TU Darmstadt / ULB / TUbiblio

Highly Porous Silicon Embedded in a Ceramic Matrix: A Stable High-Capacity Electrode for Li-Ion Batteries

Vrankovic, Dragoljub and Graczyk-Zajac, Magdalena and Kalcher, Constanze and Rohrer, Jochen and Becker, Malin and Stabler, Christina and Trykowski, Grzegorz and Albe, Karsten and Riedel, Ralf (2017):
Highly Porous Silicon Embedded in a Ceramic Matrix: A Stable High-Capacity Electrode for Li-Ion Batteries.
In: ACS Nano, ACS Publications, pp. 11409-11416, 11, (11), ISSN 1936-0851,
DOI: 10.1021/acsnano.7b06031,
[Online-Edition: https://doi.org/10.1021/acsnano.7b06031],
[Article]

Abstract

We demonstrate a cost-effective synthesis route that provides Si-based anode materials with capacities between 2000 and 3000 mAh·g_Si^–1 (400 and 600 mAh·g_composite^–1), Coulombic efficiencies above 99.5%, and almost 100% capacity retention over more than 100 cycles. The Si-based composite is prepared from highly porous silicon (obtained by reduction of silica) by encapsulation in an organic carbon and polymer-derived silicon oxycarbide (C/SiOC) matrix. Molecular dynamics simulations show that the highly porous silicon morphology delivers free volume for the accommodation of strain leading to no macroscopic changes during initial Li–Si alloying. In addition, a carbon layer provides an electrical contact, whereas the SiOC matrix significantly diminishes the interface between the electrolyte and the electrode material and thus suppresses the formation of a solid–electrolyte interphase on Si. Electrochemical tests of the micrometer-sized, glass-fiber-derived silicon demonstrate the up-scaling potential of the presented approach

Item Type: Article
Erschienen: 2017
Creators: Vrankovic, Dragoljub and Graczyk-Zajac, Magdalena and Kalcher, Constanze and Rohrer, Jochen and Becker, Malin and Stabler, Christina and Trykowski, Grzegorz and Albe, Karsten and Riedel, Ralf
Title: Highly Porous Silicon Embedded in a Ceramic Matrix: A Stable High-Capacity Electrode for Li-Ion Batteries
Language: English
Abstract:

We demonstrate a cost-effective synthesis route that provides Si-based anode materials with capacities between 2000 and 3000 mAh·g_Si^–1 (400 and 600 mAh·g_composite^–1), Coulombic efficiencies above 99.5%, and almost 100% capacity retention over more than 100 cycles. The Si-based composite is prepared from highly porous silicon (obtained by reduction of silica) by encapsulation in an organic carbon and polymer-derived silicon oxycarbide (C/SiOC) matrix. Molecular dynamics simulations show that the highly porous silicon morphology delivers free volume for the accommodation of strain leading to no macroscopic changes during initial Li–Si alloying. In addition, a carbon layer provides an electrical contact, whereas the SiOC matrix significantly diminishes the interface between the electrolyte and the electrode material and thus suppresses the formation of a solid–electrolyte interphase on Si. Electrochemical tests of the micrometer-sized, glass-fiber-derived silicon demonstrate the up-scaling potential of the presented approach

Journal or Publication Title: ACS Nano
Volume: 11
Number: 11
Publisher: ACS Publications
Uncontrolled Keywords: Li-ion battery, molecular dynamics simulations, nanocomposite anode material, porous Silicon, silicon oxycarbide
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
11 Department of Materials and Earth Sciences > Material Science > Materials Modelling
Zentrale Einrichtungen > University IT-Service and Computing Centre (HRZ) > Hochleistungsrechner
11 Department of Materials and Earth Sciences > Material Science
Zentrale Einrichtungen > University IT-Service and Computing Centre (HRZ)
11 Department of Materials and Earth Sciences
Zentrale Einrichtungen
Date Deposited: 07 Dec 2017 10:42
DOI: 10.1021/acsnano.7b06031
Official URL: https://doi.org/10.1021/acsnano.7b06031
Funders: We gratefully acknowledge the financial support of the German Research Foundation (DFG) within SPP 1473/JP8, RO 4542/2-1 and IO 64/7-1.
Export:
Suche nach Titel in: TUfind oder in Google

Optionen (nur für Redakteure)

View Item View Item