This project introduces the design and testing of a small-scale solid-state lithium-ion battery using a polymer-based electrolyte. Students prepare a solid electrolyte film by combining polyethylene oxide (PEO) with lithium salts and assemble electrodes from lithium cobalt oxide or graphite slurries coated onto metal foils. The solid electrolyte is layered between the anode and cathode in a coin-cell housing, creating a safer alternative to conventional liquid-based batteries. Measurements of open-circuit voltage, charging behavior, and discharging capacity allow learners to evaluate the functionality of the prototype while developing skills in energy storage systems, solid-state chemistry, and electrochemical testing.
 
Performance analysis focuses on energy capacity, cycling stability, and electrolyte efficiency, highlighting the advantages and challenges of solid-state designs. Comparisons with conventional lithium-ion cells demonstrate the potential of solid electrolytes to improve safety and energy density while reducing the risk of leakage and thermal runaway. Optimization studies explore variations in electrolyte composition, cathode selection, and electrode thickness, linking laboratory experimentation to the broader development of next-generation batteries for consumer electronics, electric vehicles, and renewable energy storage.