NKULU KALALA JEAN

This document discusses the roles of the positive electrode NiOOH, the negative electrode Cd, and the electrolyte KOH during the discharge of a Ni-Cd cell. The objective is to illustrate the electrochemical reactions taking place and the significance of each component in ensuring efficient energy conversion and storage. The methodology includes an in-depth analysis of the discharge reactions, highlighting the reduction of NiOOH to nickel hydroxide and the oxidation of cadmium to cadmium hydroxide, alongside the function of KOH as a facilitator of ionic transport. Results show that while the electrolyte is crucial for conductivity, it does not participate in the overall reaction due to the compensatory nature of the hydroxide ions consumed and produced. Additionally, the document addresses capacity reduction observed with repeated cycles without complete discharge, explaining the 'memory effect' and proposing maintenance practices such as complete discharges followed by recharges. Finally, a comparison of hydrometallurgy and pyrometallurgy for recycling Ni-Cd batteries is presented, emphasizing the advantages of hydrometallurgy in terms of selectivity and lower environmental impact, which indicates a shift towards more sustainable practices in battery recycling.