Solid State Ionics最新文献_第6页

Structural effects on oxygen vacancies and redox behavior in Mn-based perovskite oxides mn基钙钛矿氧化物中氧空位和氧化还原行为的结构影响

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-30 DOI: 10.1016/j.ssi.2025.117067

Vika Arzumanyan , Cijie Liu , Dawei Zhang , Wei Li , Jian Luo , Xingbo Liu , Yue Qi

{"title":"Structural effects on oxygen vacancies and redox behavior in Mn-based perovskite oxides","authors":"Vika Arzumanyan , Cijie Liu , Dawei Zhang , Wei Li , Jian Luo , Xingbo Liu , Yue Qi","doi":"10.1016/j.ssi.2025.117067","DOIUrl":"10.1016/j.ssi.2025.117067","url":null,"abstract":"<div><div>A series of perovskite oxides <math><mfenced><mrow><msub><mi>Ln</mi><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msub><msub><mi>A</mi><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msub></mrow></mfenced><mi>Mn</mi><msub><mi>O</mi><mn>3</mn></msub></math> (Ln = La, Pr, Nd, Gd; A = Ba, Sr) was investigated to understand the effects of A-site cation size on oxygen vacancy formation. Quasirandom <math><mfenced><mrow><mi>L</mi><msub><mi>n</mi><mrow><mn>2</mn><mo>/</mo><mn>3</mn></mrow></msub><msub><mi>A</mi><mrow><mn>1</mn><mo>/</mo><mn>3</mn></mrow></msub></mrow></mfenced><mi>Mn</mi><msub><mi>O</mi><mn>3</mn></msub></math> mixed structures were generated using Alloy Theoretic Automated Toolkit (ATAT), followed by density functional theory (DFT) calculations. While mixing the orthorhombic <math><mtext>LnMn</mtext><msub><mi>O</mi><mn>3</mn></msub></math> structures with the hexagonal AMnO3 structures leads to lattices and global symmetries closer to cubic, the average volume generally increases with the average ionic size, and the local bond and angles exhibit more variations due to A-site mixing. DFT calculations and a statistical model were combined to predict oxygen reduction abilities. Thermogravimetric analysis (TGA) provided experimental validation of these predictions by measuring changes in oxygen non-stoichiometry (<math><mi>Δδ</mi></math>) under controlled conditions. Both indicated that larger A-site ionic size differences lead to greater <math><mi>Δδ</mi></math>, consistent with the larger variation in local structures, and enhanced redox capabilities. This combined computational-experimental approach highlights the importance of local structure variation, instead of average properties, in A-site cation engineering to optimize perovskite oxides for different devices relying on oxygen vacancy redox activity.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117067"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413868","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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Organic weak acid pretreatment enables surface-engineered Li-rich cathodes with suppressed voltage decay and enhanced kinetics 有机弱酸预处理使表面工程的富锂阴极具有抑制电压衰减和增强动力学

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-24 DOI: 10.1016/j.ssi.2025.117051

Jinhua Wu , Chao Han , Haijiao Yang , Zhonglei Zhao , Feifei Ling , Hang Zhao

{"title":"Organic weak acid pretreatment enables surface-engineered Li-rich cathodes with suppressed voltage decay and enhanced kinetics","authors":"Jinhua Wu , Chao Han , Haijiao Yang , Zhonglei Zhao , Feifei Ling , Hang Zhao","doi":"10.1016/j.ssi.2025.117051","DOIUrl":"10.1016/j.ssi.2025.117051","url":null,"abstract":"<div><div>Lithium-rich Mn-based layered oxides (LLOs) are regarded as promising cathodes owing to exceptional energy density and cost-effectiveness. Nevertheless, three primary drawbacks impede their commercialization: insufficient initial Coulombic efficiency (ICE), limited rate capability, and progressive voltage decay. In this study, the effects of pretreatment using an organic weak acid (tannic acid) and an inorganic strong acid (hydrochloric acid) on the structure, morphology, and electrochemical properties of Li1.2Mn0.6Ni0.2O2(LMNO) are systematically investigated. Acid pretreatment can cause the dissolution of Li2O and hence increase electrodes ICE. Compared with the pristine LMNO (73.9 %), the ICE values of tannic acid-treated(LTA) and hydrochloric acid-treated (LHC) samples reach 82.6 % and 81.9 %, respectively. Unlike the severe structural damage caused by hydrochloric acid treatment, tannic acid pretreatment generates only nano-vacancy defects and a minor spinel phase on the LMNO surface. These modifications facilitate Li+ transport while suppressing capacity and voltage decay. As a result, the LTA sample exhibits superior rate capability (150 mAh g−1 at 5C; 125 mAh g−1 at 8C), good capacity retention (96.3 % after 100 cycles at 1C), and minimal voltage decay (1.24 mV per cycle). This work establishes organic weak acid pretreatment as a scalable strategy to simultaneously address ICE, rate capability, and voltage decay in LLOs.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117051"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360229","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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The doping factor approach in solid state ionics 固体离子学中的掺杂因子方法

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-23 DOI: 10.1016/j.ssi.2025.117068

Yoed Tsur, Rawan Halabi

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Quantifying protons in triple conducting perovskite-type oxides via laser-induced breakdown spectroscopy – A comparative validation approach 通过激光诱导击穿光谱定量三重导电钙钛矿型氧化物中的质子-一种比较验证方法

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-15 DOI: 10.1016/j.ssi.2025.117033

Melanie Maurer, Maximilian Weiss, Matthias Weil, Andreas Limbeck, Alexander Karl Opitz

{"title":"Quantifying protons in triple conducting perovskite-type oxides via laser-induced breakdown spectroscopy – A comparative validation approach","authors":"Melanie Maurer, Maximilian Weiss, Matthias Weil, Andreas Limbeck, Alexander Karl Opitz","doi":"10.1016/j.ssi.2025.117033","DOIUrl":"10.1016/j.ssi.2025.117033","url":null,"abstract":"<div><div>Proton-conducting oxides are promising materials for renewable energy technologies - e.g. as electrolytes and electrodes in solid oxide cells or membranes for hydrogen purification. Particularly relevant for these applications are perovskites, which can accommodate high concentrations of protons in their crystal structure. However, quantifying the proton concentration is challenging under reducing conditions, OH uptake and oxygen loss occur simultaneously, causing compensating weight changes. Thus, attributing weight changes directly to OH uptake is not possible without complementary techniques for validation. Here, we focus on quantifying the proton concentration in the triple conducting perovskite-type oxide BaFe0.85Y0.15O3–δ (BFY) under various oxidation and protonation states. To do so, we introduce an alternative analytical method, which is capable of direct proton detection in perovskites and well-suited for in-situ quantification: Laser-induced breakdown spectroscopy (LIBS). This technique analyses characteristic emissions from the plasma generated by UV-laser irradiation of the material. Validation of results involved gravimetry and Fourier-transform infrared spectroscopy (FT-IR). While gravimetry was used to determine the proton concentration under special experimental conditions, FT-IR spectroscopy was used to distinguish the protons – located in the perovskite structure in the form of <math><msubsup><mfenced><mi>OH</mi></mfenced><mi>O</mi><mo>•</mo></msubsup></math> point defects - from molecular water (e.g. at the surface). The results underscore the reliability of LIBS for the quantification of bulk protons in perovskite-type oxides, positioning it as a valuable alternative to conventional methods.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117033"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322997","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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Research on synthesis process and calcination reaction mechanism of porous LLZO with high specific surface area 高比表面积多孔LLZO的合成工艺及煅烧反应机理研究

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-11-26 DOI: 10.1016/j.ssi.2025.117086

Shengdong Tao , Jian Li , Yali Liu , Zulv Huang , Hui Fu , Guowen He , Kun Shen , Zheng Liu , Zhifang Yin

{"title":"Research on synthesis process and calcination reaction mechanism of porous LLZO with high specific surface area","authors":"Shengdong Tao , Jian Li , Yali Liu , Zulv Huang , Hui Fu , Guowen He , Kun Shen , Zheng Liu , Zhifang Yin","doi":"10.1016/j.ssi.2025.117086","DOIUrl":"10.1016/j.ssi.2025.117086","url":null,"abstract":"<div><div>Garnet-type Li7La3Zr2O12 (LLZO), a promising solid-state electrolyte due to its high ionic conductivity, wide electrochemical window, and stability against metallic lithium, has attracted significant attention in recent years. However, its practical application is severely limited by drawbacks, including insufficient mechanical flexibility, prolonged synthesis/calcination times and challenging process control. This study proposes a metal-organic framework (MOF)-mediated strategy for LLZO synthesis. Specifically, La-Zr-MOF was constructed via hydrothermal self-assembly in solution, leveraging the strong coordination of carboxylate ligands with La3+ and Zr4+ ions. Subsequent incorporation of a lithium salt yields an LLZO precursor with atomic-level homogeneous dispersion of La, Zr, and Li. Direct calcination of the precursor produced phase-pure LLZO in a single step. Through process optimization, employing polyethylene glycol-200 (PEG-200) as the MOF synthesis solvent, LiAc as the lithium source, and 20 mol% lithium excess, cubic-phase LLZO with a high specific surface area (144.76 m2 g−1) was successfully synthesized at a relatively low temperature (1000 °C) with a short holding time (5 h). Furthermore, the calcination mechanism of LLZO was elucidated by SEM, XRD, TEM, specific surface area analysis and pore size distribution analysis of samples calcined at different temperatures. This research provides a novel strategy for the low-temperature, rapid synthesis of high-surface-area cubic-phase LLZO.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"433 ","pages":"Article 117086"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621542","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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Materials discovery through interpretation: An application to proton-conducting oxides 通过解释发现材料：在质子导电氧化物中的应用

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-27 DOI: 10.1016/j.ssi.2025.117054

Yoshihiro Yamazaki , Kota Tsujikawa , Junji Hyodo , Susumu Fujii

{"title":"Materials discovery through interpretation: An application to proton-conducting oxides","authors":"Yoshihiro Yamazaki , Kota Tsujikawa , Junji Hyodo , Susumu Fujii","doi":"10.1016/j.ssi.2025.117054","DOIUrl":"10.1016/j.ssi.2025.117054","url":null,"abstract":"<div><div>Machine learning has become a pivotal tool in materials discovery, but conventional data-driven models often behave as “black boxes” limited by the scope of their training data. In this perspective, we outline the current status of machine learning-driven materials discovery and present Materials Discovery through Interpretation (MDI), a framework that integrates scientific reasoning into the ML loop to enhance the reliability and impact of materials design. Instead of relying solely on statistical correlations, the MDI iteratively incorporates domain knowledge and insights from experimental and/or computational results such as phase formability and materials functionality into the predictive process. This interpretive strategy enables meaningful extrapolation even when underlying physics and chemical correlations remain poorly understood, guiding the identification of new candidate materials while simultaneously refining the models. Applied to proton-conducting oxides, MDI successfully identified previously unrecognized compounds, including those achieving conductivity above 0.01 Scm−1 at 300 °C, a critical benchmark for fuel cell electrolytes, while providing clear rationales for their selection. By combining predictive power with interpretability, MDI offers a flexible pathway for accelerating materials innovation beyond the confines of existing data.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117054"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413867","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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A revised bond valence based approach to identify descriptor for correlated migration in superionic conductors 一种改进的基于键价的方法来识别超离子导体中相关迁移描述子

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-24 DOI: 10.1016/j.ssi.2025.117053

Bowei Pu , Zheyi Zou , Bing He , Fan Huang , Zuer Ye , Siqi Shi

{"title":"A revised bond valence based approach to identify descriptor for correlated migration in superionic conductors","authors":"Bowei Pu , Zheyi Zou , Bing He , Fan Huang , Zuer Ye , Siqi Shi","doi":"10.1016/j.ssi.2025.117053","DOIUrl":"10.1016/j.ssi.2025.117053","url":null,"abstract":"<div><div>Multi-ion correlated migration has become one of the critical features for superionic conductors (SICs). Finding a computable descriptor for correlated migration is a significant step for rational design of SICs. Here, we develop a revised bond valence based approach with the consideration of repulsive interactions between mobile ions to calculate Coulomb repulsion energy of crystal structure (Ec), which can quantify the correlated migration tendency. The SICs in which ion transport is governed by correlated migration are characterized by strong Coulomb repulsion energies, as seen in garnet-type Li7La3Zr2O12 (0.851 eV) and NASICON-type Na3.15Zr2Si2.15P0.85O12 (0.898 eV). In contrast, the SICs with insignificant correlated migration exhibit much weaker Coulomb repulsion energies, exemplified by Li3YCl6 (0.441 eV) and Li3YBr6 (0.279 eV). Based on high-throughput calculations of 5226 Li-containing and 9363 Na-containing compounds, a threshold Ec of 0.7 eV is proposed to identify the SICs with significant correlated migration. These findings validate the effectiveness and universality of correlated migration descriptor, providing an efficient approach for the future design of superionic conductors.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117053"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360226","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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Oxygen reduction reaction kinetics and H/D effects in electrodes in contact with proton-conducting electrolyte BaCe0.9Gd0.1O3-δ 质子导电电解质BaCe0.9Gd0.1O3-δ接触电极的氧还原反应动力学及H/D效应

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-10-22 DOI: 10.1016/j.ssi.2025.117065

E.P. Antonova , D.A. Osinkin

{"title":"Oxygen reduction reaction kinetics and H/D effects in electrodes in contact with proton-conducting electrolyte BaCe0.9Gd0.1O3-δ","authors":"E.P. Antonova , D.A. Osinkin","doi":"10.1016/j.ssi.2025.117065","DOIUrl":"10.1016/j.ssi.2025.117065","url":null,"abstract":"<div><div>Solid oxides with proton conductivity have great potential for application in high-temperature electrochemical devices. These devices encompass fuel cells, electrolyzers, hydrogen sensors, and membrane reactors for the production of high-purity hydrogen. In order to ensure the efficient operation of these devices, active electrodes are required. In recent studies, complex oxides with triple proton/electron/oxygen conductivity have been identified as a promising solution. Concurrently, numerous studies have demonstrated that conventional mixed oxygen-ionic/electronic conductors (MIECs) with high electronic conductivity exhibit high efficiency in terms of their use as electrodes with proton-conducting electrolyte. In this study, we investigated the electrochemical behavior of the most popular electrode materials La0.6Sr0.4Fe0.8Co0.2O3-δ, La2NiO4+δ and La0.75Sr0.2MnO3±δ in contact with BaCe0.9Gd0.1O3-δ electrolyte in terms of oxygen reduction kinetics. A feature of this study was the use of regular and heavy water (D2O) for the humidification of the air when conducting impedance studies followed by analysis of impedance spectra by the method of distribution of relaxation times (DRT) with the subsequent determination of the stage of the oxygen reduction reaction in which the proton and/or water takes part. On the basis of the obtained results, oxygen adsorption, dissociation, and diffusion are proposed to be the rate-determining steps of the oxygen reduction reaction for La0.6Sr0.4Fe0.8Co0.2O3-δ and La0.75Sr0.2MnO3±δ electrodes.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117065"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360230","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}

引用次数: 0

Polycarbonate-based polymer electrolytes for potassium batteries 钾电池用聚碳酸酯基聚合物电解质

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-11-12 DOI: 10.1016/j.ssi.2025.117069

Isabell Lee Johansson , Timofey I. Kolesnikov , Anna Khudyshkina , Ulf-Christian Rauska , Daniel Brandell , Jonas Mindemark , Guiomar Hernández , Fabian Jeschull

{"title":"Polycarbonate-based polymer electrolytes for potassium batteries","authors":"Isabell Lee Johansson , Timofey I. Kolesnikov , Anna Khudyshkina , Ulf-Christian Rauska , Daniel Brandell , Jonas Mindemark , Guiomar Hernández , Fabian Jeschull","doi":"10.1016/j.ssi.2025.117069","DOIUrl":"10.1016/j.ssi.2025.117069","url":null,"abstract":"<div><div>Polycarbonate-based solid polymer electrolytes (SPEs) are being intensively studied for use in all-solid-state batteries as a viable alternative to the commonly used poly(ethylene oxide)-based SPEs. Specifically, poly(trimethylene carbonate) (PTMC) and poly(ε-caprolactone–co–trimethylene carbonate) (P(CL-TMC)) as a well-performing copolymeric derivative represent two materials classes that so far have not been studied in potassium battery applications. Herein, we aim to close this knowledge gap by studying physical material properties of PTMC and P(CL-TMC) solid electrolytes with potassium bis(trifluoromethanesulfonyl)imide (KTFSI) as conductive salt and examine their electrochemical stability and characteristics in K-metal/K2Fe[Fe(CN)6] (KFF), as well as Fe[Fe(CN)6/K2Fe[Fe(CN)6] cell configurations. While operation of polycarbonate-based solid-state potassium batteries at temperatures as low as 40 °C is feasible, comparatively low discharge capacities and capacity retention were observed in comparison to polyether-based systems. For the P(CL-TMC) material, rapid degradation through depolymerization processes in direct contact with potassium metal represents a major bottleneck. With this study, we set a starting point for further materials development in alternative polymer hosts for SPE applications in potassium batteries.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117069"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517279","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}

引用次数: 0

Electrical properties and conductivity mechanism for Ca2KH7(PO4)4·2H2O and Ca2(NH4)H7(PO4)4·2H2O Ca2KH7(PO4)4·2H2O和Ca2(NH4)H7(PO4)4·2H2O的电学性质及导电机理

IF 3.3 4区材料科学

Solid State Ionics Pub Date : 2025-12-01 Epub Date: 2025-11-10 DOI: 10.1016/j.ssi.2025.117070

K. Najkov , V. Koleva , V. Stefov , M. Pecovska Gjorgjevich

{"title":"Electrical properties and conductivity mechanism for Ca2KH7(PO4)4·2H2O and Ca2(NH4)H7(PO4)4·2H2O","authors":"K. Najkov , V. Koleva , V. Stefov , M. Pecovska Gjorgjevich","doi":"10.1016/j.ssi.2025.117070","DOIUrl":"10.1016/j.ssi.2025.117070","url":null,"abstract":"<div><div>For the first time the acid salts Ca2KH7(PO4)4·2H2O and Ca2(NH4)H7(PO4)4·2H2O are studied as potential proton conductors by complex impedance spectroscopy. Their electrical and dielectric properties, as well as conductivity are examined as a function of frequency (10 Hz–10 MHz) at various temperatures (293 K–363 K). The complex impedance spectra showed semicircle arcs depending on temperature indicating conductivity through grain boundaries with semiconducting behavior. It was found that for the two salts in the investigated temperature range the ac conductivity follows Joncher's power law and dc conductivity follows the Arrhenius behavior with activation energy 0.552 eV for Ca2KH7(PO4)4·2H2O and 0.713 eV for Ca2(NH4)H7(PO4)4·2H2O. The results were confirmed with electric modulus analysis. The conductivity mechanism of the two compounds was also investigated and the experimental results were analyzed using various theoretical models. It has been established that the overlapping large polaron tunneling (OLPT) was the best model to explain the proton conduction of both acidic salts. Comparison of the conductivity with other phosphate proton conductors was made.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"432 ","pages":"Article 117070"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517280","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}

引用次数: 0