMIBF4/

PVDF-HFP

HMIPF6/ PSS-b- PMB

- 3 0.025 Square wave 10.4 4 S8

SWCNT/ EMIBF4/

PVDF-HFP

Im-doped PSS-b-

PMB/ZImS - 3 0.5 Square wave 14 1.3 S9

rGO/EMIBF4/ PVDF

EMIBF4/ PEO-NBR

- 3 0.1 Square wave 4.5 0.32 S10

g-CN/EMIBF4/ PVDF

EMIBF4/ PEO-NBR

- 3 0.1 Square wave 16.45 0.93 S10

graphdiyne/EMIBF4/ PVDF

EMIBF4/ PVDF

420 2.5 0.1 Square wave 32 0.78 S11

PEDOT: PSS graphene/ EMIBF4/

TOBC - 1 0.1 Sinusoidal

wave 8 0.26 S12

MWCNT/PEDOT: PSS

EMIBF4/ TPU

82.18 2.5 0.1 - 15.7 0.75 S13

G-CNT-Ni/PEDOT: PSS

G-CNT-Ni/ EMIBF4/ Nafion

- 1 0.1 Sinusoidal wave 6.59 0.52 S14

MoS2-SNrGO/ PEDOT: PSS

EMIBF4/ Nafion

106 0.5 0.1 Sinusoidal wave 9.9 0.49 S15

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Electrode layer Electrolyte layer

Young’s modulus of

actutors (MPa)

Voltage (V)

Frequency(Hz)

Waveform Peak-to-peak displacement

(mm)

Peak-to-peak strain (%) References

GCN-NG/PEDOT: PSS

EMIBF4/ Nafion

- 0.5 0.1 Sinusoidal wave 6.5 0.52 S16

Th-SNG/PEDOT: PSS

EMIBF4/ SPBI

- 1 0.1 Sinusoidal wave 9 0.4 S17

HPNC900/PEDOT: PSS

EMIBF4/ Nafion

- 0.5 0.1 Sinusoidal wave 6.99 0.52 S18

BS-COF-C 900/PEDOT: PSS

EMIBF4/ Nafion

- 0.5 0.1 Sinusoidal wave 8 0.62 S19

PGNR-G/PEDOT: PSS

EMIBF4/ Nafion

- 0.5 0.1 Sinusoidal wave 17.4 0.51 S20

Ti3C2Tx/PEDOT: PSS

EMIBF4/ Nafion

- 1 0.1 Sinusoidal wave 2 1.37 S21

References [S1] Li, J.; Ma, W.; Song, L.; Niu, Z.; Cai, L.; Zeng, Q.; Zhang, X.; Dong, H.; Zhao, D.; Zhou, W.; Xie, S. Superfast-response and ultrahigh-power-density

electromechanical actuators based on hierarchal carbon nanotube electrodes and chitosan. Nano Lett 2011, 11, 4636-4641. [S2] Lu, L.; Liu, J.; Hu, Y.; Zhang, Y.; Randriamahazaka, H.; Chen, W. Highly stable air working bimorph actuator based on a graphene nanosheet/carbon

nanotube hybrid electrode. Adv. Mater. 2012, 24, 4317-4321. [S3] Wu, G.; Li, G. H.; Lan, T.; Hu, Y.; Li, Q. W.; Zhang, T.; Chen, W. An interface nanostructured array guided high performance electrochemical

actuator. J. Mater. Chem. A 2014, 2, 16836-16841. [S4] Wu, G.; Wu, X.; Xu, Y.; Cheng, H.; Meng, J.; Yu, Q.; Shi, X.; Zhang, K.; Chen, W.; Chen, S. High-performance hierarchical black-phosphorous-based

soft electrochemical actuators in bioinspired applications. Adv. Mater. 2019, 31, 1806492. [S5] Wu, G.; Hu, Y.; Zhao, J.; Lan, T.; Wang, D.; Liu, Y.; Chen, W. Ordered and active nanochannel electrode design for high-performance electrochemical

actuator. Small 2016, 12, 4986-4992. [S6] Lu, L.; Chen, W. Biocompatible composite actuator: A supramolecular structure consisting of the biopolymer chitosan, carbon nanotubes, and an

ionic liquid. Adv. Mater. 2010, 22, 3745-3748. [S7] Mukai, K.; Asaka, K.; Sugino, T.; Kiyohara, K.; Takeuchi, I.; Terasawa, N.; Futaba, D. N.; Hata, K.; Fukushima, T.; Aida, T. Highly conductive

sheets from millimeter-long single-walled carbon nanotubes and ionic liquids: Application to fast-moving, low-voltage electromechanical actuators operable in air. Adv. Mater. 2009, 21, 1582-1585.

[S8] Kim, O.; Shin, T. J.; Park, M. J. Fast low-voltage electroactive actuators using nanostructured polymer electrolytes. Nat Commun 2013, 4, 2208. [S9] Kim, O.; Kim, H.; Choi, U. H.; Park, M. J. One-volt-driven superfast polymer actuators based on single-ion conductors. Nat Commun 2016, 7, 13576. [S10] Wu, G.; Hu, Y.; Liu, Y.; Zhao, J.; Chen, X.; Whoehling, V.; Plesse, C.; Nguyen, G. T.; Vidal, F.; Chen, W. Graphitic carbon nitride nanosheet electrode-

based high-performance ionic actuator. Nat Commun 2015, 6, 7258. [S11] Lu, C.; Yang, Y.; Wang, J.; Fu, R.; Zhao, X.; Zhao, L.; Ming, Y.; Hu, Y.; Lin, H.; Tao, X.; Li, Y.; Chen, W. High-performance graphdiyne-based

electrochemical actuators. Nat Commun 2018, 9, 752. [S12] Kim, S. S.; Jeon, J. H.; Kim, H. I.; Kee, C. D.; Oh, I. K. High-fidelity bioelectronic muscular actuator based on graphene-mediated and

tempo-oxidized bacterial cellulose. Adv. Funct. Mater. 2015, 25, 3560-3570. [S13] Wang, D.; Lu, C.; Zhao, J.; Han, S.; Wu, M.; Chen, W. High energy conversion efficiency conducting polymer actuators based on

PEDOT:PSS/MWCNTs composite electrode. RSC Advances 2017, 7, 31264-31271. [S14] Kim, J.; Bae, S. H.; Kotal, M.; Stalbaum, T.; Kim, K. J.; Oh, I. K. Soft but powerful artificial muscles based on 3D graphene-CNT-Ni

heteronanostructures. Small 2017, 13, 1701314. [S15] Manzoor, M. T.; Nguyen, V. H.; Umrao, S.; Kim, J. H.; Tabassian, R.; Kim, J. E.; Oh, I. K. Mutually exclusive p-type and n-type hybrid electrode

of MoS2 and graphene for artificial soft touch fingers. Adv. Funct. Mater., 2019, 29, 1905454. [S16] Moumita, K.; Jaehwan, K.; Rassoul, T.; Sandipan, R.; Hiep, N. V.; Nikhil, K.; Oh, I. K. Highly bendable ionic soft actuator based on nitrogen-enriched

3D hetero-nanostructure electrode. Adv. Funct. Mater. 2018, 28, 1802464. [S17] Kotal, M.; Kim, J.; Kim, K. J.; Oh, I. K. Sulfur and nitrogen co-doped graphene electrodes for high-performance ionic artificial muscles. Adv.

Mater. 2016, 28, 1610-1615. [S18] Roy, S.; Kim, J.; Kotal, M.; Kim, K. J.; Oh, I. K. Electroionic antagonistic muscles based on nitrogen-doped carbons derived from

poly(triazine-triptycene). Adv. Sci. 2017, 4, 1700410. [S19] Roy, S.; Kim, J.; Kotal, M.; Tabassian, R.; Kim, K. J.; Oh, I. K. Collectively exhaustive electrodes based on covalent organic framework and

antagonistic co-doping for electroactive ionic artificial muscles. Adv. Funct. Mater. 2019, 29, 1900161. [S20] Kotal, M.; Tabassian, R.; Roy, S.; Oh, S.; Oh, I. K. Metal-organic framework-derived graphitic nanoribbons anchored on graphene for electroionic

artificial muscles. Adv. Funct. Mater. 2020, 30, 1910326. [S21] Umrao, S.; Tabassian, R.; Kim, J.; Nguyen, V. H.; Zhou, Q.; Nam, S.; Oh, I. K. MXene artificial muscles based on ionically cross-linked Ti3C2Tx

electrode for kinetic soft robotics. Sci. Robot. 2019, 4, eaaw7797.