title: Breathing silicon anodes for durable high-power operations.
abstract: Silicon anode materials have been developed to achieve high capacity lithium ion batteries for operating smart phones and driving electric vehicles for longer time. Serious volume expansion induced by lithiation, which is the main drawback of silicon, has been challenged by multi-faceted approaches. Mechanically rigid and stiff polymers (e.g. alginate and carboxymethyl cellulose) were considered as the good choices of binders for silicon because they grab silicon particles in a tight and rigid way so that pulverization and then break-away of the active mass from electric pathways are suppressed. Contrary to the public wisdom, in this work, we demonstrate that electrochemical performances are secured better by letting silicon electrodes breathe in and out lithium ions with volume change rather than by fixing their dimensions. The breathing electrodes were achieved by using a polysaccharide (pullulan), the conformation of which is modulated from chair to boat during elongation. The conformational transition of pullulan was originated from its α glycosidic linkages while the conventional rigid polysaccharide binders have β linkages.
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 Energy and Chemical Engineering, UNIST, Ulsan 689-798, Korea.
authors.forename: Sehun
authors.initials: S
authors.lastname: Joo
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: School of Energy and Chemical Engineering, UNIST, Ulsan 689-798, Korea.
authors.forename: Tae-Hee
authors.initials: TH
authors.lastname: Kim
authors.affiliation: School of Energy and Chemical Engineering, UNIST, Ulsan 689-798, Korea.
authors.forename: Yuju
authors.initials: Y
authors.lastname: Jeon
authors.affiliation: School of Energy and Chemical Engineering, UNIST, Ulsan 689-798, Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Kim
authors.affiliation: KCC Corp., Seoul 137-703, Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Kim
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: Sang-Kyu
authors.initials: SK
authors.lastname: Kwak
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: D055119:Elastic Modulus / Q000502:physiology*; D004553:Electric Conductivity; D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D004566:Electrodes; D005936:Glucans / Q000737:chemistry; D006244:Hardness / Q000502:physiology; D008094:Lithium / Q000737:chemistry*; D008968:Molecular Conformation; D036103:Nanotechnology; D012825:Silicon / Q000737:chemistry*
chemical_list: D005936:Glucans; C009109:pullulan; D008094:Lithium; D012825:Silicon