Adsorption of insoluble polysulfides Li2Sx (x = 1, 2) on Li2S surfaces. Issue 14 (10th March 2015)

• Record Type: Journal Article
• Authors: Liu, Zhixiao; Hubble, Dion; Balbuena, Perla B.; Mukherjee, Partha P.
• Is Part Of: Physical chemistry chemical physics. Volume 17:Issue 14(2015)
• Page Start: 9032
• Page End: 9039
• Publication Date: 2015-03-10
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c4cp06118g
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The growth of Li2 S film is predominated by direct Li2 S deposition during the Li–S battery discharge process. Abstract : In lithium–sulfur batteries, the growth of insulating discharge product Li2 S film affects the cathode microstructure and the related electron as well as lithium ion transport properties. In this study, chemical reactions of insoluble lithium polysulfides Li2 S x ( x = 1, 2) on crystal Li2 S substrate are investigated by a first-principles approach. First-principles atomistic thermodynamics predicts that the stoichiometric (111) and (110) surfaces are stable around the operating cell voltage. Li2 S x adsorption is an exothermic reaction with the (110) surface being more active to react with the polysulfides than the stoichiometric (111) surface. There is no obvious charge transfer between the adsorbed molecule and the crystal Li2 S substrate. Analysis of the charge density difference suggests that the adsorbate interacts with the substrate via a strong covalent bond. The growth mechanism of thermodynamically stable surfaces is investigated in the present study. It is found that direct Li2 S deposition is energetically favored over Li2 S2 deposition and reduction process.