What is the half-equation for the reaction occurring at the positive electrode of the given cell?

The reaction occurring at the positive electrode, also known as the cathode, involves the reduction process, where species gain electrons. In the case of option B, the half-equation shows lithium ions (Li+) and manganese dioxide (MnO2) reacting together in the presence of an electron (e-) to form lithium manganese dioxide (LiMnO2) in its solid state.

This process signifies that electrons are being supplied to the reactants at the positive electrode, leading to their reduced forms. The overall half-equation captures the necessary components: the lithium ion, the manganese dioxide, the electron, and the product of the reaction, which is the lithium manganese dioxide. This is consistent with how cathodic reactions are represented in electrochemical cells.

This half-equation embodies the fundamental principles of charge transfer during the electrochemical process, where reduction entails the inclusion of electrons into the reactants, ultimately creating the solid lithium manganese dioxide as a product. The presence of Li+ indicates that lithium is being reduced, which is characteristic of positive electrode reactions in such electrochemical cells.