I am a battery scientist, and while I think that Argonne is one of the places where great work is done, they have set very ambitious goals for themselves.
1) Replacing Li with Mg is a lovely idea, but currently there is no fully stable electrolyte and as far as I know nobody has good candidates for electrode materials. Don't even get me started on Al.
2) Lithium-air batteries have been debated to death also here on /.. The current status is again that there seems to be no stable electrolyte, no clear idea of what exactly happens, and if we factor in the weight and complexity of adding various components to the battery assembly to make a real device out of it, the great theoretical energy density of Li-O2 is reduced to Li-ion levels, if not even less.
3) The liquid slurry electrode is an interesting concept which at least recycles materials that are available and known to be working. This is more of an engineering problem than a scientific one, and could see quick advancement in 5 years.
I hope the community as a whole will be able to find the breakthrough to finally have people stop cursing batteries.
Batteries: you hate them since 150 years!