April_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | A P R I L 2 0 2 0 2 7 (a) (b) (c) (d) (e) (f) relevant class of materials is Li-based layered foils (positive electrode, elec- trolyte) for battery applications. In the case of Li, even a few minutes of expo- sure results in the growth of an oxide layer that alters the view of the origi- nal material microstructure. JEOL has developed an air-isolated transfer sys- tem that is compatible across both its specimen preparation equipment (cross-section polisher [1] , which utiliz- es a broad argon ion beam to prepare specimen cross-sectional surfaces), as well as the various SEM and EPMA in- struments (Fig. 2). The transfer system comprises a sealed capsule with a compatible dove- tail design that can be loaded with a specimen in a glove box, sealed, and then transferred into either specimen preparation equipment and/or SEM without any environmental exposure. The sealing mechanism is subsequent- ly only opened and resealed if needed while under vacuum, thus preventing any air exposure. This enables the ob- servation of the various constituents of Li battery materials and layers with high fidelity, utilizing the low acceler- ating voltage capability of the FE-SEMs. The air-isolated capsule can be used for Fig. 2 — Specimen processing for air-isolated workflow. The specimen is shuttled in a specially designed sealed transfer vessel, which is compatible with both sample preparation equipment (ion polisher) and SEM, and can be resealed for any further processing. Fig. 3 — LiCoO 2 particles in a positive electrode before and after air exposure. Air exposure introduces various artifacts affiliated with specimen reactivity with atmospheric oxygen. Fig. 4 — Examples of nanostructured materials imaged utilizing ultra-low accelerating voltage in FE-SEM: (a) polymer membrane used as a separator in Li batteries imaged at 100 V; (b) Li battery positive electrode material imaged at 300 V; (c) cross-section of polymer sheet with graphene flakes and nanoparticles imaged at 500 V; (d) nanoporous oxide particles imaged at 200 V; (e) Anopore inorganic membrane (aluminum oxide) for filtration imaged at 10 V; and (f) blue toner particles imaged at 30V.