title: Dependency of Electrochemical Performances of Silicon Lithium-Ion Batteries on Glycosidic Linkages of Polysaccharide Binders.
abstract: Molecular structures of polysaccharide binders determining mechanical properties were correlated to electrochemical performances of silicon anodes for lithium-ion batteries. Glycosidic linkages (α and β) and side chains (-COOH and -OH) were selected and proven as the major factors of the molecular structures. Three different single-component polysaccharides were compared: pectin for α-linkages versus carboxylic methyl cellulose (CMC) for β-linkages from the linkage's standpoint, and pectin as a COOH-containing polymer and amylose as its non-COOH counterpart from the side chain's standpoint. Pectin was remarkably superior to CMC and amylose in cyclability and rate capability of battery cells based on silicon anodes. The pectin binder allowed volume expansion of silicon electrodes with keeping high porosity during lithiation due to the elastic nature caused by the chair-to-boat conformation in α-linkages of its backbone. Physical integrity of pectin-based electrodes was not challenged during repeated lithiation/delithiation cycles without crack development that was observed in rigid CMC-based electrodes. Covalent bonds formed between carboxylic side chains of pectin and silicon surface oxide prevented active silicon mass from being detached away from electric pathways. However, hydrogen bonds between hydroxyl side chains of amylose and silicon surface oxide were not strong enough to keep the silicon mass electrochemically active after cyclability tests.
authors.affiliation: School of Energy and Chemical Engineering, UNIST , Ulsan 689-798, Korea.
authors.forename: Da-Eun
authors.initials: DE
authors.lastname: Yoon
authors.affiliation: School of Energy and Chemical Engineering, UNIST , Ulsan 689-798, Korea.
authors.forename: Chihyun
authors.initials: C
authors.lastname: Hwang
authors.affiliation: School of Materials Science and Engineering, UNIST , Ulsan 689-798, Korea.|KIST-UNIST Ulsan Center for Convergent Materials, UNIST , Ulsan 689-798, Korea.
authors.forename: Na-Ri
authors.initials: NR
authors.lastname: Kang
authors.affiliation: GS Energy R&D Center, GS Energy Corp. , Seoul 134-848, Korea.
authors.forename: Ungju
authors.initials: U
authors.lastname: Lee
authors.affiliation: GS Energy R&D Center, GS Energy Corp. , Seoul 134-848, Korea.
authors.forename: Dongjoon
authors.initials: D
authors.lastname: Ahn
authors.affiliation: School of Materials Science and Engineering, UNIST , Ulsan 689-798, Korea.|KIST-UNIST Ulsan Center for Convergent Materials, UNIST , Ulsan 689-798, Korea.|IBS Research Center for Multidimensional Carbon Materials, UNIST , Ulsan 689-798, Korea.
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: School of Energy and Chemical Engineering, UNIST , Ulsan 689-798, Korea.
authors.forename: Hyun-Kon
authors.initials: HK
authors.lastname: Song
mesh_terms: D002236:Carbohydrate Conformation; D055664:Electrochemical Techniques; D008094:Lithium / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*
chemical_list: D011134:Polysaccharides; D008094:Lithium; D012825:Silicon
keywords: binder; elasticity; lithium-ion batteries; polysaccharide; silicon