Rodger Yuan Rose Hills
Solubility of Intermediary Polysulfides in Ion Conductive Block Copolymers
Batteries with high energy density have important applications as energy storage devices in portable electronics. This summer, I will be studying solid-state lithium-sulfur batteries with block copolymer electrolytes. This the benefit of this design is twofold: the Li-S chemistry has a theoretical specific capacity over 6 times that of todays lithium-ion battery and the polymer electrolyte eliminates the need to use liquid organic electrolytes, which are flammable and volatile. However, there are many challenges that must be overcome before Li-S batteries are viable as future energy storage systems. The problem I will be focusing on for the summer is the dissolution of lithium polysulfides into the polymer electrolyte. As the battery discharges, these polysulfides can dissolve into the ion-conducting polymer and migrate to the anode, causing self-discharge. Using lamellar block copolymers as a cathode binder, we hope to create complex diffusion pathways or chemical potential gradients to localize polysulfide diffusion.