The Ramprasad Research Group at Georgia Tech uses machine learning and high-throughput computations to screen the chemical space of polymers for materials with applications in energy storage. They have identified several high-performing polymer dielectrics with higher dielectric constants and energy densities than the current standard. The group is working to further improve materials by incorporating metals and exploring morphological complexity with the goal of autonomous polymer design.

1. Ramprasad Research Group, Georgia Institute of Technology
Polymer Genome:
An Informatics Platform for Polymer Dielectrics
Discovery and Beyond
Rampi Ramprasad / Georgia Institute of Technology
http://ramprasad.mse.gatech.edu

2. Ramprasad Research Group, Georgia Institute of Technology
CREDITS
2
Past members
Dr. Ghanshyam Pilania (LANL)
Dr.Vinit Sharma (ORNL)
Dr. Chenchen Wang
Dr.Arun Mannodi-Kanakkithodi (ANL)
Current members
Dr. Chiho Kim, Dr.Anand Chandrasekaran,
Dr. HuanTran, Dr. Lihua Chen, Dr. Rohit
Batra,Anurag Jha, Deepak Kamal, Shruti
Venkatram, Jordan Lightstone
Multidisciplinary University Research Initiative (MURI)
Rational Design of Advanced Polymeric Capacitor Films
https://muri2010.ims.uconn.edu
Prof. Kumar Prof. Chung Prof. BrenemanProf. Cakmak
Prof.Weiss
Prof. Sotzing
Prof. Cao
Prof. Boggs

3. Ramprasad Research Group, Georgia Institute of Technology
ENERGY STORAGE TECHNOLOGIES
3
Maximum energy density = (dielectric constant) x (breakdown field)2
Gravimetricpowerdensity(W/kg)
Gravimetric energy density (Wh/kg)
0.01 0.1 10 1000
1
101
103
105
1 msec
1 sec
1000 sec
1 100
102
104
106
107
Electrochemical
capacitor
Batteries Fuel
cells
Combustion
energy and gas
turbine
Conventional capacitors
High energy density capacitors
Adapted from: Abruna, Kiya and
Henderson, Physics Today,
December 2008 issue

4. Ramprasad Research Group, Georgia Institute of Technology
THE CURRENT STANDARD
4
Biaxially oriented polypropylene (BOPP)
Toyota Prius capacitor bank
High breakdown field (700V/μm)
Low dielectric loss (0.0001)
Cheap
But, low dielectric constant of 2.2 à Energy density of 5 J/cc
Maximum energy density = (dielectric constant) x (breakdown field)2

5. Ramprasad Research Group, Georgia Institute of Technology
HOW TO SURPASS BOPP ?
5
Search and screen the chemical space
... for materials with high dielectric constant
... and large band gap

6. Ramprasad Research Group, Georgia Institute of Technology
POLYMER CHEMICAL UNIVERSE
6
Poly selenophene
O O
Se n
O
S
O
O
O
Sulfone prophane
N
H
O
N
H
N
H
O
N
H
Polyurea
Polyimide
n
Polyethylene
n
Polyacetylene Poly oxymethylene Poly vinylidene fluoride
n
Poly naphthalene
S
S
n
Polythiophene
S
O O
n
Poly furan thiophene
H
N
n
N
H
PolypyrroleSi-aliphatic polyester
Organotin-ester [p(DMT 50/50 DL-Tar/Glu)]
S
GeNH NH
O
n
Ge-containing polyamide
Fe-containing
pytpy = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine
Ru-containing organometallic polymer
bis(ethynyl-benzene)platinum(II)
Organic
Organometallic Linear
Aromatic
Homocyclic
Heterocyclic
Group
– IV Othergroups
Mixed
Organo-Sn
Organo-Si
Organo-Ge
Metalcontaining
Staggering! Where do we start?!

7. Ramprasad Research Group, Georgia Institute of Technology
284 4-blocks polymers
n
Band gap (eV)
Dielectricconstant
1 10
10
4
3
HIGH-THROUGHPUT SCREENING
8
A. Mannodi-Kanakkithodi, G. M.Treich,T. D. Huan, R. Ma, M.Tefferi,Y. Cao, G A. Sotzing, R. Ramprasad
“Rational Co-Design of Polymer Dielectrics for Energy Storage”,Adv. Mater., 28, 6277 (2016).
NH, CO, O
Aromatic rings (C6H4, C4H2S)
à Boost ionic dielectric constant
à Boost electronic dielectric constant
NH-CO-NH-C6H4
CO-NH-CO-C6H4
NH-CS-NH-C6H4
Targeted synthesis!
Possible blocks
CH2, CO, CS, O, NH, C6H4,
C4H2S
n

8. Ramprasad Research Group, Georgia Institute of Technology
1st à 2nd GENERATION
10
A. Mannodi-Kanakkithodi, G. M.Treich,T. D. Huan, R. Ma, M.Tefferi,Y. Cao, G A. Sotzing, R. Ramprasad,“Rational Co-Design of Polymer
Dielectrics for Energy Storage”,Adv. Mater., 28, 6277 (2016).
G. M.Treich, M.Tefferi, S. Nasreen,A. Mannodi-Kanakkithodi, Z. Li, R. Ramprasad, G A. Sotzing,Y. Cao,“A rational co-design approach to the
creation of new dielectric polymers with high energy density”, IEEETrans. Dielectr. Electr. Insul., 24, 732 (2017)
Polythioureas
PDTC-HDA PDTC-ODA
PDTC-PhDA PDTC-HK511
Polyimides
BTDA-HK511 BTDA-HDA
ODPA-HDA PMDA-D230
Polyureas
Polyurethanes TDI-1,2-ethanediolTDI-2,2’-diethylene glycol TDI-1,2-propanediol
TDI-1,2-diaminoethaneTDI-2,2’-oxybis-ethamine TDI-1,2-diaminopropane
1st generation polymers 2nd generation polymers

9. Ramprasad Research Group, Georgia Institute of Technology
SYNTHETIC SUCCESS
11
Polymer name BOPP
PDTC-HDA
(Polythiourea)
BTDA-HDA
(Polyimide)
BTDA-HK511
(Polyimide)
Repeat unit
Synthesized polymer
Dielectric constant 2.2 3.7 3.6 7.8
Breakdown field (MV/m) 700 685 812 676
Energy density (J/cm3) ~5 ~9 ~10 ~16
Breakdown field competitive with BOPP, and with dielectric constant up to x 3.5 the value!
The second generation of rationally co-designed polymers
(Metallized)

10. Ramprasad Research Group, Georgia Institute of Technology
CAN WE DO BETTER?
12
Ramprasad Group
Can you make this:
(CH2)x(GeF2)y
?
Sotzing Group
Ge is too
expensive! How
about Sn ?
Oh yeah,
(CH2)x(SnCl2)y is
even better! Can
you make it ?
How about
Sn esters ?

11. Ramprasad Research Group, Georgia Institute of Technology
BEYOND PURE ORGANICS
13
A. Mannodi-Kanakkithodi, G. M.Treich,T. D. Huan, R. Ma, M.Tefferi,Y. Cao, G A. Sotzing, R. Ramprasad
“Rational Co-Design of Polymer Dielectrics for Energy Storage”,Adv. Mater., 28, 6277 (2016).
AlMg
ZnTiCa
SnCd
Hf Pb
Bandgap (eV)
Dielectricconstant
1 10
10
Metal containing
polymers
Pure organic
polymers
Metal Increase of ionic dielectric
constant due to metal-
containing polar bonds

12. Ramprasad Research Group, Georgia Institute of Technology
MACHINE LEARNING
15
Polymer Property
Data generation
via Laborious computations
or experiments
Instant property prediction
via Machine Learning
T. Mueller,A. G. Kusne, R. Ramprasad “Machine Learning in Materials Science: Recent Progress and Emerging
Applications”, Reviews in Computational Chemistry, John Wiley & Sons, Inc.,Volume 29, (2016).
R. Ramprasad, R. Batra, G. Pilania,A. Mannodi-Kanakkithodi, C. Kim,“Machine Learning and Materials Informatics: Recent
Applications and Prospects”, npj Computational Materials 3, 54 (2017).
Fingerprinting

13. Ramprasad Research Group, Georgia Institute of Technology
POLYMER GENOME
16
Dataset curation Fingerprinting
Surrogate (GPR)
model training
Property prediction
www.polymergenome.org
A machine learning based polymer property prediction platform
C. Kim,A. Chandrasekaran,T. D. Huan, D. Das and R. Ramprasad,
“Polymer Genome:A Data-Powered Polymer Informatics Platform for Property Predictions”
J. Phys. Chem. C (2018).
See also:
polymer.nims.go.jp/en (PolyInfo)
pppdb.uchicago.edu
polymerdatabase.com

14. Ramprasad Research Group, Georgia Institute of Technology
BENCHMARK DATASET
17
Computational data
via high-throughput DFT
Experimental data
from literature
& data collections
Eg, Ɛ, RI, EAtom,
Tg, ρ, solubility, …
Data source
Property space
Chemical space (~900 organic polymers)
+

15. Ramprasad Research Group, Georgia Institute of Technology
HIERARCHICAL FINGERPRINTING
18
Higher length-scale
+ QSPR
descriptors
Van der Waals volume
Types of blocks
Fraction of rotatable bonds
…
+ Morphological
descriptors
Distance between rings
Length of sidechain
Length of main chain
…
Atomic level
descriptors
C
S
C
C3-S2-C3
H
N
C
H1-N3-C4
Atom-triples
…
Train set (R2=0.72)
Test set (R2=0.54)
Test set RMSE=51 K
Train set (R2=0.71)
Test set (R2=0.68)
Test set RMSE=39 K
Train set (R2=0.93)
Test set (R2=0.77)
Test set RMSE=34 K

16. Ramprasad Research Group, Georgia Institute of Technology
MLpredicted(K)
Experimental (K)
Test set RMSE = 34 K
Train set (R2=0.93)
Test set (R2=0.77)
Experimental (K)
MLpredicted(K)
Test set RMSE = 24 K
Train set (R2=0.92)
Test set (R2=0.90)
FINGERPRINT-DIMENSION REDUCTION
19
All the fingerprint without RFE
Glass transition temperature
With recursive feature elimination (RFE)
Train set (R2=0.99)
Test set (R2=0.99)

17. Ramprasad Research Group, Georgia Institute of Technology
PROPERTY PREDICTION MODELS
20
RMSE = 0.6 MPa1/2 RMSE = 0.05 g/cm3RMSE = 18 K
Glass transition temperature Solubility parameter Density
RMSE = 0.3 eV RMSE = 0.5 RMSE = 0.1 RMSE = 0.01 eV/atom
Band gap Dielectric constant Refractive index Atomization energy

18. 22

19. CO-DESIGN
From theory to practice, and back
Mannodi-Kanakkithodi, et al,
Advanced Materials (2016), Materials Today (2017)
Courtesy: Sotzing & Cao Groups

20. Ramprasad Research Group, Georgia Institute of Technology
CHEMICAL SPACE SEARCH
25
Sharma, et al, Nature Communications (2014)
Mannodi-Kanakkithodi, et al,Advanced Materials (2016)
Mannodi-Kanakkithodi, et al, MaterialsToday (2017)
Baldwin, et al,Advanced Materials (2015)
Huan, et al, Progress in Materials Science (2016)
Poly selenophene
O O
Se n
O
S
O
O
O
Sulfone prophane
N
H
O
N
H
N
H
O
N
H
Polyurea
Polyimide
n
Polyethylene
n
Polyacetylene Poly oxymethylene Poly vinylidene fluoride
n
Poly naphthalene
S
S
n
Polythiophene
S
O O
n
Poly furan thiophene
H
N
n
N
H
PolypyrroleSi-aliphatic polyester
Organotin-ester [p(DMT 50/50 DL-Tar/Glu)]
S
GeNH NH
O
n
Ge-containing polyamide
Fe-containing
pytpy = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine
Ru-containing organometallic polymer
bis(ethynyl-benzene)platinum(II)
OrganicOrganometallic
Linear
Aromatic
Homocyclic
Heterocyclic
Group
– IV
Othergroups
Mixed
Organo-Sn
Organo-Si
Organo-Ge
Metalcontaining
Our “hits” so far!

21. Ramprasad Research Group, Georgia Institute of Technology
NEXT STEPS …
• Synthesis planning / design
• Other applications / properties
• Experimental data
• Morphological complexity
• Dataset uncertainty
• Autonomous ”active” learning & design
26

22. Ramprasad Research Group, Georgia Institute of Technology
CREDITS
27
Past members
Dr. Ghanshyam Pilania (LANL)
Dr.Vinit Sharma (ORNL)
Dr. Chenchen Wang
Dr.Arun Mannodi-Kanakkithodi (ANL)
Current members
Dr. Chiho Kim, Dr.Anand Chandrasekaran,
Dr. HuanTran, Dr. Lihua Chen, Dr. Rohit
Batra,Anurag Jha, Deepak Kamal, Shruti
Venkatram, Jordan Lightstone
Toyota Research Institute
Kolon Industries
National Science Foundation
Office of Naval Research