Electrochemical kinetics of SEI growth on carbon black, II: Modeling

Abstract

Mathematical models of capacity fade can reduce the time and cost of lithium-ion battery development and deployment, and growth of the solid-electrolyte interphase (SEI) is a major source of capacity fade. Experiments in Part I reveal nonlinear voltage dependence and strong charge-discharge asymmetry in SEI growth on carbon black negative electrodes, which is not captured by previous models. Here, we present a theoretical model for the electrochemical kinetics of SEI growth coupled to lithium intercalation, which accurately predicts experimental results with few adjustable parameters. The key hypothesis is that the initial SEI is a mixed ion-electron conductor, and its electronic conductivity varies approximately with the square of the local lithium concentration, consistent with hopping conduction of electrons along percolating networks. By including a lithium-ion concentration dependence for the electronic conductivity in the SEI, the bulk SEI thus modulates the overpotential and exchange current of the electrolyte reduction reaction. As a result, SEI growth is promoted during lithiation but suppressed during delithiation. This new insight establishes the fundamental electrochemistry of SEI growth kinetics. Our model improves upon existing models by introducing the effects of electrochemical SEI growth and its dependence on potential, current magnitude, and current direction in predicting capacity fade.

1 manuscript, 7 main text figures, 2 supplementary information figures

References in corpus (4)

• Theory of Chemical Kinetics and Charge Transfer based on Nonequilibrium Thermodynamics
• Identifying the Mechanism of Continued Growth of the Solid-Electrolyte Interphase
• Locomotion of Electrocatalytic Nanomotors due to Reaction Induced Charge Auto-Electrophoresis
• Electrochemical kinetics of SEI growth on carbon black, I: Experiments

Cited by in corpus (10)

• "Knees" in lithium-ion battery aging trajectories
• Electrochemical kinetics of SEI growth on carbon black, I: Experiments
• Chemo-Mechanical Model of SEI Growth on Silicon Electrode Particles
• Growth of the Solid-Electrolyte Interphase: Electron Diffusion versus Solvent Diffusion
• Systematic Feature Design for Cycle Life Prediction of Lithium-Ion Batteries During Formation
• A four parameter model for the solid-electrolyte interphase to predict battery aging during operation
• Theory of layered-oxide cathode degradation in Li-ion batteries by oxidation-induced cation disorder
• Microstructure-Resolved Degradation Simulation of Lithium-Ion Batteries in Space Applications
• Population Effects Driving Active Material Degradation in Intercalation Electrodes
• Transition between growth of dense and porous films: Theory of dual-layer SEI