a metal-free organic-based aqueous flow battery for

Organic-Based Aqueous Flow Batteriesfor Massive Electrical Energy Storage

Brian Huskinson1, Michael P. Marshak1, Changwon Suh2, Süleyman Er2, Michael R. Gerhardt1, Cooper J. Galvin1, Xudong Chen2, Qing Chen1, Liuchuan Tong2, Alán Aspuru-Guzik2, Roy G. Gordon1,2 & Michael J. Aziz1

1 Harvard School of Engineering &Applied Sciences

2 Dept. of Chemistry & ChemicalBiology, Harvard University

• Grid-scale storage• Flow Batteries• Quinones and hydroquinones• Quinone-based flow batteries: First results• Future prospects

Andlinger Center for Energy & Environment, Princeton University, 10/20/2014

Wind Power Becomes Competitive

The state’s biggest utilities, in a milestone for New England’s wind power industry, have signed long-term contracts to buy wind-generated electricity at prices below the costs of most conventional sources, such as coal and nuclear plants.The contracts, filed jointly Friday with the Department of Public Utilities, represent the largest renewable energy purchase to be considered by state regulators at one time. If approved, the contracts would eventually save customers between 75 cents and $1 a month, utilities estimated.“This proves that competitively priced renewable power exists and we can get it, and Massachusetts can benefit from it,” said Robert Rio, a spokesman for Associated Industries of Massachusetts, a trade group that represents some of the state’s biggest electricity users.The utilities — National Grid, Northeast Utilities, and Unitil Corp. — would buy 565 megawatts of electricity from six wind farms in Maine and New Hampshire, enough to power an estimated 170,000 homes.... initial reaction to the price — on average, less than 8 cents per kilowatt hour? “Wow.” ...

Boston Globe 9/23/2013, http://www.bostonglobe.com/business/2013/09/22/suddenly-wind-competitive-with-conventional-power-sources/g3RBhfV440kJwC6UyVCjhI/story.html

Electricity Prices Go Negative (Europe)

10/12/2013

Electricity Prices Go Negative (US)

Slide courtesy of Prof. George Baker, HBS https://www.misoenergy.org/LMPContourMap/MISO_MidWest.html

Intermittency Causes California to Require Storage

California adopts energy storage mandate for major utilitiesCalifornia today became the first state in the country to require utilities to invest in energy storage, a move...

10/17/2013

Enersys Nickel-Cadmium + Valve-regulated Lead-Acid1 MWh, 1.5 MWhttp://www.windpowerengineering.com/featured/business-news-projects/improving-grid-lots-stored-mws/

USA electric power (Dec. 2013):

1100 GWe gen. capacity

24.6 GW (2.3%) storage:= 23.37 GW PHES,+1.23 GW other storage

Large-Scale Deployment of Off-Grid Storage

No access to grid: 1.4 Billion people (incl. 550 million in Africa, 400 million in India)

http://www.raisinahill.org/2013/02/indo-us-dispute-on-solar-panel.htmlhttp://3.bp.blogspot.com/-beOrvaf2wzw/URT3ohD796I/AAAAAAAABkA/

9xwL0o5qO6I/s1600/Home+Lighting+System+in+a+hut+in+Jaisalmer+District+of+Rajasthan..jpg

Photo courtesy of Prof. Sri Narayan,University of Southern California

Storage Makes Intermittent Renewables Dispatchable

Wind supply

Grid demand

Solar supply

J. Rugolo and M.J. Aziz, “Electricity Storage for Intermittent Renewable Sources”, Energy Environ. Sci. 5, 7151 (2012)

3 weeks

Pow

erP

ower

Pow

er

Some Grid Supply Scenarios Enabled by Storage


Grid minus baseload

5 hr peak-consumption centered square wave

Completely Levelized

Pow

erP

ower

Pow

er

Electrochem storage: a distribution of instantaneous efficienciesRequirement: high system efficiency

Three storage scenarios: Power and energy requirements, 1 MW nameplate production

5 hr centered square wave

Grid minus baseload (GMB)

Constant output


wind production

PV production

1 MW

1 MW

Pow

erP

ower

1 MW nameplate wind requirement:~?? MW peak power capacity; ?? MWh energy capacity (Energy/Power = ?? hr)

1 MW nameplate PV requirement:~?? MW peak power capacity; ?? MWh energy capacity (Energy/Power = ?? hr)

STORAGE

supplied to grid

Storage: A Distribution of Efficiencies

Realistic

Thermo. limitThermo. limit

Linear Potential Approximation:

Peaks at:

Electrolytic(Charging mode)

Galvanic(Discharging mode)

i, Current Density [mA/cm2]

E, C

ell P

oten

tial [

V]

p, P

ower

Den

sity

[mW

/cm

2 ]

Power dens’y:

HowmuchA?


Storage Requirements for 1 MW Nameplate Production Capacity

Pow

er [M

W]

Pow

er [M

W]

Supplied power to grid = 0.276 MW

Supplied power to grid = 0.119 MW

Storage characteristics:ηavg = 85%Max. power = 0.480 MWStored energy = 23 MWhrE/P ratio = 48 hr

Storage characteristics:ηavg = 85%Max. power = 0. 568 MWStored energy = 8.0 MWhrE/P ratio = 14 hr

Wind characteristics:Nameplate = 1 MW CF = 32.5%

PV characteristics:Nameplate = 1 MW CF = 14%


Diminishing Returns on Buying Storage Power

SolarSolar

Wind

Wind

, Galvanic Power Capacity [MW]


Energy/Power ratio [hr]

Lead Acid

Lithium ion

NiMH

Batteries: 100x too little energy per power

25 50 75

Three storage scenarios: Power and energy requirements, 1 MW nameplate production

5 hr centered (SW) in pinkGrid minus baseload (GMB) in redConstant output (CONS) in blue J. Rugolo and M.J. Aziz, “Electricity Storage for Intermittent Renewable Sources”, Energy Environ. Sci. 5, 7151 (2012)

25 50 75

NiMHPb-acidLi+ ion

Batteries Have Only About 1%of the Required Energy for a Given Power


Requirements for Efficient Storage, 1 MW nameplate

Solar Wind

Power 1 MW 1 MW

Energy 16 MWhr

60 MWhr

16 hr 60 hrpower

energyRatio




Available

Solar Wind Batteries

Power 1 MW 1 MW 1 MW

Energy 16 MWhr

60 MWhr

0.2 MWhr

16 hr 60 hr 12minutespower

energyRatio

1 MW0.2 MWhr

$40k




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Energy 16 MWhr

60 MWhr

0.4 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




Available



Energy 16 MWhr

60 MWhr

0.6 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




Available



Energy 16 MWhr

60 MWhr

0.8 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




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Energy 16 MWhr

60 MWhr

1.0 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




Available



Energy 16 MWhr

60 MWhr

2.0 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




Available



Energy 16 MWhr

60 MWhr

3.0 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k




Available



Energy 16 MWhr

60 MWhr

60 MWhr


energyRatio

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MW

1 MW0.2 MW

1 MW0.2 MW

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 M

1 MW0.2 M

1 MW0.2 M1 MW

0.2 MWhr1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 M

1 MW0.2 M

1 MW0.2 M

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

1 MW0.2 MWhr

$40k

Flow Batteries Independently Size Energy and Power


power

energyRatio

energystorageunit

pump pump

electrodeion-transport

separator

1 MW powerconversion unit

energystorageunit

Power sourceand load

1MWhr

1MWhr

Electrolyte Electrolyte


Solar Wind

Power 1 MW 1 MW

Energy 16 MWhr

60 MWhr

16 hr 60 hr

based on image from vrbpower.com

power

energyRatio



energystorageunit

pump pump


separator


energystorageunit

power

energyRatio




Solar Wind

Power 1 MW 1 MW

Energy 16 MWhr

60 MWhr

16 hr 60 hr

10MWhr

10MWhr


power

energyRatio



energystorageunit

pump pump


separator


energystorageunit

power

energyRatio


ElectrolyteElectrolyte


Solar Wind

Power 1 MW 1 MW

Energy 16 MWhr

60 MWhr

16 hr 60 hr60

MWhr60

MWhr


power

energyRatio



energystorageunit

pump pump


separator


energystorageunit

power

energyRatio




Solar Wind

Power 1 MW 1 MW

Energy 16 MWhr

60 MWhr

16 hr 60 hr100

MWhr100

MWhr


power

energyRatio

“Hope and Change” for Electrical Energy Storage

Vanadium Redox Flow Battery:the Most Commercialized RFB


Red

Ox

Red

Ox

Quinones for Battery Storage

+2 H+,+2 e–

+2 H+,+2 e–

+2 H+,+2 e– +2 H+,

+2 e–

Plastoquinonein photosynthesis

simplestquinone

oxidized

reduced

Quinones/Hydroquinones: Reversible

Quan, Sanchez, Wasylkiw, Smith, “Voltammetry of Quinones in Unbuffered Aqueous Solution...”, JACS 129, 12847 (2007)

proton and electron addition reactionswith known and estimated pKa’s

QH

para-benzo-quinone

hydro-quinone

OH

OH

O–

O–

OH

O–

O

O

OH+

OH+

OH+

O

QQ-Q2-

QH- QH+

QH22+QH2 QH2

+

-e-

+H+

-e-

-e--e-

-e--e-

+H+

+H+

+H+

+H+

+H+

~ -7~ -7

< -7

4.1

~ -1

4.1

~ -1

11.84

9.85

+H+

+H+

+e-+e-

+e-+e-

+e-+e-

“pBQ”

QH

Quinones/Hydroquinones: Reversible or Irreversible

Quan, Sanchez, Wasylkiw, Smith, “Voltammetry of Quinones in Unbuffered Aqueous Solution...”, JACS 129, 12847 (2007)

proton and electron addition reactionswith known and estimated pKa’s

hydro-quinone

OH

OH

O–

O–

OH

O–

O

O

OH+

OH+

OH+

O

QQ-Q2-

QH- QH+

QH22+QH2 QH2

+

-e-

+H+

-e-

-e--e-

-e--e-

+H+

+H+

+H+

+H+

+H+

~ -7~ -7

< -7

4.1

~ -1

4.1

~ -1

11.84

9.85

+H+

+H+

+e-+e-

+e-+e-

+e-+e-

para-benzo-quinone

“pBQ”

Quinone-Based Flow Batteries

Primary requirements:• Reduction potential• Solubility• Redox kinetics• Stability• Cost

Compound $/kg Source $/kAhper side

$/kWh per side

Vanadium pentoxide (V2O5)

14.37 USGS (2011) 48.77 40.64

Anthraquinone <4.74 eBioChem <18.41 <21.46

Benzoquinone 5.27 Shanghai Smart Chemicals Co. 10.63 10.63

Bromine 1.76 USGS (2006) 5.25 6.12

Full Cell $/kAh $/kWhAnthraquinone with Bromine <23.66 <27.58Anthraquinone with Benzoquinone <29.04 <32.09Vanadium with Vanadium 97.54 81.28

Cost of Chemicals Sets Floor on System Cost / kWh

“I wish I could get that price!”

-100 0 100 200 300 400 500-300

-200

-100

0

100

200

Cur

rent

Den

sity

(A

cm–2

)

Potential (mV vs. SHE)

Anthraquinone Di-sulfonate (AQDS)+ 2H+ + 2e-

Potentiostat

Working electrodeglassy C

Counterelectrode

Pt

ReferenceelectrodeAg/AgCl

34 mV

1 M H2SO4, pH 0, 20 oC, 1 mM AQDS

AQDSAQDSH2

61

Red

Ox

Reduction

Oxidation

AQDS

OH

OH

SO3HSO3H

O

O

SO3HSO3H

O

O

SO3HSO3H

B. Huskinson, M.P. Marshak, C. Suh, S. Er, M.R. Gerhardt, C.J. Galvin, X. Chen, A. Aspuru-Guzik, R.G. Gordon and M.J. Aziz, “A metal-free organic-inorganic aqueous flow battery”, Nature 505, 195 (2014)

2 electrons,2 protons

2 electrons,1 proton

2 electrons,0 protons

AQDS Pourbaix Diagram

1 mM Quinone


AQDS: Rotating Disk Electrode Response

50 100 150 200 250 300-1400

-1200

-1000

-800

-600

-400

-200

0

Cur

rent

Den

sity

(A

cm–2

)


200 RPM

3600 RPM

iL = Current limited by mass transport

Levich Equation:iL = 0.62n F A D2/3 ω1/2 1/6 CO*D = 3.8 × 10−6 cm2/s.

0 2 4 6 8 10 12 14 16 18 200

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

Lim

iting

Cur

rent

(A)

1/2 (Rad/s)1/2



Koutecký-Levich Plot:Extrapolate to infinite rotation rateGives the kinetically-limited current, iK

50 100 150 200 250 300-1400

-1200

-1000

-800

-600

-400

-200

0

Cur

rent

Den

sity

(A

cm–2

)


200 RPM

3600 RPM

0.00 0.04 0.08 0.12 0.16 0.20 0.240

-10

-20

-30

-40

-50

-60

/ mV 13 18 23 28 33 38 363

i–1 (m

A–1)

–1/2 (s1/2 rad–1/2)

Current is limited by mass transportand electrode kinetics

iK1



Koutecký-Levich Plot:Extrapolate to infinite rotation rateGives the kinetically-limited current, iK

0.00 0.04 0.08 0.12 0.16 0.20 0.240

-10

-20

-30

-40

-50

-60

/ mV 13 18 23 28 33 38 363

i–1 (m

A–1)

–1/2 (s1/2 rad–1/2)

iK1

exchange current density ik0 rate const k0 = ik0/(FAC) = 7.2 × 10−3 cm/s

*Weber, A. Z.; Mench, M. M.; Meyers, J. P.; Ross, P. N.; Gostick, J. T.; Liu, Q. J. Appl. Electrochem. 2011, 41, 1137

Redox couple

k0 [cm/s] (electrode)

AQDS/ AQDSH2

7.2 x 10-3 (carbon)

Br2/Br- 5.8 X 10-4 (carbon)*Fe3+/Fe2+ 2.2 x 10-5 (gold)*Cr3+/Cr2+ 2 x 10-4 (mercury)*VO2

+/VO2+ 3 x 10-6 (carbon)*V3+/V2+ 4 x 10-3 (mercury)*

F = Faraday’s constantA = surface areaC = concentration

Quinone-Bromide Flow Battery

Porous carbonpaper electrode(no catalyst)

AQDSH2

AQDS


AQDS

+ 2H+ + 2e-AQDSAQDSH2 Red

Ox

OH

OH

SO3HSO3H

O

O

SO3HSO3H

AQDSH2

E0: +0.21 V +1.09 V

Cell AssemblyCarbon paper Nafion membrane

Teflon gasket

Serpentineflow field

Interdigitatedflow fieldor

Assembled single-cell stack

Cell Performance

• Interdigitated flow fields

• Toray carbon paper electrodes (pretreated, 6 layers/side,no added catalyst)

• Nafion 212 (50 um),40 oC

• posolyte: 3 M HBr+ 0.5 M Br2

• negolyte:1 M 2,7-AQDS

+ 1 M H2SO4

State of Charge (SOC)


Cell Performance

• 40 oC• posolyte: 3 M HBr + 0.5 M Br2• negolyte: 1 M AQDS + 1 M H2SO4

spans decades of VRB developmentin 1 year

Peak galvanic power density > 0.6 W cm-2 SOC

Galvanic power density

Electrolytic power density of 3.3 W cm-2

at 2.25 A cm-2

Electrolytic power density


now 1.0 W/cm2

Voltage Efficiency

-0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.40.70

0.75

0.80

0.85

0.90

0.95

1.00

Vol

tage

Effi

cien

cy

Power Density (W cm-2)

charge discharge

10% SOC25%50%75%90%

Discharge:75-150 mW cm-2

at 90% voltage efficiency

Charge:125-200 mW cm-2 at 90% voltage efficiency


Cycling to ~102

75

0 20 40 60 80 100 120 140 160 180 2000.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Cel

l Pot

entia

l (V

)

Time (hrs)

0 20 40 60 80 100

80

82

84

86

88

90

92

94

96

98

100

Cycle Number

Dis

char

ge C

apac

ity R

eten

tion

(%)

100 102 104 106 1080.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Cel

l Pot

entia

l (V

)

Time (hrs)

49 50 51 52 53

80

82

84

86

88

90

92

94

96

98

100

Dis

char

ge C

apac

ity R

eten

tion

(%)

Cycle Number

99.986% average

• Nafion 115 (125 um); 30 oC• Toray carbon electrodes 2 cm2, 6 layers, no catalyst• Negolyte: 1 M AQDS in 1 M H2SO4• Posolyte: 3 M HBr + 0.5 M Br2 in H2O

Capacity Retention = (Coulombs of discharge) / (immediately preceding coulombs of discharge)

Impose ±0.25 A/cm2 square wave, switched at 0, +1.5 V

B. Huskinson, M.P. Marshak, M.R. Gerhardt and M.J. Aziz,“Cycling of a quinone-bromide flow battery for large-scale electrochemical energy storage”, ECS Trans. 61, 27 (2014)

0 100 200 300 400 500 600 7000.0

0.2

0.4

0.6

0.8

1.0

Cur

rent

Effi

cien

cy (%

)

Cycle Number

0.0

0.2

0.4

0.6

0.8

1.0

Dis

char

ge C

apac

ity R

eten

tion

(%)

750 cycles0.75 A cm-2

Cycling to ~103

76

99.84% avg. discharge capacity retention

98.35% avg. current efficiency

Capacity Retention = (Coulombs of discharge) / (immediately preceding coulombs of discharge)Current Efficiency = (Coulombs of discharge) / (immediately preceding coulombs of charge)

• ±0.75 A/cm2 square wave, switched at 0, +1.5 V• Nafion 115 (125 um); 40 oC• Toray carbon electrodes, 6 layers, no catalyst• Negolyte: 1 M AQDS in 1 M H2SO4• Posolyte: 3 M HBr + 0.5 M Br2 in H2O

B. Huskinson, M.P. Marshak, M.R. Gerhardt and M.J. Aziz,“Cycling of a quinone-bromide flow battery for large-scale electrochemical energy storage”, ECS Trans. 61, 27 (2014)

current efficiency loss:• Br2 crossover?• O2 permeation?• H2 evolution?

0.00 0.25 0.50 0.75 1.00

0.98

0.99

1.00

Current density (A/cm2)

Cur

rent

Effi

cien

cy

Current Efficiency

0.0

0.2

0.4

0.6

0.8

1.0

Volta

ge E

ffici

ency

Voltage Efficiency

0.00 0.25 0.50 0.75 1.00

0.98

0.99

1.00

Cur

rent

Effi

cien

cy

Current density (mA/cm2)

Current Efficiency

0.0

0.2

0.4

0.6

0.8

1.0

Voltage Efficiency

Volta

ge E

ffici

ency

0.00 0.25 0.50 0.75 1.000.0

0.2

0.4

0.6

0.8

1.0


Ener

gy E

ffici

ency Energy Efficiency

0.00 0.25 0.50 0.75 1.000.0

0.2

0.4

0.6

0.8

1.0


Ener

gy E

ffici

ency

Energy Efficiency

Efficiency vs. Current Density

Nafion 212 Nafion 115

Negolyte: 20 mL (1M AQDS + 1M H2SO4)Posolyte: 125 mL (3.5M HBr + 0.5M Br2)Electrode Area: 5 cm2

Additional Advantages of Quinones for Energy Storage

Redox couple k0 [cm/s] (electrode material)AQDS/AQDSH2 7.2 x 10-3 (carbon)Br2/Br- 5.8 X 10-4 (carbon)Fe3+/Fe2+ 2.2 x 10-5 (gold)Cr3+/Cr2+ 2 x 10-4 (mercury)VO2

+/VO2+ 3 x 10-6 (carbon)V3+/V2+ 4 x 10-3 (mercury)

Quinone kinetics on glassy carbon exceed those of most other battery redox couples

Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kW

Additional Advantages of Quinones for Energy Storage

• Dianions: reduced crossover through cation-exchange membranes• Quinones on both sides would eliminate Br2 exposure and Br2 crossover

hydrocarbon membranes• Bulky molecules may enable inexpensive separator• Possibility of functionalizing with additional R groups for physical or chemical membrane

exclusion

Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separator

Quinones as an Energy Storage Medium

Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separatorAll-liquid storage: Enables inexpensive BOS and high cycle life


Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separatorAll-liquid storage: Enables inexpensive BOS and high cycle lifeAqueous electrolyte: Enables fireproof operation

• Damaged/overheated Li‐ion cells can ignite spontaneously & create fierce fires

9‐Nov‐2008—Li‐ion fire destroys Pearl Harbor‐docked Advanced SEAL Delivery System (ASDL); $237M in damage

3‐Sep‐2010—Li battery fire ignites aboard UPS 747 departing Dubai; crash kills both pilots

7‐Jan‐2013—fire ignites in Li-ion battery pack (2×size of a car battery) of auxiliary power unit in 787 Dreamliner while on the ground in Boston

Li-ion batteries ubiquitous. . . but safety concerns are not going away

Li-ion batteries ubiquitous. . . but safety concerns are not going away

May‐2011—fire ignites in battery pack 3 weeks after crash test of Chevy Volt

• Li cells have been implicated in at least 24 combustion incidents on or around aircraft in 2010‐2012, both in cargo and carry‐on bags (Wall Street Journal, 12/30/2012)

• Li‐ion batteries containing more than 25 grams (0.88 oz) equivalent lithium content (ELC) are forbidden in air travel (safetravel.dot.gov)

Slide courtesy of Dr. Debra Rolison, NRL


Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separatorAll-liquid storage: Enables inexpensive BOS and high cycle lifeAqueous electrolyte: Enables fireproof operationNon-toxic: Ideal for commercial, residential markets


Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separatorAll-liquid storage: Enables inexpensive BOS and high cycle lifeAqueous electrolyte: Enables fireproof operationNon-toxic: Ideal for commercial, residential marketsScalability: Enables rapid chemistry scaleup

Scalability

Bulk synthesis of AQDS mixtures without purification leads to nearly identical half-cell performance.

Estimated electrolyte cost of <$21/kWh for AQDS and $6 for BrGives <$27/kWh cost of chemicals for QBFB.


Low chemicals cost: Enables low cost/kWhRapid redox kinetics: Enable low cost/kWSmall organic molecules: Enable inexpensive separatorAll-liquid storage: Enables inexpensive BOS and high cycle lifeAqueous electrolyte: Enables fireproof operationNon-toxic: Ideal for commercial, residential marketsScalability: Enables rapid chemistry scaleupTunability: Enables performance improvements

Computational Screening

Electron-donating –OH groups lower the reduction potential.

-400 -300 -200 -100 0 100 200 300 400

0

1

2

3

4

5

6 Calc. Calc. Exp.

Num

ber o

f –O

H G

roup

s


AQDS

DHAQDS

Changwon Suh, Süleyman Er, Michael Marshak, Alán Aspuru-Guzik

-100 0 100 200 300 400 500

-300

-200

-100

0

100

200

Cur

rent

Den

sity

(A

cm–2

)


AQDS 1,8-DHAQDS MH-AQDS

Tunability

Reduction

Oxidation

AQDSE0 = 0.210 V

end

start

Electron-donating –OH groups lower the reduction potential.

-100 0 100 200 300 400 500

-300

-200

-100

0

100

200

Cur

rent

Den

sity

(A

cm–2

)



Tunability

HO3SO

O

SO3HOH OH

Reduction

Oxidation

AQDSE0 = 0.210 V

1,8-DHAQDSE0 = 0.118 V

end

start

Cooper Galvin

-100 0 100 200 300 400 500

-300

-200

-100

0

100

200

Cur

rent

Den

sity

(A

cm–2

)



Tunability

HO3SO

O

SO3HOH OH

Reduction

Oxidation

AQDSE0 = 0.210 V

1,8-DHAQDSE0 = 0.118 V

end

start

• Addition of OH groups lowers the reduction potential by ~170 mV

• Expect ~20% increase in OCV of Quinone-Bromide cell

MH-AQDSE0 = 0.039 V

Cooper Galvin,Michael Marshak

Tunability Demonstration in Quinone-Bromide Cell

Michael Gerhardt (unpublished)

AQDSE0 = 0.210 V

State of Charge (%)0 20 40 60 80 100

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

0.5 M DHAQDS 0.5 M AQS 0.5 M AQDS 1 M AQDS

Preliminary results from DHAQDS and AQS flow cells against HBr/Br2show open circuit voltage rising above 1.0 V at high state of charge.

Ope

n C

ircui

t Vol

tage

(V)

2 ln 2



O

O

SO3H

AQDSE0 = 0.210 V

AQSE0 = 0.193 V

17 mV OCV gainState of Charge (%)

0 20 40 60 80 1000.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10



Ope

n C

ircui

t Vol

tage

(V)



O

O

SO3H

AQDSE0 = 0.210 V

AQSE0 = 0.193 V

17 mV OCV gain

DHAQDSE0 = 0.118 V

92 mV OCV gain

State of Charge (%)0 20 40 60 80 100

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10



Ope

n C

ircui

t Vol

tage

(V)

1.0 V Quinone-Quinone Cell

0.1 M in H2OOpen Circuit Potential = 1.03 VPeak power density = 50 mA cm−2

>99% current Efficiency

High cell resistance due (primarily?) to low ion conc.

Michael Marshak, Liuchuan Tong (unpublished)

Are quinones special?

“[Quinones] seem to involve a different kind of process from such irreversible reductions as the hydrogenation of ethylene derivatives, or the reduction of aldehydes, ketones, and nitriles.”

J.B. Conant, H.M. Kahn, L.F. Fieser, S.S. Kurtz,, J. Am. Chem. Soc. 44, 1382 (1922).

ethane ethylene

hydroquinone benzoquinoneJ. B. Conant

L. F. Fieser

Quinone Redox Scheme

QH2

Q

Redox-Active Orbital of Quinone

e– e–

e– e–

e– e–

H+

H+

H+

H+

H+

H+

LUMOHOMO SOMO

• Hydroquinone HOMO is π-type

• Virtually identical to quinone LUMO

• Zero electron density on O-H bond

• Near zero motion of any other atoms

Q

DFT Calculations using Gaussian03; B3LYP functional / TZVP basis set (Michael Marshak)

-+ -+- +-+ QH2

Ethane/Ethylene Orbitals

Degenerate HOMO of Ethane consists of C−H σ bonds

LUMO of Ethylene is the π* (anti-bond)

C2H6

C2H4

Outlook

• Cost and tunability of redox-active organics look promising for E storage, other apps?

• High power density, low cost quinone-bromine Redox Flow Battproves the concept

• There is plenty of room for improvement• molecules• separators• porous electrodes and fluidics

• How low can the capital cost be?

Fun Facts about Quinones

Hydroquinone cream is used to bleachdark spots, moles, etc off of skin

Blatellaquinone is a sex pheromone female cockroaches use to attract males

Emodin is found in Aloe Vera

Vitamin K1 is part of the electron transport chain in photosystem I,found in all green plants

Acknowledgments

Not pictured: Dr. Brian Huskinson, Professor Theodore Betley, SarafNawar, Rachel Burton, Cooper Galvin, Sidharth Chand, Tyler Van Valkenburg, Bilen Aküzüm, Ryan Duncan, Dr. Süleyman Er, Dr. Xudong Chen, Phil Baker, Dr. Trent MolterTop Row: Prof. Alán Aspuru-Guzik, Dr. Rafa Gómez-Bombarelli, Tim Hirzel, Louise Eisenach, Dr. Jorge Aguilera Iparraguirre, Prof. Mauricio SallesSecond Row: Jessa Piaia, Drew Wong, Kaixiang Lin, Prof. Xin Li, Dr. David Hardee, Dr. Michael MarshakThird Row: Jennifer Wei, Dr. Qing Chen, Michael Gerhardt, Liuchuan Tong, Xinyou KeFront Row: Dr. Ed Pyzer-Knapp, Dr. Changwon Suh, Lauren Hartle, Prof. Michael Aziz, Prof. Roy GordonNot pictured: Prof. Theodore Betley, Saraf Nawar, Bilen Aküzüm, Rachel Burton, Cooper Galvin, Sidharth Chand, Phil Baker, Dr. Trent Molter, Dr. Brian Huskinson, Ryan Duncan, Dr. Süleyman Er, Dr. Xudong Chen

Harvard U Ctr for the Environment, Harvard School of Engrg & Appl SciHarvard Physics Department,NSF Grad Rsch Fellowship Program, DOE ARPA-E award DE-AR0000348

a metal-free organic-based aqueous flow battery for

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