电动汽车动力电池热管理系统基础科学问题研究

锂离子动力电池是发展电动汽车的关键。电池温度过高或过低以及分布的不均衡都不利于其性能的正常发挥和安全性，严重时甚至导致爆炸。本项目针对锂离子电池最佳工作和安全温度，提出基于环路热管耦合相变材料的紧凑型热管理系统。拟将开展如下基础科学问题研究: (1) 锂离子的嵌入、脱嵌及电解液流动的耦合作用对产热量、电池温度及其性能的影响规律。(2) 超薄型环路热管启动及传热极限的影响因素、影响规律及其设计理论模型。(3)基于烷烃的高导热高潜热相变材料的设计理论与微介观热力学特性表征。 . 通过理论、实验和数值模拟结合的研究方法，提出电池产热传热的耦合模型，揭示动力电池产热机理、温度分布及性能衰退规律；提出超薄型环路热管的设计理论模型，阐明非恒定热源条件下，汽-液/固-液相变耦合的热质传递规律；提出基于烷烃的相变材料设计与强化传热的有效方法。研究成果可为动力电池温控系统设计和性能提升提供指导。

The lithium-ion power battery plays a cruial role in developing of electric vehicles. However, excessive high or low temperature and uneven temperature distribution are disadvantages for the performance and safety of the batteries, leading to explosion in some extremely serious conditions. A compact thermal management system, which has integrated a novel loop heat pipe and phase change material , is proposed based on the optimal operation and safety temperature of lithium-ion battery. The main focused scientific issues of this project are listed as following: (1) the coupled effect for Lithium ion intercalation, deintercalate and electrolyte flow and the influence of this effect on heat generation quantity, battery temperature and performance. (2) the theoretical design model for ultra-thin loop heat pipe and some key factors that affect the starting performance and heat transfer limit. (3) the design theory of phase change materials with high thermal conductivity and latent heat, and the thermodynamics properties of phase change materials at microscopic and mesoscopic scale level..By combining the theoretical, experimental and numerical research methods, a coupled model for battery heat generation and its transfer is proposed to reveal the heat generation mechanism, temperature distribution and performance degradation mechanism. The theoretical model for the design of ultra-thin loop heat pipe is proposed to identify the coupled heat and mass transfer characteristics in vapor-liquid/solid-liquid phase under conditions with unsteady heat sources. Some effective design methods and heat transfer enhancement approaches for phase change materials based on alkanes are proposed. The present work is expected to provide guidelines for thermal management system design and performane improvement for power battery.