1. The Design and Investigation Zinc-Air Flow Battery with Automatic Control System (Phase II)
JINGYU SI
Mechanical Engineering Department
University of Wisconsin–Milwaukee

2. Outline Introduction of zinc-air flow battery system
Build up and test the reactor of zinc-air flow battery system
Morphological study of the surface change on zinc particles in zinc slurry anode during charge/discharge
Conclusion
Future work

3. Introduction of zinc-air flow battery system
WHY 01
WHAT 02
HOW 03

4. Energy densities for various types of batteries

5. Raw material costs

6. Zinc air battery Four major components Three main reactions
Two key problems

7. Redox flow battery Distinct structure Unique features
Low energy density

8. Zinc air flow battery system

9. Build up and test the reactor of zinc-air flow battery system
Introduction of reactor
The control component and algorithm
Study the performance of reactor
Study the durability of reactor

10. Reactor and reactor in system

11. The control component and algorithm

12. Polarization characteristics of for a single air-cathode reactor.
Polarization characteristics of 1st and 2nd generation prototype with single air electrodes(0.95 cm2) at constant flowing rate

13. Test up to DoD 10% discharge on the lifespan of the 1st generation reactor
Galvanostatic discharge up to 10% DoD of bi-air electrodes of 1st generation prototype at a current density of 40 mA cm-2 (respect to the geometric area of air cathode) constant flowing rate

14. Polarization characteristics of 2nd generation prototype
Polarization characteristics of 2nd generation prototype with single air electrodes (2.16 cm2) at constant flowing rate for 6 days

15. Galvanostatic discharge 1 hour of single air electrodes of 2nd generation prototype
Galvanostatic discharge 1 hour of single air electrodes of 2nd generation prototype at a current density of 100 mA cm-2 (respect to the geometric area of air cathode) constant flowing rate

16. Morphological study of the surface change on zinc particles in zinc slurry anode during charge/discharge
Half-cell discharge(oxidation) and charge(reduction) test
Morphology of the zinc particles in various DoD during oxidation in the half-cell setup.
Morphology of zinc particle in cell partial (DoD 20%-DoD 30%) reduction-oxidation cycling in half-cell setup

17. Half-cell discharge(oxidation) and charge(reduction) test
Three electrodes setup
Zinc particle was on the top of flat disc electrode
6 M KOH electrolyte
Potentiostatic oxidation/reduction

18. Morphology of the zinc particles in various DoD during oxidation in the half-cell setupB C D
DoD 0%
DoD 10%
DoD 20%
DoD 30%

19. Morphology of zinc particle in cell partial (DoD 20%-DoD 30%) reduction-oxidation cycling in half-cell setup A B C D
3rd DoD 30%
4th DoD 30%
5th DoD 30%
6th DoD 30%

20. Conclusion
The reactor with automatic control of rechargeable Zn-air flow battery has built up
The reactor show the power density was up to 280mW cm-2 and the current density was up to 330 mA cm-2 at constant flowing rate  (at 1V cut-off voltage).
The reactor shows the durability was up to 240 hours with little degradation.
The 20%-30% DoD state of zinc particle anode would be  suitable for zinc- based rechargeable battery

21. More studies about electrolytes, air cathode and battery configuration are needed to further improve performance and stability
The regenerator will be researched to charge the ZnO back to zinc without dendrites grow.
The control algorithm for other components in system will be created and studied.
Future work

22. Thank you
Questions ?