Pub Date : 2024-10-24DOI: 10.1016/j.ssi.2024.116721
Xuelei Li , Weibo Yang , Yinzhou Wang , Liu Tonggang
Ultra-high‑nickel layered oxide cathodes are extensively explored in lithium-ion battery research owing to their high specific capacity. However, the rapid decline in discharge specific capacity considerably limits their long-term performance. The choice of lithium precursors is crucial in enhancing both the structural and cycle stability of these batteries, yet this aspect has not been adequately addressed in existing studies. In this study, Li2O, LiOH, and Li2CO3 were used as lithium precursors to synthesize LiNi0.92Co0.04Mn0.04O2 (NCM92) cathodes. We compare the structure and electrochemical properties of NCM92 cathode materials prepared with these three lithium precursors, examining a lithium residual layer on the surface of three NCM92 and thus inferring the varying amounts of Li incorporation into the bulk lattice. Our findings highlight the effect of lithium precursors on the rapid degradation of NCM92's discharge capacity. Notably, the NCM92–Li2O cathode demonstrates a higher discharge specific capacity and superior capacity retention after 100 cycles compared to cathodes synthesized with LiOH and Li2CO3. This study provides valuable insights and guidance for further research on ultra-high‑nickel layered oxide cathode materials.
{"title":"Electrochemical performance of ultra-high‑nickel layered oxide cathode synthesized using different lithium sources","authors":"Xuelei Li , Weibo Yang , Yinzhou Wang , Liu Tonggang","doi":"10.1016/j.ssi.2024.116721","DOIUrl":"10.1016/j.ssi.2024.116721","url":null,"abstract":"<div><div>Ultra-high‑nickel layered oxide cathodes are extensively explored in lithium-ion battery research owing to their high specific capacity. However, the rapid decline in discharge specific capacity considerably limits their long-term performance. The choice of lithium precursors is crucial in enhancing both the structural and cycle stability of these batteries, yet this aspect has not been adequately addressed in existing studies. In this study, Li<sub>2</sub>O, LiOH, and Li<sub>2</sub>CO<sub>3</sub> were used as lithium precursors to synthesize LiNi<sub>0.92</sub>Co<sub>0.04</sub>Mn<sub>0.04</sub>O<sub>2</sub> (NCM92) cathodes. We compare the structure and electrochemical properties of NCM92 cathode materials prepared with these three lithium precursors, examining a lithium residual layer on the surface of three NCM92 and thus inferring the varying amounts of Li incorporation into the bulk lattice. Our findings highlight the effect of lithium precursors on the rapid degradation of NCM92's discharge capacity. Notably, the NCM92–Li<sub>2</sub>O cathode demonstrates a higher discharge specific capacity and superior capacity retention after 100 cycles compared to cathodes synthesized with LiOH and Li<sub>2</sub>CO<sub>3</sub>. This study provides valuable insights and guidance for further research on ultra-high‑nickel layered oxide cathode materials.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116721"},"PeriodicalIF":3.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533607","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}
La0.1Sr0.9TiO3 (LST) perovskite has been studied as anode material for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) applications. LST powders were synthesized by two chemical methods, one employed hexamethylenetetramine (HMTA) as a complexing agent while the other utilized ethylenediaminetetraacetic acid (EDTA). These approaches yielded different microstructures as evidenced by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms studies. The effect of the microstructure on the electrochemical behavior of the obtained electrodes was studied by Electrochemical Impedance Spectroscopy (EIS) by varying the hydrogen partial pressure and the temperature. In addition, the evolution of specific area resistance with the hydrogen partial pressure allowed the identification of the reaction mechanism. The results of EIS were studied by electrical equivalent circuit (EEC) and distribution of relaxation times (DRT). The results suggest that the hydrogen oxidation reaction (HOR) limiting step for both samples is controlled by hydrogen dissociative-adsorption at the surface. The hydrogen adsorption is faster at the electrode formed by smaller nanoparticles, in which the activation energy decreases and the rate coefficient changes.
{"title":"Study of La0.1Sr0.9TiO3 electrochemical response as anode for SOFC and its relation with microstructure","authors":"Ernesto Tagarelli , Jesús Vega-Castillo , Mariela Ortiz , Horacio Troiani , Corina M. Chanquía , Alejandra Montenegro-Hernández","doi":"10.1016/j.ssi.2024.116719","DOIUrl":"10.1016/j.ssi.2024.116719","url":null,"abstract":"<div><div>La<sub>0.1</sub>Sr<sub>0.9</sub>TiO<sub>3</sub> (LST) perovskite has been studied as anode material for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) applications. LST powders were synthesized by two chemical methods, one employed hexamethylenetetramine (HMTA) as a complexing agent while the other utilized ethylenediaminetetraacetic acid (EDTA). These approaches yielded different microstructures as evidenced by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and N<sub>2</sub> adsorption/desorption isotherms studies. The effect of the microstructure on the electrochemical behavior of the obtained electrodes was studied by Electrochemical Impedance Spectroscopy (EIS) by varying the hydrogen partial pressure and the temperature. In addition, the evolution of specific area resistance with the hydrogen partial pressure allowed the identification of the reaction mechanism. The results of EIS were studied by electrical equivalent circuit (EEC) and distribution of relaxation times (DRT). The results suggest that the hydrogen oxidation reaction (HOR) limiting step for both samples is controlled by hydrogen dissociative-adsorption at the surface. The hydrogen adsorption is faster at the electrode formed by smaller nanoparticles, in which the activation energy decreases and the rate coefficient changes.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116719"},"PeriodicalIF":3.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533011","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 : 2024-10-23DOI: 10.1016/j.ssi.2024.116720
Yuliya A. Fadeeva, Liudmila E. Shmukler, Liubov P. Safonova
Fuel cells (FC) with proton exchange membranes (PEMs) are seen as an alternative energy source due to their efficiency, power density, low emissions, and reliable energy supply. Proton exchange membranes based on polybenzimidazole have shown potential for operating at high and medium temperatures to enhance FCs performance. New composite membranes made from m-PBI and diethylammonium mesylate [DEAH/MsO] ionic liquid were prepared trough a solution casting method. Silica nanopowder (SiO2) was used as an inorganic filler at varying concentrations (0.5–20 wt%). The ionic liquid content in the membranes ranged from 1 to 2.5 mol per mole of PBI monomer units. Our study is focused on the thermal properties, such as thermal stability and phase transition temperatures, morphology, conductivity, and electrochemical stability of the membranes. The influence of the inorganic filler on these properties was also discussed.
{"title":"Ionic liquid/polybenzimidazole/SiO2 composite membranes for medium temperature operating","authors":"Yuliya A. Fadeeva, Liudmila E. Shmukler, Liubov P. Safonova","doi":"10.1016/j.ssi.2024.116720","DOIUrl":"10.1016/j.ssi.2024.116720","url":null,"abstract":"<div><div>Fuel cells (FC) with proton exchange membranes (PEMs) are seen as an alternative energy source due to their efficiency, power density, low emissions, and reliable energy supply. Proton exchange membranes based on polybenzimidazole have shown potential for operating at high and medium temperatures to enhance FCs performance. New composite membranes made from <em>m</em>-PBI and diethylammonium mesylate [DEAH/MsO] ionic liquid were prepared trough a solution casting method. Silica nanopowder (SiO<sub>2</sub>) was used as an inorganic filler at varying concentrations (0.5–20 wt%). The ionic liquid content in the membranes ranged from 1 to 2.5 mol per mole of PBI monomer units. Our study is focused on the thermal properties, such as thermal stability and phase transition temperatures, morphology, conductivity, and electrochemical stability of the membranes. The influence of the inorganic filler on these properties was also discussed.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116720"},"PeriodicalIF":3.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533501","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 : 2024-10-17DOI: 10.1016/j.ssi.2024.116710
D.N. Karimov, N.I. Sorokin
The single crystals with the composition La1−y(Sm3+1−xSm2+x)yF3−xy (y = 0.04) were grown from melt by the vertical Bridgman technique. A part of the Sm3+ doping ions in LaF3 matrix is reduced to the Sm2+oxidation state due to interaction with carbon during the growth process. The crystals were studied by X-ray diffraction analysis, optical and impedance spectroscopy. The Sm-doped crystals LaF3 are single-phase, retaining the tysonite-type structure (sp. gr. P-3c1) and demonstrate a bipolar electrical conductivity mechanism. Both the ionic conductivity σi = 4.7 × 10−5 S/cm caused by heterovalent substitutions of La3+ for Sm2+ and the comparable electronic conductivity σe = 3 × 10−5 S/cm due to the variable oxidation states Sm2+/Sm3+ ions were detected for the grown crystals. The discovered mixed ionic-electronic conductivity of La0.96Sm3+0.004Sm2+0.036F2.964 crystals opens up a new direction for the practical application of the tysonite-type fluorides as a component of electrode materials for fluorine-ion current sources.
{"title":"Mixed-valence Sm-doped LaF3 crystals as ion-electron conductors: Crystal growth and impedance characterization","authors":"D.N. Karimov, N.I. Sorokin","doi":"10.1016/j.ssi.2024.116710","DOIUrl":"10.1016/j.ssi.2024.116710","url":null,"abstract":"<div><div>The single crystals with the composition La<sub>1−<em>y</em></sub>(Sm<sup>3+</sup><sub>1−<em>x</em></sub>Sm<sup>2+</sup><sub><em>x</em></sub>)<sub><em>y</em></sub>F<sub>3−<em>xy</em></sub> <span><math><mi>L</mi><msub><mi>a</mi><mrow><mn>1</mn><mo>−</mo><mi>y</mi></mrow></msub><msub><mfenced><mrow><mi>S</mi><msubsup><mi>m</mi><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msubsup><mi>S</mi><msubsup><mi>m</mi><mi>x</mi><mrow><mn>2</mn><mo>+</mo></mrow></msubsup></mrow></mfenced><mi>y</mi></msub><msub><mi>F</mi><mrow><mn>3</mn><mo>−</mo><mi>xy</mi></mrow></msub></math></span>(<em>y</em> = 0.04) were grown from melt by the vertical Bridgman technique. A part of the Sm<sup>3+</sup> doping ions in LaF<sub>3</sub> matrix is reduced to the Sm<sup>2+</sup> <em>oxidation</em> state due to interaction with carbon during the growth process. The crystals were studied by X-ray diffraction analysis, optical and impedance spectroscopy. The Sm-doped crystals LaF<sub>3</sub> are single-phase, retaining the tysonite-type structure (sp. gr. <em>P-3c1</em><span><math><mi>P</mi><mover><mn>3</mn><mo>̄</mo></mover><mi>c</mi><mn>1</mn></math></span>) and demonstrate a bipolar electrical conductivity mechanism. Both the ionic conductivity σ<sub>i</sub> = 4.7 × 10<sup>−5</sup> S/cm caused by heterovalent substitutions of La<sup>3+</sup> for Sm<sup>2+</sup> and the comparable electronic conductivity σ<sub>e</sub> = 3 × 10<sup>−5</sup> S/cm due to the variable <em>oxidation states</em> Sm<sup>2+</sup>/Sm<sup>3+</sup> ions were detected for the grown crystals. The discovered mixed ionic-electronic conductivity of La<sub>0.96</sub>Sm<sup>3+</sup><sub>0.004</sub>Sm<sup>2+</sup><sub>0.036</sub>F<sub>2.964</sub> crystals opens up a new direction for the practical application of the tysonite-type fluorides as a component of electrode materials for fluorine-ion current sources.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116710"},"PeriodicalIF":3.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445251","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 : 2024-10-16DOI: 10.1016/j.ssi.2024.116718
Jingxiu Tian , Li-ang Zhu , Hongshun Miao , Xiangxin Li , Yan Liu
O3-NaNi1/3Fe1/3Mn1/3O2 (NaNFM) materials are susceptible to complex phase transitions during electrical cycling leading to poor structural, capacity retention and multiplicity properties. These drawbacks hinder the application of NaNFM in sodium-ion batteries. Here, Mg2+ with larger ionic radius was used to dope its transition metal layer Ni site. The effects of Mg2+ doped NaNFM crystal structure and transition metal valence states on its electrochemical properties were investigated by XRD, SEM, and XPS. The capacity retention of NaNMFM-0.02 (84.05 %) was higher than that of NaNFM (73 %) after 200 cycles of the material at 5C. In addition, NaNMFM-0.02 achieved a first discharge specific capacity of 146.5 mAh/g at high voltage. Based on structural and electrochemical analyses, this improvement is attributed to the fact that magnesium acts as a “pillar” to stabilize the crystal structure of NaNFM, while magnesium doping reduces the Jahn-Teller effect. As a result, the material has better electrochemical properties.
{"title":"Effect of the position of Mg replacing Ni on O3-NaNi1/3Fe1/3Mn1/3O2 on the structural stability of cathode materials","authors":"Jingxiu Tian , Li-ang Zhu , Hongshun Miao , Xiangxin Li , Yan Liu","doi":"10.1016/j.ssi.2024.116718","DOIUrl":"10.1016/j.ssi.2024.116718","url":null,"abstract":"<div><div>O3-NaNi<sub>1/3</sub>Fe<sub>1/3</sub>Mn<sub>1/3</sub>O<sub>2</sub> (NaNFM) materials are susceptible to complex phase transitions during electrical cycling leading to poor structural, capacity retention and multiplicity properties. These drawbacks hinder the application of NaNFM in sodium-ion batteries. Here, Mg<sup>2+</sup> with larger ionic radius was used to dope its transition metal layer Ni site. The effects of Mg<sup>2+</sup> doped NaNFM crystal structure and transition metal valence states on its electrochemical properties were investigated by XRD, SEM, and XPS. The capacity retention of NaNMFM-0.02 (84.05 %) was higher than that of NaNFM (73 %) after 200 cycles of the material at 5C. In addition, NaNMFM-0.02 achieved a first discharge specific capacity of 146.5 mAh/g at high voltage. Based on structural and electrochemical analyses, this improvement is attributed to the fact that magnesium acts as a “pillar” to stabilize the crystal structure of NaNFM, while magnesium doping reduces the Jahn-Teller effect. As a result, the material has better electrochemical properties.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116718"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441521","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 : 2024-10-16DOI: 10.1016/j.ssi.2024.116711
Tianxin Zhao, Lulu Wang, Yang Zhang, Fan Zhang, Jilin Wang
A series of anion exchange membranes (AEMs) with highly ion conductivity suitable for practical application in fuel cells were prepared in this paper. Polysulfone (PSf) was used as backbone to prepare chloromethylation polysulfone (CMPSf). Then the synthesized CMPSf was blended with tetramethyldiaminopropane (TMPDA) and polyethylene glycol (PEG 400), to construct interpenetrating polymer networks with hydrogen-bonding conduction sites. In this paper the chemical structure of the AEM is confirmed by nuclear magnetic resonance spectrum (1H NMR) spectroscopy and fourier transform infrared spectroscopy (FT-IR). The morphologies of synthesized membranes in this paper are investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrochemical and physical properties of AEMs are tested comprising water uptake (WU), ion exchange capacity (IEC), alkaline stability, thermal stability and mechanical stability. The introduction of hydrogen-bonding networks enhanced the OH− conductivity of the membranes (from 37.03 mS·cm−1 of QAPSf-PEG0% to 104.67 mS·cm−1 of QAPSf-PEG30%). The interpenetrating polymer networks make the membranes have good mechanical property (tensile strengh is 19.61 MPa, elongation at break is 20.30 %) and anti-swelling properties (29.3 %, 80 °C). Due to the introduction of hydrogen-bonding conduction networks, the alkaline stability of the AEMs can be enhanced by reducing the modification of the polysulfone backbone. Thus, even after soaking in 6 mol·L−1 KOH solution for 30 days, the retained OH− conductivity of QAPSf-PEG30% still reached 92.0 %. At the same time, the addition of PEG leads to the increased water uptake, so that the OH− ions could be better transported. And the single cell performance of QAPSf-PEG30% was also revealed that the power density increases significantly from 323.35 mW·cm−2 at 60 °C to 514.8 mW·cm−2 at 80 °C as the temperature increases. Overall, QAPSf-PEG30% exhibits promising development potential in the fuel cells.
{"title":"High conductivity of a fuel cell through a hydrogen bond network within an interpenetrating anion exchange membrane","authors":"Tianxin Zhao, Lulu Wang, Yang Zhang, Fan Zhang, Jilin Wang","doi":"10.1016/j.ssi.2024.116711","DOIUrl":"10.1016/j.ssi.2024.116711","url":null,"abstract":"<div><div>A series of anion exchange membranes (AEMs) with highly ion conductivity suitable for practical application in fuel cells were prepared in this paper. Polysulfone (PSf) was used as backbone to prepare chloromethylation polysulfone (CMPSf). Then the synthesized CMPSf was blended with tetramethyldiaminopropane (TMPDA) and polyethylene glycol (PEG 400), to construct interpenetrating polymer networks with hydrogen-bonding conduction sites. In this paper the chemical structure of the AEM is confirmed by nuclear magnetic resonance spectrum (<sup>1</sup>H NMR) spectroscopy and fourier transform infrared spectroscopy (FT-IR). The morphologies of synthesized membranes in this paper are investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrochemical and physical properties of AEMs are tested comprising water uptake (WU), ion exchange capacity (IEC), alkaline stability, thermal stability and mechanical stability. The introduction of hydrogen-bonding networks enhanced the OH<sup>−</sup> conductivity of the membranes (from 37.03 mS·cm<sup>−1</sup> of QAPSf-PEG<sub>0%</sub> to 104.67 mS·cm<sup>−1</sup> of QAPSf-PEG<sub>30%</sub>). The interpenetrating polymer networks make the membranes have good mechanical property (tensile strengh is 19.61 MPa, elongation at break is 20.30 %) and anti-swelling properties (29.3 %, 80 °C). Due to the introduction of hydrogen-bonding conduction networks, the alkaline stability of the AEMs can be enhanced by reducing the modification of the polysulfone backbone. Thus, even after soaking in 6 mol·L<sup>−1</sup> KOH solution for 30 days, the retained OH<sup>−</sup> conductivity of QAPSf-PEG<sub>3</sub><sub>0%</sub> still reached 92.0 %. At the same time, the addition of PEG leads to the increased water uptake, so that the OH<sup>−</sup> ions could be better transported. And the single cell performance of QAPSf-PEG<sub>30%</sub> was also revealed that the power density increases significantly from 323.35 mW·cm<sup>−2</sup> at 60 °C to 514.8 mW·cm<sup>−2</sup> at 80 °C as the temperature increases. Overall, QAPSf-PEG<sub>30%</sub> exhibits promising development potential in the fuel cells.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116711"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441523","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 : 2024-10-16DOI: 10.1016/j.ssi.2024.116717
K. Mitsuishi , T. Ohnishi , K. Niitsu , T. Masuda , S. Miyoshi , K. Takada
For realizing oxide-based all-solid-state lithium-ion batteries, lowering sintering temperature of LiCoO2 cathode during battery fabrication is important subject to prevent undesired chemical reaction with other constituent substances. Here we report that the addition of LiOH aqueous solution to the LiCoO2 powder upon sintering improves the battery performance. Comparative study for the samples with and without LiOH solution, and with pure water by in situ transmission electron microscopy reveals that the liquid phase appears at much lower temperatures for the sample with the LiOH addition that improves the connectivity of LiCoO2 particles.
{"title":"Lowering the sintering temperature of LiCoO2 using LiOH aqueous solution","authors":"K. Mitsuishi , T. Ohnishi , K. Niitsu , T. Masuda , S. Miyoshi , K. Takada","doi":"10.1016/j.ssi.2024.116717","DOIUrl":"10.1016/j.ssi.2024.116717","url":null,"abstract":"<div><div>For realizing oxide-based all-solid-state lithium-ion batteries, lowering sintering temperature of LiCoO<sub>2</sub> cathode during battery fabrication is important subject to prevent undesired chemical reaction with other constituent substances. Here we report that the addition of LiOH aqueous solution to the LiCoO<sub>2</sub> powder upon sintering improves the battery performance. Comparative study for the samples with and without LiOH solution, and with pure water by <em>in situ</em> transmission electron microscopy reveals that the liquid phase appears at much lower temperatures for the sample with the LiOH addition that improves the connectivity of LiCoO<sub>2</sub> particles.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116717"},"PeriodicalIF":3.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441522","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 : 2024-10-15DOI: 10.1016/j.ssi.2024.116712
Fei Ruan, Chonggui Lei, Xi Wu, Jinxiao Bao, Fen Zhou, Jianquan Gao, Guoqi Liu
Zr-site doped CaZrO3 is a promising high temperature proton conductor solid electrolyte material used for metal melt hydrogen sensor. To understand the electrochemical properties of ytterbium doped calcium zirconate electrolyte in more detail, the CaZr1−xYbxO3−α (x = 0, 0.025, 0.05, 0.075 and 0.1, hereafter named CZY) solid electrolyte specimens were prepared by use of high temperature solid state reaction process. The structure of the electrolyte samples was characterized by Raman spectrum, XRD and SEM. The densities of the specimens were measured based on Archimedes method. The electrical conductivities of the CZY specimens were measured at the temperature of 573–1373 K in hydrogen-rich or oxygen-rich atmosphere by the two-terminal AC impedance spectroscopy method. The H/D isotope effect of the CZY electrolyte at 973–1373 K was tested to clarify the dominant conducting carrier in predetermined temperature and atmosphere. It is demonstrated that proton is the predominant charge carrier both in oxygen-rich and hydrogen-rich atmosphere at the lower temperature below 1073 K. However, at higher temperature above 1073 K, the dominant charge carrier seems to be to be electron hole in oxygen-rich atmosphere, whereas, oxygen ion vacancy in hydrogen-rich based on the analysis of the atmospheric dependence of the electrical conductivity and the H/D isotope effect. Besides, partial conductivities of conducting species(such as interstitial proton, electron hole and oxygen ion vacancy), the active doping amount of ytterbium and the standard Gibbs free energy changes for interstitial proton production by dissolution of water and hydrogen in the CZY electrolyte were estimated based on crystal defect chemistry theory.
掺杂锆酸钙的 CaZrO3 是一种很有前途的高温质子导体固体电解质材料，可用于金属熔体氢传感器。为了更详细地了解掺杂镱的锆酸钙电解质的电化学特性，研究人员采用高温固态反应工艺制备了 CaZr1-xYbxO3-α （x = 0、0.025、0.05、0.075 和 0.1，以下简称 CZY）固体电解质试样。拉曼光谱、XRD 和 SEM 对电解质样品的结构进行了表征。根据阿基米德法测量了试样的密度。采用两端交流阻抗光谱法测量了 CZY 试样在富氢或富氧气氛中于 573-1373 K 温度下的电导率。测试了 973-1373 K 温度下 CZY 电解质的氢/氧同位素效应，以明确在预定温度和气氛下的主要导电载体。但在 1073 K 以上的高温条件下，根据电导率的大气依赖性和 H/D 同位素效应分析，在富氧大气中，主导电荷载流子似乎是电子空穴，而在富氢大气中，主导电荷载流子则是氧离子空穴。此外，还根据晶体缺陷化学理论估算了导电物种（如间隙质子、电子空穴和氧离子空位）的部分电导率、镱的活性掺杂量以及水和氢在 CZY 电解质中溶解产生间隙质子的标准吉布斯自由能变化。
{"title":"The electrical conductive properties analysis of ytterbium doped calcium zirconate proton conductor solid electrolyte based on crystal defect chemistry","authors":"Fei Ruan, Chonggui Lei, Xi Wu, Jinxiao Bao, Fen Zhou, Jianquan Gao, Guoqi Liu","doi":"10.1016/j.ssi.2024.116712","DOIUrl":"10.1016/j.ssi.2024.116712","url":null,"abstract":"<div><div>Zr-site doped CaZrO<sub>3</sub> is a promising high temperature proton conductor solid electrolyte material used for metal melt hydrogen sensor. To understand the electrochemical properties of ytterbium doped calcium zirconate electrolyte in more detail, the CaZr<sub>1<em>−x</em></sub>Yb<sub><em>x</em></sub>O<sub>3<em>−α</em></sub> (<em>x</em> = 0, 0.025, 0.05, 0.075 and 0.1, hereafter named CZY) solid electrolyte specimens were prepared by use of high temperature solid state reaction process. The structure of the electrolyte samples was characterized by Raman spectrum, XRD and SEM. The densities of the specimens were measured based on Archimedes method. The electrical conductivities of the CZY specimens were measured at the temperature of 573–1373 K in hydrogen-rich or oxygen-rich atmosphere by the two-terminal AC impedance spectroscopy method. The H/D isotope effect of the CZY electrolyte at 973–1373 K was tested to clarify the dominant conducting carrier in predetermined temperature and atmosphere. It is demonstrated that proton is the predominant charge carrier both in oxygen-rich and hydrogen-rich atmosphere at the lower temperature below 1073 K. However, at higher temperature above 1073 K, the dominant charge carrier seems to be to be electron hole in oxygen-rich atmosphere, whereas, oxygen ion vacancy in hydrogen-rich based on the analysis of the atmospheric dependence of the electrical conductivity and the H/D isotope effect. Besides, partial conductivities of conducting species(such as interstitial proton, electron hole and oxygen ion vacancy), the active doping amount of ytterbium and the standard Gibbs free energy changes for interstitial proton production by dissolution of water and hydrogen in the CZY electrolyte were estimated based on crystal defect chemistry theory.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116712"},"PeriodicalIF":3.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434261","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}
Tracer diffusion coefficients of lithium-ions in the sintered samples of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) have been measured through the neutron radiography (NR) technique in the wide temperature range from 25 °C to 500 °C. The diffusion data above and below 300 °C were collected using pulsed and reactor-generated neutrons, respectively, which coincide with each other at 300 °C exhibiting a single curve in the Arrhenius plot. The room-temperature diffusion coefficient and the activation energy below 300 °C are obtained as 1.47 × 10−9 cm2 s−1 and 0.37 eV, respectively. The activation energy of the conductivity diffusion coefficient almost agrees with the tracer one, and the deduced Haven ratio of 0.40 is consistent with the concerted migration model of the lithium-ions.
{"title":"Tracer diffusion coefficient measurements on NASICON-type Lithium-ion conductor LAGP using neutron radiography between 25 °C and 500 °C","authors":"Honoka Takagi , Takeshi Yabutsuka , Hirotoshi Hayashida , Fangzhou Song , Tetsuya Kai , Takenao Shinohara , Keisuke Kurita , Hiroshi Iikura , Norio Yamamoto , Minoru Nakajima , Shigeomi Takai","doi":"10.1016/j.ssi.2024.116716","DOIUrl":"10.1016/j.ssi.2024.116716","url":null,"abstract":"<div><div>Tracer diffusion coefficients of lithium-ions in the sintered samples of Li<sub>1.5</sub>Al<sub>0.5</sub>Ge<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> (LAGP) have been measured through the neutron radiography (NR) technique in the wide temperature range from 25 °C to 500 °C. The diffusion data above and below 300 °C were collected using pulsed and reactor-generated neutrons, respectively, which coincide with each other at 300 °C exhibiting a single curve in the Arrhenius plot. The room-temperature diffusion coefficient and the activation energy below 300 °C are obtained as 1.47 × 10<sup>−9</sup> cm<sup>2</sup> s<sup>−1</sup> and 0.37 eV, respectively. The activation energy of the conductivity diffusion coefficient almost agrees with the tracer one, and the deduced Haven ratio of 0.40 is consistent with the concerted migration model of the lithium-ions.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116716"},"PeriodicalIF":3.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434262","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 : 2024-10-11DOI: 10.1016/j.ssi.2024.116715
Pengsen Wu , Longfei Zhao , Yang Wang , Jiajia Ge , Zijin Li , Zhenzhen Li , Guanzhou Qiu
In this paper, FePO4∙2H2O and FePO4 have been successfully accomplished by utilizing titanium white by-product ferrous sulfate via two-step synthesis method, which is further employed to react with Li2CO3 via carbothermal reduction to prepare LiFePO4 cathode materials. The composition and structure characteristics of obtained samples are studied in detail by TG-DSC, XRD, XPS, FESEM and TEM, and the electrochemical performances of prepared LiFePO4 are also carefully investigated. The results indicate that the discharge specific capacity of LiFePO4 synthesized from FePO4 achieves 162.4 and 153.7 mAh∙g−1 at 0.1C and 1C, which is 2.2 and 2.9 mAh∙g−1 higher than that from FePO4∙2H2O, and the capacity retention rate reaches as high as 97.5 % after 450 cycles at 1C, correspondingly 94.8 % for LiFePO4 from FePO4∙2H2O. It is mainly ascribed to the smaller particle size of LiFePO4 synthesized from FePO4, and the intimately ordered interface structure between the carbon layer and LiFePO4, which greatly promotes the migration of lithium ions in the lithiation and delithiation process.
{"title":"Preparation of lithium iron phosphate with superior electrochemical performances from titanium white by-product ferrous sulfate","authors":"Pengsen Wu , Longfei Zhao , Yang Wang , Jiajia Ge , Zijin Li , Zhenzhen Li , Guanzhou Qiu","doi":"10.1016/j.ssi.2024.116715","DOIUrl":"10.1016/j.ssi.2024.116715","url":null,"abstract":"<div><div>In this paper, FePO<sub>4</sub>∙2H<sub>2</sub>O and FePO<sub>4</sub> have been successfully accomplished by utilizing titanium white by-product ferrous sulfate via two-step synthesis method, which is further employed to react with Li<sub>2</sub>CO<sub>3</sub> via carbothermal reduction to prepare LiFePO<sub>4</sub> cathode materials. The composition and structure characteristics of obtained samples are studied in detail by TG-DSC, XRD, XPS, FESEM and TEM, and the electrochemical performances of prepared LiFePO<sub>4</sub> are also carefully investigated. The results indicate that the discharge specific capacity of LiFePO<sub>4</sub> synthesized from FePO<sub>4</sub> achieves 162.4 and 153.7 mAh∙g<sup>−1</sup> at 0.1C and 1C, which is 2.2 and 2.9 mAh∙g<sup>−1</sup> higher than that from FePO<sub>4</sub>∙2H<sub>2</sub>O, and the capacity retention rate reaches as high as 97.5 % after 450 cycles at 1C, correspondingly 94.8 % for LiFePO<sub>4</sub> from FePO<sub>4</sub>∙2H<sub>2</sub>O. It is mainly ascribed to the smaller particle size of LiFePO<sub>4</sub> synthesized from FePO<sub>4</sub>, and the intimately ordered interface structure between the carbon layer and LiFePO<sub>4</sub>, which greatly promotes the migration of lithium ions in the lithiation and delithiation process.</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"417 ","pages":"Article 116715"},"PeriodicalIF":3.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423114","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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