The performance of electric vehicles (EVs) is largely determined by the properties of lithium-ion batteries (LIBs), particularly in terms of range, charging efficiency, and usage safety. Ambient temperature plays a critical role in influencing these properties, with low temperatures causing a notable decline in energy availability and power output. Moreover, prolonged exposure to such conditions accelerates battery degradation, ultimately reducing its lifespan. The commonly used LIBs for EVs have a noticeable decrease in capacity and operating voltage at −10 ℃. At −20 ℃, the performance significantly declines, marked by a drastic reduction in discharge capacity, retaining only approximately 30% of the specific capacity observed at normal temperatures. Meanwhile, in low-temperature environments, it is difficult to charge LIBs. Metal lithium is prone to accumulate on the anode’s surface during charging. The lithium dendrites formation can penetrate the battery separator, leading to an internal short circuit. This not only results in irreversible damage to the battery but also triggers thermal runaway. Research data shows that the battery power characteristics deterioration and the charge–discharge coulombic efficiency’s decrease caused by low temperature are one of the objective factors that restrict the play of electric vehicle technical advantages and practical application. Therefore, the following will be through battery single cell testing research, and carry out low-temperature charge–discharge tests on the currently mainstream nickel–cobalt-manganese system (LiNi1/3Co1/3Mn1/3O2/C) and lithium iron phosphate system (LiFePO4/C) batteries, to explore the lithium-ion batteries characteristics under low temperature and the key factors that restrict their low-temperature performance.