Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System
Ternary glassy electrolytes containing K<sub>2</sub>S as a glass modifier and P<sub>2</sub>S<sub>5</sub> as a network former are synthesized by introducing a new type of complex and asymmetric salt, potassium triflate (KOTf), to obtain unprecedented K<sup>+&...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-11-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/24/23/16855 |
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| author | Ram Krishna Hona Alexa D. Azure Mandy Guinn Uttam S. Phuyal Kianna Stroh Arjun K. Thapa |
| author_facet | Ram Krishna Hona Alexa D. Azure Mandy Guinn Uttam S. Phuyal Kianna Stroh Arjun K. Thapa |
| author_sort | Ram Krishna Hona |
| collection | DOAJ |
| description | Ternary glassy electrolytes containing K<sub>2</sub>S as a glass modifier and P<sub>2</sub>S<sub>5</sub> as a network former are synthesized by introducing a new type of complex and asymmetric salt, potassium triflate (KOTf), to obtain unprecedented K<sup>+</sup> ion conductivity at ambient temperature. The glasses are synthesized using a conventional quenching technique at a low temperature. In general, alkali ionic glassy electrolytes of ternary systems, specifically for Li<sup>+</sup> and Na<sup>+</sup> ion conductivity, have been studied with the addition of halide salts or oxysalts such as M<sub>2</sub>SO<sub>4</sub>, M<sub>2</sub>SiO<sub>4</sub>, M<sub>3</sub>PO<sub>4</sub> (M = Li or Na), etc. We introduce a distinct and complex salt, potassium triflate (KOTf) with asymmetric anion, to the conventional glass modifier and former to synthesize K<sup>+</sup>-ion-conducting glassy electrolytes. Two series of glassy electrolytes with a ternary system of (0.9–x)K<sub>2</sub>S-xP<sub>2</sub>S<sub>5</sub>-0.1KOTf (x = 0.15, 0.30, 0.45, 0.60, and 0.75) and z(K<sub>2</sub>S-2P<sub>2</sub>S<sub>5</sub>)-yKOTf (y = 0.05, 0.10, 0.15, 0.20, and 0.25) on a straight line of z(K<sub>2</sub>S-2P<sub>2</sub>S<sub>5</sub>) are studied for their K<sup>+</sup> ionic conductivities by using electrochemical impedance spectroscopy (EIS). The composition 0.3K<sub>2</sub>S-0.6P<sub>2</sub>S<sub>5</sub>-0.1KOTf is found to have the highest conductivity among the studied glassy electrolytes at ambient temperature with the value of 1.06 × 10<sup>−7</sup> S cm<sup>−1</sup>, which is the highest of all pure K<sup>+</sup>-ion-conducting glasses reported to date. Since the glass transition temperatures of the glasses are near 100 °C, as demonstrated by DSC, temperature-dependent conductivities are studied within the range of 25 to 100 °C to determine the activation energies. A Raman spectroscopic study shows the variation in the structural units <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>P</mi><mi>S</mi></mrow><mrow><mn>4</mn></mrow><mrow><mn>3</mn><mo>−</mo></mrow></msubsup><msubsup><mrow><mo>,</mo><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>7</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup><mo>,</mo><mo> </mo><msubsup><mrow><mi mathvariant="normal">a</mi><mi mathvariant="normal">n</mi><mi mathvariant="normal">d</mi><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>6</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> of the network former for different glassy electrolytes. It seems that there is a role of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>7</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup><msubsup><mrow><mo> </mo><mi mathvariant="normal">a</mi><mi mathvariant="normal">n</mi><mi mathvariant="normal">d</mi><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>6</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> in K<sup>+</sup>-ion conductivity in the glassy electrolytes because the spectroscopic results are compatible with the composition-dependent, room-temperature conductivity trend. |
| first_indexed | 2024-03-09T01:49:44Z |
| format | Article |
| id | doaj.art-49253258106344edb86e77693a356f1f |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-09T01:49:44Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-49253258106344edb86e77693a356f1f2023-12-08T15:17:24ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-11-0124231685510.3390/ijms242316855Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf SystemRam Krishna Hona0Alexa D. Azure1Mandy Guinn2Uttam S. Phuyal3Kianna Stroh4Arjun K. Thapa5Environmental Science Department, United Tribes Technical College, Bismarck, ND 58504, USAEngineering Department, United Tribes Technical College, Bismarck, ND 58504, USAEnvironmental Science Department, United Tribes Technical College, Bismarck, ND 58504, USASchool of Arts and Science, University of Mt. Olive, Mount Olive, NC 28365, USAEnvironmental Science Department, United Tribes Technical College, Bismarck, ND 58504, USAConn Center for Renewable Energy Research, University of Louisville, Louisville, KY 40292, USATernary glassy electrolytes containing K<sub>2</sub>S as a glass modifier and P<sub>2</sub>S<sub>5</sub> as a network former are synthesized by introducing a new type of complex and asymmetric salt, potassium triflate (KOTf), to obtain unprecedented K<sup>+</sup> ion conductivity at ambient temperature. The glasses are synthesized using a conventional quenching technique at a low temperature. In general, alkali ionic glassy electrolytes of ternary systems, specifically for Li<sup>+</sup> and Na<sup>+</sup> ion conductivity, have been studied with the addition of halide salts or oxysalts such as M<sub>2</sub>SO<sub>4</sub>, M<sub>2</sub>SiO<sub>4</sub>, M<sub>3</sub>PO<sub>4</sub> (M = Li or Na), etc. We introduce a distinct and complex salt, potassium triflate (KOTf) with asymmetric anion, to the conventional glass modifier and former to synthesize K<sup>+</sup>-ion-conducting glassy electrolytes. Two series of glassy electrolytes with a ternary system of (0.9–x)K<sub>2</sub>S-xP<sub>2</sub>S<sub>5</sub>-0.1KOTf (x = 0.15, 0.30, 0.45, 0.60, and 0.75) and z(K<sub>2</sub>S-2P<sub>2</sub>S<sub>5</sub>)-yKOTf (y = 0.05, 0.10, 0.15, 0.20, and 0.25) on a straight line of z(K<sub>2</sub>S-2P<sub>2</sub>S<sub>5</sub>) are studied for their K<sup>+</sup> ionic conductivities by using electrochemical impedance spectroscopy (EIS). The composition 0.3K<sub>2</sub>S-0.6P<sub>2</sub>S<sub>5</sub>-0.1KOTf is found to have the highest conductivity among the studied glassy electrolytes at ambient temperature with the value of 1.06 × 10<sup>−7</sup> S cm<sup>−1</sup>, which is the highest of all pure K<sup>+</sup>-ion-conducting glasses reported to date. Since the glass transition temperatures of the glasses are near 100 °C, as demonstrated by DSC, temperature-dependent conductivities are studied within the range of 25 to 100 °C to determine the activation energies. A Raman spectroscopic study shows the variation in the structural units <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><mi>P</mi><mi>S</mi></mrow><mrow><mn>4</mn></mrow><mrow><mn>3</mn><mo>−</mo></mrow></msubsup><msubsup><mrow><mo>,</mo><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>7</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup><mo>,</mo><mo> </mo><msubsup><mrow><mi mathvariant="normal">a</mi><mi mathvariant="normal">n</mi><mi mathvariant="normal">d</mi><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>6</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> of the network former for different glassy electrolytes. It seems that there is a role of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mrow><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>7</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup><msubsup><mrow><mo> </mo><mi mathvariant="normal">a</mi><mi mathvariant="normal">n</mi><mi mathvariant="normal">d</mi><mo> </mo><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub><mi mathvariant="normal">S</mi></mrow><mrow><mn>6</mn></mrow><mrow><mn>4</mn><mo>−</mo></mrow></msubsup></mrow></semantics></math></inline-formula> in K<sup>+</sup>-ion conductivity in the glassy electrolytes because the spectroscopic results are compatible with the composition-dependent, room-temperature conductivity trend.https://www.mdpi.com/1422-0067/24/23/16855glass electrolyteimpedanceionic conductivityXRDternary composition |
| spellingShingle | Ram Krishna Hona Alexa D. Azure Mandy Guinn Uttam S. Phuyal Kianna Stroh Arjun K. Thapa Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System International Journal of Molecular Sciences glass electrolyte impedance ionic conductivity XRD ternary composition |
| title | Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System |
| title_full | Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System |
| title_fullStr | Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System |
| title_full_unstemmed | Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System |
| title_short | Ionic Conductivity of K-ion Glassy Solid Electrolytes of K<sub>2</sub>S-P<sub>2</sub>S<sub>5</sub>-KOTf System |
| title_sort | ionic conductivity of k ion glassy solid electrolytes of k sub 2 sub s p sub 2 sub s sub 5 sub kotf system |
| topic | glass electrolyte impedance ionic conductivity XRD ternary composition |
| url | https://www.mdpi.com/1422-0067/24/23/16855 |
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