锂离子电池组低温预热放电特性与不一致性研究OA

Performance degradation and consistency deterioration of lithium-ion battery packs in low-temperature environments are key bottlenecks for their widespread application,and external preheating is considered an important solution.Taking lithium-ion battery packs for electric vehicles as the research object,this paper systematically studies the effects of external preheating on the low-temperature discharge performance and consistency of the battery pack by comparing low-temperature discharge experiments under different preheating durations.The results show that at-20℃,moderate preheating can increase the battery pack's discharge voltage by up to 9.74V,boost discharge capacity by 0.9%～3.8%,and ensure sustainable high-rate discharge of the battery pack.At the same time,moderate preheating can reduce the standard deviation of temperature between individual cells by up to 49.6%,improving consistency during discharge.However,excessively long preheating times do not further improve consistency and instead accelerate the accumulation of differences due to worsening temperature distribution.