Synergetic charge transfer from Ti[sbnd]O2− basic centers at Li4Ti5O12 spinel surface

Abstract

Interfacial chemistry plays an important role in understanding electrode process kinetics of many chemical reactions, e.g. photocatalyst, electrocatalyst, and electrochemistry. In this context, a systematic investigation is conducted to reveal the mechanism of electrode-electrolyte interface between Li4Ti5O12 (LTO) spinel and electrolyte molecule, aiming to tackle the notorious package swelling issue in rechargeable batteries. Using the gas chromatography–mass spectrometry and electron microscopy techniques, the interplays between the LTO and dimethyl carbonate (DMC) are uncovered to be a synergetic chemical catalytic process involving the truncated oxygens of the surface TiO dangling bonds, which are negatively polarized as the catalytic centers with the strong Lewis basicity. The Lewis basic centers catalyze the nucleophilic substitution of DMC with only trace amounts of water, resulting in the gaseous products, such as CO2 and methanol. These findings deepen the understandings on the fundamental chemistry and catalysis of solid-liquid interfaces, especially the metal oxide-organic interfaces.