Details
| Original language | English |
|---|---|
| Pages (from-to) | 1687-1693 |
| Number of pages | 7 |
| Journal | Journal of the American Ceramic Society |
| Volume | 99 |
| Issue number | 5 |
| Publication status | Published - 2 Mar 2016 |
Abstract
In many cases fast solid ion conductors are characterized by a large number fraction of defects and vacant positions that enable the ions to move over long distances in a facile way. The introduction of structural disorder via high-energy mechanical impact represents a very promising possibility to improve and to tune the transport properties of otherwise poorly conducting solids. Lithium tetraborate, Li2B4O7, in its single crystalline form or with an average crystallite size in the μm range, is known as a very poor Li ion conductor and can serve as a model compound to study the influence of structural disorder on ion dynamics. In the present study, we used high-energy ball milling to prepare nanocrystalline defect-rich Li2B4O7 characterized by a mean crystallite diameter of ca. 20 nm. With increasing milling time the sample became partly amorphous. Polycrystalline Li2B4O7 with crystallite sizes in the order of 100 nm served as starting material. The nanostructured samples obtained show dc conductivities σdc in the order of 2.5 × 10-7 S/cm at 490 K which represents an increase by more than four orders of magnitude compared to the source material. While conductivity spectroscopy was applied to study the effect of different milling times on ionic conductivity in detail; Li ion self-diffusion in nanostructured Li2B4O7 as well as in the starting material was investigated by variable-temperature solid-state 7Li nuclear magnetic resonance (NMR) relaxometry. While the first is sensitive to long-range ion transport, lithium NMR is able to access also short-ranged ion motions.
ASJC Scopus subject areas
- Materials Science(all)
- Ceramics and Composites
- Materials Science(all)
- Materials Chemistry
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Journal of the American Ceramic Society, Vol. 99, No. 5, 02.03.2016, p. 1687-1693.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - High-Energy Mechanical Treatment Boosts Ion Transport in Nanocrystalline Li2B4O7
AU - Wohlmuth, Dominik
AU - Epp, Viktor
AU - Stanje, Bernhard
AU - Welsch, Anna Maria
AU - Behrens, Harald
AU - Wilkening, Martin
PY - 2016/3/2
Y1 - 2016/3/2
N2 - In many cases fast solid ion conductors are characterized by a large number fraction of defects and vacant positions that enable the ions to move over long distances in a facile way. The introduction of structural disorder via high-energy mechanical impact represents a very promising possibility to improve and to tune the transport properties of otherwise poorly conducting solids. Lithium tetraborate, Li2B4O7, in its single crystalline form or with an average crystallite size in the μm range, is known as a very poor Li ion conductor and can serve as a model compound to study the influence of structural disorder on ion dynamics. In the present study, we used high-energy ball milling to prepare nanocrystalline defect-rich Li2B4O7 characterized by a mean crystallite diameter of ca. 20 nm. With increasing milling time the sample became partly amorphous. Polycrystalline Li2B4O7 with crystallite sizes in the order of 100 nm served as starting material. The nanostructured samples obtained show dc conductivities σdc in the order of 2.5 × 10-7 S/cm at 490 K which represents an increase by more than four orders of magnitude compared to the source material. While conductivity spectroscopy was applied to study the effect of different milling times on ionic conductivity in detail; Li ion self-diffusion in nanostructured Li2B4O7 as well as in the starting material was investigated by variable-temperature solid-state 7Li nuclear magnetic resonance (NMR) relaxometry. While the first is sensitive to long-range ion transport, lithium NMR is able to access also short-ranged ion motions.
AB - In many cases fast solid ion conductors are characterized by a large number fraction of defects and vacant positions that enable the ions to move over long distances in a facile way. The introduction of structural disorder via high-energy mechanical impact represents a very promising possibility to improve and to tune the transport properties of otherwise poorly conducting solids. Lithium tetraborate, Li2B4O7, in its single crystalline form or with an average crystallite size in the μm range, is known as a very poor Li ion conductor and can serve as a model compound to study the influence of structural disorder on ion dynamics. In the present study, we used high-energy ball milling to prepare nanocrystalline defect-rich Li2B4O7 characterized by a mean crystallite diameter of ca. 20 nm. With increasing milling time the sample became partly amorphous. Polycrystalline Li2B4O7 with crystallite sizes in the order of 100 nm served as starting material. The nanostructured samples obtained show dc conductivities σdc in the order of 2.5 × 10-7 S/cm at 490 K which represents an increase by more than four orders of magnitude compared to the source material. While conductivity spectroscopy was applied to study the effect of different milling times on ionic conductivity in detail; Li ion self-diffusion in nanostructured Li2B4O7 as well as in the starting material was investigated by variable-temperature solid-state 7Li nuclear magnetic resonance (NMR) relaxometry. While the first is sensitive to long-range ion transport, lithium NMR is able to access also short-ranged ion motions.
UR - http://www.scopus.com/inward/record.url?scp=84963812847&partnerID=8YFLogxK
U2 - 10.1111/jace.14165
DO - 10.1111/jace.14165
M3 - Article
AN - SCOPUS:84963812847
VL - 99
SP - 1687
EP - 1693
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
SN - 0002-7820
IS - 5
ER -