Andrea Lamberti

22 September 2015

Wire-shaped supercapacitor by hydrothermal self-assembly of graphene

on copper wires

Outline

Introduction Supercapacitors Wearable SCs

Graphene Aerogels Synthesis Characterizations

Wire-shaped Supercapacitors Device assembly Characteriztion Electrochemical performance

Conclusions

Outline

Introduction Supercapacitors Wearable SCs

Graphene Aerogels Synthesis Characterizations

Wire-shaped Supercapacitors Device assembly Characteriztion Electrochemical performance

Conclusions

Electrical double layer capacitance (EDLC) electrostatic energy storage by separating charges at the interface between the surface of a conductive electrode and an electrolyte without faradaic reactions

Pseudo-capacitance faradaic electrochemical energy storage by fast reversible surface redox reactions, intercalation or electrosorption at or near the surface of some electrode materials

Electrochemical supercapacitors

-1 0 1

-0,0021

-0,0014

-0,0007

0,0000

0,0007

0,0014

0,0021

Cu

rre

nt (A

)

Voltage (V)

10 mV/s

50 mV/s

100 mV/s

Ragone chart EDL SCs high power density excellent cycling stability low energy density due to a limited specific capacitance of carbon materials

Pseudocapacitive materials (transition metal oxides or hydroxides) much higher specific capacitance, as much as ten times that of an EDLC. poor rate capability and low electrical conductivity

Common approach to improve the SC performance is to use composites of

pseudocapacitive materials and carbon as electrodes

General characteristics

Conventional SCs have 2D planar architectures with two metal plates as current collectors, two “flat” electrodes, one membrane

charge separator, and electrolyte sandwiched together.

small-sized flexible energy storage units for low power electronics and sensors

Wearable electronics and smart textile

microsupercaps

fiber-based supercaps

Development of hybrid devices with integrated energy harvesting and storage

μbial fuel cell-SC hybrid device

solar harvester-SC hybrid device

mechanical harvester-SC hybrid device

Our goals/target applications

SCs configurations

To date a fully developed textile energy storage device does not exist, nor does a

streamlined manufacturing process integrating the various components.

Wearable energy storage applications: provide power to medical biomonitoring devices or

implants, military equipment for soldiers in combat, safety and construction gear like illuminated

vests, …

Notable examples of wearable technology : Adidas MiCoach, Cutecircuit Galaxy Dress and

T-shirtOS, “Hi-call” Bluetooth enabled phone-glove, all are powered with conventional batteries

and capacitors.

Wearable electronics or e-Textile

Design concept for a smart power bodysuit. (a) Piezoelectric patch converts body

movements to electrical energy; (b) textile antennas to transmit communications; (c)

textile electrochemical energy storage to store energy from harvesting devices; (d) integrated

conductive yarns act as leads to transmit energy or information throughout the garment.

Energy Environ. Sci., 2013, 6, 2698–2705

Smart power bodysuit

Low costand flexible mesh-based supercapacitors for promising large-area flexible/wearable energy storage . Nano Energy(2014) 6, 82–91 An all-cotton-derived, arbitrarily foldable, high-

rate, electrochemical supercapacitor Phys.Chem. Chem. Phys., 2013, 15, 8042

Wearable supercapacitors

A coaxial single fibre supercapacitor for energy Storage. Phys.Chem. Chem. Phys., 2013, 15, 12215

Electrolyte: PVA–H3PO4–H2O gel solution; this layer serves as both the ion transport layer and separator between two electrodes

Wire-shaped supercapacitors

All-Graphene Core-Sheath Microfi bers for All-Solid-State, Stretchable Fibriform Supercapacitors and Wearable Electronic Textiles. Adv. Mater. 2013, 25, 2326–2331

Wire-shaped supercapacitors

Outline

Introduction Supercapacitors Wearable SCs

Graphene Aerogels Synthesis Characterizations

Wire-shaped Supercapacitors Device assembly Characteriztion Electrochemical performance

Conclusions

Requirements

high electrical conductivity

controlled porosity

high exposed area

Reduced graphene oxide aerogel

Process flow

Carbon based scaffolds

200°C 12 h R. Giardi et al.

2015 - Applied Materials Today

In press

Typically SSA for ELDCs: > 1000 m²/g Theoretical value for graphene: ~ 2620 m²/g

XPS good results in GO reduction

Carbon based scaffolds

R. Giardi et al. 2015 - Applied

Materials Today In press

Planar device as test bench

Dispersion of active material and 2.8 wt% of PVDF in NMP 13:1 ratio Slurry A: Graphite + Acetylene black + PVDF 13:1:1 ratio Slurry B: 50% rGO + 50% Graphite + Acetylene black + PVDF 13:1:1 ratio Platinum sputtered on top of glass slides Current collectors

Graphite/PVDF Graphene/PVDF

-1 0 1

-0,0021

-0,0014

-0,0007

0,0000

0,0007

0,0014

0,0021

Cu

rre

nt (A

)

Voltage (V)

10 mV/s

50 mV/s

100 mV/s

-1 0 1

-0,003

-0,002

-0,001

0,000

0,001

0,002

0,003

Cu

rre

nt (A

)

Voltage (V)

10 mV/s

50 mV/s

100 mV/s

R. Giardi 2015 - Applied

Materials Today In press

Outline

Introduction Supercapacitors Wearable SCs

Graphene Aerogels Synthesis Characterizations

Wire-shaped Supercapacitors Device assembly Characteriztion Electrochemical performance

Conclusions

Cu wire

RGO@Cu wire Pro

cess

flo

w

Graphene aerogel self-assembly

200°C 12 h

A.Lamberti et al. Submitted to ADV. ENER.

MATER.

Material characterizations

A.Lamberti et al. - Submitted to ADV. ENER. MATER.

G

D

Polyvinylpyrrolidone (PVP) gel was prepared by dissolving 10g PVP in 10 ml H2O at 90°C PVP gel electrolyte was prepared by dissolving 1g NaI in 20g PVP gel water at 90°C.

Device assembly

A.Lamberti et al. - Submitted to ADV. ENER. MATER.

Electrochemical characterizations

A.Lamberti et al. - Submitted to ADV. ENER. MATER.

Electrochemical characterizations

Yu, Dingshan, et al. "Emergence of fiber supercapacitors." Chemical Society Reviews 44.3 (2015): 647-662.

62 F/g

Electrochemical characterizations

Yu, Dingshan, et al. "Emergence of fiber supercapacitors." Chemical Society Reviews 44.3 (2015): 647-662.

13 mF/cm

Outline

Introduction Supercapacitors Wearable SCs

Graphene Aerogels Synthesis Characterizations

Wire-shaped Supercapacitors Device assembly Characteriztion Electrochemical performance

Conclusions

Conclusions

Development of a graphene aerogel self-assembly process on

copper wires

Deep characterization by chemico-phisical point on view

Good performance of assembled and integrated devices (bending)

Test different current collectors

Test different electrolytes

Pseudosupercapacitors exploiting Metal-Oxides or Graphene

composites

Packaging

Self-powered devices (energy harvesting & storage)

Future developments

Energy harvesting & storage P

ho

tovo

ltai

cs: D

ye-

sen

siti

zed

so

lar

cells

LOAD

1 DSC

2 DSCs

Energy harvesting & storage

Mechanical harvester: piezo-nanogenerator

S. Stassi et al 2015 - Submitted to NANOENERGY

Acknoledgements

FILGREEN – national project

Prof. E. Tresso Prof. F. Pirri

Dr. S. Bianco

Dr. R. Giardi

Dott. A. Gigot

Dr. P. Rivolo

Dr. M. Castellino

Dr. D. Mombello

Dr. S.Marasso

Dr. M. Cocuzza

Dr. M. Fontana

Dr. M. Serrapede

Thank you for

your kind attention!

Questions?

960 956 952 948 944 940 936 932 928 924

a)

Cu2+

Cu2+

Cu+

Cu2+

satellite

Cu2p1/2

Inte

ns

ity

(a

rb. u

n.)

Binding energy (eV)

before sputtering

after sputtering

Cu2p3/2

Cu+

585 580 575 570 565 560 555 550

b) before sputtering

after sputtering

Inte

ns

ity

(a

rb. u

n.)

Binding energy (eV)

Cu LMM Auger peaks

FIB & XPS characterizations

Bare cross-section

without FIB

A.Lamberti et al. - Submitted to ADV. ENER. MATER.

Other metal wires

A.Lamberti et al. - Submitted to ADV. ENER. MATER.

Optimizations

Cover Cu with Graphene monolayer by CVD

Exploit different current collector carbon fibers

Reference With G CVD

Alternative textile electrolyte

SU8 lithography (200 μm) Graphene-based (or carbon-based) paste

deposited by doctor blade

Liquid electrolyte (1M Na2SO4)+ microfluidic cap

-0,10 -0,05 0,00 0,05 0,10

-0,003

-0,002

-0,001

0,000

0,001

0,002

Cu

rre

nt

/ A

Voltage / V

Grafene "in-situ"

Microsupercapacitors

Graphite/PVDF Graphene/PVDF

Graphene/MoO2/PVDF

-1 0 1

-0,0021

-0,0014

-0,0007

0,0000

0,0007

0,0014

0,0021

Cu

rre

nt (A

)

Voltage (V)

10 mV/s

50 mV/s

100 mV/s

-1 0 1

-0,003

-0,002

-0,001

0,000

0,001

0,002

0,003

Cu

rre

nt (A

)

Voltage (V)

10 mV/s

50 mV/s

100 mV/s

0,00 0,05 0,10

0

100

200

300

Sp

ecific

Ca

pa

cita

nce

(F

/g)

Scan Rate (V/s)

Graphite/without PVDF_NaCl

Graphite/PVDF_15/1_NaCl

Graphene/PVDF_15/1_NaCl

Graphene+MoO2/PVDF_15/1_NaCl

Graphene+MoS2/PVDF_15/1_NaCl

-1 0 1

-0,006

-0,004

-0,002

0,000

0,002

0,004

0,006

Cu

rre

nt (A

)

Voltage (V)

0.5 mV/s

10 mV/s

50 mV/s

100 mV/s

Planar device as test bench

Pseudo SCs – CuxO nanostructures

Poster n° 185 ANM-Posters 20 July (16.00-18.00hrs) A. Lamberti et al. Flexible copper oxide-based supercapacitor by thermal oxidation of copper foils

Pseudo SCs – TiO2 Nanotubes

In situ synthesis of MoO2 nanoparticles

from a liquid precursor

Decoration with MoO2 NPs

Packaging: stereolithography

Asymmetric carbon nanotube–MnO2 two-ply yarn supercapacitors for wearable Electronics, Nanotechnology 25 (2014) 135401 (8pp)

Industrial integration