Dra. Ana Karina Cuentas-Gallegos

Instituto de Energías Renovables-UNAM

Cap

ac

ito

res

Supercondensadores

Electroquímicos

Baterías

Celd

as

de

Co

mb

us

tib

le

Cap

aci

tors

BatteriesFuel

Cells

Supercapacitors

Combustion Energy

P & E

Li

Ni-Cd

Pb-acid

Based on Porous

Carbon Materials

Ragone Plot (cycle life is not considered)

Energy Storage Devices

2-plates in parallel separated

by a dielectric material

C=A/dThe dielectric material polarizes, keeping the

electrode charged.

Same configuration as capacitors and batteries:

•The electrolyte and separator are used instead of the dielectric material

•Polarization occurs in the electrode-electrolyte interphase

•Charge is retained by what is known as double layer (non-faradaic)

Pseudocapacitance: faradaic nature, is determined in a half cell and NOT in a 2-electrode

assembly.

ELECTROSORPTION REDOX INTERCALATION

1. “Understandind

supercapacitors based on

nano-hybrid materials with

interfacial conjugation”

Prog.Nat.Sci:Mater Int.

2013, 23 (3) 245-255

2. To be or not to be

Pseudocapacitive?

J.Electrochem. Soc. 2015,

162(5) A5185-A5189.

What are we looking for in a Supercapacitor?

E =1/2 CV2

P = V2/4R

High Power

•Decrease R of the device (Electrolyte conductivity, porosity characteristics of carbon, elaboration of electrode materials, current collectors)• Increase V

Increase Energy Density

•Increase V by the right selection of electrolyteasymmetric assemblies.

•Increase C by introduction of pseudocapacitance:

Conducting polymers, oxides or functional groups in C

•Cheap and Non-Toxic Materials

C=It/V= Q/V

Environmentally-Friendly Supercapacitors

GREEN DEVICES

Current Collectors

SS, Al, Ni foams and paper(High ash content)

Carbon cloth

Separator

PTFE/PP

CelluloseElectrolyte

Organic,

Aqueous

PackagingSS, Al foil (High ash content)

HDPE

B. Dyatkin, V. Presser, M. Heon, M.R. Lukatskaya, M. Beidaghi, Y. Gogotsi; ChemSusChem 2013, 6, 2269-2280

• Environmental hazards

once disposed

• harmful if discarded by

using conventional

landfill or incineration

methods.

• Substitution of

components for less

enviroment impact.

Electroactive Material

Activated C from Biomass and their composites

BINDER

PTFE, PVDF,

NAFION

PVA

PTFE

PVAc/Polyisoprene

Lamellar PVA

Crosslinked PVA

• We will show the use of activated carbon from biomass as electrode

material, nanocomposites to improve energy density with

sustainable metallic oxides, the use of environmentally friendly

binders to fabricate electrodes, and packaging with polymers to

obtain green devices with good performance

BIOMASS

CARBON MATERIALS

STRUCTURAL CHARACTERIZATION

DRX, RAMAN, SAX, HRSEM,

PHYSISORPTION

CHEMICALCHARACTERIZATION

TGA, EDX, FTIR, XPS, CHONS, BOHEM TITRATIONS

ELECTROCHEMICAL CHARACTERIZATION

CYCLIC VOLTAMMETRY, SPECS, GALVANOSTATIC CYCLING

Carbons from Solar PyrolysisGrupo de Radiación Solar Aplicada

HoSIER

Solar Oven

Reaction Chamber

• Experimental set-up

vacumm

Ar flow

Agave Biomass

9.3% AshCaCO3

Sulfatos de Ca, Mg y K

Celulosa

+

Hemicelulosa

44% Lignina

+

Hemicelulosa

14%

Hemicelulosa

15%

0 10 20 30 40 50 60 70 80

Inte

nsity (

Arb

itra

ry u

nits)

2 (Degrees)

Cf-1-L

Cf-2-L

Cf-3-L

Cf-4-L

Cf-6-L

Cf-7-L

Cf-9.L

T

450°C

1564°C

XRDO%

-

+

-1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6-4

-3

-2

-1

0

1

2

Cu

rre

nt d

en

sity (

A/g

)

Potential vs SSE (V)

Cf-9-L

Cf-7-L

Cf-6-L

Cf-4-L

Cf-3-L

Cf-2-L

Cf-1-L

Electrochemical Storage Performance

0

10

20

30

40

50

60

70

80

Capacitance (

F/g

)

Cf-9-L

Cf-7-L

Cf-6-L

Cf-4-L

Cf-3-L

Cf-2-L

Cf-1-L

20

.88

°C

/min

25

.77

°C

/min

23

.98

°C

/min

30

.31

°C

/min

26.4

1 °

C/m

in

29

.64

°C

/min

22

.27

°C

/min

45

0°C

60

0°C

80

0°C

93

5°C

11

00°C

14

30°C

15

64°C

80F/g without any activation

Biomass from Tomato Pruning

40% AshCaCO3

H4KNO4S

More

Hemicelulose

than AGAVE

Celulosa

+

Hemicelulosa

28%

Lignina

+

Hemicelulosa

14% Hemicelulosa

25%

0 20 40 60 80 100

40

60

80

100

120

140

160

180

200

Capacitancia

(F

/g)

Velocidad de barrido (mV/s)

Cj-450

Cj-600

Cj-900

H2SO

4 0.5 M

Cycling Properties& Rate Capability

160 F/g

Without any activation

Cesp= Q/∆E x m

O% + -

500m2/g

1130m2/g 806m2/g

0 1000 2000 3000 4000 50000

10

20

30

40

50

Capacitancia

(F

/g)

Ciclo

Cj-600

Cj-900

Cj-450

SUPERCAPACITOR CELLS

C= I td/ V m(+-)

0.25A/g

Carbons from Traditional Pyrolysis

Collaboration with Coahuila, Puebla & G2E

Activated C from Sawdust Wastes

-0.8 -0.4 0.0 0.4 0.8 1.2

-800

-600

-400

-200

0

200

400

600

800

H2SO4Aserrin

C (

F/g

)

E (V)

5 mV / s

10 mV / s

20 mV / s

100 mV / sPretreated in FeCl2 solution,

followed by H3PO4 solution

treatment.

•T=450 °C; t= 90 min.

Up to 350 F/g at low rates and 175 F/g at

higher rates with excellent cyclability in

acidic electrolyte

Activated C from Corn Crops

0.0 0.2 0.4 0.6 0.8 1.0

0

200

400

600

800

1000

Qu

an

tity

Ad

so

rbed

(cm

³/g

ST

P)

Relative Pressure (P/P0)

LAB

GAS

800°C, H3PO4 50% vol, 5°C/min

Ambient conditions

1462m2/g

Gasifier, 1000°C,

800m2/g

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0-6

-4

-2

0

2

4 a)

I (A

g-1)

E (V vs Ag/AgCl)

Lab

Gas

2 n

d c

ycle

2 n

d c

ycle

2 n

d c

ycle

500 t

h c

ycle

500 t

h c

ycle

500 t

h c

ycle

0

20

40

60

80

100

120

140

C (

F g

-1)

Gas

Lab

CH3COONaH

2SO

4

Electrolyte

Lab

20mV/s

0.5M H2SO4130F/g at 20mV/s with

excellent cyclabity

Carbon from gasifier is an

interesting sustainable option

for supercapacitor electrodes

Production of Activated C

21

Proper combination of micro-

mesopores is important for

supercapacitor applications.

Activated C from Leather

Sample PyrolysisBET

(m2/g)

PL700700°C, N2, 90 min, 10°C/min

18

AL700Same as PL700 butactivated with KOH

2330

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0-8

-6

-4

-2

0

2

4

6 a)

I (A

g-1)

E (V vs Ag/AgCl)

PL700

AL700

0 20 40 60 80 1000

50

100

150

200

250

PL700

AL700

AL700

H2SO

4

Na2SO

4

Li2SO

4

CH3COONa

C (

F g

-1)

Scan Rate (mV s-1)

PL700

0

50

100

150

200

250

CH3COONaNa

2SO

4Li

2SO

4H

2SO

4

C (

F g

-1)

Electrolyte

Cycle 2

Cycle 500

0.5M H2SO4

200 F/g in 0.5M H2SO4

Commercial Activated C from Coconut Shell (Norit)

Carbon SBET (m2/g) N2 SDR (m2/g) CO2

Microporosity

Norit C 1609 m2/g 884.6 m2/g

m+/m-Relación Celda AsimétricaRelación Celda simétrica

m+/m- =1 =0.63

+-

asimétrica

asimétrica

simétrica

simétrica

Symmetric and Asymmetric assemblies DLC

1000 Charge/Discharge Cycles

Asymmetric Supercapacitor Cells

0

20

40

60

80

100

0 200 400 600 800 1000

Cuero

CMK

Olote ACC

Olote G2E

Aserrin

Nuez L1

Nuez L2

DLC

Cap

acit

an

cia

( F

/ g

)

Ciclos

0

10

20

30

40

50

60

0 1000 2000 3000 4000 5000

Nuez L1 acetatoCMK acetato

Ca

pa

cit

an

cia

( F

/ g

)

Ciclos

0.5M H2SO4

1M CH3COONa

Ragone Plot

102

103

104

100

101

DLCCueroCMKCMK acetatoOlote ACC

Olote G2EAserrínNuez L1Nuez L2Nuez L1 acetato

Den

sid

ad

de p

ote

ncia

(W

/ k

g)

Densidad de Energía (Wh / kg)

Design of Nanocomposite Materials

introduction of functionalities in carbon to promote an intimate interaction with the inorganic compound for

Capacitance improvement.

E (mV) vs Ag/AgCl

I (m

A)

-0,010

0,0

0,010

0,80,70,60,50,40,30,20,10,0-0,1-0,2-0,3

ENERGY DENSITYRedox POWER DENSITY

Double layer

ACTIVATED CARBONPOMs

WO3-x

+WO3-x

Capacitance improvement

100F/g to 150F/g

and retention with scan

rate

Nanocomposites with Sustainable WO3-x

1000°C, 100%O2

Cristalline phase: Monoclinic

Triclinic

Solar Concentration

Nanocomposite MaterialsAsymmetric Supercapacitor Cells

DLC

DLC1.5WO31000

0.5 A/g

Seems that WO3 is facilitating

charge transfer improving Energy

storage properties

Simulation GROUP working on

Explanation

.

Que Ofrecemos?

Evaluación de aglutinantes en

Capacitores.

Evaluación de Materiales

en Capacitores Asimétricos

Infraestructura: Diversas técnicas de fabricación de electrodos, Caracterización por

fisisorción y HRSEM, DRX, Potenciostato de 6 canales para evaluación de ensambles.

Optimización de la fabricación de

electrodos y ensambles.

StudentsIvan Mascorro (undergraduate)

Carolina Medrano (undergraduate)

Melisa Nava (undergraduate)

Osmar Moreno (undergraduate)

Diego Lobato (Master)

Alejandro Ayala (Master

Nelly Rayón López (PhD)

Diana Martínez Casillas (Posdoc)

Jose Luis Gutierrez (posdoc)

Collaborations • Theory Group: Dr. Jesus Muñiz, Dr. Miguel Robles, Dr. Nestor Espinosa• Applied solar radiation group: Dr. Camilo Arancibia, Dr. Heidi Villafan, Jesús Quiñones• Dra. Margarita Miranda Hernández• Daniella Pacheco Catalán from CICY, Enrique Quiroga BUAP, Ivonne Alonso-Lemus CINVESTAV-

Saltillo, Víctor Sánchez-Ramos UACH.• Starting collaboration with CNyN-UNAM, Mildred Quintana (UASLP), Próspero Acevedo (CICATA-

IPN, Unidad Legaria)

Funded Projects• Group Project PAPIIT IG100257• Lab. Nacional de Conversión y Almacenamiento de Energía• Red Nacional de Almacenamiento de Energía

Thank you for your attention

akcg@ier.unam.mx

We are always looking for New STUDENTS

“Environmentally Friendly Supercapacitors”A.K. Cuentas-Gallegos, M. Miranda-Hernández, D. Pacheco-Catalán.

En “Materials for Sustainable Energy Applications. COnversion, Storage, Transmission and Consumption”

Pan Stanford publishing, 2015, xx-xx. ISBN 978-981-4411-81-3 (Hardcover), 978-981-4411-82-0 (eBook).