An electrochemical–thermomechanical model for the description of charging and discharging processes in lithium electrodes is presented. Multi-physics coupling is achieved through the constitutive relations, obtained within a consistent thermodynamic framework based on the definition of the free energy density, sum of distinct contributions from different physics. The system is characterized by finite kinematics, under the assumption of locality of deformation, and the deformation gradient is decomposed into the product of elastic and inelastic parts. Specifically, a Taylor series expansion is used to approximate the inelastic deformation due to ion intercalation. The elastic part can be described alternatively by two finite kinematics models of neo-Hookean elasticity, and a Maxwell-type viscoelastic model accounts for time-dependent mechanical aspects. The model is implemented into a finite element code that uses B-spline basis functions. We illustrate the features of the model by means of selects examples, showing that chemo-mechanical interaction affects the equilibrium concentrations of the phases. The model captures the fundamental aspects of the anode charging and discharging processes.

介绍了用于描述锂电极充电和放电过程的电化学热力学模型。多物理场耦合是通过本构关系实现的，本构关系是在自由能密度定义的基础上，在一个一致的热力学框架内获得的，该总和来自不同物理学的不同贡献。该系统具有有限运动学特性，在假设变形局部的情况下，将变形梯度分解为弹性和非弹性零件的乘积。具体地，泰勒级数展开被用于近似由于离子嵌入而引起的非弹性变形。弹性部分可以用新霍克弹性的两个有限运动学模型来描述，麦克斯韦型粘弹性模型解释了与时间有关的力学方面。该模型被实现为使用B样条基函数的有限元代码。我们通过选择实例来说明该模型的特征，表明化学机械相互作用会影响各相的平衡浓度。该模型捕获了阳极充电和放电过程的基本方面。