A special TEM Li-ion battery sample preparation and application technique for investigating the nano structural properties of the SEI in lithium ion batteries. (2020)

• Record Type: Journal Article
• Authors: Song, Xiangyun; Fu, Yanbao; Song, Chengyu; Ross, Philip; Battaglia, Vince
• Is Part Of: MRS advances. Volume 5:Number 27/28(2020)
• Page Start: 1415
• Page End: 1421
• Publication Date: 2020
• Subjects: Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/adv.2020.262
• Languages: English
• ISSNs: 2059-8521

Abstract

Abstract: Herein we describe a technique for preparing samples from cycled Li-ion batteries with minimal contact with atmospheric water for examination by TEM and to provide the results of an analysis of the SEI in Li-ion cells. The electrode samples were prepared in a glove box by manipulation with a diamond tipped pen to carefully dislodge particles directly onto the TEM sample holder. Electrodes were extracted from Li-ion cells that contained a cathode of high capacity, manganese rich NCM (HCMR-NCM). Nanometer-sized MnF2 crystal particles embed themselves in the SEI layer of the anodes as observed and confirmed by HRTEM lattice image analysis and EELS. Cross-sections of the SEI layer reveal that the thickness of the SEI and propensity for MnF2 crystal deposition is non-uniform.