Enzymatically-Catalyzed Polymerization (ECP)- Derived Polymer Electrolyte for Rechargeable Li-Ion Batteries

摘要

Report developed under SBIR contract covers the syntheses and electrochemical characterizations of novel polymer electrolytes derived from compounds synthesized via enzyme-catalyzed polymerization(ECP) techniques. A reproducible method was developed to functionalize target monomers via the Mitsunobu reagent, and subsequently polymerizing the modified monomers utilizing enzyme catalytic method. Specifically, polyphenols were reacted with three main types of alcohols in order to establish trends for the incorporation of enhanced ionic conductivity in these materials. The materials synthesized were found to be complex mixtures of derivatized polyphenols which we sought plus coupled polyphenols and coupled alcohols. This molecular complexity maybe beneficial in ensuring that the materials remain amorphous over a broad temperature range. This is an important feature of solid-state polymer electrolyte for battery applications. Functionalization of a biphenol, with subsequent enzyme-catalyzed polymerization, was also attempted and this effort was successful in obtaining samples for polymer film processing and later electrochemical characterizations. Conductivities of polyphenol-derived polymers were found to be superior to pure PEO, and the materials were found to be electrochemically stable up to 5.0 volt versus Li. The use of inert additives such as TiO2 and SiO2 should further enhance the conductivity of the polyphenol-derived polymer electrolyte films.