Synthesis and Electrochemical Studies of Aryl-Substituted Group 14 Compounds

Judith Maja Biedermann

Publikation: StudienabschlussarbeitDissertationForschung

Abstract

Organosilicon and -tin compounds are already used in various industries ranging from surface modifying silicones, thin films for electronic transistors and opto-electronic devices. Future consumer electronics and electric vehicles could also rely on high-performance Li-ion batteries with silicon or tin-based anodes. Their fully lithiated phases Li4.4E(IV) boast theoretical capacities of 4200 mAh g–1 for silicon and 990 mAh g–1 for tin. So far, however, such anodes still suffer from immense volume expansions of up to 400%vol which eventually fractures the material and thus limits cycle-life. These complications are mitigated when the silicon or tin are nanostructured or embedded in carbon (Si/C or Sn/C).
In this work, novel and previously published aryl-substituted silanes and stannanes were synthesised, comprehensively characterised and processed in order to develop nanostructured Si/C or Sn/C anode materials for Li-ion batteries. The silanes and stannanes were substituted with aryl groups such as phenyl, o-tolyl, 2,5-xylyl and 1-naphthyl or, hitherto uncharacterised, mixtures thereof. The effects of substituent bulk on the 29Si chemical shifts, the solid-state interactions in single crystals and the electrochemical properties are discussed. Electrochemical characterisation of aryl silanes was carried out in non-aqueous environment in a purpose-built, optimised cyclic voltammetry cell. Subsequently, the aryl silanes were pyrolysed and the arylstannanes coupled to form Si/C and Sn/C anode materials, respectively. These materials displayed specific capacities exceeding the capacities of state-of-the-art graphite anodes by up to 20% and excellent cyclic stability.
Originalspracheenglisch
Gradverleihende Hochschule
  • Technische Universität Graz (90000)
Betreuer/-in / Berater/-in
  • Uhlig, Frank, Betreuer
  • Hanzu, Ilie, Berater
PublikationsstatusVeröffentlicht - 13 Aug 2018

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Silanes
Anodes
Tin
Silicon
Tin Compounds
Consumer electronics
Graphite
Chemical shift
Silicones
Electric vehicles
Electrochemical properties
Optoelectronic devices
Cyclic voltammetry
Life cycle
Transistors
Carbon
Single crystals
Thin films
Industry
stannane

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    Synthesis and Electrochemical Studies of Aryl-Substituted Group 14 Compounds. / Biedermann, Judith Maja.

    2018. 163 S.

    Publikation: StudienabschlussarbeitDissertationForschung

    Biedermann, JM 2018, 'Synthesis and Electrochemical Studies of Aryl-Substituted Group 14 Compounds', Technische Universität Graz (90000).
    @phdthesis{9e8f2671559748758e989065caefb16b,
    title = "Synthesis and Electrochemical Studies of Aryl-Substituted Group 14 Compounds",
    abstract = "Organosilicon and -tin compounds are already used in various industries ranging from surface modifying silicones, thin films for electronic transistors and opto-electronic devices. Future consumer electronics and electric vehicles could also rely on high-performance Li-ion batteries with silicon or tin-based anodes. Their fully lithiated phases Li4.4E(IV) boast theoretical capacities of 4200 mAh g–1 for silicon and 990 mAh g–1 for tin. So far, however, such anodes still suffer from immense volume expansions of up to 400{\%}vol which eventually fractures the material and thus limits cycle-life. These complications are mitigated when the silicon or tin are nanostructured or embedded in carbon (Si/C or Sn/C).In this work, novel and previously published aryl-substituted silanes and stannanes were synthesised, comprehensively characterised and processed in order to develop nanostructured Si/C or Sn/C anode materials for Li-ion batteries. The silanes and stannanes were substituted with aryl groups such as phenyl, o-tolyl, 2,5-xylyl and 1-naphthyl or, hitherto uncharacterised, mixtures thereof. The effects of substituent bulk on the 29Si chemical shifts, the solid-state interactions in single crystals and the electrochemical properties are discussed. Electrochemical characterisation of aryl silanes was carried out in non-aqueous environment in a purpose-built, optimised cyclic voltammetry cell. Subsequently, the aryl silanes were pyrolysed and the arylstannanes coupled to form Si/C and Sn/C anode materials, respectively. These materials displayed specific capacities exceeding the capacities of state-of-the-art graphite anodes by up to 20{\%} and excellent cyclic stability.",
    keywords = "Synthesis, Electrochemistry, Silicon, Tin, Inorganic Chemistry, Batteries, Single Crystals",
    author = "Biedermann, {Judith Maja}",
    year = "2018",
    month = "8",
    day = "13",
    language = "English",
    school = "Graz University of Technology (90000)",

    }

    TY - THES

    T1 - Synthesis and Electrochemical Studies of Aryl-Substituted Group 14 Compounds

    AU - Biedermann, Judith Maja

    PY - 2018/8/13

    Y1 - 2018/8/13

    N2 - Organosilicon and -tin compounds are already used in various industries ranging from surface modifying silicones, thin films for electronic transistors and opto-electronic devices. Future consumer electronics and electric vehicles could also rely on high-performance Li-ion batteries with silicon or tin-based anodes. Their fully lithiated phases Li4.4E(IV) boast theoretical capacities of 4200 mAh g–1 for silicon and 990 mAh g–1 for tin. So far, however, such anodes still suffer from immense volume expansions of up to 400%vol which eventually fractures the material and thus limits cycle-life. These complications are mitigated when the silicon or tin are nanostructured or embedded in carbon (Si/C or Sn/C).In this work, novel and previously published aryl-substituted silanes and stannanes were synthesised, comprehensively characterised and processed in order to develop nanostructured Si/C or Sn/C anode materials for Li-ion batteries. The silanes and stannanes were substituted with aryl groups such as phenyl, o-tolyl, 2,5-xylyl and 1-naphthyl or, hitherto uncharacterised, mixtures thereof. The effects of substituent bulk on the 29Si chemical shifts, the solid-state interactions in single crystals and the electrochemical properties are discussed. Electrochemical characterisation of aryl silanes was carried out in non-aqueous environment in a purpose-built, optimised cyclic voltammetry cell. Subsequently, the aryl silanes were pyrolysed and the arylstannanes coupled to form Si/C and Sn/C anode materials, respectively. These materials displayed specific capacities exceeding the capacities of state-of-the-art graphite anodes by up to 20% and excellent cyclic stability.

    AB - Organosilicon and -tin compounds are already used in various industries ranging from surface modifying silicones, thin films for electronic transistors and opto-electronic devices. Future consumer electronics and electric vehicles could also rely on high-performance Li-ion batteries with silicon or tin-based anodes. Their fully lithiated phases Li4.4E(IV) boast theoretical capacities of 4200 mAh g–1 for silicon and 990 mAh g–1 for tin. So far, however, such anodes still suffer from immense volume expansions of up to 400%vol which eventually fractures the material and thus limits cycle-life. These complications are mitigated when the silicon or tin are nanostructured or embedded in carbon (Si/C or Sn/C).In this work, novel and previously published aryl-substituted silanes and stannanes were synthesised, comprehensively characterised and processed in order to develop nanostructured Si/C or Sn/C anode materials for Li-ion batteries. The silanes and stannanes were substituted with aryl groups such as phenyl, o-tolyl, 2,5-xylyl and 1-naphthyl or, hitherto uncharacterised, mixtures thereof. The effects of substituent bulk on the 29Si chemical shifts, the solid-state interactions in single crystals and the electrochemical properties are discussed. Electrochemical characterisation of aryl silanes was carried out in non-aqueous environment in a purpose-built, optimised cyclic voltammetry cell. Subsequently, the aryl silanes were pyrolysed and the arylstannanes coupled to form Si/C and Sn/C anode materials, respectively. These materials displayed specific capacities exceeding the capacities of state-of-the-art graphite anodes by up to 20% and excellent cyclic stability.

    KW - Synthesis

    KW - Electrochemistry

    KW - Silicon

    KW - Tin

    KW - Inorganic Chemistry

    KW - Batteries

    KW - Single Crystals

    M3 - Doctoral Thesis

    ER -