Yuki Sasaki, Subin Song, Satoshi Hori, Naoki Matsui, Kuniharu Nomoto, Kota Suzuki, Masaaki Hirayama, Inwoo Song, Yongjun Jang, Ryoji Kanno
{"title":"Synthesis and Structural Characterization of Lithium Ionic Conductors Li2MS3 (M = Si, Si0.5Ge0.5, Ge) and Li16Ge5S18","authors":"Yuki Sasaki, Subin Song, Satoshi Hori, Naoki Matsui, Kuniharu Nomoto, Kota Suzuki, Masaaki Hirayama, Inwoo Song, Yongjun Jang, Ryoji Kanno","doi":"10.1021/acs.chemmater.4c00885","DOIUrl":null,"url":null,"abstract":"To develop inorganic Li conductors for all-solid-state Li-ion batteries, the present study clarified temperature-dependent structural changes in the Li<sub>2</sub><i>M</i>S<sub>3</sub> (<i>M</i> = Si, Si<sub>0.5</sub>Ge<sub>0.5</sub>, Ge) phases, where new crystal structures favoring ionic conduction are potentially formed. Structural analysis was performed on powder X-ray diffraction data obtained at high temperatures. At 600 °C, tetragonal phases were formed in all three cases. Meanwhile, structural changes on cooling from 600 °C were different according to the <i>M</i> species, leading to various crystal systems at room temperature (monoclinic for <i>M</i> = Si, orthorhombic for Si<sub>0.5</sub>Ge<sub>0.5</sub>, and hexagonal for Ge). Their ionic conductivities at 25 °C were 2.3 × 10<sup>–5</sup>, 1.7 × 10<sup>–7</sup>, and 8.6 × 10<sup>–9</sup> S cm<sup>–1</sup>, respectively, indicating that the conductivity depends significantly on the framework of the crystal structure. These phase identification results were further utilized to search the Li<sub>2</sub>S–GeS<sub>2</sub> pseudobinary system, revealing that the structure of Li<sub>16</sub>Ge<sub>5</sub>S<sub>18</sub> could not be assigned to any polymorphs identified for Li<sub>2</sub><i>M</i>S<sub>3</sub>. This new crystalline phase showed an ionic conductivity of 7.2 × 10<sup>–5</sup> S cm<sup>–1</sup> at room temperature, which is 4 orders of magnitude higher than that of hexagonal Li<sub>2</sub>GeS<sub>3</sub>. This study highlights a drastic increase in the lithium conductivity achieved by controlling the crystal structure of the Li<sub>2</sub><i>M</i>S<sub>3</sub>-related materials.","PeriodicalId":33,"journal":{"name":"Chemistry of Materials","volume":null,"pages":null},"PeriodicalIF":7.2000,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemistry of Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1021/acs.chemmater.4c00885","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
To develop inorganic Li conductors for all-solid-state Li-ion batteries, the present study clarified temperature-dependent structural changes in the Li2MS3 (M = Si, Si0.5Ge0.5, Ge) phases, where new crystal structures favoring ionic conduction are potentially formed. Structural analysis was performed on powder X-ray diffraction data obtained at high temperatures. At 600 °C, tetragonal phases were formed in all three cases. Meanwhile, structural changes on cooling from 600 °C were different according to the M species, leading to various crystal systems at room temperature (monoclinic for M = Si, orthorhombic for Si0.5Ge0.5, and hexagonal for Ge). Their ionic conductivities at 25 °C were 2.3 × 10–5, 1.7 × 10–7, and 8.6 × 10–9 S cm–1, respectively, indicating that the conductivity depends significantly on the framework of the crystal structure. These phase identification results were further utilized to search the Li2S–GeS2 pseudobinary system, revealing that the structure of Li16Ge5S18 could not be assigned to any polymorphs identified for Li2MS3. This new crystalline phase showed an ionic conductivity of 7.2 × 10–5 S cm–1 at room temperature, which is 4 orders of magnitude higher than that of hexagonal Li2GeS3. This study highlights a drastic increase in the lithium conductivity achieved by controlling the crystal structure of the Li2MS3-related materials.
期刊介绍:
The journal Chemistry of Materials focuses on publishing original research at the intersection of materials science and chemistry. The studies published in the journal involve chemistry as a prominent component and explore topics such as the design, synthesis, characterization, processing, understanding, and application of functional or potentially functional materials. The journal covers various areas of interest, including inorganic and organic solid-state chemistry, nanomaterials, biomaterials, thin films and polymers, and composite/hybrid materials. The journal particularly seeks papers that highlight the creation or development of innovative materials with novel optical, electrical, magnetic, catalytic, or mechanical properties. It is essential that manuscripts on these topics have a primary focus on the chemistry of materials and represent a significant advancement compared to prior research. Before external reviews are sought, submitted manuscripts undergo a review process by a minimum of two editors to ensure their appropriateness for the journal and the presence of sufficient evidence of a significant advance that will be of broad interest to the materials chemistry community.