For those of you that arent very familiar with PEM fuel cells, their shortcomings basically revolve around the carbon/platinum membrane and is essentially the "heart" of the fuel cell. But why does a fuel cell need a membrane to function? If you think about it, just about all energy conversion devices can switch from generating to producing and vise versa just by changing the "effort" part of the power components. For example a motor can become a generator by raising and lowering the torque and voltage on the machine. A hydraulic gerotor can go from motor to pump by adjusting torque or pressure. Now the reverse equivalent of a PEM fuel cells is an electrolysis cell. Almost identical in concept except for that pesky membrane. You can even reverse a PEM fuel cell to make it an electrolysis cell but you cant reverse an electrolysis cell to make a fuel cell unless you have that membrane. Now it just seems to me that their just has to be away to sort of "reverse" that electric field created in electrolysis cells to make the reaction happen the other way without the membrane. Theoretically, does this sound possible? Is there some law that will prove my theory wrong? If there is one Im thinking its gonna be the second law of thermodynamics.