ORGANIC ELECTRODE MATERIALS AND THEIR APPLICATIONS IN ... · ORGANIC ELECTRODE MATERIALS AND THEIR...

ORGANIC ELECTRODE MATERIALS AND

THEIR APPLICATIONS IN RECHARGEABLE

BATTERIES

Burak Esat1, Sümeyye Bahçeci1, Sevda Akay1, Muhammed Aydın2, Anton Momchilov3

1Fatih University Department of Chemistry, Istanbul/Turkey

2Gebze Institute of Technology, Gebze Kocaeli/Turkey

3 2Bulgarian Academy of Sciences

COST-EXIL

October 2015 in

Belek

Assoc. Prof. Burak ESAT

Fatih University, Department Of Chemistry

Istanbul-Turkey

besat@fatih.edu.tr

Outline

Introduction

Early History-Conducting Polymers(CP)

Redox Polymers (RP)

Organo-sulphur Compounds

Carbonyl Compounds

Nitroxides

Others

Our Results

Nitroxide Based RPs as Cathodes

Anthraquinone (AQ) Based RPs

AQ- Functionalized Reduced Graphene Oxide (RGO)

Conclusions

Acknowledgements

History of Organic Batteries Based on

Organic Polymers as Electrodes

Synthesis and use of organic conjugated polymers as electrode materials started after the pioneering work of McDiarmid, Heeger and Shirakawa in mid-1970s

A. Moliton et al. ,Polym. Int. 53:1397–1412 (2004)

Conjugated Polymers Cont’d

Alan J. Heeger: Semiconducting and metallic polymers, Nobel Lecture 2000

Disadvantages:

- Low charge capacity of

battery due to low doping

levels attainable

- Low battery stability &

cycle-life

Redox Polymers

Redox Polymers are the polymers with non-conjugated backbones which have electro-active groups incorporated into their structures either as pendant groups or as a part of their backbone.

Advantages:

-Light-weight

-Flexible

-Moldable into different shapes &sizes

-Low T manufacturing

-High theoretical charge capacity

-High rate capability possible

-Good cycle performance possible

-Environmentally benign

Redox Polymers

Sulfur Based Materials

Carbonyl Based Materials

Organic Radical Based Materials-

Organic Radical Batteries Organic Radical Polymers (ORP) are polymers bearing stable

organic radicals as pendant groups.

An Organic Radical Battery (ORB) can be defined as a battery that

utilizes a polymeric material (pure or composite) with pendant redox

active organic radical in at least one of its electrodes.

Hiroyuki Nishide and Kenichi Oyaizu , Science 2008:

Vol. 319 no. 5864 pp. 737-738 DOI: 10.1126/science.1151831

ORB

Oyaizu K., Nishide H., Adv. Mater. 2009,21,2339

R- e

+ eRR

- e

+ e

p-type doping

n-type doping

A Totally Organic Radical Battery

Redox Activity of

Organic Radicals

Nitroxide Type Radicals

Suga T., Nishide H., Interface. Winter 2005, 32.

P- Type Organic Radical Polymers

Polyacrylate Polystyrene

Polyether Polynorbornene Polyisocyanate

Theoretical Capacity

(mAh/g)=

(n) 96500

______________________

3600 monomer (g/mol)

1000

Nishide H . et al.© 2009 IUPAC, Pure and Applied Chemistry 81, 1961–1970

N- Type Organic Radical Polymers

C C

C

Nishide H . et al.© 2009 IUPAC, Pure and Applied Chemistry 81, 1961–1970

Graphite Anode/ORP Cathode

Suga T., Nishide H., Interface. Winter 2005, 32.

The power output per battery with a charge capacity of

5mAh increased to 7kW/L (1.4 times the level of

conventional units

Some Organic Cathode -Active Redox

Polymers Synthesized by Our Group

CR 2016 Coin Type Batteries

Cathode Composite :

20-40% Polymer

50-70% Carbon

10% PVdF Binder

Specific EnergyCapacity=

275 mWh/g

Specific ChargeCapacity=

77 mAh/g

TheoreticalCharge

Capacity

= 91 mAh/g

Specific EnergyCapacity=

250 mWh/g

Specific ChargeCapacity=

70 mAh/g

TheoreticalCharge

Capacity

= 102.6 mAh/g

Specific EnergyCapacity=

175 mWh/g

Specific ChargeCapacity=

36 mAh/g

TheoreticalCharge

Capacity

= 91 mAh/g

Specific EnergyCapacity=

280 mWh/g

Specific ChargeCapacity=

80 mAh/g

TheoreticalCharge

Capacity

= 108.8 mAh/g

Malonyl Tempo Diester Substituted

Thiophene

Theoretical Capacity=

108.8 mAh/g

Theoretical Capacity =

(n) 96500

__________________

3600 monomer (g/mol)

1000

Aydin M., Esat B., Journal of Polymer Research, 2015 available on-line

Polymer & Composite Characterization

0.5 0.6 0.7 0.8 0.9 1.0 1.1

-12

-10

-8

-6

-4

-2

0

2

4

6

8

Cu

rren

t (

A)

Voltage (V)

Poliymer

Composite

-Polymer : Eox: 0.75V , Ered: 0.66V , -Composite : Eox: 0.79V , Ered: 0.65V .

PolymerSEM image

Composite(Polymer/Graphite/PVDF:20/70/10)

CompositeSEM image

2.5-3.8 V at 0.1 mA (~0.3C)

0 20 40 60 80 100

180

200

220

240

260

280

Sp

ecific

En

erg

y C

ap

acity (

mW

h/g

)

Cycle ID

Charge

Discharge

0 20 40 60 80 100

40

60

80

Sp

ecific

Ch

arg

e C

ap

acity (

mA

h/g

)Cycle ID

Charge

Discharge

0 20 40 60 80

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

4.0

Vo

lta

ge

(V

)

Specific Charge Capacity

Specific EnergyCapacity=

180 mWh/g

Specific ChargeCapacity=

55 mAh/g

PROBLEM: Capacity fading due to

polymer dissolution

0 20 40 60 80

2,9

3,0

3,1

3,2

3,3

3,4

3,5

3,6

3,7

3,8

Vo

ltag

e (V

)

Capacity (mAh/g)

0,2 C

0,5 C

1 C

2 C

4 C

3V—3.9V

0 2 4 6 8 10

260

280

300

320

340

360

380

Sp

ecific

En

erg

y C

ap

acity (

mW

h/g

)

Cycle ID

Charge

Discharge

5 mol% Thiophene added intopolymerization rxn mixture

to decrease solubility in electrolyte

Specific EnergyCapacity=

280 mWh/g

Specific ChargeCapacity=

80 mAh/g

0.2 C

0 10 20 30 40 50

75

80

85

90

95

100

105

Sp

ecific

Ch

arg

e C

ap

acity (

mA

h/g

)

Cycle ID

Charge

Discharge

Less soluble polymer= Smaller capacity fading

Anode Materials: Quinones

Synthesis

Anode Materials: Quinones

-1.6 -1.4 -1.2 -1.0 -0.8 -0.6

-8

-6

-4

-2

0

2

4

6

8

10

12

14

Cu

rre

nt (

A)

Voltage vs. Ag/Ag+

(V)

Scan Rate= 0.0005V/s

Vs Ag/AgCl

TheoreticalCharge

Capacity

= 160.3 mAh/g

Organic Electrolyte

Aqueous Electrolyte

AQ Functionalized Reduced Graphene

Oxide (RGO)

AQ Functionalized Reduced Graphene

Oxide (RGO)

Synthesis

Conductivity

RGO-AQ 50%: 657 S/m

RGO-AQ-AQ 200%: 517 S/m

RGO-AQ 500%: 316 S/m

(RGO-AQ 50% = AQ to RGO

Ratio =50% w/w during preparation)

RGO-AQ| 30% NaOH | NiOOH

Conclusions

We have proved that organic RPs (Redox Polymers) with pendant TEMPO radicals which are obtained via simple & efficient low T organic synthetic methods can be used as cathode-active materials.

The cathode materials initially showed charge capacities close to their theoretical capacities, but the capacity degraded over time in most of the cases possibly due to polymer dissolution or electrode material degradation

These problems may be solved by:

Appropriate electrolyte choice

Chemical crosslinking of polymer or covalent attachment of the polymer on carbon surface

Anthraquinone-bearig RPs can be used as anode-active materials although they show sluggish redox behavior in organic elecrolytes.

AQ group is shown to be a good candidate in anode materials in high-rate aqoueous batteries when used with conventional cathode materials such as NiOOH.

RGO functionalization with electro-active groups such as AQ and Nitroxide radicals is a good strategy which avoids the use of redundant polymeric backbones and is thus promising for increasing the capacity.

Acknowledgements

This research has been supported by

Fatih University (BAP P50021103_G)

TUBITAK (Project # 112T516 & 114Z295)

Thank you for your attention