title: Delicate Structural Control of Si-SiOx-C Composite via High-Speed Spray Pyrolysis for Li-Ion Battery Anodes.
abstract: Despite the high theoretical capacity, silicon (Si) anodes in lithium-ion batteries have difficulty in meeting the commercial standards in various aspects. In particular, the huge volume change of Si makes it very challenging to simultaneously achieve high initial Coulombic efficiency (ICE) and long-term cycle life. Herein, we report spray pyrolysis to prepare Si-SiOxcomposite using an aqueous precursor solution containing Si nanoparticles, citric acid, and sodium hydroxide (NaOH). In the precursor solution, Si nanoparticles are etched by NaOH with the production of [SiO4]4-. During the dynamic course of spray pyrolysis, [SiO4]4-transforms to SiOxmatrix and citric acid decomposes to carbon surface layer with the assistance of NaOH that serves as a decomposition catalyst. As a result, a Si-SiOxcomposite, in which Si nanodomains are homogeneously embedded in the SiOxmatrix with carbon surface layer, is generated by a one-pot process with a residence time of only 3.5 s in a flow reactor. The optimal composite structure in terms of Si domain size and Si-to-O ratio exhibited excellent electrochemical performance, such as reversible capacity of 1561.9 mAh g-1at 0.06C rate and ICE of 80.2% and 87.9% capacity retention after 100 cycles at 1C rate.
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Seung Jong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Hwang
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Sunghun
authors.initials: S
authors.lastname: Choi
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Sung Hyeon
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University , P.O. Box 2713, Doha, Qatar.
authors.forename: Erhan
authors.identifier: 0000-0002-0265-9912
authors.initials: E
authors.lastname: Deniz
authors.affiliation: Energy & Environmental Division, Korea Institute of Ceramic Engineering & Technology (KICET) , 101 Soho-ro, Jinju-si, Gyeongsangnam-do 52581, Republic of Korea.
authors.forename: Dae Soo
authors.initials: DS
authors.lastname: Jung
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and KAIST Institute NanoCentury, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehakro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Jang Wook
authors.identifier: 0000-0001-8783-0901
authors.initials: JW
authors.lastname: Choi
keywords: Cycle life; initial Coulombic efficiency; pulverization; silicon monoxide; spray pyrolysis