Opto-chemical sensors for direct measurement of state of energy in electric battery cells

电池组是电动汽车（EV）的主要能源，其管理在促进消费者广泛采用EV方面发挥着重要作用。需要确定单个电池单元的真实化学能量状态（SOE），以实现实时电池组性能管理，同时预测退化和故障。目前，性能管理是使用诸如电流、电压和表面温度的参数来完成的，这些参数由布置在电池组中而不是电池组中的每个单个电池中的电传感器提供;通过这种方法，某些参数，诸如单个电池中剩余的化学能的确切量或其健康状态（SOH）不能被揭示。此外，电池内部工作温度的变化会影响电池内部化学过程的动力学，导致电池退化或直接影响SOE。潜在的故障和过早的电池退化通常通过不使电池满容量运行和过度设计电池组来避免。该研究计划的长期目标是使用光纤（FO）传感器为电动汽车电池组开发一种新的传感框架，从而更有效地管理其性能。（1）开发用于直接测量电池单元的SOE和内部温度的多功能FO传感器的可行制造方法：由申请人开发的用于监测内部单元能量的嵌入式光化学FO传感器将被多路复用以允许在同一光纤内进行内部温度感测;（2）用于直接测量SOE和温度的多功能光化学传感器的建模和验证：建模将集中于（i）使用传感器数据来更好地估计电池的SOE;以及（ii）监测嵌入阶段转变中的漂移或变化以及温度变化来估计SOH。这些模型将使用当前的工业基准进行验证;以及（3）嵌入式多功能光化学FO传感器的实施和封装：一个经过验证的紧凑型基于LED的光学系统，带有信号放大电路，将被多路复用，以同时测量SOE和内部温度，从而准确估计单个电池的SOH，这对于实时EV电池组监控至关重要。这将实现新的管理策略，从而更安全和最佳地利用真正的电池容量，这将改善电池组昂贵的保守设计，从而有助于加速电动汽车的大众消费者采用。申请人经过验证的记录和最先进的传感器开发实验室将为HQP提供成功实现上述研究目标所需的工具，并将帮助加拿大成为电动汽车技术的全球领导者。

The battery pack is the main source of energy in electric vehicles (EVs) and its management plays a big role in promoting widespread adoption of EVs by consumers. Determination of the true chemical state of energy (SOE) of individual battery cells is needed to enable real-time battery pack performance management while predicting degradation and failure. Currently, performance management is done using parameters such as current, voltage and surface temperature, provided by electrical sensors collocated in groups of cells rather than in every single cell in the pack; through this approach, certain parameters, such as the exact amount of chemical energy left in a single cell or its state of health (SOH) cannot be revealed. Additionally, variations in cell internal operating temperature influence the kinetics of the chemical process within it, causing cell degradation or directly influencing the SOE. Potential failure and premature cell degradation are usually avoided by not operating the cells to their full capacity and over-engineering the battery packs. The long-term goal of this research program is to develop a new sensing framework for EVs battery packs using fiber optic (FO) sensors leading to a more effective management of their performance. To do so, the applicant has identified the following short-term objectives: (1) Development of viable fabrication methods for multifunctional FO sensors for direct measurement of SOE and internal temperature of battery cells: an embedded opto-chemical FO sensor developed by the applicant to monitor internal cell energy will be multiplexed to allow internal temperature sensing within the same fiber; (2) Modeling and validation of multifunctional opto-chemical sensors for direct measurement of SOE and temperature: the modeling will focus on (i) using the sensor data to better estimate the SOE of the cell; and (ii) monitoring drifts or changes in the intercalation stage transitions together with temperature variations to estimate SOH. The models will be validated using current industrial benchmarks; and (3) Implementation and packaging of embedded multifunctional opto-chemical FO sensors: a demonstrated compact LED-based optical system interrogator with signal amplification circuitry will be multiplexed to simultaneously measure SOE and internal temperature for accurate estimation of SOH of individual cells, crucial for real-time EV battery pack monitoring. This will enable new management strategies that will lead to safer and optimal utilization of true cell capacity which will improve costly conservative design of battery packs, thus helping to accelerate mass consumer adoption of EVs. The applicant's proven record and state-of-the-art sensor development laboratory will provide HQP with the necessary tools to succeed in achieving the above research objectives and will help position Canada as a global leader in EVs technology.