You need a membrane permeable to negative ions too for that.

In fact, I think you'll need that membrane for electricity generation too. Otherwise you will only get to make a single layer of it, what is underwhelming.

But it is a large breakthrough.

I think the GP was making a joke. What they suggested strongly implies the existence of perpetual motion machines, contradicting the laws of thermodynamics.

Indeed he is.

I'll just post here that it does not violate the second law of thermodynamics. It is a completely real phenomenon that one can verify at home with the ion exchange membranes used to make batteries. (Get some aluminum electrodes, on the scheme salty-fresh-salty water, and add some aluminum hydroxide on the negative side, so you'll have a neutral oxidation and reduction of aluminum on both sides.)

What those people created was just an incredibly better ion exchange membrane.