Every fuel cell, which generates electricity by a chemical reaction (as opposed to combustion), has an electrolyte.

FORBES: Salt Water Fuel Cells - Coming Soon?

The question is when storing of electricity in batteries or a fuel cell feedstock will become more eonomicial than burning a form of chemical energy to gain mechanical power.

FORBES: Why Solar-Powered Cars Won't Go: They Can't Keep Up With The Combustion Engine

Illinois-based company Renew Power has said it has already come up with a fuel cell compatible with mobile phones, by using formic acid, the chemical sprayed by black ants on the attack.

CNN: Search for better phone power