Al is known as a unique element to enhance the stability of Sc2O3-stabilized ZrO2 (ScSZ); however, understanding the Al state in the material is insufficient for the mechanism to be understood. In this study, the states and roles of Al in the ScSZ-based materials are elucidated by 27Al NMR spectroscopy, DFT calculations, and detailed structural analysis concerning cubicity. The 27Al NMR and DFT calculations reveal that Al substitutes Zr sites as 6-, 7- and 8-coordinated states in ScSZ even though the ionic radius of Al is much smaller than that of Zr. The formation of 6-coordinated Al with two oxygen vacancies in its vicinity indicates oxygen vacancies are preferentially located around the smaller cations. The local structure revealed by DFT calculations suggests that the coordination polyhedron of 7- and 8-coordinated Al is effectively 4-coordinated Al. The 27Al NMR results also support this unique local structure. The results of this study show that manipulating the Al state is a key step in stabilizing Sc2O3-stabilized ZrO2 and help to clarify the suppression mechanism of the degradation of conductivity.
{"title":"Four and six-coordinated Al in a fluorite-type structure: A key to the stabilization of Sc2O3-stabilized ZrO2","authors":"Itaru Oikawa , Akihiro Fujimaki , Akihiro Ishii , Fuminori Tamazaki , Hiroshi Okamoto , Hitoshi Takamura","doi":"10.1016/j.ssi.2025.116997","DOIUrl":"10.1016/j.ssi.2025.116997","url":null,"abstract":"<div><div>Al is known as a unique element to enhance the stability of Sc<sub>2</sub>O<sub>3</sub>-stabilized ZrO<sub>2</sub> (ScSZ); however, understanding the Al state in the material is insufficient for the mechanism to be understood. In this study, the states and roles of Al in the ScSZ-based materials are elucidated by <sup>27</sup>Al NMR spectroscopy, DFT calculations, and detailed structural analysis concerning cubicity. The <sup>27</sup>Al NMR and DFT calculations reveal that Al substitutes Zr sites as 6-, 7- and 8-coordinated states in ScSZ even though the ionic radius of Al is much smaller than that of Zr. The formation of 6-coordinated Al with two oxygen vacancies in its vicinity indicates oxygen vacancies are preferentially located around the smaller cations. The local structure revealed by DFT calculations suggests that the coordination polyhedron of 7- and 8-coordinated Al is effectively 4-coordinated Al. The <sup>27</sup>Al NMR results also support this unique local structure. The results of this study show that manipulating the Al state is a key step in stabilizing Sc<sub>2</sub>O<sub>3</sub>-stabilized ZrO<sub>2</sub> and help to clarify the suppression mechanism of the degradation of conductivity.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"430 ","pages":"Article 116997"},"PeriodicalIF":3.3,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-26DOI: 10.1016/j.ssi.2025.116995
Kazuya Terabe , Takashi Tsuchiya , Tohru Tsuruoka , Hirofumi Tanaka , Ilia Valov , James K. Gimzewski , Tsuyoshi Hasegawa
Today's scientific and technological growth relies on rapid advances in electronic information technologies. Semiconductor devices such as transistors are essential to these technologies, and they are constantly being improved by being made smaller and more integrated. However, there is a concern that these improvements may slow down in the near future. Thus, creating new types of devices that can overcome the problems and/or enhance the capabilities of traditional semiconductor devices has become an important challenge. In particular, solid-state ionic devices can potentially meet this challenge. In this review, we describe the design of such devices using ionic nanoarchitectonics techniques that locally control ion conduction and electrochemical behavior in ion conductors and mixed conductors. In addition, we describe solid-state ionic devices developed for electronic information technology as well as the electrical, magnetic, optical, and brain-inspired neuromorphic functionalities of these devices.
{"title":"Ionic nanoarchitectonics for electronic information devices","authors":"Kazuya Terabe , Takashi Tsuchiya , Tohru Tsuruoka , Hirofumi Tanaka , Ilia Valov , James K. Gimzewski , Tsuyoshi Hasegawa","doi":"10.1016/j.ssi.2025.116995","DOIUrl":"10.1016/j.ssi.2025.116995","url":null,"abstract":"<div><div>Today's scientific and technological growth relies on rapid advances in electronic information technologies. Semiconductor devices such as transistors are essential to these technologies, and they are constantly being improved by being made smaller and more integrated. However, there is a concern that these improvements may slow down in the near future. Thus, creating new types of devices that can overcome the problems and/or enhance the capabilities of traditional semiconductor devices has become an important challenge. In particular, solid-state ionic devices can potentially meet this challenge. In this review, we describe the design of such devices using ionic nanoarchitectonics techniques that locally control ion conduction and electrochemical behavior in ion conductors and mixed conductors. In addition, we describe solid-state ionic devices developed for electronic information technology as well as the electrical, magnetic, optical, and brain-inspired neuromorphic functionalities of these devices.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"430 ","pages":"Article 116995"},"PeriodicalIF":3.3,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-22DOI: 10.1016/j.ssi.2025.116996
Alessandro Raffaele Ferrari, Diego Stucchi, Tommaso Caielli, Raziyeh Akbari, Ivan Claudio Pellini, Carlo Antonini, Piercarlo Mustarelli
The main requirement for the development of Anion Exchange Membranes Fuel Cells (AEMFCs) and Water Electrolyzers (AEMFEs) on an industrial scale is the improvement of Anion Exchange Membranes performance. Besides good ionic conductivity, dimensional stability and mechanical properties in the wet state, the main challenge to be overcome is the improvement of AEMs chemical resistance in harsh alkaline environment. Poly(aryl piperidinium)s are among the most promising AEMs in terms of conductivity, mechanical properties, and chemical stability. Here we report the fabrication and physico-chemical characterization of composite AEMs based on poly(biphenyl piperidinium) (PBP) with the addition of zirconium oxide as a filler to improve membrane properties, including anionic conductivity, water uptake and alkali resistance. The optimal ZrO2 filler content was found to be 5 wt% of dry polymer mass. Compared to plain PBP, composite membranes exhibit increased hydroxide conductivity (from 75 to 116 mS cm−1 at 80 °C), reduced water uptake (from 427 % to 278 % at 80 °C) and swelling ratio (from 85 to 62 % at 80 °C), and a limited reduction (41 %) of cationic groups after ageing in KOH 1 M for 500 h at 80 °C. We demonstrate that ZrO2 filler hinders Hoffman elimination reaction on the piperidinium ring.
阴离子交换膜燃料电池（aemfc）和水电解槽（AEMFEs）产业化发展的主要要求是提高阴离子交换膜的性能。除了在湿态下具有良好的离子电导率、尺寸稳定性和力学性能外，需要克服的主要挑战是提高AEMs在恶劣碱性环境下的耐化学性。在电导率、机械性能和化学稳定性方面，聚芳基胡椒啶是最有前途的AEMs之一。本文报道了基于聚联苯哌啶（PBP）的复合AEMs的制备和物理化学表征，并添加氧化锆作为填料来改善膜的性能，包括阴离子导电性、吸水性和耐碱性。ZrO2填料的最佳含量为干聚合物质量的5 wt%。与普通PBP相比，复合膜表现出更高的氢氧化物导电性（在80°C时从75到116 mS cm−1），降低的吸水率（在80°C时从427%到278%）和溶胀率（在80°C时从85%到62%），并且在80°C下KOH 1 M中老化500小时后阳离子基团的有限减少（41%）。我们证明了ZrO2填料阻碍了哌啶环上的霍夫曼消去反应。
{"title":"Composite anion exchange membranes based on poly(biphenyl piperidinium) / ZrO2","authors":"Alessandro Raffaele Ferrari, Diego Stucchi, Tommaso Caielli, Raziyeh Akbari, Ivan Claudio Pellini, Carlo Antonini, Piercarlo Mustarelli","doi":"10.1016/j.ssi.2025.116996","DOIUrl":"10.1016/j.ssi.2025.116996","url":null,"abstract":"<div><div>The main requirement for the development of Anion Exchange Membranes Fuel Cells (AEMFCs) and Water Electrolyzers (AEMFEs) on an industrial scale is the improvement of Anion Exchange Membranes performance. Besides good ionic conductivity, dimensional stability and mechanical properties in the wet state, the main challenge to be overcome is the improvement of AEMs chemical resistance in harsh alkaline environment. Poly(aryl piperidinium)s are among the most promising AEMs in terms of conductivity, mechanical properties, and chemical stability. Here we report the fabrication and physico-chemical characterization of composite AEMs based on poly(biphenyl piperidinium) (PBP) with the addition of zirconium oxide as a filler to improve membrane properties, including anionic conductivity, water uptake and alkali resistance. The optimal ZrO<sub>2</sub> filler content was found to be 5 wt% of dry polymer mass. Compared to plain PBP, composite membranes exhibit increased hydroxide conductivity (from 75 to 116 mS cm<sup>−1</sup> at 80 °C), reduced water uptake (from 427 % to 278 % at 80 °C) and swelling ratio (from 85 to 62 % at 80 °C), and a limited reduction (41 %) of cationic groups after ageing in KOH 1 M for 500 h at 80 °C. We demonstrate that ZrO<sub>2</sub> filler hinders Hoffman elimination reaction on the piperidinium ring.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"430 ","pages":"Article 116996"},"PeriodicalIF":3.3,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-22DOI: 10.1016/j.ssi.2025.116998
Han-Ill Yoo
All the mass/charge transport properties of a material with, e.g., single-type ions (i) and electrons (e) as mobile charged components may be documented exhaustively and succinctly in terms of a coupling coefficient matrix L of the Onsagerian causality as
,
where Jk and ηk stand for the flux and electrochemical potential, respectively, of the mobile charged-component k(=i,e), and T the absolute temperature. Due to the Onsager reciprocity and the L-matrix transformation rule,
,
where is the transported entropy of k, the sum of its partial entropy, and entropy-of-transport, or
{"title":"Transient-state methods to determine all the mass/charge transport properties of a material","authors":"Han-Ill Yoo","doi":"10.1016/j.ssi.2025.116998","DOIUrl":"10.1016/j.ssi.2025.116998","url":null,"abstract":"<div><div>All the mass/charge transport properties of a material with, e.g., single-type ions (i) and electrons (e) as mobile charged components may be documented exhaustively and succinctly in terms of a coupling coefficient matrix L of the Onsagerian causality as</div><div><span><math><mfenced><mtable><mtr><mtd><msub><mi>J</mi><mi>i</mi></msub></mtd></mtr><mtr><mtd><msub><mi>J</mi><mi>e</mi></msub></mtd></mtr></mtable></mfenced><mo>=</mo><mfenced><mtable><mtr><mtd><msub><mi>L</mi><mi>ii</mi></msub></mtd><mtd><msub><mi>L</mi><mi>ie</mi></msub></mtd><mtd><msub><mi>L</mi><mi>iT</mi></msub></mtd></mtr><mtr><mtd><msub><mi>L</mi><mi>ei</mi></msub></mtd><mtd><msub><mi>L</mi><mi>ee</mi></msub></mtd><mtd><msub><mi>L</mi><mi>eT</mi></msub></mtd></mtr></mtable></mfenced><mfenced><mtable><mtr><mtd><mo>−</mo><mo>∇</mo><msub><mi>η</mi><mi>i</mi></msub></mtd></mtr><mtr><mtd><mo>−</mo><mo>∇</mo><msub><mi>η</mi><mi>e</mi></msub></mtd></mtr><mtr><mtd><mo>−</mo><mo>∇</mo><mi>T</mi></mtd></mtr></mtable></mfenced></math></span>,</div><div>where J<sub>k</sub> and η<sub>k</sub> stand for the flux and electrochemical potential, respectively, of the mobile charged-component k(=i,e), and T the absolute temperature. Due to the Onsager reciprocity and the L-matrix transformation rule,</div><div><span><math><msub><mi>L</mi><mi>ie</mi></msub><mo>=</mo><msub><mi>L</mi><mi>ei</mi></msub><mo>;</mo><mspace></mspace><mfenced><mtable><mtr><mtd><msub><mi>L</mi><mi>iT</mi></msub></mtd></mtr><mtr><mtd><msub><mi>L</mi><mi>eT</mi></msub></mtd></mtr></mtable></mfenced><mo>=</mo><mfenced><mtable><mtr><mtd><msub><mi>L</mi><mi>ii</mi></msub></mtd><mtd><msub><mi>L</mi><mi>ie</mi></msub></mtd></mtr><mtr><mtd><msub><mi>L</mi><mi>ei</mi></msub></mtd><mtd><msub><mi>L</mi><mi>ee</mi></msub></mtd></mtr></mtable></mfenced><mfenced><mtable><mtr><mtd><msub><mover><mover><mi>S</mi><mo>̄</mo></mover><mo>̄</mo></mover><mi>i</mi></msub></mtd></mtr><mtr><mtd><msub><mover><mover><mi>S</mi><mo>̄</mo></mover><mo>̄</mo></mover><mi>e</mi></msub></mtd></mtr></mtable></mfenced></math></span>,</div><div>where <span><math><msub><mover><mover><mi>S</mi><mo>̄</mo></mover><mo>̄</mo></mover><mi>k</mi></msub></math></span>is the transported entropy of k, the sum of its partial entropy, <span><math><msub><mover><mi>S</mi><mo>̄</mo></mover><mi>k</mi></msub><mspace></mspace></math></span>and entropy-of-transport, <span><math><msubsup><mi>S</mi><mi>k</mi><mo>∗</mo></msubsup></math></span> or<span><span><span><math><msub><mover><mover><mi>S</mi><mo>̄</mo></mover><mo>̄</mo></mover><mi>k</mi></msub><mo>≡</mo><msub><mover><mi>S</mi><mo>̄</mo></mover><mi>k</mi></msub><mo>+</mo><msubsup><mi>S</mi><mi>k</mi><mo>∗</mo></msubsup><mo>;</mo><mspace></mspace><msubsup><mi>S</mi><mi>k</mi><mo>∗</mo></msubsup><mo>≡</mo><mfrac><msubsup><mi>q</mi><mi>k</mi><mo>∗</mo></msubsup><mi>T</mi></mfrac></math></span></span></span></div><div>with <span><math><msubsup><mi>q</mi><mi>k</mi><mo>∗</mo></msubsup></math></span> being the reduced heat-of-","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"430 ","pages":"Article 116998"},"PeriodicalIF":3.3,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144890523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-21DOI: 10.1016/j.ssi.2025.117000
Oncu Akyildiz , Ezgi Yılmaz
We investigated the electrochemical behavior of binary blend cathodes made by mixing micro-spheres of LiNi0.5Mn0.3Co0.2O2 and smaller micro-platelets of LiFePO4 in different proportions (10–40 wt%). Results show that the discharge profiles of the blended electrodes at 0.1C are predictable through a model based on the weighted averages of specific differential capacities of pristine electrodes. However, at high C-rates (>1C), the blended electrode contains 20 wt% LiFePO4 (coined as the synergy-electrode) shows significantly higher discharge capacity and better capacity retention (observed up to the 100th cycle) than other electrodes. The synergy is rationalized using cyclic voltammetry and electrochemical impedance spectroscopy, indicating the facilitation of the charge-discharge reactions, reduction of both the bulk and the charge-transfer resistances, and higher Li diffusion coefficients observed for the synergy-electrode.
{"title":"Synergy-electrode based on micron-sized LiNi0.5Mn0.3Co0.2O2/LiFePO4 particles with bimodal size distribution","authors":"Oncu Akyildiz , Ezgi Yılmaz","doi":"10.1016/j.ssi.2025.117000","DOIUrl":"10.1016/j.ssi.2025.117000","url":null,"abstract":"<div><div>We investigated the electrochemical behavior of binary blend cathodes made by mixing micro-spheres of LiNi<sub>0.5</sub>Mn<sub>0.3</sub>Co<sub>0.2</sub>O<sub>2</sub> and smaller micro-platelets of LiFePO<sub>4</sub> in different proportions (10–40 wt%). Results show that the discharge profiles of the blended electrodes at 0.1C are predictable through a model based on the weighted averages of specific differential capacities of pristine electrodes. However, at high C-rates (>1C), the blended electrode contains 20 wt% LiFePO<sub>4</sub> (coined as the synergy-electrode) shows significantly higher discharge capacity and better capacity retention (observed up to the 100th cycle) than other electrodes. The synergy is rationalized using cyclic voltammetry and electrochemical impedance spectroscopy, indicating the facilitation of the charge-discharge reactions, reduction of both the bulk and the charge-transfer resistances, and higher Li diffusion coefficients observed for the synergy-electrode.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"430 ","pages":"Article 117000"},"PeriodicalIF":3.3,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-11DOI: 10.1016/j.ssi.2025.116951
Judith Schuett, Steffen Neitzel-Grieshammer
Sodium superionic conductors (NaSICONs) have garnered significant attention as promising solid electrolytes for all-solid-state batteries, owing to their high ionic conductivity at room temperature. The ionic motion in these materials at the atomistic scale can be investigated by computational approaches such as Density Functional Theory (DFT) to gain deeper insights into their transport properties. In this work, we present a comprehensive review of DFT-based studies, focusing on site occupancies and transport mechanisms that govern the Li+ conduction in NaSICONs. The reported site and migration energies show significant variations, primarily attributed to differences in the size of the calculated supercells. Despite these discrepancies, our analysis confirms that both vacancy-assisted and interstitial migration occur in the NaSICON structure, with the latter being crucial for enabling superionic conduction. Therefore, a comprehensive understanding of the Li+ migration in NaSICONs requires consideration of both mechanisms as well as the various migration pathways involved.
{"title":"Lithium ion conducting NaSICON materials: Migration mechanisms and energies","authors":"Judith Schuett, Steffen Neitzel-Grieshammer","doi":"10.1016/j.ssi.2025.116951","DOIUrl":"10.1016/j.ssi.2025.116951","url":null,"abstract":"<div><div>Sodium superionic conductors (NaSICONs) have garnered significant attention as promising solid electrolytes for all-solid-state batteries, owing to their high ionic conductivity at room temperature. The ionic motion in these materials at the atomistic scale can be investigated by computational approaches such as Density Functional Theory (DFT) to gain deeper insights into their transport properties. In this work, we present a comprehensive review of DFT-based studies, focusing on site occupancies and transport mechanisms that govern the Li<sup>+</sup> conduction in NaSICONs. The reported site and migration energies show significant variations, primarily attributed to differences in the size of the calculated supercells. Despite these discrepancies, our analysis confirms that both vacancy-assisted and interstitial migration occur in the NaSICON structure, with the latter being crucial for enabling superionic conduction. Therefore, a comprehensive understanding of the Li<sup>+</sup> migration in NaSICONs requires consideration of both mechanisms as well as the various migration pathways involved.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"429 ","pages":"Article 116951"},"PeriodicalIF":3.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-05DOI: 10.1016/j.ssi.2025.116917
Shu Wang, Jing-Jing Shen, Peter Vang Hendriksen, Bhaskar Reddy Sudireddy
Solid oxide cells offer unrivalled efficiency in energy conversion and can become a key technology for the green transition of the energy system. The state-of-the-art fuel electrode of such cells, a Ni-zirconia composite, suffers from some limitations: poor durability at high polarization, sensitivity to detrimental coke formation, and limited redox stability. Electrodes made from perovskite materials may offer a solution to these challenges; they show a reduced tendency for coke formation and have the potential to enhance stability and performance. To this end, developing perovskite materials with enhanced mixed ionic and electronic conductivity (MIEC) and the capacity to exsolve nanoparticles to boost performance is important. This study introduces a defect chemistry model for a promising “exsolution” material (La0.49Sr0.31Ti0.94Fe0.03Ni0.03O3, LSFNT) and reports on the transport properties of the material. LSFNT retains a stable cubic perovskite structure across a wide oxygen partial pressure range (0.21 to 10−21 bar) and ex-solves Ni1-xFex nanoparticles in pure hydrogen. The conductivity of LSFNT increases with decreasing oxygen partial pressure, displaying an approximate dependence in the range of 10−14 to 10−18 bar. Below this threshold, the dependence of the conductivity deviates from this trend due to oxygen vacancy annihilation and Fe/Ni nanoparticle exsolution, consistent with the proposed defect chemistry model. This work also demonstrates the mixed ionic and electronic conductivity in LSFNT. Electron-blocking experiments reveal a high ionic conductivity of LSFNT (0.054 S/cm at 850 °C), which exceeds that of yttria-stabilized zirconia (8YSZ) and is comparable to gadolinium-doped ceria (Ce0.9Gd0.1O2, CGO). Overall, these findings underscore the good stability of LSFNT alongside noteworthy electronic and ionic conductivity, rendering it a strong candidate as a fuel electrode backbone material for solid oxide cells.
{"title":"Defect chemistry, ionic and electronic conductivity of an Fe/Ni-substituted La0.49Sr0.31TiO3 exsolution material","authors":"Shu Wang, Jing-Jing Shen, Peter Vang Hendriksen, Bhaskar Reddy Sudireddy","doi":"10.1016/j.ssi.2025.116917","DOIUrl":"10.1016/j.ssi.2025.116917","url":null,"abstract":"<div><div>Solid oxide cells offer unrivalled efficiency in energy conversion and can become a key technology for the green transition of the energy system. The state-of-the-art fuel electrode of such cells, a Ni-zirconia composite, suffers from some limitations: poor durability at high polarization, sensitivity to detrimental coke formation, and limited redox stability. Electrodes made from perovskite materials may offer a solution to these challenges; they show a reduced tendency for coke formation and have the potential to enhance stability and performance. To this end, developing perovskite materials with enhanced mixed ionic and electronic conductivity (MIEC) and the capacity to exsolve nanoparticles to boost performance is important. This study introduces a defect chemistry model for a promising “exsolution” material (La<sub>0.49</sub>Sr<sub>0.31</sub>Ti<sub>0.94</sub>Fe<sub>0.03</sub>Ni<sub>0.03</sub>O<sub>3,</sub> LSFNT) and reports on the transport properties of the material. LSFNT retains a stable cubic perovskite structure across a wide oxygen partial pressure range (0.21 to 10<sup>−21</sup> bar) and ex-solves Ni<sub>1-<em>x</em></sub>Fe<sub><em>x</em></sub> nanoparticles in pure hydrogen. The conductivity of LSFNT increases with decreasing oxygen partial pressure, displaying an approximate <span><math><msup><msub><mi>pO</mi><mn>2</mn></msub><mrow><mo>−</mo><mn>1</mn><mo>/</mo><mn>6</mn></mrow></msup></math></span> dependence in the range of 10<sup>−14</sup> to 10<sup>−18</sup> bar. Below this threshold, the <span><math><msub><mi>pO</mi><mn>2</mn></msub></math></span> dependence of the conductivity deviates from this trend due to oxygen vacancy annihilation and Fe/Ni nanoparticle exsolution, consistent with the proposed defect chemistry model. This work also demonstrates the mixed ionic and electronic conductivity in LSFNT. Electron-blocking experiments reveal a high ionic conductivity of LSFNT (0.054 S/cm at 850 °C), which exceeds that of yttria-stabilized zirconia (8YSZ) and is comparable to gadolinium-doped ceria (Ce<sub>0.9</sub>Gd<sub>0.1</sub>O<sub>2</sub>, CGO). Overall, these findings underscore the good stability of LSFNT alongside noteworthy electronic and ionic conductivity, rendering it a strong candidate as a fuel electrode backbone material for solid oxide cells.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"429 ","pages":"Article 116917"},"PeriodicalIF":3.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-05DOI: 10.1016/j.ssi.2025.116990
Andrea Zambotti , Gugulethu Charmaine Nkala , Supriti Dutta , Sree Harsha Bhimineni , Nicolas Leport , Aimeric Laperruque , Johanna Nelson Weker , Philippe Sautet , Laurent Pilon , Bruce Dunn
In this study, we determine the role of oxygen vacancies and preferred surface orientation on the charge storage properties of the lithium intercalation host, pseudohexagonal TT-Nb2O5. Two different morphologies were synthesized, namely nanosheets and nanowires. We employed a set of advanced characterization techniques including entropic potential measurements, high-resolution synchrotron X-ray diffraction and synchrotron X-ray absorption spectroscopy together with electrochemical measurements and density functional theory calculations. Our results indicate that the two morphologies exhibit different oxygen vacancy characteristics as nanosheets have oxygen vacancies limited to the surface while nanowires possess vacancies which tend to be located in the bulk solid. Oxygen vacancies in the bulk of TT-Nb2O5 lead to an appreciable increase in specific capacity compared to nanosheets where oxygen vacancies confined to specific crystallographic surfaces do not make a significant contribution to the electrochemical response of the TT-Nb2O5 anodes. These results show how the distribution and concentration of oxygen vacancies play a major role in the lithiation mechanisms of TT-Nb2O5.
{"title":"Probing the effect of atomic and morphological arrangements in the pseudocapacitive properties of TT-Nb2O5 nanostructures","authors":"Andrea Zambotti , Gugulethu Charmaine Nkala , Supriti Dutta , Sree Harsha Bhimineni , Nicolas Leport , Aimeric Laperruque , Johanna Nelson Weker , Philippe Sautet , Laurent Pilon , Bruce Dunn","doi":"10.1016/j.ssi.2025.116990","DOIUrl":"10.1016/j.ssi.2025.116990","url":null,"abstract":"<div><div>In this study, we determine the role of oxygen vacancies and preferred surface orientation on the charge storage properties of the lithium intercalation host, pseudohexagonal <em>TT-</em>Nb<sub>2</sub>O<sub>5</sub>. Two different morphologies were synthesized, namely nanosheets and nanowires. We employed a set of advanced characterization techniques including entropic potential measurements, high-resolution synchrotron X-ray diffraction and synchrotron X-ray absorption spectroscopy together with electrochemical measurements and density functional theory calculations. Our results indicate that the two morphologies exhibit different oxygen vacancy characteristics as nanosheets have oxygen vacancies limited to the surface while nanowires possess vacancies which tend to be located in the bulk solid. Oxygen vacancies in the bulk of <em>TT-</em>Nb<sub>2</sub>O<sub>5</sub> lead to an appreciable increase in specific capacity compared to nanosheets where oxygen vacancies confined to specific crystallographic surfaces do not make a significant contribution to the electrochemical response of the <em>TT-</em>Nb<sub>2</sub>O<sub>5</sub> anodes. These results show how the distribution and concentration of oxygen vacancies play a major role in the lithiation mechanisms of <em>TT-</em>Nb<sub>2</sub>O<sub>5</sub>.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"429 ","pages":"Article 116990"},"PeriodicalIF":3.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-05DOI: 10.1016/j.ssi.2025.116993
Fei Han, Bi Xu, Qinan Zhou, Yuanyuan Wang, Hongxue Li, Haochen Shi
The ceria-based electrolytes with high ionic conductivity are promising for SOFCs, garnering extensive research interest. This study examines Y and Pr co-doped Ce1-xYx/2Prx/2O2-δ (x = 0–0.30) electrolytes for IT-SOFCs. The synthesized compositions are characterized to assess their functional properties. All samples formed cubic fluorite structures at 600 °C. YPDC20 shows the highest relative density (94.8 %) and, the smallest grain size, highest dislocation density, and largest micro strain. X-ray photoelectron spectroscopy (XPS) reveals the mixed valence states of cerium (Ce4+/Ce3+) in both CeO2 and YPDC20, along with coexisting Pr3+/Pr4+ states in YPDC20. Electrochemical impedance spectroscopy combined with capacitance calculations confirms significant differences in the contributions of grain, grain boundary, and electrode components. The study reveals that for YPDC05, the characteristic grain boundary resistance arc shifts to higher frequencies with increasing temperature, with only electrode response observed at 800 °C. As doping concentration increases, the disappearance temperature of grain boundary response significantly decreases: YPDC10 exhibits only electrode contribution at 700 °C, while higher-doped samples (x > 0.10) reached this state at 600 °C. Notably, YPDC20 demonstrates optimal performance, achieving an ionic conductivity of 1.2 × 10−1 S cm−1 at 800 °C—nearly two orders of magnitude higher than undoped CeO₂. This performance enhancement primarily stems from the dual effects of Y/Pr co-doping: the introduction of cations (Y3+/Pr3+/4+) significantly increases oxygen vacancy concentration, while the optimized microstructure provides fast transport channels for oxygen ions. These characteristics make YPDC20 a highly promising electrolyte material for IT-SOFCs.
{"title":"Optimizing Y and Pr co-doped CeO2 electrolytes for intermediate-temperature solid oxide fuel cells","authors":"Fei Han, Bi Xu, Qinan Zhou, Yuanyuan Wang, Hongxue Li, Haochen Shi","doi":"10.1016/j.ssi.2025.116993","DOIUrl":"10.1016/j.ssi.2025.116993","url":null,"abstract":"<div><div>The ceria-based electrolytes with high ionic conductivity are promising for SOFCs, garnering extensive research interest. This study examines Y and Pr co-doped Ce<sub>1-x</sub>Y<sub>x/2</sub>Pr<sub>x/2</sub>O<sub>2-δ</sub> (x = 0–0.30) electrolytes for IT-SOFCs. The synthesized compositions are characterized to assess their functional properties. All samples formed cubic fluorite structures at 600 °C. YPDC20 shows the highest relative density (94.8 %) and, the smallest grain size, highest dislocation density, and largest micro strain. X-ray photoelectron spectroscopy (XPS) reveals the mixed valence states of cerium (Ce<sup>4+</sup>/Ce<sup>3+</sup>) in both CeO<sub>2</sub> and YPDC20, along with coexisting Pr<sup>3+</sup>/Pr<sup>4+</sup> states in YPDC20. Electrochemical impedance spectroscopy combined with capacitance calculations confirms significant differences in the contributions of grain, grain boundary, and electrode components. The study reveals that for YPDC05, the characteristic grain boundary resistance arc shifts to higher frequencies with increasing temperature, with only electrode response observed at 800 °C. As doping concentration increases, the disappearance temperature of grain boundary response significantly decreases: YPDC10 exhibits only electrode contribution at 700 °C, while higher-doped samples (x > 0.10) reached this state at 600 °C. Notably, YPDC20 demonstrates optimal performance, achieving an ionic conductivity of 1.2 × 10<sup>−1</sup> S cm<sup>−1</sup> at 800 °C—nearly two orders of magnitude higher than undoped CeO₂. This performance enhancement primarily stems from the dual effects of Y/Pr co-doping: the introduction of cations (Y<sup>3+</sup>/Pr<sup>3+/4+</sup>) significantly increases oxygen vacancy concentration, while the optimized microstructure provides fast transport channels for oxygen ions. These characteristics make YPDC20 a highly promising electrolyte material for IT-SOFCs.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"429 ","pages":"Article 116993"},"PeriodicalIF":3.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144771402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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