Significant attention has been paid to lithium-ion batteries (LIBs) with high energy density and excellent cycle life, because new applications such as electric vehicles (EVs) and energy storage systems (ESSs) are rapidly emerging into the market. However, current LIBs cannot satisfy the low temperature performance for further applications of EVs in cold climates. It is common that the LIBs lose most of their reversible capacity and power density as the temperature decreases below 0 ^oC.^1,2 Therefore, improving low temperature performance has been an important subject for many researchers. In our study, we firstly try to investigate the factors that limit the low temperature performance of LIBs by using electrochemical impedance spectroscopy (EIS) analysis. Furthermore, we examine the electrochemical characteristics of LIBs with electrolyte solution containing small amounts of different low-temperature additives. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analyses have been also implemented to identify and inspect the detailed mechanism for improving the low temperature performance.

References

1. S.S. Zhang, K. Xu and T.R. Jow, Electrochim. Acta, 49, 1057 (2004).
2. K. Xu, Chem. Rev., 104, 4303 (2004).