Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites
The study demonstrates that the introduction of the electrochemically inactive dielectric additive Li<sub>2</sub>TiO<sub>3</sub> to LTO results in a strong decrease in the grain boundary resistance of LTO-Li<sub>2</sub>TiO<sub>3</sub> (LTC) composites...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-09-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/15/17/6079 |
| _version_ | 1797494450384011264 |
|---|---|
| author | Anna Kozlova Nikolai Uvarov Artem Ulihin |
| author_facet | Anna Kozlova Nikolai Uvarov Artem Ulihin |
| author_sort | Anna Kozlova |
| collection | DOAJ |
| description | The study demonstrates that the introduction of the electrochemically inactive dielectric additive Li<sub>2</sub>TiO<sub>3</sub> to LTO results in a strong decrease in the grain boundary resistance of LTO-Li<sub>2</sub>TiO<sub>3</sub> (LTC) composites at a low concentration of Li<sub>2</sub>TiO<sub>3</sub>. With the increase in the concentration of Li<sub>2</sub>TiO<sub>3</sub> in LTC composites, the grain boundary resistance goes through a minimum and increases again due to the growth of the insulation layer of small Li<sub>2</sub>TiO<sub>3</sub> particles around LTO grains. For LTO-TiO<sub>2</sub> (LTT) composites, a similar effect was observed, albeit not as strong. It was found that LTC composites at low concentration of Li<sub>2</sub>TiO<sub>3</sub> have unusually high charge–discharge capacity exceeding the theoretical value for pure LTO. This effect is likely to be caused by the occurrence of the electrochemical activity of Li<sub>2</sub>TiO<sub>3</sub> in the vicinity of the interfaces between LTO and Li<sub>2</sub>TiO<sub>3</sub>. The increase in the capacity may be qualitatively described in terms of the model of two-phase composite in which there is the interface layer with a high capacity. Contrasting with LTC composites, in LTT composites, no capacity enhancement was observed, which was likely due to a noticeable difference in crystal structures of LTO and TiO<sub>2</sub> preventing the formation of coherent interfaces. |
| first_indexed | 2024-03-10T01:34:28Z |
| format | Article |
| id | doaj.art-4e3e1af5a5ef4510b83befe71ad33498 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T01:34:28Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-4e3e1af5a5ef4510b83befe71ad334982023-11-23T13:35:11ZengMDPI AGMaterials1996-19442022-09-011517607910.3390/ma15176079Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> CompositesAnna Kozlova0Nikolai Uvarov1Artem Ulihin2Institute of Solid State Chemistry and Mechanochemistry, SB RAS, Kutateladze Str. 18, 630128 Novosibirsk, RussiaInstitute of Solid State Chemistry and Mechanochemistry, SB RAS, Kutateladze Str. 18, 630128 Novosibirsk, RussiaInstitute of Solid State Chemistry and Mechanochemistry, SB RAS, Kutateladze Str. 18, 630128 Novosibirsk, RussiaThe study demonstrates that the introduction of the electrochemically inactive dielectric additive Li<sub>2</sub>TiO<sub>3</sub> to LTO results in a strong decrease in the grain boundary resistance of LTO-Li<sub>2</sub>TiO<sub>3</sub> (LTC) composites at a low concentration of Li<sub>2</sub>TiO<sub>3</sub>. With the increase in the concentration of Li<sub>2</sub>TiO<sub>3</sub> in LTC composites, the grain boundary resistance goes through a minimum and increases again due to the growth of the insulation layer of small Li<sub>2</sub>TiO<sub>3</sub> particles around LTO grains. For LTO-TiO<sub>2</sub> (LTT) composites, a similar effect was observed, albeit not as strong. It was found that LTC composites at low concentration of Li<sub>2</sub>TiO<sub>3</sub> have unusually high charge–discharge capacity exceeding the theoretical value for pure LTO. This effect is likely to be caused by the occurrence of the electrochemical activity of Li<sub>2</sub>TiO<sub>3</sub> in the vicinity of the interfaces between LTO and Li<sub>2</sub>TiO<sub>3</sub>. The increase in the capacity may be qualitatively described in terms of the model of two-phase composite in which there is the interface layer with a high capacity. Contrasting with LTC composites, in LTT composites, no capacity enhancement was observed, which was likely due to a noticeable difference in crystal structures of LTO and TiO<sub>2</sub> preventing the formation of coherent interfaces.https://www.mdpi.com/1996-1944/15/17/6079Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub>Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> compositessolid-state synthesisionic conductivitygrain boundary resistanceexcess charge capacity |
| spellingShingle | Anna Kozlova Nikolai Uvarov Artem Ulihin Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites Materials Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> composites solid-state synthesis ionic conductivity grain boundary resistance excess charge capacity |
| title | Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites |
| title_full | Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites |
| title_fullStr | Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites |
| title_full_unstemmed | Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites |
| title_short | Transport and Electrochemical Properties of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> and Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> Composites |
| title_sort | transport and electrochemical properties of li sub 4 sub ti sub 5 sub o sub 12 sub li sub 2 sub tio sub 3 sub and li sub 4 sub ti sub 5 sub o sub 12 sub tio sub 2 sub composites |
| topic | Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Li<sub>2</sub>TiO<sub>3</sub> Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-TiO<sub>2</sub> composites solid-state synthesis ionic conductivity grain boundary resistance excess charge capacity |
| url | https://www.mdpi.com/1996-1944/15/17/6079 |
| work_keys_str_mv | AT annakozlova transportandelectrochemicalpropertiesoflisub4subtisub5subosub12sublisub2subtiosub3subandlisub4subtisub5subosub12subtiosub2subcomposites AT nikolaiuvarov transportandelectrochemicalpropertiesoflisub4subtisub5subosub12sublisub2subtiosub3subandlisub4subtisub5subosub12subtiosub2subcomposites AT artemulihin transportandelectrochemicalpropertiesoflisub4subtisub5subosub12sublisub2subtiosub3subandlisub4subtisub5subosub12subtiosub2subcomposites |