scholarly journals Nanocrystalline Surface Layer of WO3 for Enhanced Proton Transport during Fuel Cell Operation

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1595
Author(s):  
Xiang Song ◽  
Weiqing Guo ◽  
Yuhong Guo ◽  
Naveed Mushtaq ◽  
M. A. K. Yousaf Shah ◽  
...  
Keyword(s):  
Surface Layer ◽  
Fuel Cell ◽  
Ionic Conductivity ◽  
Ionic Transport ◽  
High Ionic Conductivity ◽  
Energy Storage And Conversion ◽  
Practical Applications ◽  
Fuel Cell Performance ◽  
Energy Devices ◽  
Ion Conducting

High ionic conductivity in low-cost semiconductor oxides is essential to develop electrochemical energy devices for practical applications. These materials exhibit fast protonic or oxygen-ion transport in oxide materials by structural doping, but their application to solid oxide fuel cells (SOFCs) has remained a significant challenge. In this work, we have successfully synthesized nanostructured monoclinic WO3 through three steps: co-precipitation, hydrothermal, and dry freezing methods. The resulting WO3 exhibited good ionic conductivity of 6.12 × 10−2 S cm−1 and reached an excellent power density of 418 mW cm−2 at 550 °C using as an electrolyte in SOFC. To achieve such a high ionic conductivity and fuel cell performance without any doping contents was surprising, as there should not be any possibility of oxygen vacancies through the bulk structure for the ionic transport. Therefore, laterally we found that the surface layer of WO3 is reduced to oxygen-deficient when exposed to a reducing atmosphere and form WO3−δ/WO3 heterostructure, which reveals a unique ionic transport mechanism. Different microscopic and spectroscopic methods such as HR-TEM, SEM, EIS, Raman, UV-visible, XPS, and ESR spectroscopy were applied to investigate the structural, morphological, and electrochemical properties of WO3 electrolyte. The structural stability of the WO3 is explained by less dispersion between the valence and conduction bands of WO3−δ/WO3, which in turn could prevent current leakage in the fuel cell that is essential to reach high performance. This work provides some new insights for designing high-ion conducting electrolyte materials for energy storage and conversion devices.

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

scholarly journals Performance-tuning of PVA-based gel electrolytes by acid/PVA ratio and PVA molecular weight

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Saeideh Alipoori ◽  
M. M. Torkzadeh ◽  
Saeedeh Mazinani ◽  
Seyed Hamed Aboutalebi ◽  
Farhad Sharif
Keyword(s):  
Molecular Weight ◽  
Ionic Conductivity ◽  
Charge Carrier Concentration ◽  
Fine Tuning ◽  
Performance Tuning ◽  
Practical Applications ◽  
High Performing ◽  
Flexible Devices ◽  
Gel Electrolytes ◽  
Ion Conducting

AbstractThe significant breakthroughs of flexible gel electrolytes have attracted extensive attention in modern wearable electronic gadgets. The lack of all-around high-performing gels limits the advantages of such devices for practical applications. To this end, developing a multi-functional gel architecture with superior ionic conductivity while enjoying good mechanical flexibility is a bottleneck to overcome. Herein, an architecturally engineered gel, based on PVA and H3PO4 with different molecular weights of PVA for various PVA/H3PO4 ratios, was developed. The results show the dependence of ionic conductivity on molecular weight and also charge carrier concentration. Consequently, fine-tuning of PVA-based gels through a simple yet systematic and well-regulated strategy to achieve highly ion-conducting gels, with the highest ionic conductivity of 14.75 ± 1.39 mS cm-1 have been made to fulfill the requirement of flexible devices. More importantly, gel electrolytes possess good mechanical robustness while exhibiting high-elasticity (%766.66 ± 59.73), making it an appropriate candidate for flexible devices.

scholarly journals Effective suppression of lithium dendrite growth using fluorinated polysulfonamide-containing single-ion conducting polymer electrolytes

2020 ◽  
Vol 1 (4) ◽  
pp. 873-879
Author(s):  
Yunyun Zhong ◽  
Jianwei Zhang ◽  
Shuanjin Wang ◽  
Dongmei Han ◽  
Min Xiao ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Conducting Polymer ◽  
Network Structure ◽  
Polymer Electrolytes ◽  
High Ionic Conductivity ◽  
Sei Layer ◽  
Effective Suppression ◽  
Ion Conducting ◽  
Lithium Dendrite ◽  
Ion Conducting Polymer

A flexible artificial SEI layer with a 3D cross-linked network structure exhibits high ionic conductivity and single-ion conductive characteristics.

Comparative Studies Regarding the Synthesis and Characterization of Cellulose Based-Polymer Assemblies for Fuel Cell Applications

2019 ◽  
Vol 957 ◽  
pp. 475-482
Author(s):  
Ioana Maior ◽  
Ana Maria Albu ◽  
Marius Stelian Popa
Keyword(s):  
Fuel Cell ◽  
Ionic Conductivity ◽  
Comparative Studies ◽  
Electrochemical Impedance ◽  
Molecular Size ◽  
Solid Polymer ◽  
Synthesis And Characterization ◽  
Fuel Cell Performance ◽  
Vis Spectroscopy

The aim of these comparative studies consists of synthesis and characterization of membrane assemblies from cellulose acetate (CelAc) and acrylic acid (AA), using as dopant in-situ generated pyrrole–aniline (Py–AN) copolymer intended for use in fuel cells fabrication. The synthesis was conducted through free radical polymerization in a semi-homogeneous system and the casting method was used to form the solid polymer membranes. In selecting the optimal compositional parameters, the influence of the molecular size of the majority matrix component was also observed. These membrane assemblies were studied using FT-IR spectroscopy, UV-Vis spectroscopy, and X-Ray diffraction analysis which highlighted the structure–composition dependence. With the electrochemical impedance spectroscopy the ionic conductivity of the membrane was determined, in order to evaluate the PEM fuel cell performance. In case of thicker membranes, there is an increase in ionic conductivity values over those of lower thickness, which is due to short-order structural order. Also, a superunitary Py:AN is more favorable to conductivity increase than a less than one ratio.

scholarly journals A combined experimental and computational approach reveals how aromatic peptide amphiphiles self-assemble to form ion-conducting nanohelices

2020 ◽  
Vol 4 (10) ◽  
pp. 3022-3031
Author(s):  
Yin Wang ◽  
Yaxin An ◽  
Yulia Shmidov ◽  
Ronit Bitton ◽  
Sanket A. Deshmukh ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Computational Approach ◽  
High Ionic Conductivity ◽  
Peptide Amphiphiles ◽  
Self Assembled ◽  
Ion Conducting

Salt-triggered conversion of nanoribbons into nanohelices was studied experimentally and computationally, revealing unexpectedly high ionic conductivity in these self-assembled nanomaterials.

scholarly journals Structural phase transitions and conducting properties in Bimetallic sulfates

2014 ◽  
Vol 70 (a1) ◽  
pp. C74-C74
Author(s):  
Vaishali Sharma ◽  
Diptikanta Swain ◽  
Chandrabhas Narayana ◽  
Tayur Guru Row
Keyword(s):  
Phase Transitions ◽  
Ionic Conductivity ◽  
Structural Phase ◽  
Functional Materials ◽  
High Ionic Conductivity ◽  
Monoclinic Space Group ◽  
Structural Phase Transitions ◽  
Space Group ◽  
Ion Conducting ◽  
Fast Ion

Bimetallic sulfate minerals, hydrated as well as anhydrous are important multifunctional materials which exhibit interesting properties like fast-ion conduction, ferroelectricity and magnetism with variation in temperature [1,2,3]. These properties are generally entwined with structural phase transitions and show structural frameworks made of interconnection of octahedra and tetrahedra [1]. Bimetallic sulfates, indeed are intercalation compounds of alkali ions generated by these frameworks and they possess high ionic conductivity [1]. In the present study, anhydrous and hydrous compounds of Na6M(SO4)4, (M=Mn, Ni, Co) were synthesized to understand the structural phase transitions and its relation to fast-ion conducting properties. Na6Mn(SO4)4, is monoclinic, space group P21/c with Z=2 and is isostructural to its Co and Ni analogues and shows high ionic conductivity and structural phase transition > 4500C. Na6Co(SO4).2H2O, Na6Ni(SO4).2H2O are isostructural with triclinic system having space group P-1 with Z =1. In addition, structural features and correlation with ionic conductivity in Na6Co(SO4).2H2O, Na6Ni(SO4).2H2O and Na6Mn(SO4) will be outlined. These studies open up the utility of hydrated bimetallic sulfates as possible precursor for the design of functional materials.

Ionic conductivity of apatite-type solid electrolyte material, La10−XBaXSi6O27−X/2 (X=0–1), and its fuel cell performance

2010 ◽  
Vol 195 (13) ◽  
pp. 4059-4064 ◽  
Author(s):  
Y. Nojiri ◽  
S. Tanase ◽  
M. Iwasa ◽  
H. Yoshioka ◽  
Y. Matsumura ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Cell Performance ◽  
Fuel Cell Performance ◽  
Apatite Type

scholarly journals Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

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