Energy Storage using Zinc-Air Batteries

Energy Storage using Zinc-Air Batteries

Battery technology is becoming more and more important for different reasons. Some examples are electric cars and buffer storage of regenerative energy. Zinc-air batteries are very promising candidates because of their high energy density and good recyclability. However, the lower power density compared to lithium-ion cells, so far prevents these typical applications. Therefore, the cell chemistry and geometry is analyzed and optimized in this research project in order to increase the power density of zinc-air cells.

In an earlier research project, a test system with 12 zinc-air cells was already set up and evaluated at the PV system of University of Applied Sciences Münster. Now, a much larger demonstrator, using a total of 72 cells, is being developed and tested at the 100kW peak PV system of Stadtwerke Steinfurt. The demonstrator is assembled in a standard server cabinet, with the cells stored in 6 drawer modules of 12 cells each. The other two drawers contain the power electronics, the control unit and the electrolyte management. Each cell has a capacity of approx. 100 Ah, giving Demonstrator a total capacity of 7.2 kWh. All drawers are connected to the control unit via CAN bus. This controls the entire demonstrator and, for example, switches individual drawers to charging or discharging, depending on the available PV power.