Properties of ZEBRA Cells

ZEBRA cells have a high open-circuit voltage (OCV) of 2.58 V at 300 °C. The temperature dependency of the OCV is shown in Fig. 2. 

The thermoneutral potential is 2.72 V this means that during charging at voltage below this value ZEBRA cells will be cooled thermodynamically. 

The second electrolyte, the melt of sodium aluminum chloride, provides another advantage for the ZEBRA system. This second electrolyte makes the system tolerant to overcharge and overdischarge. In the overcharge reaction NaAlCl4 reacts with nickel to form sodium, nickel chloride, and 

This reaction will take place after total consumption of the salt in the cell. The emf of this reaction amounts to 3.05 V. 

When all the nickel chloride has been discharged, the remaining sodium will react with sodium aluminum chloride to form sodium chloride and aluminum  

Molten salt electrolyte Sodium aluminium chloride. Ceramic solid electrolyte 

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The properties of the molten electrolyte sodium aluminum chloride influence the performance and the behavior of the ZEBRA cell. 

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