Micron-Sized SiOx-Graphite Compound as Anode Materials for Commercializable Lithium-Ion Batteries

The electrode concept of graphite and silicon blending has recently been utilized as the anode in the current lithium-ion batteries (LIBs) industry, accompanying trials of improvement of cycling life in the commercial levels of electrode conditions, such as the areal capacity of approximately 3.3 mAh/cm(2) and volumetric capacity of approximately 570 mAh/cm(3). However, the blending concept has not been widely explored in the academic reports, which focused mainly on how much volume expansion of electrodes could be mitigated. Moreover, the limitations of the blending electrodes have not been studied in detail. Therefore, herein we investigate the graphite blending electrode with micron-sized SiOx anode material which is one of the most broadly used Si anode materials in the industry, to approach the commercial and practical view. Compared to the silicon micron particle blending electrode, the SiOx blending electrode showed superior cycling performance in the full cell test. To elucidate the cause of the relatively less degradation of the SiOx blending electrode as the cycling progressed in full-cell, the electrode level expansion and the solid electrolyte interphase (SEI) thickening were analyzed with various techniques, such as SEM, TEM, XPS, and STEM-EDS. We believe that this work will reveal the electrochemical insight of practical SiOx-graphite electrodes and offer the key factors to reducing the gap between industry and academic demands for the next anode materials.

Automated summary

The graphite and silicon blending electrode concept has been utilized in the lithium-ion batteries industry to improve cycling life. However, the limitations and detailed analysis of the blending electrodes have not been widely explored. This study investigates the blending electrode with SiOx anode material and demonstrates its superior cycling performance compared to silicon micron particle blending electrode. The analysis of electrode expansion and solid electrolyte interphase thickening provides insight into reducing the gap between industry and academic demands for anode materials.