Abstract: To enhance the adaptability of thermal storage phase change materials (PCMs) to heating power and ambient temperature, a new idea was proposed to expand the temperature control range by using binary double-peak PCMs with two heat absorption peaks. Through thermal simulation of battery thermal management process, the influence of thermal conductivity on the temperature control performance of PCMs was explored. At the same time, the temperature control performance of LA30-SA70 was tested under six ambient temperatures and three heating power levels. The results indicate that the temperature control performance gradually improves as thermal conductivity increases, but the improvement tends to stabilize. When the thermal conductivity reaches 1.5 W/(m·K), the optimization of the battery pack's temperature control performance reaches a critical point. Compared with conventional single-peak PCMs containing lauric and stearic acids, LA30-SA70 demonstrates superior performance across six ambient temperatures, with a maximum temperature difference of less than 1.8 K and excellent ambient temperature adaptability. Under three heating power conditions, LA30-SA70 can not only keep the battery pack temperature within a reasonable range under low heating power (10000 W/m3), but also, under the combined effect of extremely high temperature (323.15 K) and extremely high heating power (100000 W/m3), it can still maintain the battery within the normal operating temperature range (< 333.15 K), showing excellent heating power adaptability.