Graphene based electrodes for high performance supercapacitorseuronanoforum2015.eu/wp-content/uploads/2015/06/Bondavalli-Paolo.pdf · Graphene based electrodes for high performance

HORIZON 2020 EUROPEAN UNION FUNDING FOR RESEARCH & INNOVATION

Graphene based electrodes for high performance supercapacitors

Paolo Bondavalli, Head of nanomaterial topicUMR 137 Thales/CNRS Joint team, Physics GroupThales Research and Technology

Outline

Thales group presentationWhat’s a supercapacitors? Visible applications of supercapacitorsWhy to use nanomaterials?Supercapacitors based on Graphene related materialsConclusion and perspectivesFunding

Outline

Thales group presentationWhat’s a supercapacitors? Visible applications of supercapacitorsWhy to use nanomaterials?Supercapacitors based on Graphene related materialsConclusion and perspectivesFunding

Research & Technology

The Thales Group

A technology leader providing safety and security• A global company with 68,000 employees

and €13.1 billion in revenues

– We help our customers to:

• Provide reliable and secure solutions

• Monitor and control

• Protect and defend

– In two major sectors

Thales: a reliable, long-term partner

with operations in 50 countries

Defence and Security

60%

Aerospace and Transport

40%

Key figures

2010 revenues 13.1 billion euros

2010 order intake 13.1 billion euros

Order book at 31 /12/ 201025.4 billion euros(approx. 2 years of revenues)

Research and development2.5 billion euros(approx. 20% of revenues)

Employees 68,000

Shareholders

French State27%

Dassault Aviation 26%

Float47%

of which employees: 3%of which Thales: 1.9%

A global player

Global reach, local expertise68,000 employees in

50 countries

THALES RESEARCH & TECHNOLOGY

THALES RESEARCH &TECHNOLOGYFrance (Palaiseau)

How innovation is pushed in Thales group

TRT INNOVATION PLATFORMSWork on concrete cases of technology implementation

in the products of the group.

DIVISIONS

TRT

TRT INDUSTRIAL JOINT LABSThose common labs have common personnel,

common equipment and shared research agenda

ACADEMICS JOINT LABSThose common labs have common personnel,

common equipment and shared research agenda

INDUSTRIALSALCATEL

ACADEMICSCNRS-Ecole

Polytechnique…

THE JOINT LABS

Mission– THALES Research & Technologies is a portal for emerging technologies into THALES Group

– Open organisation, co-located close to or within some of the best research campus in our fields, according to the Group worldwide map of locations

• France (Palaiseau) : 350 p + 70 PhD + 80 CNRS-Universities

– Ecole Polytechnique – Plateau de Saclay

• UK (Reading) : 130 p

– University of Surrey

• Netherlands (Delft) : 15 p

– Technological University of Delft - University of Twente

• Singapore : 15 p

– Nanyang Technical University

Corporate Communications February 2011

Thales R&TPalaiseau

Thales R&TReading

Ecole Polytechnique

Institut d’Optique

ONERA

Thales R&TDelft

Thales R&TSingapore

+CINTRA

Physics Dept.

– Nanomagnetism and spintronics

– HighTc superconductors for filters sensors and oscillators

– Carbon Nanotubes for electron tubes (RF and Xrays) and sensors

– Optoelectronic processing of microwave signals

– Optoelectronic oscillators

– Laser Sources (high power, fiber based, OPOs, for RF applications,..)

– Lidars & Active Imaging

– Quantum computing

– Photonic crystal based structures

– Fiber based sensors, lasers and processing archtectures

– THz techniques

Outline

Thales group presentationWhat’s a supercapacitors? Visible applications of supercapacitorsWhy to use nanomaterials?Supercapacitors based on Graphene related materials Conclusion and perspectivesFunding

C=(ε/δ)AE=(1/2)CV²P=V²/(4R)

Helmotz’s model

What’s a supercapacitor?

separator

Two electrodes

Technically is defined Electrical Double Layer Capa citor (EDLC)

Supercapacitor is the name done by NEC in 1971

δ

Battery-like devices

Advantages Very high rates of charge and dischargeHigher life cycle (>500000, rechargeable batteries can attain 10000)Good reversibilityLow toxicity of material usedHigh cycle efficiencyLow internal resistance (Higher output power)Extremely low heating levels

DrawbacksLow amount of energy stored (3-5 Wh/Kg vs 30-40 Wh/ Kg for batteries)It requires sophisticated control and switching equ ipment(from batteries to supercaps)

Outline


Some visible supercap applications

.

Aerial lift

Nuremberg Shangai

London

Emergency issues

Emergency issues

Wind Turbine pitch control

Forklift Truck

Outline


Activated carbon

Activated Carbon• Large surfaces (3000m²/g)• Low-cost material

Main parameters• Surface (energy)• High breakdown voltage (energy)• Pore size (to exploit surface completely and to promote easy ion diffusion)

The main issue :• Very bad mesoporous distribution!!!2/3 of the pore size are smaller than 2 nm and so are unpercolated)

Outline


Electrode material

� CNT/graphene/graphite composite

2. Experimental section


22

U. Khan, J. N. Coleman et al Carbon (2010)

Can we improve the Power output (P∝∝∝∝ 1/R)?

Why to use Graphite/Graphite/CNTs mixings?

Resistance is reduced by a factor of 4 compared tobare CNTs layers

75% the conductivity is optimized

2. Experimental sectionWhy to use Graphite/Graphite/CNTs mixings?

Pristine graphene/graphite

Graphene/graphite/CNTsmixing

• CNTs prevent restacking (higher surface, higher energy stored)• CNTs/graphite/graphene improve conduction (higher power delivered)• CNTs prevent the disintegration of the composite

reduced charge diffusion

and surface


Graphite flakes

OUR APPROACH

CNTs

Separated weighing

Separated dispersion (solvent = NMP )

Dilution to get Csolide = 0,5g/l

25


Initial sonication- CNT : 10’ high power- Graphite : 18h low power

Centrifugation 10 minutes x2

OUR APPROACH

Final sonication of the mixture : 18h low power

OUR APPROACH

Deposition method

� Excellent reproducibility

� Versatile, easily scalable for large-area applications

� Extremely uniform deposition with no “coffee-ring” effect

Introduction

27

z

y

x

Noozle

Heating plate3-axes displacement

Dynamic spray-gun deposition method

Process patented

Air-brush deposition

� Gun spraying

� Masking

� Several samples fabricated at the same time


28


Supercapacitor CellFlexible electrodes

Electrode design and cell fabrication

2cm²

Electrode design

Panasonic Graphite bucky paper


29

2. Experimental sectionSample Morphology (cross section)

Graphite/graphene

Excellent intercalation of graphite/graphene layers

A - Influence of the CNT concentration (Electrodes)

� Energy max. ~4,5Wh/kg for 75wt%CNT

� Power max. ~35 kW/kg for 25wt%CNT (enhancement of 2,5)

3. Results

30Results : Energy and Power as a function of the concentration

25% 75%

Sample characteristics : • weight = 1.8mg• surface = 2cm² (circular design)• thickness ~ 20µm

Last measurements : new option for green suspension s

Advantages• Aqueous based supensions• Very stable suspensions• Low temperature process (120°C)

Mixing of Graphene Oxyde and Oxydised Carbon Nanotu bes in water

GO dispersion CNTox dispersion

Blending of the suspensionsUltrasonication

CNT oxidation

Depot/coating on collectorSpray

Surface expansion Thermal treatment

HNO3H2SO4

CNTs

bundlesSWCNTs

HO

O

HOOC

HO

OH

O

HOOC

COOHCOOH COOH

COOH

COOH

Aqueous dispersion

Nanostructuredmaterials

Mixed dispersion pre-assembly

Hybrid hierarchical architectureHigh electrolyte-accessible area

Aqueous dispersion

Stacking graphene structureLow electrolyte-accessible area

Electrodes preparation

Bought

Oxidised CNTs can be put into water based suspensio ns very easily

Non-oxidised CNTsOxidized CNTs

New packaged prototypes

GO

GO 50% CNT 50%CNT 100%

Previous results

Patent submitted

C (F/g)

mV/s

Strong enhancement of the capacitance For spray gan based samples compared to Bucky paper

Performances for different GO concentrations

E vs Ag/AgC (V)0,50-0,5

I (A

/g)

3

2

1

0

-1

-2

-3

-4

spray 60/40 GO/CNToxspray 70/30 GO/CNToxspray 80/20 GO/CNToxspray 90/10 GO/CNTox

Three-electrodes configuration

Aqueous electrolyte : LiNO 3 3M

Windows of potentiel : 1,6 V

C = 88 F/gC = 109 F/g

C = 106 F/g

C = 117 F/g

C = 112 F/g

spray 100% GO

At 20 mV/s :

Power density

Re(Z)/Ohm5000

-Im

(Z)/

Ohm

450

400

350

300

250

200

150

100

50

0

Re(Z)/Ohm151050

-Im

(Z)/

Oh

m

6

5

4

3

2

1

0

GO/SWCNT 80/20GO/SWCNT 70/30GO 100%G3-IIT/SWCNT

Power density :

100 % GO : 14 kW/kg90/10 : 31 kW/kg80/20 : 29 kW/kg70/30 : 21 kW/kg

To be improved :

- on large surface electrode- by changing the current collector- on large scale- by optimizing the interface electrode material/current collectorand electrode material/electrolyte- By changing electrolyte

Graphene from IIT / SWCNT

0

20

40

60

80

100

120

140

0 100 200 300 400 500 600

Spray graphene exfolié 50/50 et CNT dans NMP

Spray GO pur 170 °C

Spray GO pur 200 °C

Spray GO/SWCNT (75/25) 200 °C



Spray SWCNT pur 200 °C

C (

F/g

)

Scan rate (mV/s)

Spray graphene IIT and CNT 50/50 in NMP

Electrochemical performances

Graphene 50%

GO 50%

GO 50% SWCNT 50% and Graphene 50% SWCNT 50% show similar capacitance

GO 75% SWCNT 25%

E (V)1,210,80,60,40,20

0,5

0,4

0,3

0,2

0,1

0

-0,1

-0,2

-0,3

-0,4

-0,5

-0,6

I (A

/g)

initial1000 cycles2000 cycles3000 cycles4000 cycles5000 cycles

-1 0 1 2 3 4 5 6 7

0,0

0,2

0,4

0,6

0,8

1,0

1,2

E (

V)

time (s)

initial after 1000 cycles after 2000 cycles after 3000 cycles after 4000 cycles after 5000 cycles

Galvanostatic charge/discharge experiment

two-electrodes configuration

�� complete system

m = 1,15 mg (x2)

5000 cycles

I= 10mA

Graphene exfoliated by IIT :

- Loss essentially during the 1000 first cycles

-P= 92,3 kW/kg

Electrochemical performances

P=V²/(4RESR2m)

P∝∝∝∝ 1/RESR

0,0 0,5 1,0 1,5 2,0 2,5 3,00

20

40

60

80

100

120

140

160

180

200

220S

peci

fic P

ower

(kW

/Kg)

Weight (mg)

200kW/kg0.25mg (~6Wh/Kg)

60kW/kg

42kW/kg20kW/kg

Graphene exfoliated by IIT :

P= 92,3 kW/kg (It was 16kW/Kg)

Before : (with the mixture Graphene platelets-Graphi te-/CNT)�� High Power density only with very thin layer of act ive material

Now : (with the IIT graphene/CNT)�� High power density, even with such a mass of active material

Factor 5

Outline

Thales group presentationWhat’s a supercapacitors? Visible applications of supercapacitorsWhy to use nanomaterials?Supercapacitors based on Graphene related materials Conclusions and perspectivesFunding

� New patent on supercaps based electrodes using mixtures of GO andOxidized CNT. Green solution and reduction of process time and of energy(reduced temperature of the process ~120°C, for NMP it was 250°C)

� Improvement of the capacitance using a CNT oxidized/GO composite

� Graphene shows a massive increase in power

� Graphene and Graphene oxide shows similar performances in case ofcapacitance (120F/g) a sample at 90% of GO showed a 100F/g capacitancefor a whole cell (work in progress)

� Very good capacitance with easily implementable fabrication technique

44

Conclusion

Conclusions and perspectives

Perspectives

� To scale up fabrication �

� To transfer the process (Thales Research and Technology is a technology provider)

� To increase the voltage windows by using other kind of electrolytes : organic, ionic liquids…

Supercapacitor electrode based on mixtures of graphite and carbonnanotubes deposited using a new dynamic air-brush deposition technique, PBondavalli, C.Delfaure, P.Legagneux, D.Pribat JECS 160 (4 ) A1-A6, 2013

Non-faradic carbon nanotubes based supercapacitors : state of the art, P.Bondavalli, D.Pribat, C.Delfaure, P.Legagneux, L. Baraton, L.Gorintin, J-P. Schnell, Eur. Phys. J. Appl. Phys. 60,10401, 2012

[email protected]

Outline

Thales group presentationWhat’s a supercapacitors? Visible applications of supercapacitorsWhy to use nanomaterials?Supercapacitors based on Graphene related materialsConclusion and perspectivesFundings

Funding S

Thanks to

In the frame of the Graphene Flagship• Francesco Bonaccorso of IIT for exfoliated Graphene• Graphenea for GO in water

My colleague• Gregory Pognon (Chemistry Lab) Electrochemical characterizationand nanomaterial functionalisation

Thank you for your attention!!!

Graphene based electrodes for high performance supercapacitorseuronanoforum2015.eu/wp-content/uploads/2015/06/Bondavalli-Paolo.pdf · Graphene based electrodes for high performance

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