Water electrolysis with in-series electrodes

Question

I'm trying to improve my efficiency when doing water electrolysis. For my specific application, I don't need to separate the hydrogen and oxygen gasses, in fact it's important that I don't. But it's also important that I don't crank up the voltage and create corrosion and by products, so I want to keep the voltage as low as possible.

So, to increase current I need to increase the surface area of my electrodes. So my idea is this: Use a 1x1" stainless steel strip for my cathode and anode each, about 2cm apart. Then insert an additional 1x1" stainless steel strip in the middle between them.

So like this (cathode on the left): |||

The current should flow from my cathode on the left, through the solution, to the left side of the middle strip, which now becomes an anode, out the right side of the middle strip, which now becomes a cathode, through the solution, and to the final anode. Thus I'm able to double my total surface area.

This makes sense to me, but can anyone confirm whether or not this is a sound solution or not? Since the middle strip becomes a cathode on one side, and anode on the other, would I get strange edge behavior where they meet?

Answer 1

It would make sense if the middle electrode galvanically separated the solutions on the left and the right. Otherwise it would not work.

If you need higher production using larger electrode areas, you have two options:

• If the power source can provide high enough current, connect two or several electrodes in parallel, forming one electrode with large surface. If possible, you can create a combed structure of alternating anode and cathode, i.e. all odd electrodes mutually connected and the same for all even ones. That also leads to short distance between electrodes and overall high conductivity.
• If the power source cannot provide high enough current or if the power source has too high voltage, you can create a series of cells, an anode of one cells connected by wire to cathode of other cell. This ways, at the same current, but with high voltage, you can multiple you gas output.

But beware of danger of explosion, as manipulation with electrodes under voltage may produce a spark and mighty explosion of hydrogen and oxygen mix.