I will admit that I still have a bit of trouble when it comes to reading the table of standard electrode potentials. (Though, I do think my understanding is improving.) However, unless I am mistaken, should not Daniell cells (zinc anode, copper cathode, sulfate solutions) not rechargeable? I mean, during discharge, the zinc could be thought of as converting to zinc sulphate, and the copper sulfate to copper. Now, to reverse the process... Clearly, the problem is not the zinc. Zinc sulphate can be used to electroplate zinc onto a cathode. Since copper appears above oxygen on the table of standard electrode potentials, should it not be what is oxidized at the anode?