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High‐Performance High‐Loading Lithium–Sulfur Batteries by Low Temperature Atomic Layer Deposition of Aluminum Oxide on Nanophase S Cathodes
Author(s) -
Meng Xiangbo,
Liu Yuzi,
Cao Yanqiang,
Ren Yang,
Lu Wenquan,
Elam Jeffrey W.
Publication year - 2017
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201700096
Subject(s) - faraday efficiency , atomic layer deposition , materials science , chemical engineering , cathode , nanoparticle , nanotechnology , electrolyte , lithium–sulfur battery , sulfur , layer (electronics) , metallurgy , electrode , chemistry , engineering
This study examines the effects of nanophase S and surface coatings via atomic layer deposition (ALD) on high‐loading sulfur cathodes for developing high‐performance and high‐energy lithium–sulfur (Li–S) batteries. It is first verified that ball milling is an effective and facile route for nanoengineering microsized S powders and the resultant nanoscale S particles exhibit better performance. Using these ball milled nanoscale S cathodes, it is found that ALD Al 2 O 3 performed at 50 °C yields deposits that evolve with ALD cycles from dispersed nanoparticles, to porous, connected films, and finally to dense and continuous films. Moreover, this low temperature ALD process suppresses S loss by sublimation. The ALD Al 2 O 3 greatly improves sulfur cathode sustainable capacity and Coulombic efficiency. This study postulates two different mechanisms underlying the effects of ALD Al 2 O 3 surface coatings depending on their morphology. ALD Al 2 O 3 nanoparticles dispersed on the sulfur surface mainly function to adsorb polysulfides, thereby inhibiting S shuttling and improving sustainable capacity and Coulombic efficiency. By contrast, ALD Al 2 O 3 films behave as a physical barrier to prevent polysulfides from contacting the liquid electrolyte and dissolving. The dispersed Al 2 O 3 nanoparticles improve both sustainable capacity and Coulombic efficiency while the closed Al 2 O 3 films improve Coulombic efficiency while decreasing the capacity.