Pradeep, V. S. and Graczyk-Zajac, Magdalena and Riedel, Ralf and Sorarù, Gian Domenico (2014):
New Insights in to the Lithium Storage Mechanism in Polymer Derived SiOC Anode Materials.
119, In: Electrochimica Acta, Elsevier Science Publishing, pp. 78-85, ISSN 00134686, [Online-Edition: http://dx.doi.org/10.1016/j.electacta.2013.12.037],
[Article]
Abstract
Polymer derived silicon oxycarbide (SiOC) materials are prepared by the pyrolysis of preceramic polymers obtained from polyhydridomethylsiloxane using 1,3,5,7-tetramethyl1,3,5,7-tetravinyl cyclotetrasiloxane or divinyl benzene as a cross-linking agent. The pyrolysis is carried out in an inert atmosphere at 1000 and 1300 °C. The carbon content of SiOC is varied by changing the amount of starting precursors maintaining the same O/Si atomic ratio of about 1. Electrochemical measurements are performed in order to evaluate the materials in terms of their application as anodes in Li-ion batteries. Detailed structural characterization study is performed using complementary techniques with the aim of correlating the electrochemical behavior with the structure of the SiOC anodes. Results suggest that SiOC anodes behave as a composite material consisting of a disordered silicon oxycarbide phase having a very high first insertion capacity of ca 1300 mAh g−1 and a free C phase. However, the charge irreversible trapped into the amorphous silicon oxycarbide network is also high and therefore the maximum reversible lithium storage capacity of 650mAh g−1 is measured on high-C content SiOCs for which the balance between the two phases, namely the amorphous silicon oxycarbide and the free C phase, is optimal. The high carbon content SiOC show also an excellent cycling stability and performance at high charging/discharging rate: the reversible capacity at 2 C rate being around 200 mAh g−1. Increasing the pyrolysis temperature has an opposite effect on the low-C and high-C materials: for the latter one the reversible capacity decreases following a known trend while the former shows an increase of the reversible capacity which has never been observed before for similar materials.
| Item Type: | Article |
|---|---|
| Erschienen: | 2014 |
| Creators: | Pradeep, V. S. and Graczyk-Zajac, Magdalena and Riedel, Ralf and Sorarù, Gian Domenico |
| Title: | New Insights in to the Lithium Storage Mechanism in Polymer Derived SiOC Anode Materials |
| Language: | English |
| Abstract: | Polymer derived silicon oxycarbide (SiOC) materials are prepared by the pyrolysis of preceramic polymers obtained from polyhydridomethylsiloxane using 1,3,5,7-tetramethyl1,3,5,7-tetravinyl cyclotetrasiloxane or divinyl benzene as a cross-linking agent. The pyrolysis is carried out in an inert atmosphere at 1000 and 1300 °C. The carbon content of SiOC is varied by changing the amount of starting precursors maintaining the same O/Si atomic ratio of about 1. Electrochemical measurements are performed in order to evaluate the materials in terms of their application as anodes in Li-ion batteries. Detailed structural characterization study is performed using complementary techniques with the aim of correlating the electrochemical behavior with the structure of the SiOC anodes. Results suggest that SiOC anodes behave as a composite material consisting of a disordered silicon oxycarbide phase having a very high first insertion capacity of ca 1300 mAh g−1 and a free C phase. However, the charge irreversible trapped into the amorphous silicon oxycarbide network is also high and therefore the maximum reversible lithium storage capacity of 650mAh g−1 is measured on high-C content SiOCs for which the balance between the two phases, namely the amorphous silicon oxycarbide and the free C phase, is optimal. The high carbon content SiOC show also an excellent cycling stability and performance at high charging/discharging rate: the reversible capacity at 2 C rate being around 200 mAh g−1. Increasing the pyrolysis temperature has an opposite effect on the low-C and high-C materials: for the latter one the reversible capacity decreases following a known trend while the former shows an increase of the reversible capacity which has never been observed before for similar materials. |
| Journal or Publication Title: | Electrochimica Acta |
| Volume: | 119 |
| Publisher: | Elsevier Science Publishing |
| Uncontrolled Keywords: | SiOC, Li-ion batteries, Polymer derived ceramics, Anodes |
| Divisions: | 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > A - Synthesis DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > A - Synthesis > Subproject A4: Novel functional ceramics using anionic substitution in oxidic systems 11 Department of Materials and Earth Sciences > Material Science 11 Department of Materials and Earth Sciences Zentrale Einrichtungen DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres DFG-Collaborative Research Centres (incl. Transregio) |
| Date Deposited: | 08 Jan 2014 09:54 |
| Official URL: | http://dx.doi.org/10.1016/j.electacta.2013.12.037 |
| Additional Information: | SFB 595 A4 |
| Identification Number: | doi:10.1016/j.electacta.2013.12.037 |
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