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
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
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
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).