Voltage and Current density for different materials?

[mortarsprayer]

Hello Everyone.
I am wondering about Voltage and current densities for different materials.
Would it be the same for Titanium as Stainless steel?
Is anyone else working with Titanium?

I am putting together a Titanium cell with 2000 square inches of Cathode for a home heater. Is anyone else doing something similar?

Thank you,
Nolan

[Philldpapill]

What do you mean by "voltage and current densities"? Are you talking about the voltage drop between cells, needed for electrolysis to happen for different plate materials? If so, the answer is yes - but negligible.

As far as the current density goes, it's just a function of the resistance of the material... I'm not sure of the resistivity of Titanium, but I think it's fairly high - not the BEST material to use. Stainless Steel is also pretty high, but very corrosion resistant.

Elaborate a bit more as to what you are asking for...

[mortarsprayer]

Hello Phill.
Thank you.
I see that people are aiming towards a few volts per cell to cut down on heat. Most of the time they are adding neutrals to lower the voltage on each plate. Since I will have 1 big cathode and 1 big anode, I'm collecting parts for a low voltage high current power supply. I am thinking that 3-5 volts and 0.6 amps per square inch of Cathode is about what I should aim for. I am wondering if anyone has more precise numbers.

I have moved away from 316 Stainless because of the brown sludge, deteriorating plates and concerns about Hex Chrome. I am not totally against stainless, just looking to get something cleaner. Right now I am also playing with Pepsi concentrate containers as the container and cathode for a large bath cell. It make a very easy and inexpensive cell.

Best regards,
Nolan

[mileageseeker]

Hello Nolan.

I'm sure it goes without saying you're aware that pure TI does not work as an anode. I was wondering what coating are you using on your TI to enable it to be your anode? All that I'm aware of use iridium oxide, is that your choice or have you found something other that works well?

Regards,
MS

[IM2L844]

Hello, Nolan.

There have been lots of in depth studies done on this and as a matter of cost effective practicality, 316 SS is still your best choice even if you need to replace your electrodes from time to time. If you will keep your current density to 0.5 amps per square inch or less, you should not have the sludge and deterioration problems you mentioned. However, even with distilled water and lab grade electrolytes, there are going to be impurities that can cause some minimal side reactions that can produce some precipitates and reduce current efficiency.