CAREER: Enabling High Performance Battery Charging Systems: Adaptive and Optimal Charging Algorithms Based on Dynamic Battery Characteristics

锂离子电池具有较高的能量密度，是一种优良的储能设备。锂离子电池相当昂贵，人们希望尽可能延长它们的循环寿命。然而，传统的电池充电算法没有考虑电池的时变电化学性质，因为电化学行为背后的理论是复杂的，并且在计算上具有挑战性，难以将其纳入充电算法。该项目的主要目标是提供一种新的创新方法，实现电动汽车的高充电效率和长循环寿命，可再生能源储存，并建立备用电源应用。基于电化学参数的自适应充电算法将根据电池的内部状态调整充电电流，从而提高充电效率并降低热应力。因此，该项目不仅将提供一种提高充电效率的方法，从而延长循环寿命、节省能源并降低维护成本；而且电力电子技术现在将能够在其充电算法中嵌入针对时变电化学行为的控制能力，而无需额外成本。我们期望通过这项研究，我们将对高功率电池组中发生的复杂行为有一个深刻的了解，并由此显著提高这类系统的性能和可负担性。因此，该项目的成果不仅有望从根本上推动电池充电算法领域的发展，而且还将产生广泛和高度积极的社会影响。更具体地说，本项目的目标是研究一种新的框架，将动态电池阻抗测量集成到电池充电算法中，以提高电池的充电效率、可靠性和循环寿命。阻抗的变化与电化学状态的变化相关，特别是与电池内的电导率程度相关。研究的重点是：1)有效和高效地在线测量时变电化学阻抗；2)开发自适应正弦充电算法；3)构建用于电池寿命周期测试的实时半实物试验台，并验证伴随的自适应充电算法。对电池充电的基本了解和先进的能量接口将为支持节能、可靠和长周期寿命电池的充电算法的开发带来重大飞跃。此外，这项研究的结果不仅将提高当今最先进的储能技术的能力，而且将适用于所有电池化学，因为其他电化学设备的内部现象表现出相似之处。这确保了这项研究将使储能系统设计者受益，无论他们选择的材料和设计如何。这还具有第二个好处，即提高以电化学储存为组成部分的综合可再生能源的效率和寿命。这项研究的结果将被整合到现有的与电力电子和电力系统相关的研究生和本科课程中。除了研究生/本科生教育，基于项目的学习计划将通过技校报告、K-12学生示范和暑期学校教师研讨会来开发和传播。

Lithium-ion batteries are excellent energy storage devices due to their high energy density. Lithium-ion batteries are rather costly, and it is desirable to extend their cycle life as much as possible. However, conventional battery charging algorithms do not consider the time-varying electrochemical properties of batteries because the theory behind electrochemical behavior is complex and computationally challenging to incorporate within charging algorithms. The primary target of this project is to provide a new, innovative approach enabling high charging efficiency and long cycle life in electric vehicles, renewable energy storage, and building back-up power applications. Adaptive charging algorithms based on electrochemical parameters will enhance charging efficiency and reduce thermal stress by adjusting the charging current with respect to the internal state of the batteries. As a result, this project will not only provide a method for improved charging efficiency, which will enable increased cycle life, energy savings, and reduced maintenance costs; but also power electronics technologies will now be able to embed control capability with respect to time-varying electrochemical behavior in their charging algorithms without extra cost. It is our expectation that we will gain a profound understanding of the complex behavior occurring within high power battery stacks as a result of this research, and from this we may significantly improve the performance and affordability of such systems. Thus, the outcomes of this project are not only expected to fundamentally advance the field of battery charging algorithms, but also to have broad and highly positive societal impact. More specifically, the objective of this project is to investigate a novel framework that integrates dynamic battery impedance measurements into battery charging algorithms in order to enhance the charging efficiency, reliability, and cycle life of batteries. The variations in impedance are correlated with changes in the electrochemical state, and, particularly, the degree of conductivity within the battery. The research thrusts will be: 1) effective and efficient on-line measurement of the time-varying electrochemical impedance, 2) development of an adaptive sinusoidal charging algorithm, and 3) construction of a real-time hardware-in-the-loop test-bed for battery life cycle testing and validation of the concomitant adaptive charging algorithms.A fundamental understanding of battery charging and advanced energy interfaces will provide a significant leap in the development of charging algorithms supporting energy efficient, reliable, and long cycle life batteries. Moreover, results of this research will not only improve the capabilities of today's state-of-the-art energy storage technologies, but will be applicable to all battery chemistries because the internal phenomena of other electrochemical devices exhibit similarities. This ensures that this research will benefit energy storage system designers, regardless of their choice of materials and design. This also has the secondary benefit of improving the efficiency and lifespan of integrated renewable energy sources featuring electrochemical storage as a constituent component. The results of this research will be integrated into existing graduate and undergraduate courses related to power electronics and power systems. Beyond graduate/undergraduate student education, project based learning programs will be developed and disseminated via technical school presentations, K-12 student demonstrations, and summer school teacher workshops.