摘要随着石油等非再生资源日益减少，新能源革新的时代已经到来。汽车行业也不例外，研发出采用锂离子电池的纯电动汽车和混合动力汽车。锂离子电池电池具有高电压平台、单位质量释放电量大、自放电低、可循环使用且环保等优点，目前很多专家都很重视锂离子电池的研发。纯电动汽车也因为锂电池的发展被国际上知名的汽车公司大力推广。由于锂离子电池在充放电过程中会产生大量的热量，会导致电池组内部热量累积温度升高，降低锂电池的工作性能和电池的使用寿命，严重时甚至会导致锂电池发生爆炸。混合动力汽车采用风冷散热系统就能满足散热需求，但是纯电动汽车采用电池组作为唯一动力源，发热量较大，就需要用散热性能更好的液冷系统。86279

本文以LiFePO4软包电池为研究对象，根据LiFePO4电池参数和任务书要求，工作如下:

1)通过网上和图书馆查阅了大量资料，了解目前锂离子电池和电池箱的液冷散热机构的研究现状，根据目前液冷散热系统的不足设计出一个有效的电池散热箱体结构；

2)研究并分析锂离子电池的工作原理、生热机理和热特性，提供理论数据基础；

3)首先使用Solidworks Simulation分析在自然空气对流情况下锂电池组的温度场，观察电池组散热情况。再利用SolidWorks Flow Simulation仿真软件对电池组进行仿真模拟，模拟出电池组正常工作时液冷电池箱的温度场，探究电池箱在液冷情况下的散热情况，分析问题所在。

4)强化电池组箱体的散热效果，将液冷管嵌入下板中，增加直接接触面积，再利用Solidworks flow simulation 进行瞬态分析，对比两者的温度场，完成最终的优化。

毕业论文关键词: 纯电动汽车；软包电池；电池组箱体；液冷机构；模拟仿真

Abstract With dwindling oil and other non-renewable resources, a new era of energy innovation has come。Car industry in no exception, develops lithium ion battery of pure electric vehicles and hybrid cars。Lithium ion batteries battery platform with high voltage, large unit mass release energy, low self-discharge, reusable and environmental protection advantages, now many experts are attaching great importance to research and development of lithium ion batteries。Because lithium-ion batteries in charging and discharging process will produce a lot of heat, can cause battery internal heat accumulated temperature, degrade the performance of lithium-ion batteries and battery life, serious when even lead to lithium battery explosion。Hybrid vehicle USES the water cooling system can meet the demand of heat dissipation, but pure electric vehicles use battery as the sole source of power, calorific value is bigger, you need use the cooling performance better surface system。

Taking LiFePO4 battery soft packages as the research object, according to the request of LiFePO4 battery parameters and specification, work is as follows:

(1)Through Internet and library to consult a large amount of data, understand the current lithium ion battery and battery box liquid-cooled heat dissipation mechanism research present situation, according to the current lack of liquid-cooled heat dissipation system design a effective battery cooling box structure;

(2)Research and analysis of the working principle of lithium-ion battery, heat generating mechanism and thermal characteristics, provides the theoretical data base;

(3)The first to use Solidworks Simulation analysis in the natural air convection condition the temperature field of a lithium-ion battery pack, observe the battery cooling conditions。 Using SolidWorks Flow Simulation Simulation software Simulation was carried out on the battery pack, simulate the battery work normally when surface the temperature field of a battery box, explore the battery box under the condition of surface cooling conditions, analysis of the problem。