This document summarizes work on preparing a test bed and analyzing performance of a single cell vanadium redox flow battery (VRFB). Key points: 1) The experimental setup of the single cell VRFB test bed was successfully completed. 2) Initial testing showed reasonable cell voltage profiles during synthesis of vanadium ions and concentration changes over time matched modeling results. 3) Future work will involve charging and discharging the battery while optimizing electrolyte concentration, flow rate, and current to calculate columbic and voltage efficiencies and scale the system to multiple cells.

1. 04-07-2015
Test-bed Preparation and Performance Analysis of a
Single Cell Advanced Vanadium Redox Flow Battery
Rabiul Islam, Benjamin Eckerson and Cameron Nolen
Advisor:
Dr. David Jeong, P.E
Department of Mechanical Engineering
Arkansas State University
1

2. Contents
 Research backgrounds
 Research objective
 Experimental setup
 Schematic of the VRFB
 Reactions in cell
 Results
 Conclusions
 Future works
 Acknowledgements
2

3. Research backgrounds
 To convert intermittent to baseload*
3
*Energy Department Releases Grid Energy Storage Report, 12 December 2013
Demand

4. Research objective
 Improvement of system efficiency:
 screening of materials and its optimization
 optimizing operation variables
 𝜂 𝑒𝑛𝑒𝑟𝑔𝑦= 𝜂 𝑐𝑜𝑙𝑢𝑚𝑏𝑖𝑐 ∗ 𝜂 𝑣𝑜𝑙𝑡𝑎𝑔𝑒
4

5. Experimental setup
5
Power
Supply
Oscilloscope
Pump
Storage
Tank
Cell
Flowmeter
Voltmeter
Laptop

6. Schematic of the VRFB
6

7. Reactions in the cell
At positive electrode:
At negative electrode:
7

8. Tests results: V(III) and V(V) were
synthesized from V(IV)
8
V(IV)V(III)
V(V)

9. Tests results: Cell voltage profile during
synthesis of V(III) and V(V)
9
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
0 3 6 9 12 15 18 21 24 27
CellVoltage(Volt)
Time (h)
Concentration: 1 M, Flowrate: 100 ml/min, Applied
Current: 0.75 A
Concentration: 2 M, Flowrate: 200 ml/min, Applied
Current: 0.45 to 1.25 A

10. Modeling- Equations

𝑑2 𝑥1
𝑑𝑡2 + 𝑊
1
𝜇1
+
1
𝜇2
𝑑𝑥1
𝑑𝑡
∓
1
𝜇1 𝐹
𝑑𝑥3
𝑑𝑡
∓
𝑊
𝜇1 𝜇2
𝑥3
𝐹
= 0
 𝑥4= 𝐸𝑒
0 +
2𝑅𝑇
𝐹
𝑙𝑛
𝑥1
𝜇3−𝑥1
 𝑥5= 𝑥4 ∓ 𝑥3 𝜇3 + 𝜇5
10

11. Modeling results: Concentration of electrolyte
during discharge and charge
11
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 5000 10000 15000 20000 25000
Concentration(Mole/L)
Time (Second)
Flow rate: 0.125 (L/min)
Flow Rate: 0.208 (L/min)
Flow Rate: 0.300 (L/min)

12. Modeling results: On load voltage during
discharge
12

13. Conclusions
 Single cell VRFB test bed setup was done
successfully
 A reasonable cell voltage profile has been found
from synthesis operations
 Modeling results of electrolyte concentration
change and on load voltage during operation
has been obtained
13

14. Future works
 Charging and discharging operations will be carried
out by optimizing the electrolyte concentration, flowrate
and induced current
 Columbic efficiency and voltage efficiency will be
calculated and optimized
𝜂 𝑐𝑜𝑙𝑢𝑚𝑏𝑖𝑐 =
𝑄 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒
𝑄 𝑐ℎ𝑎𝑟𝑔𝑒
𝜂 𝑣𝑜𝑙𝑡𝑎𝑔𝑒 =
𝑈 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒
𝑈𝑐ℎ𝑎𝑟𝑔𝑒
 The system will be scaled up to multiple cells VRFB
system
14

15. Acknowledgements
 National Science Foundation (NSF)
(EPSCoR: EPS-1003970 as Subaward SA1306027: Test-Bed Development
of Advanced Flow Battery for Renewable Energy Storage)
15

16. Thank you!
16