= Solution
\b[A useful aqueous <anode> must deliver the desired oxidation current while limiting parasitic corrosion and hydrogen evolution.] <Thermodynamics> sets the driving force, while <activation overpotential>, surface films and mass transport control the rate.
For <zinc>, the acid calculation favours dissolution with hydrogen evolution, but a substantial kinetic barrier to hydrogen evolution on a clean zinc surface can slow this loss. Impurities and catalytic inclusions can increase it. In alkaline electrolyte, zinc can be useful in batteries, but the unit-activity $\mathrm{Zn^{2+}}$ calculation is incomplete: soluble zincate and zinc oxide or hydroxide alter the relevant equilibrium. A surface film can protect against corrosion or obstruct useful discharge, depending on its conductivity and transport properties.
For <lead>, acid corrosion has a much smaller driving force in the stipulated model, and slow hydrogen kinetics can permit practical use. The electrolyte anion matters: a lead sulfate layer in a lead–acid system has a different role from arbitrary soluble lead salts. In alkaline media, hydroxide formation, soluble complexes and <passivation> again need consideration before drawing a practical conclusion from the free-ion potential.
\b[Metallic <lithium> is unsuitable as an exposed anode in an ordinary aqueous electrolyte.] Its strongly favourable reaction with water overwhelms the argument for simply relying on a hydrogen overpotential. A lithium-ion host electrode is a different material and must be judged by its own operating potential and interfacial chemistry.
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