Nucleation and Growth Mode of Solid Electrolyte Interphase in Li-Ion Batteries

Abstract

The solid electrolyte interphase (SEI) is regarded as the most important yet least understood component in Li-ion batteries. Considerable effort has been devoted to unravelling its chemistry, structure, and ion-transport mechanism; however, the nucleation and growth mode of SEI, which underlies all these properties, remains the missing piece. We quantify the growth mode of two representative SEIs on carbonaceous anodes based on classical nucleation theories and in situ atomic force microscopy imaging. The formation of inorganic SEI obeys the mixed 2D/3D growth model and is highly dependent on overpotential, whereby large overpotential favors 2D growth. Organic SEI strictly follows the 2D instantaneous nucleation and growth model regardless of overpotential and enables perfect epitaxial passivation of electrodes. We further demonstrate the use of large current pulses during battery formation to promote 2D inorganic SEI growth and improve capacity retention. These insights offer the potential to tailor desired interphases at the nanoscale for future electrochemical devices.

Proximity Matters: Interfacial Solvation Dictates Solid Electrolyte Interphase Composition

“…This SEI formation process continues until most of the Cu surface is covered (and hence passivated) (Figure c). The illustration of SEI formation shown in Figure c is consistent with those reported in other SEI formation studies. , …”

Highly Catalytic CoP@N, P-Codoped Porous Carbon Synthesized by a Supramolecular Gel and Salt Template Method for Li–S Batteries

“…The scatter data in the figure are test data, and the four curves correspond to four classical electrochemical deposition modes. When the crystal is two-dimensionally nucleated, the nucleation behavior is subdivided into two-dimensional progressive nucleation (2DP) and instantaneous nucleation (2DI) according to the Bewick, Fleischman, and Thirsk models. , Similarly, the three-dimensional nucleation behavior is subdivided into three-dimensional progressive nucleation (3DP) and instantaneous nucleation (3DI) according to the Scharifter–Hills model . The dimensionless equations corresponding to the four nucleation behaviors are as follows:…”

Role of Oxygen in the Formation of the Solid-Electrolyte Interphase Evaluated by Online Electrochemical Mass Spectrometry and Electrochemical Atomic Force Microscopy

“…Furthermore, since it is unnecessary to worry about the influences of the Faradic and non-Faradic currents on the tunneling current for EC-STM, one of the other important surface imagining techniques, the EC-AFM is relatively easier to apply in the electrochemical system with slightly lower spatial resolution. Several excellent EC-AFM studies have been carried out on the electrode surfaces of secondary batteries, such as Li-ion batteries, ,− Li–oxygen batteries, − and Li–sulfur batteries. − These studies provide a fundamental understanding of the cathode or anode reaction mechanisms during the charge and discharge processes from the in situ observation of their morphological changes.…”