Inhibition of vacuum sublimation artefacts for (Scanning) Transmission Electron Microscopy ((S)TEM) of sulphur samples via encapsulation

Open Res Eur. 2022 Feb 1:2:1. doi: 10.12688/openreseurope.14378.2. eCollection 2022.

Abstract

Lithium-sulfur battery is one of promising candidates for next-generation energy storage device due to the sulfur cathode material with low cost and nontoxicity, and super high theoretical energy density (nearly 2600Wh kg -1) and specific energy (2567Wh kg -1). Sulphur, however, poses a few interesting challenges before it can gain widespread utilisation. The biggest issue is known as the polysulphide shuttling effect which contributes to rapid capacity loss after cycling. Accurate characterisation of sulphur cathodic materials becomes critical to our understanding polysulphide shuttling effect in the quest of finding mitigating solutions. Electron microscopy is playing a crucial role in battery research in determining structure-property-function relations. However, sulphur undergoes sublimation at a point above the typical pressures found in the column of a transmission electron microscope (TEM) at room temperature. This makes the imaging and characterisation of any sort of nanostructured sulphur samples challenging, as the material will be modified or even disappear rapidly as soon as it is inserted into the TEM vacuum. As a result, materials characterised by such methods are prone to deviation from normal conditions to a great extent. To prevent this, a novel method of encapsulating sulphur particles between silicon nitride (SiN x) membranes is demonstrated in this work.

Keywords: Transmission Electron Microscopy (TEM); gas cell.; in-situ; sublimation; sulfur.

Grants and funding

This research was financially supported by the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 681544 (project 3D2DPrint). This publication has emanated from research supported in part by a grant from Science Foundation Ireland under Grant number [12/RC/2278_P2].