Stability of lithium superoxide LiO2 in the gas phase: Computational study of dimerization and disproportionation reactions

Vyacheslav S. Bryantsev; Mario Blanco; Francesco Faglioni

doi:10.1021/jp1047584

Stability of lithium superoxide LiO₂ in the gas phase: Computational study of dimerization and disproportionation reactions

Vyacheslav S. Bryantsev
, Mario Blanco
, Francesco Faglioni

Research output: Contribution to journal › Article › peer-review

77 Scopus citations

Abstract

Knowledge of the precise molecular mechanisms during the discharge and recharge processes in the lithium-air battery is critical for achieving desired improvements in specific capacity, current density, and cyclability. The initial oxygen reduction product formed in the presence of Li⁺ ions is lithium superoxide LiO₂. In this study, we report the computed structures and thermodynamic parameters of LiO₂ dimerization in the gas phase, which enables us to provide a baseline for the reaction free energy profile of the subsequent disproportionation of (LiO₂)₂ to lithium peroxide Li₂O₂ and O₂. Our calculations identified several low-lying (LiO₂)₂ dimers, with the singlet bipyramidal structure giving IR bands that are consistent with the characteristic IR vibration frequencies of (LiO₂)₂ in the oxygen matrix at T = 15-40 K. The activation barrier for (LiO ₂)₂ = Li₂O₂+O₂ is 10.9 kcal/mol at the UCCSD(T)/CBS level (T = 298 K), suggesting that in the gas phase LiO₂ and its aggregates could only be observed at low temperatures.

Original language	English
Pages (from-to)	8165-8169
Number of pages	5
Journal	Journal of Physical Chemistry A
Volume	114
Issue number	31
DOIs	https://doi.org/10.1021/jp1047584
State	Published - Aug 12 2010
Externally published	Yes

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title = "Stability of lithium superoxide LiO2 in the gas phase: Computational study of dimerization and disproportionation reactions",

abstract = "Knowledge of the precise molecular mechanisms during the discharge and recharge processes in the lithium-air battery is critical for achieving desired improvements in specific capacity, current density, and cyclability. The initial oxygen reduction product formed in the presence of Li+ ions is lithium superoxide LiO2. In this study, we report the computed structures and thermodynamic parameters of LiO2 dimerization in the gas phase, which enables us to provide a baseline for the reaction free energy profile of the subsequent disproportionation of (LiO2)2 to lithium peroxide Li2O2 and O2. Our calculations identified several low-lying (LiO2)2 dimers, with the singlet bipyramidal structure giving IR bands that are consistent with the characteristic IR vibration frequencies of (LiO2)2 in the oxygen matrix at T = 15-40 K. The activation barrier for (LiO 2)2 = Li2O2+O2 is 10.9 kcal/mol at the UCCSD(T)/CBS level (T = 298 K), suggesting that in the gas phase LiO2 and its aggregates could only be observed at low temperatures.",

author = "Bryantsev, \{Vyacheslav S.\} and Mario Blanco and Francesco Faglioni",

year = "2010",

month = aug,

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doi = "10.1021/jp1047584",

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volume = "114",

pages = "8165--8169",

journal = "Journal of Physical Chemistry A",

issn = "1089-5639",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Stability of lithium superoxide LiO2 in the gas phase

T2 - Computational study of dimerization and disproportionation reactions

AU - Bryantsev, Vyacheslav S.

AU - Blanco, Mario

AU - Faglioni, Francesco

PY - 2010/8/12

Y1 - 2010/8/12

N2 - Knowledge of the precise molecular mechanisms during the discharge and recharge processes in the lithium-air battery is critical for achieving desired improvements in specific capacity, current density, and cyclability. The initial oxygen reduction product formed in the presence of Li+ ions is lithium superoxide LiO2. In this study, we report the computed structures and thermodynamic parameters of LiO2 dimerization in the gas phase, which enables us to provide a baseline for the reaction free energy profile of the subsequent disproportionation of (LiO2)2 to lithium peroxide Li2O2 and O2. Our calculations identified several low-lying (LiO2)2 dimers, with the singlet bipyramidal structure giving IR bands that are consistent with the characteristic IR vibration frequencies of (LiO2)2 in the oxygen matrix at T = 15-40 K. The activation barrier for (LiO 2)2 = Li2O2+O2 is 10.9 kcal/mol at the UCCSD(T)/CBS level (T = 298 K), suggesting that in the gas phase LiO2 and its aggregates could only be observed at low temperatures.

AB - Knowledge of the precise molecular mechanisms during the discharge and recharge processes in the lithium-air battery is critical for achieving desired improvements in specific capacity, current density, and cyclability. The initial oxygen reduction product formed in the presence of Li+ ions is lithium superoxide LiO2. In this study, we report the computed structures and thermodynamic parameters of LiO2 dimerization in the gas phase, which enables us to provide a baseline for the reaction free energy profile of the subsequent disproportionation of (LiO2)2 to lithium peroxide Li2O2 and O2. Our calculations identified several low-lying (LiO2)2 dimers, with the singlet bipyramidal structure giving IR bands that are consistent with the characteristic IR vibration frequencies of (LiO2)2 in the oxygen matrix at T = 15-40 K. The activation barrier for (LiO 2)2 = Li2O2+O2 is 10.9 kcal/mol at the UCCSD(T)/CBS level (T = 298 K), suggesting that in the gas phase LiO2 and its aggregates could only be observed at low temperatures.

UR - https://www.scopus.com/pages/publications/77955683390

U2 - 10.1021/jp1047584

DO - 10.1021/jp1047584

M3 - Article

AN - SCOPUS:77955683390

SN - 1089-5639

VL - 114

SP - 8165

EP - 8169

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

IS - 31

ER -

Stability of lithium superoxide LiO₂ in the gas phase: Computational study of dimerization and disproportionation reactions

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