Synergistic Mixture of Electrolyte Additives: A Route to a High-Efficiency Mg-Air Battery.

Magnesium primary cells are currently experiencing a renaissance following the suggestion of new strategies to boost their performance. The strategies suggested will maintain utilization efficiencies of 30-70%, which is considered to be relatively modest. In this work, the highest ever reported level of utilization efficiency of 82% is achieved for a Mg-based primary cell using a synergistic combination of electrolyte additives.

Use of synergistic mixture of chelating agents for in situ LDH growth on the surface of PEO-treated AZ91.

The principal possibility to grow layered double hydroxide (LDH) at ambient pressure on plasma electrolytic oxidation (PEO) treated magnesium alloy AZ91 in the presence of chelating agents is demonstrated for the first time. It avoids hydrothermal autoclave conditions, which strongly limit wide industrial application of such coating systems, and the presence of carbonate ions in the electrolyte, which lead to the formation of "passive" non-functionalizable LDH. A combination of chelating agents (sodium diethylenetriamine-pentaacetate (DTPA) and salicylate) were introduced to the treatment solution.

Chelating agent-assisted in situ LDH growth on the surface of magnesium alloy.

In situ formation of layered double hydroxides (LDH) on metallic surfaces has recently been considered a promising approach for protective conversion surface treatments for Al and Mg alloys. In the case of Mg-based substrates, the formation of LDH on the metal surface is normally performed in autoclave at high temperature (between 130 and 170 °C) and elevated pressure conditions. This hampers the industrial application of MgAl LDH to magnesium substrates.