Graczyk-Zajac, Magdalena ; Reinold, Lukas ; Kaspar, Jan ; Sasikumar, Pradeep ; Soraru, Gian-Domenico ; Riedel, Ralf (2015):
New Insights into Understanding Irreversible and Reversible Lithium Storage within SiOC and SiCN Ceramics.
In: Nanomaterials, 5 (1), pp. 233-245. MDPI AG, Schweiz, ISSN 2079-4991,
[Article]
Abstract
Within this work we define structural properties of the silicon carbonitride (SiCN) and silicon oxycarbide (SiOC) ceramics which determine the reversible and irreversible lithium storage capacities, long cycling stability and define the major differences in the lithium storage in SiCN and SiOC. For both ceramics, we correlate the first cycle lithiation or delithiation capacity and cycling stability with the amount of SiCN/SiOC matrix or free carbon phase, respectively. The first cycle lithiation and delithiation capacities of SiOC materials do not depend on the amount of free carbon, while for SiCN the capacity increases with the amount of carbon to reach a threshold value at ~50% of carbon phase. Replacing oxygen with nitrogen renders the mixed bond Si-tetrahedra unable to sequester lithium. Lithium is more attracted by oxygen in the SiOC network due to the more ionic character of Si-O bonds. This brings about very high initial lithiation capacities, even at low carbon content. If oxygen is replaced by nitrogen, the ceramic network becomes less attractive for lithium ions due to the more covalent character of Si-N bonds and lower electron density on the nitrogen atom. This explains the significant difference in electrochemical behavior which is observed for carbon-poor SiCN and SiOC materials.
| Item Type: | Article |
|---|---|
| Erschienen: | 2015 |
| Creators: | Graczyk-Zajac, Magdalena ; Reinold, Lukas ; Kaspar, Jan ; Sasikumar, Pradeep ; Soraru, Gian-Domenico ; Riedel, Ralf |
| Title: | New Insights into Understanding Irreversible and Reversible Lithium Storage within SiOC and SiCN Ceramics |
| Language: | English |
| Abstract: | Within this work we define structural properties of the silicon carbonitride (SiCN) and silicon oxycarbide (SiOC) ceramics which determine the reversible and irreversible lithium storage capacities, long cycling stability and define the major differences in the lithium storage in SiCN and SiOC. For both ceramics, we correlate the first cycle lithiation or delithiation capacity and cycling stability with the amount of SiCN/SiOC matrix or free carbon phase, respectively. The first cycle lithiation and delithiation capacities of SiOC materials do not depend on the amount of free carbon, while for SiCN the capacity increases with the amount of carbon to reach a threshold value at ~50% of carbon phase. Replacing oxygen with nitrogen renders the mixed bond Si-tetrahedra unable to sequester lithium. Lithium is more attracted by oxygen in the SiOC network due to the more ionic character of Si-O bonds. This brings about very high initial lithiation capacities, even at low carbon content. If oxygen is replaced by nitrogen, the ceramic network becomes less attractive for lithium ions due to the more covalent character of Si-N bonds and lower electron density on the nitrogen atom. This explains the significant difference in electrochemical behavior which is observed for carbon-poor SiCN and SiOC materials. |
| Journal or Publication Title: | Nanomaterials |
| Journal volume: | 5 |
| Number: | 1 |
| Publisher: | MDPI AG, Schweiz |
| 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 > A - Synthesis > Subproject A4: Novel functional ceramics using anionic substitution in oxidic systems 11 Department of Materials and Earth Sciences > Material Science 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 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: | 26 Feb 2015 09:35 |
| Official URL: | http://dx.doi.org/10.3390/nano5010233 |
| Additional Information: | SFB 595 A4 This article belongs to the Special Issue Ceramic Nanocomposites: Design Concepts towards Tailor-Made (Multi)Functionality and Prospective Energy-Related Applications |
| Identification Number: | doi:10.3390/nano5010233 |
| Funders: | Financial support from the German Research Foundation within SFB 595/A4 and SPP 1473/JP8 programs is greatly acknowledged., Ralf Riedel, Gian-Domenico Soraru and Pradeep Vallachira Warriam Sasikumaracknowledge the financial support from the EU through the Marie Curie ITN 7th Framework Programme, Functional Nitrides for Energy Applications (MC INT FUNEA), CT-264873. |
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