In a Nickel-Iron cell, which of the following best describes the working principle during the discharging process?
1
Nickel at the positive electrode is reduced to metallic nickel, and iron hydroxide at the negative electrode is oxidised.
2
Iron at the negative electrode is oxidised to iron oxide, and nickel at the positive electrode is reduced to nickel hydroxide.
3
Nickel hydroxide at the positive electrode is reduced to metallic nickel, and iron is oxidised at the negative electrode.
4
Iron at the negative electrode is reduced to metallic iron, and nickel hydroxide at the positive electrode is oxidised.