动力电池组全寿命周期高效能均衡策略研究

Lithium-ion battery has become the mainstream of new energy vehicle battery due to its advantages of high specific energy, long cycle life, low self-discharge rate and low pollution to the environment. However, the use performance, cycle life and safety of the power battery pack have not been fundamentally solved. It has become an important bottleneck restricting the development of electric vehicle industrialization, which has seriously affected the range, power performance, service life and safety of the vehicle. This project takes Li-ion battery as the research object. Firstly, the influence law of the battery's electrochemical characteristics, thermal characteristics and aging process is revealed, and the coupled electro-thermal-aging model is established to design battery multi-state co-estimation algorithm. Then, the mechanism of battery life recession is expounded and cycle life model is built in multi-stress and multi-interval to develop inconsistency diagnostic methods of battery pack. Finally, a multi-constraint conversion equalization mechanism is established to form a set of theory and method for battery high efficiency balancing strategy in full life cycle. These provide basic theory and key technical support for improving the performance of electric vehicle battery system in our country.

锂离子动力电池因具有比能量高、循环寿命长、自放电率低和对环境污染小等优点，目前成为主流的新能源汽车动力电池。然而，动力电池成组后的使用性能、循环寿命和安全性等问题并未得到根本解决，严重影响整车的续航里程、动力性能、使用寿命和安全性等，已成为制约电动汽车产业化发展的重要瓶颈。本项目以锂离子动力电池组为研究对象，首先揭示电池电化学特性、热特性以及老化过程之间的影响规律，建立电池电-热-老化耦合模型，设计电池多状态联合估计算法；然后，阐明电池多应力多区间的寿命衰退机理，构建多应力多区间循环寿命模型，开发电池组不一致诊断方法；最后，建立全寿命周期多约束转换均衡机制，形成一套动力电池组全寿命周期高效能均衡策略的理论与方法。为提高我国电动汽车动力电池系统性能提供基础理论和关键技术支撑。

锂离子动力电池因具有比能量高、循环寿命长、自放电率低和对环境污染小等优点，目前成为主流的新能源汽车动力电池。然而，动力电池成组后的使用性能、循环寿命和安全性等问题并未得到根本解决，严重影响整车的续航里程、动力性能、使用寿命和安全性等，已成为制约电动汽车产业化发展的重要瓶颈。项目执行以来，主要创新性成果包括：1、综述类代表性成果，电动汽车串联电池组均衡管理策略，面向先进电池管理的状态估计：关键挑战与未来趋势；2、电池单体多维度耦合建模及状态联合估计代表性成果，固液混合电解质锂离子电池在不同条件下的电化学阻抗特性研究，基于电化学-热-神经网络融合模型的SOC和SOT联合估计；3、电池组多应力多区间不一致演化机理及诊断方法代表性成果，动力电池组不一致性演化机制及诊断方法，串联电池组结构模型综合评价研究，基于模糊自适应联邦滤波的电池组可靠荷电状态估计；4、电池组全寿命周期多约束转换均衡策略研究，基于多时间尺度SOC和容量的锂离子电池组均衡策略，基于模型预测控制的串联电池组全寿命周期均衡策略。. 本项目实施过程中，已发表期刊学术论文13篇，全部为SCI论文，其中，ESI高被引论文3篇，中科院SCI一区论文9篇，其中包括：Renewable & Sustainable Energy Reviews、Journal of Power Sources、Applied Energy、Energy等杂志。共申请发明专利14项，其中已授权3项，已受理11项。