Nucleation and Growth Mechanism of Anion‐Derived Solid Electrolyte Interphase in Rechargeable Batteries

• Published in: Angewandte Chemie International Edition Vol. 60; no. 15; pp. 8521 - 8525
• Main Authors: Yan, Chong, Jiang, Li‐Li, Yao, Yu‐Xing, Lu, Yang, Huang, Jia‐Qi, Zhang, Qiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 06.04.2021
• Edition: International ed. in English
• Subjects: Anions; Atomic force microscopes; Atomic force microscopy; Batteries; Crystallization; Electrochemistry; Electrolytes; Growth models; interfacial chemistry; Interphase; Ion transport; isothermal electrochemical crystallization; Lithium; Nucleation; nucleation and growth mechanism; Rechargeable batteries; solid electrolyte interphase; Solid electrolytes; Surface reactions; Two dimensional models; two-dimension (2D) growth; nucleation and growth mechanism; isothermal electrochemical crystallization; two-dimension (2D) growth; solid electrolyte interphase; interfacial chemistry
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202100494

Solid electrolyte interphase (SEI) has been widely employed to describe the new phase formed between anode and electrolyte in working batteries. Significant advances have been achieved on the structure and composition of SEI as well as on the possible ion transport mechanism. However, the nucleation and growth mechanism of SEI catches little attention, which requires the establishment of isothermal electrochemical crystallization theory. Herein we explore the virgin territory of electrochemically crystallized SEI. By using potentiostatic method to regulate the decomposition of anions, an anion‐derived SEI forms on graphite surface at atomic scale. After fitting the cur‐rent‐time transients with Laviron theory and Avrami formula, we conclude that the formation of anion‐derived interface is surface reaction controlled and obeys the two‐dimensional (2D) progressive nucleation and growth model. Atomic force microscope (AFM) images emphasize the conclusion, which reveals the mystery of isothermal electrochemical crystallization of SEI. The nucleation and growth behavior of anion‐derived SEI on graphite electrode is revealed, the number of nucleation sites increases progressively, and each nucleus undergoes 2D growth before overlapping with others. Only when the whole electrode surface is completely covered by reduced products, an ion‐conducting but electron‐insulating polycrystalline film forms, which marks the end of SEI growth.