This project developed methods to extract zinc, manganese, and carbon from spent primary batteries and repurpose these materials for zinc-ion battery applications. Initial laboratory experiments explored various acid leaching conditions to extract zinc and manganese ions from used battery electrodes. When scaled up to a 50-liter pilot reactor, the process achieved extraction efficiencies exceeding 80% for both metals. The extracted solutions were used to deposit zinc films on stainless steel, copper, and brass substrates, while manganese dioxide (MnO₂) and MnO₂/carbon composites were synthesized via hydrothermal techniques. Researchers also developed a one-step hydrothermal method to produce MnO₂/carbon composites without acid leaching. These recycled materials were then incorporated as anode and cathode components in various zinc-ion battery configurations (CR2032, pouch-cell, and prismatic formats). Performance testing demonstrated that the recycled MnO₂ and MnO₂/carbon materials performed at least as effectively as commercial equivalents, confirming the viability of these recycled materials for zinc-ion battery applications.