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Silicon oxycarbide ceramics as anodes for lithium ion batteries: influence of carbon content on lithium storage capacity

Wilamowska-Zawlocka, Monika and Puczkarski, Paweł and Grabowska, Zofia and Kaspar, Jan and Graczyk-Zajac, Magdalena and Riedel, Ralf and Sorarù, Gian D. (2016):
Silicon oxycarbide ceramics as anodes for lithium ion batteries: influence of carbon content on lithium storage capacity.
In: RSC Adv., The Royal Society of Chemistry, pp. 104597-104607, 6, (106), ISSN 2046-2069,
[Online-Edition: http://dx.doi.org/10.1039/c6ra24539k],
[Article]

Abstract

We report here on the synthesis and characterization of silicon oxycarbide (SiOC) in view of its application as a potential anode material for Li-ion batteries. SiOC ceramics are obtained by pyrolysis of various polysiloxanes synthesized by sol–gel methods. The polysiloxanes contain different organic groups attached to silicon, which influence the chemical composition and the microstructure of the final ceramic product. The structure of the SiOC samples is investigated by XRD, micro-Raman spectroscopy, solid state 29Si MAS-NMR and TEM. All investigated samples remain amorphous. However, at the elevated temperature of pyrolysis a phase separation process begins. During this process the carbon clusters become more ordered, which is reflected in the higher intensity and narrowing of the D1 band and decreasing of the D3 band. Moreover, the elevated temperature of pyrolysis promotes consumption of mixed bonds units, SiO3C, SiO2C2, SiOC3, and increases the share of oxygen rich SiO4 and carbon rich SiC4 tetrahedra. Electrochemical studies show a clear dependence between free carbon content and lithium storage capacity. Carbon-rich samples exhibit significantly higher capacities (∼550 mA h g−1 recorded at low current rate after 140 charge–discharge cycles) compared to carbon-poor samples (up to 360 mA h g−1). Moreover, carbon-rich samples exhibit a lower irreversible capacity during their first cycles compared to low carbon samples.

Item Type: Article
Erschienen: 2016
Creators: Wilamowska-Zawlocka, Monika and Puczkarski, Paweł and Grabowska, Zofia and Kaspar, Jan and Graczyk-Zajac, Magdalena and Riedel, Ralf and Sorarù, Gian D.
Title: Silicon oxycarbide ceramics as anodes for lithium ion batteries: influence of carbon content on lithium storage capacity
Language: English
Abstract:

We report here on the synthesis and characterization of silicon oxycarbide (SiOC) in view of its application as a potential anode material for Li-ion batteries. SiOC ceramics are obtained by pyrolysis of various polysiloxanes synthesized by sol–gel methods. The polysiloxanes contain different organic groups attached to silicon, which influence the chemical composition and the microstructure of the final ceramic product. The structure of the SiOC samples is investigated by XRD, micro-Raman spectroscopy, solid state 29Si MAS-NMR and TEM. All investigated samples remain amorphous. However, at the elevated temperature of pyrolysis a phase separation process begins. During this process the carbon clusters become more ordered, which is reflected in the higher intensity and narrowing of the D1 band and decreasing of the D3 band. Moreover, the elevated temperature of pyrolysis promotes consumption of mixed bonds units, SiO3C, SiO2C2, SiOC3, and increases the share of oxygen rich SiO4 and carbon rich SiC4 tetrahedra. Electrochemical studies show a clear dependence between free carbon content and lithium storage capacity. Carbon-rich samples exhibit significantly higher capacities (∼550 mA h g−1 recorded at low current rate after 140 charge–discharge cycles) compared to carbon-poor samples (up to 360 mA h g−1). Moreover, carbon-rich samples exhibit a lower irreversible capacity during their first cycles compared to low carbon samples.

Journal or Publication Title: RSC Adv.
Volume: 6
Number: 106
Publisher: The Royal Society of Chemistry
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 11 Jan 2017 08:39
Official URL: http://dx.doi.org/10.1039/c6ra24539k
Identification Number: doi:10.1039/c6ra24539k
Funders: This work is supported by Foundation for Polish Science under grant HOMING PLUS/2012-6/16., JK, MGZ, RR acknowledge the support of German Science Foundation (SPP 1473/JP8).
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