圆柱型锂离子电池三维分层热耦合模型研究

Research on 3D Layered Thermal Coupling Model of Cylindrical Lithium-ion Battery

圆柱型锂离子电池的电芯由电池单元卷绕形成,其中电池单元由浸润在电解液中的正负极片、隔膜以及正负极耳组成。三维平均体积模型难以分析电池内部复杂的电化学系统,对此,针对实物的三维结构建立了考虑瞬态温度变化与电化学反应间相互影响的三维分层模型。通过实验验证了模型的准确性,基于模型结果详细分析了在不同放电倍率下电池内部电流密度和极化电压等电化学特征、焦耳热及反应热的产热速率和电池内部温度分布。研究结果有助于后续电池温度一致性及热管理技术的研究。

The electric core of a cylindrical lithium-ion battery is formed by winding the cell unit,which is composed of positive and negative electrodes,a separator,and positive and negative current collectors impregnated in the electrolyte.As a result,the three-dimensional(3D)average volume model is difficult to analyze the complex electrochemical system inside the battery.To solve this problem,a 3D layered model considering the interaction between transient temperature changes and electrochemical reactions is established for the 3D structure of an object.The accuracy of this model was verified through experiments.Based on the model results,the electrochemical characteristics(e.g.,the current density and polarization voltage inside the battery),the heat generation rate of Joule and reaction heat,and the internal temperature distribution within the battery were analyzed in detail at different discharge rates.The result in this paper will contribute to the sub-sequent research on the battery temperature consistency and thermal management technology.