Development of high-performance Na/NiCl2 cell

The performance of the Ni/NiCl₂ positive electrode for the Na/NiCl₂ battery has been significantly improved by lowering the impedance and increasing the usable capacity through the use of chemical additives and a tailored electrode morphology. The improved electrode has excellent performance even below 200°C and can be recharged within one hour. The performance of this new electrode was measured by a conventional galvanostatic method and by a newly developed power dynamic method. These measurements were used to project the performance of 40- to 60-kWh batteries built with this new electrode combined with the already highly developed sodium/β"-alumina negative electrode. These calculated results yielded a specific power of 150-400 W/kg and a specific energy of 110-200 Wh/kg for batteries with single-tube and bipolar cell designs. This high performance, along with the high cell voltage, mid-temperature operation, fast recharge capability, and short-circuited failure mode of the electrode couple, makes the Na/NiCl₂ battery attractive for electric vehicle applications