Simulation analysis of low-temperature heat generation of power batteries based on the ECM model

When the power battery operates in low temperatures, it encounters challenges with charging and discharging, leading to a decline in battery performance, which can prevent electric vehicles from starting and reduce their driving range. To address this, the battery must possess the capability to adapt to both extremely high and low temperatures. This article employs ANSYS software to investigate the heat generation in batteries due to their own charging and discharging processes at different discharge rates under -20°C. When the battery is heated at a 1 C discharge rate for 20 minutes, its temperature rises by approximately 1.1°C; at 2 C, the temperature rises by about 5°C; and at 3 C, it rises by about 11°C. The greater the discharge rate is, the more heat is generated, resulting in a higher temperature rise. Furthermore, prolonged heating at a certain discharge rate can elevate the temperature to a level that is optimal for lithium-iron-phosphate batteries, ultimately reaching their optimal operating range. This research contributes to enabling lithium-ion power batteries to function normally in low-temperature environments, without compromising their lifespan. It is imperative to heat the interior of lithium-ion power batteries to ensure they can start normally after prolonged overnight parking, through preheating.