Four-dimensional studies of morphology evolution in lithium-sulfur batteries

DOI: 10.1021/acsaem.8b01148

Authors: Chun Tan (University College London (UCL)) , Thomas M. M. Heenan (University College London) , Ralf F. Ziesche (University College London (UCL)) , Sohrab R. Daemi (University College London (UCL)) , Jennifer Hack (University College London (UCL)) , Maximilian Maier (University College London (UCL)) , Shashidhara Marathe (Diamond Light Source) , Christoph Rau (Diamond Light Source) , Daniel J. L. Brett (University College London) , Paul R. Shearing (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Applied Energy Materials

State: Published (Approved)
Published: August 2018
Diamond Proposal Number(s): 16110

Abstract: Lithium sulfur (Li-S) batteries have great potential as a successor to Li-ion batteries but their commercialization has been complicated by a multitude of issues stemming from their complex multi-phase chemistry. In-situ X-ray tomography investigations enable direct observations to be made about a battery, providing unprecedented insight into the microstructural evolution of the sulfur cathode and shedding light on the reaction kinetics of the sulfur phase. Here, for the first time, the morphology of a sulfur cathode was visualized in 3D as a function of state of charge at high temporal and spatial resolution. Whilst elemental sulfur was originally well dispersed throughout the uncycled cathode, subsequent charging resulted in the formation of sulfur clusters along preferred orthogonal orientations in the cathode. The electrical conductivity of the cathode was found not to be rate-limiting, suggesting the need to optimize the loading of conductive carbon additives. The carbon and binder domain, and surrounding bulk pore phase were visualized in the in-situ cell, and contrast changes within both phases were successfully extracted. The applications of this technique are not limited to microstructural and morphological characterization, and the volumetric data can serve as a valuable input for true 3D computational modelling of Li-S batteries.

Journal Keywords: Lithium sulfur; X-ray tomography; Batteries; Porous media; In-situ characterization; Synchrotron radiation

Subject Areas: Materials, Chemistry, Energy


Instruments: I13-2-Diamond Manchester Imaging