Replication data for: Stress dependence of the chemical potential of lithium in a silicon electrode

Data associated with the article "Stress dependence of the chemical potential of lithium in a silicon electrode": We report operando measurements and concurrent modeling of the stress dependence of the chemical potential of lithium in a silicon electrode. An experimental study is carried out on hydrogenated amorphous silicon thin films in which the electrode stress state is modified operando during electrochemical lithiation and delithiation by applying an external mechanical load. During galvanostatic cycling, the electrode is periodically subjected to a tensile strain, inducing stress variations that are reflected in voltage changes. The measured stress-induced voltage changes are interpreted using a well-established chemomechanical model of lithium insertion in silicon. Comparison of voltage measurements with model predictions allows us to determine the concentration-dependent Young's modulus (from 29 GPa to 26 GPa with increasing lithium content) and some of the viscoplastic parameters of lithiated silicon. The calibrated model shows good predictive capability when applied to lithiation cycles performed at a C-rate different from that of the calibration cycle. However, it shows limitations in explaining voltage changes under delithiation. These results show that thermodynamically-consistent chemomechanical models of lithiation not only adequately describe the effect of lithium insertion and deinsertion on stress, as already shown in the literature, but also capture the reverse effect of stress on lithium chemical potential in silicon. In this respect, this work opens up new perspectives for the quantitative validation and calibration of existing diffusion-deformation theories, notably by highlighting their possible limitations.

与论文《硅电极中锂化学势的应力依赖性》相关的数据集：本研究报道了硅电极中锂化学势应力依赖性的原位（operando）测量与同步建模工作。研究以氢化非晶硅薄膜为对象开展实验，在电化学嵌锂与脱锂过程中，通过施加外部机械载荷实现电极应力状态的原位调控。在恒电流循环（galvanostatic cycling）过程中，电极会周期性承受拉伸应变，由此引发的应力变化会体现在电压波动中。我们采用成熟的硅基嵌锂化学力学模型（chemomechanical model）对测得的应力诱导电压变化进行解读。通过将电压测量结果与模型预测值对比，我们得以确定锂含量依赖的杨氏模量（Young's modulus，随锂含量增加从29 GPa降至26 GPa）以及嵌锂硅的部分粘塑性参数（viscoplastic parameters）。经校准后的模型应用于与校准循环倍率（C-rate）不同的嵌锂循环时，展现出良好的预测能力，但该模型在解释脱锂过程中的电压变化时存在一定局限。上述结果表明，热力学自洽的嵌锂化学力学模型不仅能如已有文献所述，充分描述锂嵌脱过程对应力的影响，还能捕捉应力对硅中锂化学势的反向调控作用。就此而言，本研究为扩散-变形理论的定量验证与校准开辟了全新视角，尤其通过凸显其潜在局限实现了这一目标。