title: Multifunctional molecular design as an efficient polymeric binder for silicon anodes in lithium-ion batteries.
abstract: This work demonstrates the design, synthesis, characterization, and study of the electrochemical performance of a novel binder for silicon (Si) anodes in lithium-ion batteries (LIBs). Polymeric binders with three different functional groups, namely, carboxylic acid (COOH), carboxylate (COO(-)), and hydroxyl (OH), in a single polymer backbone have been synthesized and characterized via (1)H NMR and FTIR spectroscopies. A systematic study that involved varying the ratio of the functional groups indicated that a material with an acid-to-alcohol molar ratio of 60:40 showed promise as an efficient binder with an initial columbic efficiency of 89%. This exceptional performance is attributed to the strong adhesion of the binder to the silicon surface and to cross-linking between carboxyl and hydroxyl functional groups, which minimize the disintegration of the Si anode structure during the large volume expansion of the lithiated Si nanoparticle. Polymers with multiple functional groups can serve as practical alternative binders for the Si anodes of LIBs, resulting in higher capacities with less capacity fade.
authors.affiliation: Department of Chemistry, School of Natural Science, ‡School of Energy and Chemical Engineering, and §School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan, 689-798, South Korea.
authors.forename: M T
authors.initials: MT
authors.lastname: Jeena
authors.forename: Jung-In
authors.initials: JI
authors.lastname: Lee
authors.forename: Si Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Chanhoon
authors.initials: C
authors.lastname: Kim
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Soojin
authors.initials: S
authors.lastname: Park
authors.forename: Ja-Hyoung
authors.initials: JH
authors.lastname: Ryu
keywords: lithium-ion batteries; multifunctional binder; polymeric binder; silicon anode