Nickel also is a good electron donor to copper, although not as good as zinc. In a competition between Ni²⁺ and Cu²⁺ for electrons, Cu²⁺ will win, but in a contest between Zn²⁺ and Ni²⁺, the nickel ions will take the electrons.

The following reaction is spontaneous and has the indicated free energy change:

If an electrochemical cell were made up with a nickel electrode immersed in nickel sulfate, and a copper electrode in copper sulfate, nickel would be oxidized to Ni²⁺ ions, copper ions would be reduced to metallic copper, and electrons would flow through the external circuit from the Ni anode to the Cu cathode.

The cell would have an electrochemical potential of ********

Compared with the Daniell cell, this cell would have approximately half as intense an "electron pressure" between the two electrodes, available for doing work.