title: Highly Flexible Self-Assembled V2O5 Cathodes Enabled by Conducting Diblock Copolymers.
abstract: Mechanically robust battery electrodes are desired for applications in wearable devices, flexible displays, and structural energy and power. In this regard, the challenge is to balance mechanical and electrochemical properties in materials that are inherently brittle. Here, we demonstrate a unique water-based self-assembly approach that incorporates a diblock copolymer bearing electron- and ion-conducting blocks, poly(3-hexylthiophene)-block-poly(ethyleneoxide) (P3HT-b-PEO), with V2O5 to form a flexible, tough, carbon-free hybrid battery cathode. V2O5 is a promising lithium intercalation material, but it remains limited by its poor conductivity and mechanical properties. Our approach leads to a unique electrode structure consisting of interlocking V2O5 layers glued together with micellar aggregates of P3HT-b-PEO, which results in robust mechanical properties, far exceeding the those obtained from conventional fluoropolymer binders. Only 5 wt % polymer is required to triple the flexibility of V2O5, and electrodes comprised of 10 wt % polymer have unusually high toughness (293 kJ/m(3)) and specific energy (530 Wh/kg), both higher than reduced graphene oxide paper electrodes. Furthermore, addition of P3HT-b-PEO enhances lithium-ion diffusion, eliminates cracking during cycling, and boosts cyclability relative to V2O5 alone. These results highlight the importance of tradeoffs between mechanical and electrochemical performance, where polymer content can be used to tune both aspects.
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX.
authors.forename: Hyosung
authors.initials: H
authors.lastname: An
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX.
authors.forename: Jared
authors.initials: J
authors.lastname: Mike
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX.
authors.forename: Kendall A
authors.initials: KA
authors.lastname: Smith
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX.
authors.forename: Lisa
authors.initials: L
authors.lastname: Swank
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX.
authors.forename: Yen-Hao
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX.
authors.forename: Stacy
authors.initials: S
authors.lastname: L Pesek
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX.|Department of Materials Science and NanoEngineering, Rice University, Houston, TX.
authors.forename: Rafael
authors.initials: R
authors.lastname: Verduzco
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX.
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Lutkenhaus
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D011108:Polymers; D017968:Vanadium Compounds
chemical_list: D011108:Polymers; D017968:Vanadium Compounds; C066075:vanadium pentoxide