Low temperature performance of Li/S batteries

This paper relates to development of a new generation of Li/S rechargeable batteries with energy density exceeding 180 Wh/kg and rate capability comparable with aqueous systems. The cells demonstrate 5 C discharge rate at -40DGC. Retained energy and capacity at -40DGC exceeded 60 and 80%, respectively. At room temperature cells generate specific power up to 750 W/kg. Cells are inherently protected from overcharge at low and room temperatures by internal chemistry and can sustain 30 times overcharge. It was shown that at -40DGC sulfur cathode discharge includes at least five steps, in contrast to the known two steps at room temperature. Thermal effects related to different charge-discharge steps were analyzed. Cell thermal model including Ohm and Arrhenius parts of polarization allowed simulation Ragone plots and capacity over a wide range of currents and temperatures.