Solid–Electrolyte Interphase During Battery Cycling: Theory of Growth Regimes

Abstract

The capacity fade of modern lithium ion batteries is mainly caused by the formation and growth of the solid–electrolyte interphase (SEI). Numerous continuum models support its understanding and mitigation by studying SEI growth during battery storage. However, only a few electrochemical models discuss SEI growth during battery operation. In this article, a continuum model is developed that consistently captures the influence of open‐circuit potential, current direction, current magnitude, and cycle number on the growth of the SEI. The model is based on the formation and diffusion of neutral lithium atoms, which carry electrons through the SEI. Recent short‐ and long‐term experiments provide validation for our model. SEI growth is limited by either reaction, diffusion, or migration. For the first time, the transition between these mechanisms is modelled. Thereby, an explanation is provided for the fading of capacity with time t of the form t β with the scaling coefficent β , 0≤ β ≤1. Based on the model, critical operation conditions accelerating SEI growth are identified.

Understanding the Nature of Solid‐Electrolyte Interphase on Lithium Metal in Liquid Electrolytes: A Review on Growth, Properties, and Application‐Related Challenges

“…who extended the model from Ref. [27c] for cycling conditions, similarly observe a transition from linear to square‐root to linear corresponding to transition from reaction to diffusion to migration‐limited growth mechanism [28] . The authors however suggested that the transition to the linear regime for the ultra‐long time is inherent to the electrochemistry of SEI growth and not necessarily solely due to the cracks and reformation.…”

Early Battery Performance Prediction for Mixed Use Charging Profiles Using Hierarchal Machine Learning

“…The modeling framework presented here could likely account for the impact of rest SOC on long‐term degradation if the rest SOC was varied within the training set. Creating a more robust prediction will require more direct accounting, especially for LLI, as LLI associated with SEI growth is known to vary distinctly with EOC and T [14,31] …”

Effects of Optimized Electrode Surface Roughness and Solid Electrolyte Interphase on Lithium Dendrite Growth

“…The influence of the SEI on dendrite evolution can be studied from the aspects of its properties such as thickness and conductivity. The relationship between SEI thickness, L SEI , and conductivity can be expressed as [33] L…”

“…Under different conductivities, the time difference of Li ion passing through SEI is negligible. [33] The thickness of the SEI was increased to 200 nm to study the effect of conductivity on the dendrite behavior, as shown in Figure 10c. When the conductivity of the SEI is 0.0001 S m À1 , the electrode surface shows uniform deposition without dendrite formation.…”