Large Salt water battery ideas and questions

[profitis]

what you want to do is make your cathode more oxygen-catalytic to depolarize H2 gas as much as possible so etched copper would probably serve best.you want to increase surface area of the copper by soaking or splashing some hydrochloric acid on exposure to air for a few minutes before thorough rinsing.you want to etch it to roughen surface area. Copper undergoes a double reaction in seawater exposed to air under these circumstances..Cu + Cl- + O +2H+ = CuCl(precipitates on the copper)+H2O.Then CuCl acts as depolarizer 2CuCl + Zn= ZnCl2 +2Cu.copper is regenerated,acting as cyclic catalyst for O2 consumption

[Mungo]

what you want to do is make your cathode more oxygen-catalytic to depolarize H2 gas as much as possible so etched copper would probably serve best.

Thanks Pofitis.  Would scoring or abrading the copper work as well, or would etching be preferable?

[profitis]

etching defnitly better @mungo.much more surface area.use dilute nitric,or conc hydrochloric acids(swimpool acid).test it smallscale first.

[Mungo]

Ill try that.  Any feedback on the airstone idea?

[profitis]

aha,the airstone idea is nt necessary if you have sufficient porosity.  porous carbon will work but you,re going to have to order carbon slices with emphasis on porousity which is available in different degrees from industrials. you might want to try making your own lead-acid cells simply by passing current between 2 lead plates in sulfuric acid solution.this will give a more power and smoother voltage but you will have to recharge when flat.