On the Mechanism of Nonaqueous Li–O₂ Electrochemistry on C and Its Kinetic Overpotentials: Some Implications for Li–Air Batteries

Citations Over TimeTop 1% of 2012 papers

Abstract

Quantitative differential electrochemical mass spectrometry and cyclic voltammetry have been combined to probe possible mechanisms and the kinetic overpotentials, responsible for discharge and charge in a Li–O2 battery, using C as the cathode and an electrolyte based on dimethoxyethane as the solvent. Previous spectroscopy experiments (X-ray diffraction, μRaman, IR, XPS) have shown that Li2O2 is the principle product formed during Li–O2 discharge using this electrolyte/cathode combination. At all discharge potentials and charge potentials 4.0 V, the electrochemistry requires significantly more than 2e–/O2, and we take this as evidence for electrolyte decomposition. We find that sequential concerted (Li+ + e–) ion transfers to/from adsorbed O2* and LiO2* to produce/consume Li2O2 is the mechanism that is most compatible with these experiments. The kinetic overpotentials are extremely low relative to aqueous O2 reduction and evolution, and this implies that in principle a discharge–charge Li–O2 cycle is possible with high voltaic efficiency (∼85%) if electrolyte and cathode stability issues are resolved.

Related Papers

• → Conductivities of 1,2-dimethoxyethane or 1,2-dimethoxyethane-related solutions of lithium salts(1993)13 cited
• → Conductivities of 1:1 electrolytes in mixed aprotic solvents—II. dimethoxyethane mixtures with propylene carbonate and 4-butyrolactone(1985)22 cited
• → Tris(1,2-dimethoxyethane)lithium μ-chloro-μ-oxo-bis[chloro(pentamethylcyclopentadienyl)(1-pyrrolyl)zirconate(IV)] dimethoxyethane solvate, [Li(C4H10O2)3][Zr2Cl3O(C4H4N)2(C10H15)2].C4H10O2(1984)4 cited
• → Applicability of the Bertrand, Acree, and Burchfield Method of Predicting the Relative Permittivity of Ternary Mixtures(1998)
• → ChemInform Abstract: Gas Phase NMR of 1,2‐Dimethoxyethane.(1991)