3D-Printing of Three-Dimensional Graphene Aerogels with Periodic Macropores for Supercapacitor Electrodes

2018 Fall MRS oral presentation, ET07.05.03

1. 3D-Printing of Three-Dimensional Graphene
Aerogels with Periodic Macroporesfor
Supercapacitor Electrodes
Dr. TianyuLIU
YatLi Lab
Department of Chemistry and Biochemistry
University of California, Santa Cruz
11/2018
ET07.05.03

2. Outline
Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodic Macro-porous Graphene
Aerogels
Sequels
Summary

3. Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodic Macro-porous Graphene
Aerogels
Sequels
Summary
Outline

4. Supercapacitors
Electrochemical energy storage devices
Charging Time
Liu T. et al., J. Mater. Chem. A, 2017, 5, 17705-17733
< 1s to ~100 s
~ hours
(Supercapacitors)
(Batteries)
vs.

5. Capacitance
??????????????????????????????????????????????????????????????????(??????)=
Capacity(C)
PotentialWindow(V)
A measure of the
amount of charge (energy) stored
➢A figure-of-meritof supercapacitors and their electrodes

6. Mechanisms
Electrical Double
Layer Capacitance
Pseudo-
capacitance
Activated Carbon,
CNT, Grapheneetc.
Conjugated polymers,
metal oxides etc.
ET03.10.07
Th, 10:30 am –10:45 am
Hynes, Level 3, Room 302
Capacitance

7. Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodical Macro-porous Graphene
Aerogels
Sequels
Summary
Outline

8. Desirable Architecture?
Thin Film
Thick Electrode
✓Large amount of active materials –high
capacitance and energy density
Sluggish ion diffusion –low power density
✓Facile ion diffusion –high power density
Small amount of active material –low
capacitance and energy density

9. Thick Electrode
✓Large amount of active materials –high
capacitance and energy density
Sluggish ion diffusion –low power density
✓Large amount of active materials –high
capacitance and energy density
✓Facile ion diffusion –high power density
Porous Thick Electrode
Desirable Architecture?
Pore structure?

10. Ion Diffusioneff
D
D

= eff
D
D


−
−
−
−
Diffusion coefficient diffusing
through a porous structure
Diffusion coefficient within
pores
Porosity
Tortuosity
-Rate Capability
Keywords: thick; pores; straightforward ion-diffusion

11. Outline
Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodic Macro-porous Graphene
Aerogels
Sequels
Summary
Zhuand Liu et al. Nano Lett., 2016, 16, 3448-3456

12. Direct Ink Writing
Nano Lett., 2016, 16, 3448-3456

13. Synthesis Protocol
1 mm
d = 0.2 mm
L = 0.7 mm

14. Rate Capability

15. Electrochemical Impedance Spectroscopy

16. Ink Compositions
Sample
GO
(wt%)
GNP
(wt%)
SiO
2
(wt%)
SA
BET(m
2
∙g
-1
)
Resistance
(Ω∙sq
-1
)
(a) GO-SiO
2 3.3 0.0 16.7 739 61.1
(b) GO-GNP-SiO
2-13.3 4.2 12.5 302 10.3
(c) GO-GNP-SiO
2-2 3.3 12.5 4.2 418 0.96
(d) GO-GNP 3.3 16.7 0.0 436 2.22
1 µm
The scale bar of the inset is 250 µm.

17. Electrochemical Performance
3D-printed electrodes
GO-GNP-SiO
2-2
~90%

18. Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodic Macro-porous Graphene
Aerogels
Sequels
Summary
Outline

19. Rate Capability

20. #1-Ion Intercalation Capacitance Boosting
ChemNanoMat, 2016,2, 635-641
  

21. #1-Ion Intercalation Capacitance Boosting
ChemNanoMat, 2016,2, 635-641

C
G+ Li
+
+e
-
→ C
G
-
-Li
+

[surface roughening and exfoliation]

22. #1-Ion Intercalation Capacitance Boosting
ChemNanoMat, 2016,2, 635-641
  
C
G+ Li
+
+e
-
→ C
G
-
-Li
+

[surface roughening and exfoliation]
C
G+ ClO
4
-
→ C
G
+
-ClO
4
-
+e
-

C
G
+
-ClO
4
-
+ H
2O → C
G-OH + HClO
4
4C
G
+
-ClO
4
-
+ 2H
2O → 4C
G+ O
2+4H
+
+4ClO
4
-
[surface functionalization with oxygen-functionalities]

23. Morphological Evolution
Untreated
Treated
C-OH
C=O
~90%
~84%250 µm
250 µm
1 µm
1 µm

24. #2-MnO
2Pseudocapacitors
Joule, 2018,DOI: 10.1016/j.joule.2018.09.020

25. Outline
Background of Supercapacitors
Motivation –The Desirable Architecture?
3D Printed Periodic Macro-porous Graphene
Aerogels
Sequels
Summary

26. Summary
Direct Ink Writing
❑Ink preparation
Periodic Macropores
❑Facilitate ion diffusion
❑Improve rate capability
Sequels
❑Ion-intercalation modification
❑Support for high-mass-loading MnO
2

27. Acknowledgements
Prof. YatLi Group, UCSC
Christopher
Spadaccini
Our Collaborators
Cheng Zhu Marcus
Worsley
Eric
Duoss
Chancellor’s Dissertation-year Fellowship

28. ET03.10.07
10:30 am –10:45 am, 11/29
Hynes, Level 3, Room 302
Ostwald Ripening of MnO
2for Pseudocapacitors