The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform
Hong Zhu - One of the best experts on this subject based on the ideXlab platform.
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Anion Charge and Lattice Volume Maps for Searching Lithium Superionic Conductors
2020Co-Authors: Hong ZhuAbstract:<p><a>The effects of anion charge and lattice volume (lithium-anion bond length) on lithium ion migration have been investigated by utilizing the density functional theory calculations combined with the anion sublattice models, e.g. <i>fcc</i>, <i>hcp</i> and <i>bcc</i>. It is found that the anion charge and lattice volume have great impacts on the activation energy barrier (E<sub>a</sub>) of lithium ion migration, which is validated by some reported sulfides. For the tetrahedrally occupied lithium, the less negative anion charge is, the lower the lithium ion migration barrier is likely to be. While for the octahedrally occupied lithium, the more negative anion charge is, the lower the lithium ion migration barrier is. There are opposite effects of anion charge on E<sub>a</sub> and optimum lattice volumes for minimum E<sub>a</sub> of lithium ion migration along the <i>Tet-Oct-Tet</i> and <i>Oct-Tet-Oct </i>pathways in the <i>hcp</i>-type sublattices. Based on the full understandings of anion sublattice model, general design strategies for developing lithium superionic conductors were proposed. Adjusting the electronegativity difference between the anion element and non-Mobile Cation element by selecting the most suitable non-Mobile Cation element without changing the crystal structure sublattice can achieve low E<sub>a</sub> for lithium ion migration. For the desired lithium superionic conductors with tetrahedrally occupied lithium ions, the fine non-Mobile Cation element should give preferences to those elements located at the right top of the periodic table of elements with large electronegativities. For the lithium superionic conductors with octahedrally occupied lithium ions, the fine non-Mobile Cation element should give preferences to the elements located at the left bottom of the periodic table with small electronegativities.</a><br></p>
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Anion Charge and Lattice Volume Maps for Searching Lithium Superionic Conductors
2020Co-Authors: Hong ZhuAbstract:<p><a>The effects of anion charge and lattice volume (</a>lithium-anion bond length) on lithium ion migration have been investigated by utilizing the density functional theory calculations combined with the anion framework models, e.g. <i>fcc</i>, <i>hcp</i> and <i>bcc</i>. It is found that the anion charge and lattice volume have great impacts on the activation energy barrier (E<sub>a</sub>) of lithium ion migration, which is validated by some reported sulfides. For the tetrahedrally occupied lithium, the less negative anion charge is, the lower the lithium ion migration barrier is likely to be. While for the octahedrally occupied lithium, the more negative anion charge is, the lower the lithium ion migration barrier is. The large lattice volume (lithium-anion bond length) can lower E<sub>a</sub> to a certain extent. Lithium ion direct migrations along the direct <i>Tet</i>-<i>Tet</i> pathway in the <i>bcc-</i> or <i>hcp-type </i>anion framework are less sensitive to anion charge and lattice volume than other pathways. Most importantly, based on the full understandings of anion framework model, new design rules for developing alkali-metal superionic conductors were proposed. Getting the desired electronegativity difference between the anion element and non-Mobile Cation element by selecting the most suitable non-Mobile Cation element without changing the crystal structure framework can eventually achieve low E<sub>a</sub> for alkali-metal ion migration. For the desired alkali-metal superionic conductors with tetrahedrally occupied alkali-metal ions, the fine non-Mobile Cation element should give preferences to those elements located at the right top of the periodic table of elements with large electronegativities. For the alkali-metal superionic conductors with octahedrally occupied alkali-metal ions, the fine non-Mobile Cation element should give preferences to the elements located at the left bottom of the periodic table with small electronegativities.<br></p>
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Anion Charge-Lattice Volume Maps for Searching Lithium Superionic Conductors
2020Co-Authors: Hong ZhuAbstract:<p><a>The effects of anion charge and lattice volume (</a>lithium-anion bond length) on lithium ion migration have been investigated by utilizing the density functional theory calculations combined with the anion framework models, e.g. <i>fcc</i>, <i>hcp</i> and <i>bcc</i>. It is found that the anion charge and lattice volume have great impacts on the activation energy barrier (E<sub>a</sub>) of lithium ion migration, which is validated by some reported sulfides. For the tetrahedrally occupied lithium, the less negative anion charge is, the lower the lithium ion migration barrier is likely to be. While for the octahedrally occupied lithium, the more negative anion charge is, the lower the lithium ion migration barrier is. The large lattice volume (lithium-anion bond length) can lower E<sub>a</sub> to a certain extent. Lithium ion direct migrations along the direct <i>Tet</i>-<i>Tet</i> pathway in the <i>bcc-</i> or <i>hcp-type </i>anion framework are less sensitive to anion charge and lattice volume than other pathways. Most importantly, based on the full understandings of anion framework model, new design rules for developing alkali-metal superionic conductors were proposed. Getting the desired electronegativity difference between the anion element and non-Mobile Cation element by selecting the most suitable non-Mobile Cation element without changing the crystal structure framework can eventually achieve low E<sub>a</sub> for alkali-metal ion migration. For the desired alkali-metal superionic conductors with tetrahedrally occupied alkali-metal ions, the fine non-Mobile Cation element should give preferences to those elements located at the right top of the periodic table of elements with large electronegativities. For the alkali-metal superionic conductors with octahedrally occupied alkali-metal ions, the fine non-Mobile Cation element should give preferences to the elements located at the left bottom of the periodic table with small electronegativities.<br></p>
Hisahiko Einaga - One of the best experts on this subject based on the ideXlab platform.
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Electrical conduction mechanism in solid electrolytes with zirconium phosphate framework
Solid State Ionics, 1994Co-Authors: Shoichiro Ikeda, Katsuhiro Nomura, Kaname Ito, Hisahiko EinagaAbstract:Abstract The difference in the electrical conduction behavior of various kinds of MnZr2n(PO4)3n (Mn=alkali metals, alkaline earth metals, Ag, Mn, Co, Ni, Zn, Cd, Pb, Al, Ga, and In) compounds (abbreviated as MZP) has been investigated by using frequency dispersion analysis. The conductivity of MZP with a NASICON-type structure mainly depended on the hopping rate of Mobile Cation; the conductivity of MZP with a sFe2(SO2)3-type structure was more affected by the Mobile ion concentration than that with the NASICON-type one. These conclusions agree well with those obtained from crystallographic investigation.
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Ionic conduction behavior in zirconium phosphate framework
Solid State Ionics, 1993Co-Authors: Katsuhiro Nomura, Shoichiro Ikeda, Kaname Ito, Hisahiko EinagaAbstract:Abstract A series of M I Zr 2 (PO 4 ) 3 (M I ZP;M=Li, Na, K, Rb, Cs and Ag) solid electrolytes have been investigated. The crystallographic and electrochemical properties of M I ZP are compared with those of M II Zr 4 (PO 4 ) 6 (M II ZP). M I ZP and M II ZP crystallized in the NASICON- and β-Fe 2 (SO 4 ) 3 -structures: The crystal structure was determined by the size of the guest Cation. The ionic conductivity of the NASICON-type compound was highly sensitive to the size of the guest (i.e., Mobile) Cation, whereas that of the β- Fe 2 (SO 4 ) 3 -type one was slightly size-dependent. This difference is expected to arise from the difference in the nature of site in which Mobile Cation is accommodated; a six coordination site of the NASICON-type structure and a four coordination one of the β-Fe 2 (SO 4 ) 3 -type structure. M I ZP showed ca. two or three orders higher conductivity than M II ZP, when they have almost the same ionic radius of Mobile Cation. AgZP, CdZP, and BaZP, in which Mobile Cations have high polarizability, showed high conductivities for the size of the Mobile Cations.
Germa Garciabelmonte - One of the best experts on this subject based on the ideXlab platform.
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Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
Journal of Non-crystalline Solids, 2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Abstract Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 × 1016 cm−3 which is lower by many orders of magnitude than the nominal alkali concentration.
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letter to the editor Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 · 10 16 cm � 3 which is lower by many orders of magnitude than the nominal alkali concentration.
Ángeles Pitarch - One of the best experts on this subject based on the ideXlab platform.
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Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
Journal of Non-crystalline Solids, 2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Abstract Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 × 1016 cm−3 which is lower by many orders of magnitude than the nominal alkali concentration.
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Mobile Cation concentration in ionically conducting glasses calculated by means of Mott–Schottky capacitance–voltage characteristics
Journal of Non-crystalline Solids, 2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germà Garcia-belmonteAbstract:Abstract Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 × 1016 cm−3 which is lower by many orders of magnitude than the nominal alkali concentration.
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letter to the editor Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 · 10 16 cm � 3 which is lower by many orders of magnitude than the nominal alkali concentration.
Juan Bisquert - One of the best experts on this subject based on the ideXlab platform.
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Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
Journal of Non-crystalline Solids, 2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Abstract Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 × 1016 cm−3 which is lower by many orders of magnitude than the nominal alkali concentration.
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Mobile Cation concentration in ionically conducting glasses calculated by means of Mott–Schottky capacitance–voltage characteristics
Journal of Non-crystalline Solids, 2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germà Garcia-belmonteAbstract:Abstract Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 × 1016 cm−3 which is lower by many orders of magnitude than the nominal alkali concentration.
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letter to the editor Mobile Cation concentration in ionically conducting glasses calculated by means of mott schottky capacitance voltage characteristics
2003Co-Authors: Ángeles Pitarch, Juan Bisquert, Germa GarciabelmonteAbstract:Charge carrier concentration in ionically conducting glasses is a determining parameter for a meaningful interpretation of processes underlying ionic diffusion in terms of different theories and models. We suggest that Mobile ion density can be readily calculated from the bias voltage modulation of the space–charge built at the metal–glass interfaces. This effect may be modeled by using Mott–Schottky capacitance–voltage characteristics as those encountered in contacts of electronic systems. Conductivity and permittivity spectra of Na2O–0.4Al2O3–2.2SiO2 glasses were measured as a function of temperature and bias voltage showing the electrode polarization effect. We found that carrier concentration lies within the range 3–4 · 10 16 cm � 3 which is lower by many orders of magnitude than the nominal alkali concentration.