Visualization of Dissolution‐Precipitation Processes in Lithium–Sulfur Batteries
Artikel i vetenskaplig tidskrift, 2022

In this work, light is shed on the dissolution and precipitation processes S8 and Li2S, and their role in the utilization of active material in Li-S batteries. Combining operando X-ray Tomographic Microscopy and optical image analysis, in real-time; sulfur conversion/dissolution in the cathode, the diffusion of polysulfides in the bulk electrolyte, and the redeposition of the product of the electrochemical reaction, Li2S, on the cathode are followed. Using a custom-designed capillary cell, positioning the entire cathode volume within the field of view, the conversion of elemental sulfur to soluble polysulfides during discharge is quantitatively followed. The results show the full utilization of elemental sulfur in the cathode in the initial stage of discharge, with all solid sulfur converted to soluble polysulfide species. Optical image analysis shows a rapid diffusion of polysulfides as they migrate from the cathode to the bulk electrolyte at the start of discharge and back to the cathode in the later stages of discharge, with the formation and precipitation of Li2S. The results point to the redeposition of Li2S on all available surfaces in the cathode forming a continuous insulating layer, leaving polysulfide species remaining in the electrolyte, and this is the process limiting the cell's specific capacity.

Battery

Tomography

Li-S

operando

Författare

Matthew Sadd

Chalmers, Fysik, Materialfysik

Salvatore De Angelis

Danmarks Tekniske Universitet (DTU)

Sofie Colding-Jørgensen

Danmarks Tekniske Universitet (DTU)

Didier Blanchard

Danmarks Tekniske Universitet (DTU)

Rune E. Johnsen

Danmarks Tekniske Universitet (DTU)

Simone Sanna

Universita degli Studi di Roma Tor Vergata

Elena Borisova

Paul Scherrer Institut

Aleksandar Matic

Chalmers, Fysik, Materialfysik

Jacob R. Bowen

Xnovo Technology ApS

Danmarks Tekniske Universitet (DTU)

Advanced Energy Materials

1614-6832 (ISSN) 1614-6840 (eISSN)

Vol. 12 10 2103126

Ämneskategorier

Energiteknik

Atom- och molekylfysik och optik

Energisystem

DOI

10.1002/aenm.202103126

Relaterade dataset

Contour plots of the binary segmented slices from each tomogram overlaid on the corresponding raw reconstructed image for visual inspection can be obtained free of charge from the Zenodo repository. [dataset]

URI: https://zenodo.org/record/572377#.YGHVx2ixVB1

Mer information

Senast uppdaterat

2022-04-05