Instituto Tecnológico de Tijuana - gob.mx · 2017-11-16 · Instituto Tecnológico de Tijuana *...

Instituto Tecnológico de Tijuana

* Línea de Investigación de Detección y Remoción de

Contaminantes del Medio Ambiente (PCQ)

* Línea de Investigación de Nanotecnología (PCI)

Dr. Moisés Israel Salazar Gasté[email protected]

Cuernavaca, Mor. 14-15 de Noviembre de 2017

• Infinite Resources.

• Variable generation rate.

• Availability depending

upon season, weather,

geographical place, etc.

Renewable EnergyIntroduction

2

Solid state devices for the energy conversion storage:

• Capacitors

• Supercapacitors

• Batteries

• Fuel Cells

Energy Density / W-h kg-1

Po

wer

Den

sit

y /

W k

g-1

Introduction

3

Ragone diagram for energy storage devices

Renewable Energy in Mexico

• In Mexico, the capacity of power generation by renewable energy isaround 25.2% from the overall.

• During 2015, the capacity of power generation by renewable energyincreases 6.6% regarding to 2014.

• Wind Energy+Water Energy=80% of the installed capacity of renewableenergy.

4

• 203037.5%

• 205050.0%Renewable

Energy

• 2016-2030-1.9%

• 2016-2050-2.9%Energetic Intensity

R. Alexandri Rionda, et al. Prospectivas de Energías Renovables 2016-2030 SENER 2016, p. 23.

National context

Renewable Energy in Mexico

• Since solar, water and wind are intermittent sources, supercapacitors are idealdevices in order to storage electrical energy, when there is a surplus, andsupplies the energy when there is a deficit.

• The connection with solar, water and wind depend on the availability of theresources.

5R. Alexandri Rionda, et al. Prospectivas de Energías Renovables 2016-2030 SENER 2016, p. 23.

National context

6

Wind Energy


National context

Installed capacity and raw generation by wind energy in Mexico

7

Solar Energy


National context

Installed capacity and raw generation by solar energy in Mexico

8

Water Energy


National context

Installed capacity and raw generation by water energy in Mexico

Storage Mechanisms

• Double Layer Capacitor • Pseudo-capacitor 9

Theoretical framework

Storage Mechanisms

• Hybrid10

Theoretical framework

11

Super capacitors

Advantages

• Long life cycle

• Fast charging/discharging process

• Higher power density than batteries

• Low cost of production and maintenance

Disadvantages

• Limited energy density

• Lose of stored charge

Materials

• Supports

• Metallic oxides

• Ionic liquids

Electrolytes

• Aqueous

• Organic

• Polymers

Scientific Challenges

Electrochemical techniques

An electrochemical process is measured by an electric perturbation,generating an electrical response, which provides information of thechemical process:

• Imposition of potential constant pulse

• Imposition of current constant pulse

• Variation of the potential/current regarding time

12

Experimental

Cyclic Voltammetry

Cyclic voltammetry

13

Experimental

Typical voltammogram for ideal and real capacitor

Electrochemical Impedance Spectroscopy

Modeling with respect to

electrical circuits

Resistive and capacitive

phenomena in

electrochemical systems

Frequency scanning

14

Experimental

Experimental set up for EIS

Properties of carbon allotropes

FullerenesCarbon

Nanotubes

Activated

carbonGraphite Graphene

Specific Surface area

(m2 g-1)5 1315 1200 ≈ 10 2630

Intrinsic mobility

(cm2 V-1 s-1)0.56 ≈ 100,000 - 13,000

≈ 15,000

(SiO2)

≈ 200,000

(free)

Thermal conductivity

(W K-1 m-1)0.4

> 3000

(MWCNT)0.15-0.5 ≈ 3000 ≈ 5000

Young’s modulus (TPa) 0.01 0.64 0.318 1.06 ≈ 1.0

Properties

Material

15

Materials investigation

TGA Raman XRD CV y PEIS

16


+850 oC, 30 min

Ar

H2SO4 / HNO3

1 M / 3 M

Flux meter

Argon

Manometer

Nebulizer

Quartz tube

Tubular Furnace

Aguilar-Elguézabal, A.; Antúnez, W.; Alonso, G.; Delgado, F.P.; Espinosa, F.; Miki-Yoshida, M. Diam. Relat. Mater 2006, 15, 1329-1335.

Synthesis of the Carbon Nanotubes(CNT)

17


Experimental set up of spray pyrolysis method

Synthesis of the Graphene Oxide(GOx)

Graphite

NaNO3

H2SO4

KMnO4

0

1

DI H2O

0

2

H2O2

0

3

0

42 h 15 min 2 h Wash

Wang, D.; Yan, W.; Vijapur, S. H.; Botte, G. G. Electrochim. Acta 2013, 89, 732-736.

DI H2O

18


Experimental set up of Hummers modified method

Synthesis of the Graphene Oxide(GOx)

19

Graphite

GOx


Experimental set up of Hummers modified method

M. Beltrán Gastélum, “Síntesis y caracterización de electrocatalizadores nanoestructurados y su aplicación en celdas de combustible a

escala prototipo,” Instituto Tecnológico de Tijuana, 2016.

Reflux

10 min

Filter

Wash

Dry

Reflux

90 min

Reflux

20 min

Reductors

solutionCo, Fe or Ni

Microemulsion Solution

Metallic Nanoparticles deposition

20


Experimental set up for reverse microemulsion

Scanning Electron Microscopy (SEM)

SEM Micrographs of the synthesized CNT

21


Thermogravimetric Analysis (TGA)

Thermogram of CNT, Ni/CNT and Co/CNT. Thermogram of GOx, Ni/GOx and Co/GOx.

22


Temperature / °C Temperature / °C

Weig

ht / %

Weig

ht / %

GOx

Ni/GOx

Co/GOx

CNT

Ni/CNT

Co/CNT

Raman Spectroscopy

Raman spectra of CNT, Co/CNT and Ni/CNT Raman spectra of GOx, Co/Gox and Ni/GOx

Material ID/IG

CNT 0.50

Co/CNT 0.74

Fe/CNT 0.77

Ni/CNT 0.80

GOx 1.00

Co/GOx 1.21

Fe/GOx 1.21

Ni/GOx 1.19

23

Materials investigationR

am

an

Inte

nsity /

a. u.

Ram

an Inte

nsity /

a. u.

Raman Shift / cm-1Raman Shift / cm-1

X-ray Difraction (XRD)

Su, Y.; et. al. Cobalt Nanoparticles Embedded in N-Doped Carbon as an Efficient Bifunctional Electrocatalyst for Oxygen Reduction and

Evolution Reactions. Nanoscale 2014, 6 (24), 15080–15089.

Diffractogram of the materials XRD Pattern of Metallic Co , CoO y Co3O4

24


Inte

nsity /

a.

u.

Cyclic voltammetry

Cyclic voltammograms of GOx and CNT in H2SO4 1 M at scan rate of 200 mV s-1

GOx 0.67 mC

CNT 0.49 mC

25


Cyclic voltammograms of CNT, Co/CNT and Ni/CNT in H2SO4 1 M at scan rate of 200 mV s-1

26


CNT

Co/CNT

Fe/CNT

Cyclic voltammograms of Co/CNT in H2SO4 1 M at different scan rate potential

27


Cyclic voltammetry

Cyclic voltammograms of Co/CNT in H2SO4 1 M and KOH 6 M with scan rate at 200 mV s-1

Basic media 0.68 mC

Acidic media 0.40 mC

28


Basic Media

Acidic Media

Specific capacitance

Specific capacitance vs. scan rate for different materials

in H2SO4 1 M

𝐶𝑠𝑝 =𝑄𝑡

2 ∗ 𝑚 ∗ 𝑉𝑝 ∗ 𝑉𝑏

• Csp= Specific Capacitance

• Qt=Integrated electric charge

• m= catalyst loading

• Vp= Potential range

• Vb= Scan rate potential

29


Scan rate potential (mV/s)

Material R1/Ω C2/F R2/Ω S2/Ωs-1/2 Χ2

Co/GOx 25.18 2.18E-05 73.52 471.6 0.9335

Co/CNT 5.282 3.28E-04 5.36E-05 11285 5.27

GOx 7.396 6.76E-04 1.33E-05 6823 8.26

CNT 4.707 4.54E-04 1.81E-04 9884 3.26

30


Nyquist diagrams for CNT, Co/CNT, GOx and Co/GOx.

Resistive and Capacitive phenomena

• The deposition of Co NPs by the microemulsion method allows the

deposition of 18 wt% of metal loading on GOx, while the deposition of metal

loading is 12 wt% on CNT.

• ID/IG ratio increases when Co is anchored to CNT or GOx, which is related to

the heterogeneous nature of the materials

• Supports were identified by XRD analysis, Co, CoO and Co3O4 nanoparticles

were not detected by XRD, since signal/noise ratio is too low.

• GOx support exhibited higher integrated electric charge than CNT, which

implies a larger double layer capacitance.

Summary

31


• The increases of the specific capacitance was detectable in both supports

(GOx and CNT) when Co nanoparticles were anchored to the support, which

is attributed to pseudocapacitive effect.

• Basic media exhibited higher integrated electric charge than acidic media.

• Co/GOx showed the best performance, since exhibited the highest specific

capacitance.

32


Summary

20µm

5 0 n m

20µm

50

n

m

50 nm

50 nm 20µm

5 0 n m

50 nm

20µm

2 0 0 n m

200 nm

20µm2 0 0 n m

200 nm 20µm2 0 0 n m

200 nm

a)

f)

e)

d)

b) c)

Metal free SC catalystsN-doped-CNT

SEM and TEM images: d) CNT-N-800, e) CNT-N-850, and e) CNT-N-900

33

Metal free electrodes

Cyclic voltammograms of N-doped-CNT in H2SO4 1 M with scan rate at 200 mV s-1 and Csp

vs. scan rate potential for different temperatures

N-doped-CNT in acidic media

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

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

I / m

A

E / V vs. Ag/AgClsat

800

850

9000

5

10

15

20

25

30

0 50 100 150 200

Csp

/ F

g-1

Scan rate / mV s-1

MWCNT-N-doped 800

MWCNT-N-doped 850

MWCNT-N-doped 900

34


-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

-1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4

I / m

A

E / V vs. Ag/AgClsat

800

850

900

N-doped-CNT in basic media

0

5

10

15

20

25

30

35

40

45

50

0 50 100 150 200

Csp

/ F

g-1

Scan rate / mV s-1

MWCNT-N-doped 800

MWCNT-N-doped 850

MWCNT-N-doped 900

Cyclic voltammograms of N-doped-CNT in KOH 6 M with scan rate at 200 mV s-1 and Csp vs.

scan rate potential for different temperatures35


415 410 405 400 395 390

N1s

Inte

nsi

ty (

a.

u.)

Binding Energy (eV)

CNT-N-900

CNT-N-850

CNT-N-800

292 290 288 286 284 282 280 278

C1s

Inte

nsi

ty (

a.

u.)

Binding Energy (eV)

CNT-N-900

CNT-N-850

CNT-N-800

X-ray Photoelectron Spectroscopy (XPS)

36

XPS spectra of the different N-doped-CNT for C and N.


• N-doped-CNT showed higher specific capacitance than CNT.

• N-doped-CNT were synthesized varying furnace temperature, in order to

detect structural and electrochemical differences.

• N-doped-CNT synthesized at 850 °C showed the best performance for both

acidic and basic media.

• All N-doped-CNT exhibited a slightly better performance in basic than acidic.

• N-doped-CNT synthesized at 850 °C exhibited a higher N concentration,

accordingly to XPS analysis.

Summary

37


38

Graphene oxide:

Light material, excellent mechanical stability, and high surface area

Imidazolium ionic liquid:

High ionic conductivity, high decomposition temperature, and wide range

operating potentials.

Why imidazolium-functionalized graphene oxide (IFGO)?

Synergistic effects

Ionic Liquid–Functionalized Graphene

Oxide as Electrode for SCs

Ionic liquid functionalization

39

Preparation of Imidazolium-functionalized

GOx


Experimental set up for IFGOx.

Movil, O.; Schadek, C.; Staser, J. J. Electroanal. Chem. 2015, 755, 127-135.

40


Wave Number

Vibration

1050 C-O (expoxy)

1650 C=C

1750 (C=O)-OH carbonyl of

carboxyl

Wave

Number Vibration

1160 &754 Imidazolium cations

1470 C=N

2850 & 2920 CH2

Fourier Transformed Infrared Spectroscopy (FTIR)

FTIR spectra of GOx and IFGOx.


41

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Sp

ecif

ic C

urren

t (A

/g)

Working Electrode Potential (V vs. Hg/HgO)

IFGO

GO

-2.0E-04

-1.5E-04

-1.0E-04

-5.0E-05

0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

2.5E-04

3.0E-04

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70

Cu

rren

t D

en

sit

y (

A/c

m2)

Working Electrode Potential (V vs. Hg/HgO)

Pt disk

IFGO

GOx Vs IFGO IFGOx Vs Pt disk


GOx and IFGOx Voltammetry

Cyclic voltammetry in H2SO4 1 M at 200 mV s-1 for GOx, Ptdisc and IFGOx


42

GOx IFGOx

Asymmetry due to resistive

effects with some influences

from pseudocapacitance

Very limited pseudocapacitive

behavior

Clearly define

pseudocapacitive behavior

Quasireversibility of

the charge transfer

process


Gox and IFGOx Voltammetry

Cyclic voltammetry in H2SO4 1 M at different scan rate potential for GOx (Left),

IFGOx (Center) and Csp vs scan rate potential for Gox and IFGOx (Right).


43

Charge/Discharge Curves

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Work

ing E

lect

rod

e P

ote

nti

al

(V v

s. H

g/H

gO

)

Time (s)

IFGOunmodified GO


Charge/Discharge test for GOx and IFGOx.


44

• GO was successfully functionalized with imidazolium functional groups via

chemical approach.

• IFGO exhibited higher capacitance than GOx regardless of the scan rate

used.

• The higher specific capacitance observed in IFGOx is a result of the

contributions of both, the DL capacitance and faradic charge transfer

processes.


Summary


Instituto Tecnológico de Tijuana - gob.mx · 2017-11-16 · Instituto Tecnológico de Tijuana *...

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Transcript of Instituto Tecnológico de Tijuana - gob.mx · 2017-11-16 · Instituto Tecnológico de Tijuana *...