Hi, Ode. Thanks for your comments about the mechanical problems to be expected with large electrodes. A large flat spiral wire anode laying on the inside bottom ot the reaction vessel would be well-supported against mechanical distortion. A large cathode would be a different problem if it were made of .999 or .9999 wire. I don't generate much EISa.k.a.CS - but if I did, I might try a bullion coin with several equi-spaced perforations around and near its edge to hold suspension hooks of high-purity silver wire. Parallelism of the electrodes could then be easily gotten, and spacing easily adjusted.
Best regards, Matthew