Journal Article

Revealing the aging process of solid electrolyte interphase on SiOx anode

Chen, Liquan, Cheng, Junfang, Xie, Lin, Chen, Haibiao, Liu, Tongchao, Yang, Ni, Li, Yiwei, Lu, Xia, Zhao, Wenguang, Amine, Khalil, Pan, Feng, Qian, Guoyu, Yang, Xiangjie, Lin, Hai, Li, Hong, Song, Yongli, Lin, Cong, Yang, Luyi, Zhang, Meng, Li, Zikun, Nakashima, Naotoshi

2023

Overview

As one of the most promising alternatives to graphite negative electrodes, silicon oxide (SiO x ) has been hindered by its fast capacity fading. Solid electrolyte interphase (SEI) aging on silicon SiO x has been recognized as the most critical yet least understood facet. Herein, leveraging 3D focused ion beam-scanning electron microscopy (FIB-SEM) tomographic imaging, we reveal an exceptionally characteristic SEI microstructure with an incompact inner region and a dense outer region, which overturns the prevailing belief that SEIs are homogeneous structure and reveals the SEI evolution process. Through combining nanoprobe and electron energy loss spectroscopy (EELS), it is also discovered that the electronic conductivity of thick SEI relies on the percolation network within composed of conductive agents (e.g., carbon black particles), which are embedded into the SEI upon its growth. Therefore, the free growth of SEI will gradually attenuate this electron percolation network, thereby causing capacity decay of SiO x . Based on these findings, a proof-of-concept strategy is adopted to mechanically restrict the SEI growth via applying a confining layer on top of the electrode. Through shedding light on the fundamental understanding of SEI aging for SiO x anodes, this work could potentially inspire viable improving strategies in the future. Observing the evolution of the solid electrolyte interphase on SiO x -based electrodes in Li-ion batteries is challenging. Here, authors use three-dimensional tomography to visualize the growth of the interphase on single SiO x particles and propose a mechanical confinement strategy to prevent aging.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 140/146 / 142/136 / 147/135 / 147/143 / 639/301/930/12 / 639/4077/4079/891 / Aging / Anodes / batteries / Black carbon / Carbon black / characterization and analytical techniques / Electrodes / Electrolytes / Electron energy loss spectroscopy / Energy loss / ENERGY STORAGE / Evolution / Homogeneous structure / Humanities and Social Sciences / Interphase / Ion beams / Lithium-ion batteries / multidisciplinary / Percolation / Rechargeable batteries / Scanning electron microscopy / Science / Science (multidisciplinary) / Silicon / Silicon oxide / Silicon oxides / Solid electrolytes / Spectroscopy