It's hard for me to imagine some sort of energy storage that is denser then Hydro-Carbon chains. Then again if this electrolyte replacement + increased efficiency of electrical drive train is greater then gas we have great potential.

energy efficiency on infogalatic says that the max theoretical thermal efficiency is 37%, and real life is more like 18-20% so maybe we could have a fluid that is less dangerous, and gives us more power to the wheels per gallon.