Transport of Ions, Molecules, and Electrons across the Solid Electrolyte Interphase: What Is Our Current Level of Understanding?

Abstract

The solid electrolyte interphase (SEI) on the graphite particles of lithium‐ion battery anodes passivates the anode against electrolyte reduction due to electron transfer reactions, and a stable and well‐passivating SEI is an important prerequisite for a long cycle life of batteries. Despite the importance of the SEI for fast battery cycling and for battery aging, the transport of ions, electrons, and molecules across the SEI is poorly understood. This prevents the development of improved SEI formation protocols for reducing the SEI formation time during battery manufacturing as well as for slowing down SEI aging. In this perspective article, possible transport mechanisms inside the SEI are considered, and an overview of the results of transport studies on SEIs formed on carbon‐based electrodes is given. The conclusions that can be drawn from these results are discussed as well as the most important open questions, which should be addressed in future work.

Hybrid solid electrolyte-liquid electrolyte systems for (almost) solid-state batteries: Why, how, and where to?

“…The presence of pinholes that allow for the percolation and further transport of ions and molecules across SEIs in model carbon electrodes has been recently demonstrated by Roling and coworkers. [84][85][86] Fig. 3a presents a selection of SE/LE systems recently reported in the literature.…”

Sustainable Synthesis of Sulfur-Single Walled Carbon Nanohorns Composite for Long Cycle Life Lithium-Sulfur Battery

“…[3] Indeed, the decrease of the cell resistance suggests the formation of a low resistive SEI facilitating the lithium ion transfer. [53] Figure 4(c) reports the CV tests performed by increasing the scan rate from 0.05 to 0.45 mV s -1 in order to calculate Dcv within the electrode material (see Figure S1 of Supporting Information for EIS after each incremental step). As expected, by increasing the scan rate, the peak intensity increases accordingly due to the decreased size of the diffusion layer.…”

Growth of the Solid-Electrolyte Interphase: Electron Diffusion Versus Solvent Diffusion

“…in form of neutral lithium interstitial diffusion [20,26]. However, the literature also provides arguments supporting a porous SEI allowing for solvent diffusion [32]. Arguments for solvent diffusion reported in the literature are observed currents from redox shuttles through the SEI [33,34] as well as swelling of the SEI inside the electrolyte compared to a dried SEI [35].…”