Modelling stress-affected chemical reactions in non-linear viscoelastic solids with application to lithiation reaction in spherical Si particles
Modelling stress-affected chemical reactions in non-linear viscoelastic solids with application to lithiation reaction in spherical Si particles
复制标题
DOI：
10.1016/j.ijengsci.2018.03.007
复制
发表时间：
2018-07
影响因子：
6.6
通讯作者：
M. Poluektov;A. Freidin;Ł. Figiel
中科院分区：
文献类型：
--
作者：
M. Poluektov;A. Freidin;Ł. Figiel
采用基于化学亲合张量的化学力学框架，结合有限应变非线性粘弹性本构模型，对球形颗粒中受应力影响的化学反应进行了模拟。该模型被应用到锂（Li）离子和硅（Si）之间的化学反应，这已被认为是有前途的继任者石墨用作锂离子电池（LIB）阳极的活性材料。然而，在LIB的充电期间，Si进入与Li离子的化学反应，引起Si颗粒的大的体积膨胀，这导致机械应力的出现，这进而可以影响化学反应的动力学，甚至直到反应停止。在本文中，分离的化学转化和未转化的阶段的反应前沿的传播建模，和耦合的应力扩散反应问题是用有限元方法来解决。该模型预测的延迟和锁定的化学反应在Si取决于化学能量参数的值，这对应于实验观察。
This paper aims at modelling stress-affected chemical reactions in spherical particles by adopting the chemo-mechanical framework based on the chemical affinity tensor and combining it with the finite-strain non-linear viscoelastic constitutive model. The model is applied to the chemical reaction between lithium (Li) ions and silicon (Si), which has been considered as promising successor to graphite for use as active material in lithium-ion battery (LIB) anodes. However, during charging of LIBs, Si enters into the chemical reaction with Li ions, causing large volumetric expansion of Si particles, which leads to the emergence of mechanical stresses, which, in turn, can affect the kinetics of the chemical reaction even up to the reaction arrest. In this paper, the propagation of the reaction front separating the chemically transformed and the untransformed phases is modelled, and the coupled stress-diffusion-reaction problem is solved using the finite element approach. The model predicts the retardation and the locking of the chemical reaction in Si depending on the values of the chemical energy parameter, which corresponds to experimental observations.