(557c) Thin-Film Polymer Coatings By Molecular Layer Deposition for Advanced Energy Storage Electrodes

To provide both high power density and high energy density in a single electrochemical energy storage device, it is appealing to generate electrodes with a thin-film redox-active coating on a high-surface-area conductive support. Atomic layer deposition (ALD) is a proven technique to achieve this desired electrode configuration. ALD employs sequential, gas-phase surface reactions to form uniform, thin-film coatings of redox-active materials onto high-surface-area, three-dimensional substrates. Unfortunately, the ALD precursors needed to grow inorganic redox-active materials are too expensive to be viable for depositing thin-film coatings of redox-active material in commercial energy-storage devices. In this work, we report on efforts in our group to form electrodes coated with thin-film redox-active polymers using molecular layer deposition (MLD). MLD is a molecular analog to ALD and employs low-cost organic precursors. We describe experimental studies on new MLD chemistries that we use to form redox-active polymer thin-films based on conjugated amines. We examine the infiltration of these MLD coating chemistries into porous electrodes, and measure the electrochemical properties of the resulting polymer films and electrodes.