High precision modeling and targeted thermal management for lithium-ion batteries using array technique

Lithium-ion batteries tend to generate a considerable amount of heat during operation, which presents a serious challenge to both their life and safety. A detailed comprehension of the heat production distribution and temperature distribution within the battery is necessary for effective thermal management to realize precise temperature control. However, in order to reduce the computational effort, most of the commonly used modeling methods to acquire the thermal characteristics of batteries are simplified to different extents, thereby inevitably compromising the computational accuracy. To this end, this paper presents a high-precision modeling method for lithium-ion batteries using array technique. This method employs an innovative array technique to achieve complete three-dimensional coupling of the electrochemical field and the thermal field at the battery unit level. It allows the precise determination of the current density distributions, heat production rate distributions and temperature distributions of all stacked battery units in the battery cell, as well as their variations with time, while maintaining superior computational efficiency. The modeling process is described in detail using a commercial lithium-ion battery, and the accuracy and validity of the model are verified through experiments. Taking the charging process as an example, the electrochemical and thermal characteristics of the battery unit and the battery cell are analyzed and discussed in detail. Based on this modeling method, a strategy of partitioning the battery and accurately applying targeted heat sources is further proposed. Using thermal inhomogeneity to resist overpotential inhomogeneity, this strategy greatly improves the lithium precipitation uniformity and reduces the lithium precipitation degree in the battery during the fast charging process. Therefore, the lithium precipitation phenomenon could be significantly suppressed, and the battery life and safety can be remarkably improved.