Piezoelectrochemistry in Lithium Ion Batteries with Structured Separators

Abstract

Recent research has identified a relationship between the mechanical stress applied to an intercalating material and the concentration of intercalated ions. This is known as piezoelectrochemistry (PEC). This relationship has the potential to allow for the direct conversion of mechanical energy to electrical energy. However, no adequately efficient intercalating material has been identified. To speed the search for such a material, this research focuses on constructing structured epoxy separators to increase the mechanical force applied to the active material in batteries. The separators are structured through femtosecond laser ablation of thin sheets of hardened epoxy. Although the machined epoxy separator was unable to function as a battery, experimental results demonstrate that an epoxy separator in a resistor can produce coupling factors up to 5 times larger than polymer separated battery pouch cells. Additionally, the structure of the epoxy separators raises new questions about the process of pressure-induced intercalation. This work is building upon prior research that investigated the effect of ceramic separators on piezoelectrochemical phenomenon.