Sodium/nickel-chloride batteries battery technology

This section on battery-ievel information is organized the same as Sec. 40.3. That is, battery-ievei design considerations specific to the sodium/sulfur technology are presented first. Then, brief descriptions of modern battery configurations and performance for both sodium-beta technologies are provided. For reference, a schematic diagram of an integrated sodium/ nickel-chloride battery system was shown previously in Fig. 40.5b. 

In Europe, the drive system of the Impact propelled the Opel Impuls2, a conversion vehicle based on the Opel Astra Caravan in 1991. A new, specifically developed AC induction drive unit with IGBT inverter technology was used to build a small fleet of Impuls vehicles see Figure 8.4). The fleet served as an automotive test bed for the integration of various advanced battery systems such as nickel-cadmium, nickel-metal hydride, sodium-nickel chloride, sodium-sulfur, and sealed lead-acid. 

Sodium/nickel chloride is a relatively new variation of the sodium/beta technology and was being developed mainly for electric-vehicle applications. There has not been nearly the effort on this chemistry as on the sodium/sulfur battery. 

A battery system closely related to Na—S is the Na—metal chloride cell (70). The cell design is similar to Na—S however, ia additioa to the P-alumiaa electrolyte, the cell also employs a sodium chloroalumiaate [7784-16-9J, NaAlCl, molten salt electrolyte. The positive electrode active material coasists of a transitioa metal chloride such as iroa(Il) chloride [7758-94-3] EeQ.25 or nickel chloride [7791-20-0J, NiQ.25 (71,72) in Heu of molten sulfur. This technology is in a younger state of development than the Na—S. 

Africa)io is a variant of sodium-sulfur technology where sulfur is replaced with a metal chloride such as NiCl2 (nickel chloride) or FeCU. It was specifically developed for applications in electric vehicles, freight transport and public transport the ZEBRA battery is more particularly intended to serve buses and utility vehicles. As with the Na-S battery, the vibrations felt in a vehicle may cause premature aging of the ceramic/metal interface. Today, such batteries are also being considered for stationary applications. 

Sodium/sulfur and sodium/metal chloride technologies are similar in that sodium is the negative electrode material and beta-alumina ceramic is the electrolyte. The solid electrolyte serves as the separator and produces 100% coulombic efficiency. Applications are needed in which the battery is operated regularly. Sodium/nickel chloride cells have a higher open-circuit voltage, can operate at lower temperatures, and contain a less corrosive positive electrode than sodium/sulfur cells. Nevertheless, sodium/nickel chloride cells are projected to be more expensive and have lower power density than sodium/sulfur cells. 

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