Inverting the Triiodide Formation Reaction by the Synergy between Strong Electrolyte Solvation and Cathode Adsorption for Lithium-Oxygen Batteries

Xiao-Ping Zhang; Yan-Ni Li; Yi-Yang Sun; Tao Zhang

doi:10.1002/anie.201910427

Inverting the Triiodide Formation Reaction by the Synergy between Strong Electrolyte Solvation and Cathode Adsorption for Lithium-Oxygen Batteries

Angew Chem Int Ed Engl. 2019 Dec 16;58(51):18394-18398. doi: 10.1002/anie.201910427. Epub 2019 Nov 6.

Authors

Xiao-Ping Zhang^{1

2}, Yan-Ni Li^{1

2}, Yi-Yang Sun¹, Tao Zhang^{1

2}

Affiliations

¹ State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 201899, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.

PMID: 31628706
DOI: 10.1002/anie.201910427

Abstract

An exceptionally strong solvation effect of dimethyl sulfoxide (DMSO) on I₂ is identified by the largest shift observed so far of the I₂ Raman peak with respect to I₂ vapor and by elongated I-I bond lengths in first-principles molecular-dynamics simulations. This effect together with strong binding by an RuO₂ surface to I₂ is found to invert the direction of the reaction I^- +I₂ ⇌I₃ ^- to the left-hand side. Inspired by this finding, we prepared a Li-O₂ battery with the Li/DMSO+LiI/RuO₂ structure. The synergic action of DMSO and RuO₂ on I₂ is found to suppress the shuttle effect of the redox mediator (RM) by anchoring I₂ molecules, the oxidation product of the RM. Significantly enhanced stability is demonstrated over 100 cycles at charging voltage below 3.65 V.

Keywords: DMSO; RuO2; iodine; lithium-oxygen battery; shuttle effect.

Abstract

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