Large Salt water battery ideas and questions

[Mungo]

I find the porosity thing interesting.  Certainly etching the cathode would help, but going with an industrially produced cathode which had to be ordered or utilizing sulphuric acid as an electrolyte rather defeats the purpose of the experiment, which was to create a big dumb battery out of commonly available materials with low toxicity.  My other thought regarding the airstone was that it would keep the electrolyte oxygenated, and perhaps stop the voltage die off I experienced in the small model.  Thoughts?  Does the anode need to be etched as well (aluminum seems to be the top contender here, though zincs used to protect crab traps are widely available in the Chesapeake.)

[profitis]

definitely @mungo.an etching of the aluminum or zinc with hydrochloric acid beforehand will shoot up the power density.a shaking of the air electrode will be energy consuming but it will help yes but we want to try avoid putting in energy to gain efficiency.if you situate the cathode half-submerged in the seawater it may help absorbtion of air from the atmosphere and self-discharge of the clinging H2 bubbles.try putting the copper plate side-longways half-submerged.try a copper plate that is 2wice as big as the zinc plate for surface area.try folding up a giant copper plate into squigglies(like a roofing) to cram huge area into small space,half-submerged.

[profitis]

try pressing your electrodes between sponge-soaked salt water @mungo.make sure that the sponge is not overly soaked,just a tiny bit seawater will do as you want it to be an almost 'dry cell'.this should alow maximum air access via pores.try newspaper,try fabric,fibreglass as your saltwater sponge.

[Mungo]

try pressing your electrodes between sponge-soaked salt water @mungo.make sure that the sponge is not overly soaked,just a tiny bit seawater will do as you want it to be an almost 'dry cell'.this should alow maximum air access via pores.try newspaper,try fabric,fibreglass as your saltwater sponge.

could capillary action from a well of electrolyte be used to keep the sponge medium damp, or would that be too much?

[profitis]

it certainly could.you just have to work out the right sponge.it will be obviously wetter on the base but at least the top will be exposed to more air.the correct way to do this is to actualy have the zinc completely submerged under seawater and just the copper standing aloft against the sponge.we want minimum air exposure to anode and maximum air on cathode.