Electrode/electrolyte interface reactivity in high-voltage spinel LiMn 1.6Ni0.4O4/Li4Ti5O 12 lithium-ion battery
Résumé
High-voltage spinel oxides combined with Li4Ti5O 12 result in 3 V lithium-ion batteries with a high power capability; however, the electrochemical performances are limited by electrode/electrolyte interfacial reactivity at high potential. We have investigated electrode/electrolyte interfaces in LiMn1.6Ni0.4O 4/Li4Ti5O12 cells by X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectrocopy (EIS). EIS has shown that both electroadsorption and film-formation mechanisms occur at the positive electrode. XPS has revealed that very low amounts of lithiated species are deposited at the surface of the positive electrode, despite the high potential, but that great amounts of organic species are deposited. Interesting results were obtained for the Li4Ti 5O12 electrode. Whereas Li4Ti5O 12 is usually considered as a passivation-free electrode material, large amounts of organic and inorganic species were deposited at the surface of this electrode. The question of a possible interaction between both electrodes in the formation mechanisms of surface films is discussed. © 2010 American Chemical Society.
Mots clés
Electroadsorption
Surface films
Spinel oxide
Positive electrodes
Organic species
Lithium alloys
Electrochemical electrodes
Electrochemical impedance spectroscopy
Electrochemical impedance
Electrochemical performance
Electrode material
Electrode/electrolyte interfaces
Film formations
Formation mechanism
High potential
High power capability
High-voltages
Inorganic species
Interfacial reactivity
Lithium-ion battery
Lithium batteries
Lithium compounds
Passivation
Surfaces
X ray photoelectron spectroscopy
Lithium