HYDRATED TETRA-BUTYL AMMONIUM FLUORIDE – AN ADVANCED ACTIVATOR OF ALUMINUM SURFACES IN ORGANIC NON-AQUEOUS ELECTROLYTES FOR ALUMINUM-AIR BATTERIES

Aluminum (Al) has most of the appropriate electrochemical properties allowing its use as an anode in energy storage applications. However, for any battery development utilizing Al as an anode, as well as improvements of existing systems, the underlying elementary surface chemistry and detailed electrochemical processes of Al in the electrolytes have to be well understood. The native oxide layer on the Al surface challenges the electrochemical research community, as it prevents the Al anode from delivering high anodic currents, necessary for a successful power source system, having enhanced properties. In the current study, solutions consisting of organic salt dissolved in different “traditional” non-aqueous battery solvents, such as propylene carbonate (PC), tetra-ethylene glycol dimethyl ether (TEG-DME), acetonitrile (ACN) and dimethyl sulfoxide (DMSO) were examined as electrolytes, enabling Al surface activation. Conductivity and activation energy evaluations of the different electrolytes are reported alongside with electrochemical measurements and surface characterization using high resolution scanning electron microscopy (HRSEM). Furthermore, FTIR-ATR and XPS measurements were performed for the prepared electrolyte and aluminum samples that were immersed in the electrolyte for different time periods. In addition, Al-air (in a full-cell configuration) battery discharge observations were performed at various current densities and salt concentrations.