Xiangbo Meng†#, Yuzi Liu‡, Joseph A. Libera†, Kevin R. Zavadil§ and Jeffrey W. Elam†*

† Energy Systems Division, ‡ Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL, USA 60439

§ Materials Science and Engineering, Sandia National Laboratories, Albuquerque, NM, USA 87185

# Presenting author: xmeng@anl.gov; * Corresponding author: jelam@anl.gov

Electrical energy storage (EES) is critical for the widescale implementation of renewable clean energies. With the commercialization of lithium-ion batteries (LIBs) in portable electronics, new battery technologies are being intensively investigated in order to provide higher energy density for other applications such as electrical vehicles. Lithium-sulfur (Li-S) batteries are very intriguing, given their high theoretical specific energy density of 2567 Wh/kg. However, Li-S batteries suffer from a number of major hurdles in practice, such as the insulating S and Li₂S, soluble polysufides (Li₂S_x, x≥4), and lithium dendrite growth. Although a huge amount of research effort has been invested to date, a lack of viable technologies exists to create high performance for practical applications. In our recent studies, both S cathodes and lithium metal anodes were modified via atomic layer deposition (ALD). Our research disclosed that uniform and conformal ALD coatings are very beneficial for Li-S batteries to approach high performance. Specifically, effects of ALD coating were exhibited in: (1) depressing the shuttle effect of polysulfides and (2) inhibiting lithium dendrite growth. As a result, the ALD-modified Li-S batteries showed improved Coulombic efficiency, much longer cycling lifetime, and enhanced safety. In our studies, different ALD coatings were investigated, including Al₂O₃ and Li_xAl_yS. This work was supported as part of the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (BES). Electron microscopy was performed at Center for Nanoscale Materials at Argonne National Laboratory.