Current Development Trends and Challenges for Redox-Flow Batteries Jens Noack1,2, Nataliya Roznyatovskaya1,2, Nicholas Gurieff2,3, Chris Menictas2,3, Jens Tübke1,2, Maria Skyllas-Kazacos2,3 1
Fraunhofer-Institute for Chemical Technology, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal, Germany German-Australian Alliance for Electrochemical Technologies for Storage of Renewable Energy, Mechanical and Manufacturing Engineering, University of New South Wales (UNSW), UNSW Sydney NSW 2052 Australia 3 University of New South Wales (UNSW), UNSW Sydney NSW 2052 Australia 2
1900
1E+01
1800 1700
Current density (mA/cm²)
Treatment potential (mV) vs. Hg/Hg2SO4
2000
1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500
1E-03
-0,24 -0,12
0
0,12
0,24
0,36
Potential (V) vs. NHE
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1E-01
0,48
0,6
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German-Australian Alliance for Electrochemical Technologies for Storage of Renewable Energy Project to establish a center (CENELEST) at UNSW/Sydney Project start 08/2017, Collaboration Fraunhofer ICT - UNSW 2
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What is a Flow Battery?
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What is a Flow Battery?
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Development Trends – Active Material Redox Flow Batteries Aprotic conventional molecular solvents and ILs
One-phase (all-liquid)
Ru(bpy) Ni(bpy)/Fe(bpy) Ru(acac) V(acac) Cr(acac) Mn(acac) U(acac) Co(acacen) V(mnt) TEMPO/NMPI DBBB/TMQ Fe(TEA)/Br
Two-phases (suspension, nanofluids etc.)
LiCoO2/LTO Li/15D3GAQ LiFePO4/LTO Li/Fe Na/EMICl-Fe Cu/Cu(DEA-EHN) Cu/Cu(Cholinchlorid)
Protic Electrolytes
One-phase (all liquid)
V/V V/Fe V/BrCl V/Ce Cr/Fe Cr/Br Cr/Cr S/Br POxM Ti/Fe Ti/BrCl Np/Np I/I Fe(EDTA)/Br Cr(EDTA) Quinones/Br MV/TEMPO Org/Org
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Two-phases (hybrid)
Zn/Ni Zn/Br Zn/Cl Zn/BrCl Zn/V Zn/Ce V/O2 Fe/Fe Cd/Br Pb/Pb Cu/Cu Cu/Pb Zn/PANI Cd/Chloranil Pb/Tyron V/Glyoxal(O2) V/Cystine (O2)
Two-phases (liquid/gaseous)
H/Br H/Cl H/Fe H/V
Modelling for Flow Batteries
Electrochem is try Reaction mechanism
S y s tem Pumps Heat management BMS
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Half-Cell Fluid dynamics
Heat
TechnoEconom ics Costs
Cell
S tack
Membrane
Shunt currents
Microgrid LCOE Energy flow
Churrent Challenges Redox Flow Batteries General
Electrolyte
Lifetime!
Cheap and/or recycling
Invest Cost (Stack, Aktive Material)
Recombination/Regeneration ?
Current density / material cost Recycling VRFB
Stack Microporous Separators Thermoplastic Electrodes
Lifetime !
Replacement of felt
Electrode
Production Technology !
Membrane
Active Material Recycling
Organic Flow Batteries
Electrolyte Regeneration (O2, H2)
Stable redox couples in the whole potential range of the battery !
Electrolyte impurities
Potential of redox couples
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Electrochemistry Electrochemical equilibrium: Nernst Eq. Current-overpotential behavior:
-
C x z z e-
Ax
C x z c RT 0 ln zF Ax a
0'
zF (1RT) zF i i0 e e RT Butler-Volmer-Eq.
Cyclic Voltammetry Linear Sweep Voltammetry Rotating Disc Electrode Impedance Spectroscopy Chronopotentiometry & voltammetry Spectroelectrochemistry (UV-VIS, IR, RAMAN, ESR)
Properties of active materials, electrodes, electrolytes 8
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VRFB – Electrochemical Treatment of Electrodes
1
0
1,2
0,001 1E-4
1,0
1E-5
0,8
1E-6
0,6
1E-7
0,4
polished electrode
1E-8 0,2 1E-9
0,8
1,0
1,2
1,4
1,6
1,8
400
2,0
600
800
1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800
1E+00
1E-01
1E-02
700 600 500
1000 1200 1400 1600 1800 2000 2200
1E-03
0,994
Treatment potential (mV) vs. Hg/Hg2SO4
Potential (V) vs. NHE
Current density (mA/cm²)
2
iref
0,01
Symmetry factor
3
Reference current density (mA/cm²)
Current Density / mA/cm²
4
1,4
Treatment potential (mV) vs. Hg/Hg2SO4
2000
0,1 red 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000
5
1,194
1,394
1,594
1,794
Potential (V) vs. NHE
3
2
1
0
1,00 0,95
1 0,90 0,1
0,85 0,80
0,01
0,75 0,001
0,70
1E-4
0,60
iref
1E-5
1E-6
-0,3
-0,2
-0,1
0,0
0,1
0,2
0,3
0,4
600
J. Noack et al., Journal of Energy Chemistry, 2018 in Press
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800
1000
1200
1400
1600
Treatment potential (mV) vs. Hg/Hg2SO4
Potential (V) vs. NHE
9
0,55 0,50
400
-0,4
0,65
polished electrode
1800
Symmetry factor
Current Density / mA/cm²
4
Reference current density (mA/cm²)
red 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000
1900
1E+01
1800 1700
Current density (mA/cm²)
10
5
Treatment potential (mV) vs. Hg/Hg2SO4
2000
1600 1500 1400 1300 1200 1100 1000 900 800
1E-01
700 600 500
1E-03
-0,24 -0,12
0
0,12
0,24
0,36
Potential (V) vs. NHE
0,48
0,6
VRFB – Influence of Counter Ion theor. Ucell
1.38 V 1.46 V 1.40 V
Complexation: V(III) HCl>MSA>H2SO4 V(IV) H3PO4 >HCl~MSA~H2SO4
Chemical stability of V(V): HCl: unstable at SOC 100% at RT, reacts with chloride H2SO4 : stable (RT and till 2 days at 50°C)
iR post-corrected CV curves
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Energy efficiency (cell performance) 0.8V to 1.65 V HCl: 73% H2SO4 : 75%
Organic Flow Batteries
Source: Fraunhofer ICT.
• • •
rough estimate of UOCV electrochem. reversibility/irreversibility, kinetics no information about products, i.e. their stability
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•
Example: in case of crossover complete inhibition of anodic and cathodic half-cell reactions
Microporous Separators for Flow and Non-Flow Batteries 100
1,8
12 1,0
10
0,9
6
40
2 0 1,2
-2
0,8
EE, CE, VE
60
4
1,4
Capacity /Ah
Voltage /V
0,7 0,6 0,5
-4
FAP-450 Porous Mb-1 Porous Mb-2 Nafion 117
20
0 20
30
40
50
60
70
1,0
0,4
-6
Voltage Capacity
0,8 22
23
Current Density (mA/cm²)
24
25
-10 26
27
28
29
EE CE VE
0,3
-8
0,2
-12 30
0
50
100
150
200
250
300
Cycle Nr
Time /h
25
-
-
Porous MB-2 is an ASAHI for ZnBr RFB (not produced anymore) ~50 $/m² V(V) stability test can result in false negative results (O2)
20 15
Ah-Step [Ah]
Eenergy Efficiency (%)
8
1,6
80
10 5 0
-
Bjorn Hage Consulting MPM still running for 7 months now with negative V(V) stability test (2 weeks stability) ~30 $/m²
-5 -10 -15 0
-
Passive blancing possible with MPM
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50
100
Time [d]
150
200
Technoeconomics - VRFB
-> 1078 €/kWh @ 50 mA/cm²; Cpower = 7923 €/kW, Cenergy = 417 €/kWh 13
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Technoeconomics - VRFB
Iso-cost line at 30 S/m and 5000 S/m - Advantages from mechanical properties, but contact resistance Cell voltage is important for expensive power! (Cu/Cu) The same for current density (Li-RFB) 14
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Velocity (m/s)
Frame Simulation – Novel Geometries
0,025
0,025
0,1
0,020
0,020
0,08
0,015
0,015
0,06
0,010
0,010
0,04
0,005
0,005
0,02
0
0,000
0,000
0
50
100
Depth (mm)
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0
50
100
Depth (mm)
0
50
100
150
Depth (mm)
200
250
Computer Tomography of Stacks (1 kW class stack)
- 2D & 3D Measurements - Construction Details - Any size ! - Possibility for time resolved measurements - Flow distribution in cells 16
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VRFB – Upscaling to 2 MW/20 MWh
2MW wind turbine
2MW/20MWh VRFB 200 kW/200kWh LiFePo Battery
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VRFB – Upscaling to 2 MW/20 MWh
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VRFB – Upscaling to 2 MW/20 MWh
The first module has been put in operation end of December 2017. 19
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VRFB – Upscaling to 2 MW/20 MWh Foto with courtesy of J. Schmalz GmbH & Co KG
Current status: At the moment 42 Stacks are connected in the first half module and brought into operation. The first testing cycles confirms data of measured on individual stacks Nearly 360 t of the vanadium electrolyte has been filled in the tanks already. Wind turbine is in operation, but DC connection to battery will be established in 2018
Trumpf-Hüttinger DC-Power Electrinics für VRFB 20
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Thank you for your attention!
Jens Noack Fraunhofer ICT Joseph-von-Fraunhofer-Str. 7 76327 Pfinztal/Germany
Jens Noack CENELEST University of New South Wales UNSW Sydney NSW 2052 Australia
Jens.Noack@ict.fraunhofer.de
info@cenelest.org
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