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Xi Yao - One of the best experts on this subject based on the ideXlab platform.

  • Low loss flexible SrTiO3/POE dielectric composites for microwave application
    Journal of Electroceramics, 2008
    Co-Authors: Feng Xiang, Hong Wang, Haibo Yang, Ziyuan Shen, Xi Yao
    Abstract:

    Flexible, high dielectric constant and low dielectric loss composites for microwave application fabricated with SrTiO3 (STO) Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix have been studied in this paper. The dielectric property and the mechanical property of STO/POE composites filled with different volume fraction of Ceramic Filler were investigated. The results indicated that with the increase volume fraction of Ceramic Filler, both the permittivity and the dielectric loss of composites increased. Good frequency stability within a wide range was observed in all the samples. For the composites containing 40 vol% STO, the composites has a tensile strength of 2.75 MPa with an elongation of about 90% at break value. The permittivity and the dielectric loss of the composites were 11.0 and 0.01 in microwave frequency, respectively. A microstrip transmission line on the composites containing 40 vol% STO as a microwave substrate is designed and measured after bending at different angles, meanwhile the transmission coefficients of the microstrip transmission line were unchanged when bending angle is less than 60°. This indicates that the STO/POE composites have the promising characteristics for potential applications in microwave substrate, flexible dielectric waveguide and related flexible microwave devices.

  • Frequency-temperature compensation mechanism for bismuth based dielectric/PTFE microwave composites
    Journal of Electroceramics, 2007
    Co-Authors: Feng Xiang, Hong Wang, Mei Ling Zhang, Xi Yao
    Abstract:

    The dielectric property and thermal expansion property of Bi2O3-ZnO-Nb2O3-based (BZN) Ceramics Filler reinforced composites have been investigated as a function of temperature range from −50 to 175 °C. The composites with adjustable temperature coefficient of frequency (τ f ) and dielectric temperature coefficient (\( \alpha _{\varepsilon } \)) are achieved by filling the Ceramic Filler with different \( \alpha _{\varepsilon } \) into polymer matrix. A series of polytetrafluoroethylene (PTFE) based composites blended with different amount of Ceramic Filler with different \( \alpha _{\varepsilon } \) have been studied in this paper. The results indicated that with the amount of Ceramic Filler increasing, both of the relative permittivity and dissipation factor of composites increased. Composite filled with positive \( \alpha _{\varepsilon } \) (245 ppm/°C) BZN Ceramic Filler (40 vol.%) has low \( \alpha _{\varepsilon } \) (22 ppm/°C), while filled with near-zero \( \alpha _{\varepsilon } \) (10 ppm/°C) BZN Ceramic Filler (40 vol.%) have low τ f (−5 ppm/°C).

  • dielectric properties of srtio3 poe flexible composites for microwave applications
    Journal of The European Ceramic Society, 2007
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

  • dielectric properties of srtio3 poe flexible composites for microwave applications
    Journal of The European Ceramic Society, 2007
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

  • Dielectric properties of SrTiO3/POE flexible composites for microwave applications
    Journal of The European Ceramic Society, 2006
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

Hun Joon Sohn - One of the best experts on this subject based on the ideXlab platform.

  • Ferroelectric Materials as a Ceramic Filler in Solid Composite Polyethylene Oxide‐Based Electrolytes
    Journal of The Electrochemical Society, 2000
    Co-Authors: Yasuo Takeda, Nobuyuki Imanishi, O. Yamamoto, Hun Joon Sohn
    Abstract:

    The electrochemical properties of mixed-phase composite electrolytes based on poly(ethylene oxide) (PEO), lithium salts (LiClO 4 , LiBF 4 , LiPF 6 , LiCF 3 SO 3 , and Li[(CF 3 SO 2 ) 2 N]), and ferroelectric materials (BaTiO 3 , PbTiO 3 , and LiNbO 3 ) have been studied. The ion-conduction and lithium-ion transference numbers of the composite polymer electrolytes were enhanced by the addition of these ferroelectric materials as a Ceramic Filler. The conductivity behavior of the composite electrolyte depended on the combination of lithium salt and the ferroelectric materials. The conductivity enhancement in the PEO-LiX composite electrolytes with ferroelectric materials was rationalized by correlating the association tendency of anions with lithium cations and the spontaneous polarization of the ferroelectric Ceramics due to their particular crystal structure. The combined addition of rutile type TiO 2 and BaTiO 3 assured long-term interfacial stability. All the electrolytes studied here showed decomposition potentials higher than 4 V vs. Li/Li + .

  • ferroelectric materials as a Ceramic Filler in solid composite polyethylene oxide based electrolytes
    Journal of The Electrochemical Society, 2000
    Co-Authors: H. Y. Sun, Yasuo Takeda, Nobuyuki Imanishi, O. Yamamoto, Hun Joon Sohn
    Abstract:

    The electrochemical properties of mixed‐phase composite electrolytes based on poly(ethylene oxide) (PEO), lithium salts , and ferroelectric materials have been studied. The ion‐conduction and lithium‐ion transference numbers of the composite polymer electrolytes were enhanced by the addition of these ferroelectric materials as a Ceramic Filler. The conductivity behavior of the composite electrolyte depended on the combination of lithium salt and the ferroelectric materials. The conductivity enhancement in the PEO‐LiX composite electrolytes with ferroelectric materials was rationalized by correlating the association tendency of anions with lithium cations and the spontaneous polarization of the ferroelectric Ceramics due to their particular crystal structure. The combined addition of rutile type and assured long‐term interfacial stability. All the electrolytes studied here showed decomposition potentials higher than 4V vs. . © 2000 The Electrochemical Society. All rights reserved.

  • Ferroelectric Materials as a Ceramic Filler in Solid Composite Polyethylene Oxide‐Based Electrolytes
    Journal of The Electrochemical Society, 2000
    Co-Authors: H. Y. Sun, Yasuo Takeda, Nobuyuki Imanishi, O. Yamamoto, Hun Joon Sohn
    Abstract:

    The electrochemical properties of mixed‐phase composite electrolytes based on poly(ethylene oxide) (PEO), lithium salts , and ferroelectric materials have been studied. The ion‐conduction and lithium‐ion transference numbers of the composite polymer electrolytes were enhanced by the addition of these ferroelectric materials as a Ceramic Filler. The conductivity behavior of the composite electrolyte depended on the combination of lithium salt and the ferroelectric materials. The conductivity enhancement in the PEO‐LiX composite electrolytes with ferroelectric materials was rationalized by correlating the association tendency of anions with lithium cations and the spontaneous polarization of the ferroelectric Ceramics due to their particular crystal structure. The combined addition of rutile type and assured long‐term interfacial stability. All the electrolytes studied here showed decomposition potentials higher than 4V vs. . © 2000 The Electrochemical Society. All rights reserved.

B Scrosati - One of the best experts on this subject based on the ideXlab platform.

  • enhanced lithium battery with polyethylene oxide based electrolyte containing silane al2o3 Ceramic Filler
    Chemsuschem, 2013
    Co-Authors: Berhanu Zewde, Shimelis Admassie, Jutta Zimmermann, Christian Schulze Isfort, B Scrosati, Jusef Hassoun
    Abstract:

    A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF3 SO3 salt, and silane-treated Al2 O3 (Al2 O3 -ST) Ceramic Filler. The effects of the Ceramic Fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO4 cathode. We demonstrate that the membrane containing Al2 O3 -ST Ceramic Filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO4 electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al2 O3 -ST Ceramic can be efficiently used as a Ceramic Filler to enhance the performance of solid polymer electrolytes in lithium batteries.

  • High performance PEO-based polymer electrolytes and their application in rechargeable lithium polymer batteries
    Ionics, 2007
    Co-Authors: H. H. Sumathipala, J. Hassoun, S. Panero, B Scrosati
    Abstract:

    Solvent-free, lithium-ion-conducting, composite polymer electrolytes have been prepared by a double dispersion of an anion trapping compound, i.e., calyx(6)pyrrole, CP and a Ceramic Filler, i.e., super acid zirconia, S-ZrO_2 in a poly(ethylene oxide)-lithium bis(oxalate) borate, PEO–LiBOB matrix. The characterization, based on differential thermal analysis and electrochemical analysis, showed that while the addition of the S-ZrO_2 has scarce influence on the transport properties of the composite electrolyte, the unique combination of the anion-trapping compound, CP, with the large anion lithium salt, LiBOB, greatly enhances the value of the lithium transference number without depressing the overall ionic conductivity. These unique properties make polymer electrolytes, such as PEO_20LiBOB(CP)_0.125, of practical interest, as in fact confirmed by tests carried out on lithium battery prototypes.

  • advanced lithium batteries based on high performance composite polymer electrolytes
    Journal of Power Sources, 2006
    Co-Authors: F Croce, S Sacchetti, B Scrosati
    Abstract:

    Abstract Progress in lithium battery technology may be achieved by passing from a conventional liquid electrolyte structure to a solid-state, polymer configuration. In this prospect, great RD F. Croce, S. Sacchetti, B. Scrosati, J. Power Sources, in press [2] ], we have shown that composite membranes based on blends between poly(ethylene oxide) and lithium salts with the dispersion of functionalized ZrO2 Ceramic Filler, have unique transport and interfacial properties. In this paper, we complete the study of these advanced polymer electrolytes by evaluating their use in rechargeable lithium batteries. The results confirm the practical interest of these electrolytes which appear to be suitable for the fabrication of batteries directed to application in emerging technologies, such as those associated to hybrid and electric vehicles.

  • advanced high performance composite polymer electrolytes for lithium batteries
    Journal of Power Sources, 2006
    Co-Authors: F Croce, S Sacchetti, B Scrosati
    Abstract:

    Abstract Progress in lithium battery technology may be achieved by passing from a conventional liquid electrolyte structure to a solid-state, polymer configuration. In this prospect, great R&D effort has been devoted to the development of suitable lithium conducting polymer electrolytes. The most promising results have been obtained with systems based on blends between poly(ethylene oxide) and lithium salts. In this work we show that the transport and interfacial properties of these electrolytes may be greatly enhanced by the dispersion of a Ceramic Filler having an unique surface state condition. The results, in addition to their practical reflection in the lithium polymer electrolyte battery technology, also provide a valid support to the model which ascribes the enhancement of the transport properties of Ceramic-added composites to the specific Lewis acid–base interactions between the Ceramic surface states and both the lithium salt anion and the PEO-chains .

  • role of the Ceramic Fillers in enhancing the transport properties of composite polymer electrolytes
    Electrochimica Acta, 2001
    Co-Authors: F Croce, B Scrosati, L Persi, F Serrainofiory, Edward J Plichta, Mary A Hendrickson
    Abstract:

    A model to account for the role of the Ceramic Fillers in enhancing the transport properties of PEO-based composite polymer electrolytes is here proposed. The model is supported by a series of specifically addressed electrochemical tests which included the determination of the conductivity and of the lithium transference number of various composite electrolyte samples differing from the type of the surface states of the Ceramic Filler.

Feng Xiang - One of the best experts on this subject based on the ideXlab platform.

  • Low loss flexible SrTiO3/POE dielectric composites for microwave application
    Journal of Electroceramics, 2008
    Co-Authors: Feng Xiang, Hong Wang, Haibo Yang, Ziyuan Shen, Xi Yao
    Abstract:

    Flexible, high dielectric constant and low dielectric loss composites for microwave application fabricated with SrTiO3 (STO) Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix have been studied in this paper. The dielectric property and the mechanical property of STO/POE composites filled with different volume fraction of Ceramic Filler were investigated. The results indicated that with the increase volume fraction of Ceramic Filler, both the permittivity and the dielectric loss of composites increased. Good frequency stability within a wide range was observed in all the samples. For the composites containing 40 vol% STO, the composites has a tensile strength of 2.75 MPa with an elongation of about 90% at break value. The permittivity and the dielectric loss of the composites were 11.0 and 0.01 in microwave frequency, respectively. A microstrip transmission line on the composites containing 40 vol% STO as a microwave substrate is designed and measured after bending at different angles, meanwhile the transmission coefficients of the microstrip transmission line were unchanged when bending angle is less than 60°. This indicates that the STO/POE composites have the promising characteristics for potential applications in microwave substrate, flexible dielectric waveguide and related flexible microwave devices.

  • Frequency-temperature compensation mechanism for bismuth based dielectric/PTFE microwave composites
    Journal of Electroceramics, 2007
    Co-Authors: Feng Xiang, Hong Wang, Mei Ling Zhang, Xi Yao
    Abstract:

    The dielectric property and thermal expansion property of Bi2O3-ZnO-Nb2O3-based (BZN) Ceramics Filler reinforced composites have been investigated as a function of temperature range from −50 to 175 °C. The composites with adjustable temperature coefficient of frequency (τ f ) and dielectric temperature coefficient (\( \alpha _{\varepsilon } \)) are achieved by filling the Ceramic Filler with different \( \alpha _{\varepsilon } \) into polymer matrix. A series of polytetrafluoroethylene (PTFE) based composites blended with different amount of Ceramic Filler with different \( \alpha _{\varepsilon } \) have been studied in this paper. The results indicated that with the amount of Ceramic Filler increasing, both of the relative permittivity and dissipation factor of composites increased. Composite filled with positive \( \alpha _{\varepsilon } \) (245 ppm/°C) BZN Ceramic Filler (40 vol.%) has low \( \alpha _{\varepsilon } \) (22 ppm/°C), while filled with near-zero \( \alpha _{\varepsilon } \) (10 ppm/°C) BZN Ceramic Filler (40 vol.%) have low τ f (−5 ppm/°C).

  • dielectric properties of srtio3 poe flexible composites for microwave applications
    Journal of The European Ceramic Society, 2007
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

  • dielectric properties of srtio3 poe flexible composites for microwave applications
    Journal of The European Ceramic Society, 2007
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

  • Dielectric properties of SrTiO3/POE flexible composites for microwave applications
    Journal of The European Ceramic Society, 2006
    Co-Authors: Feng Xiang, Hong Wang, Xi Yao
    Abstract:

    Abstract Composites fabricated with SrTiO3 Ceramic Filler dispersed inside a thermoplastic polyolefin elastomer (POE) polymer matrix, with excellent dielectric properties and good flexibility, have been studied in this paper. The relative permittivity of SrTiO3/POE composites blended with different volume fraction of Ceramic Filler was investigated as a function of temperature and frequency. The results indicated that with the increase of Ceramic Filler, both the relative permittivity and the dissipation factor of composites increased. Good frequency stability within a wide range was observed in all the samples. The theoretical dielectric constant obtained from the effective medium theory of Bruggeman's model is in good agreement with the experimental data. For the composites containing 40 vol.% SrTiO3, the dielectric constant and the loss tangent were 11.0 and 0.01 at 900 MHz, respectively, while the mechanical test results showed good flexibility on the final quality of the composites with the elongation of 90%. This indicates that the ST/POE composites have the promising characteristics for potential applications in the flexible dielectric waveguide and related flexible microwave devices.

B. V. R. Chowdari - One of the best experts on this subject based on the ideXlab platform.

  • effect of glass Ceramic Filler on properties of polyethylene oxide licf3so3 complex
    Journal of Power Sources, 2003
    Co-Authors: C. J. Leo, G Subba V Rao, Awalendra K Thakur, B. V. R. Chowdari
    Abstract:

    Abstract Lithium-ion conducting composite polymer electrolytes (CPE),(PEO)8–LiCF3SO3 (PEO=polyethylene oxide) dispersed with a glass–Ceramic, Li1.4[Al0.4Ge1.6(PO4)3] as a Filler have been prepared as films and their thermal, mechanical, electrical and electrochemical properties have been studied. The glass transition temperature increases with Filler addition reaches a maximum value of −39 °C for x=7.5 wt.%, and then decreases. Enhancement in the electrochemical stability of the films is noted; a maximum working voltage of 3.75 V is found at x=10 wt.%. Addition of Filler decreases the ionic conductivity for x=7.5 wt.%, σ=1.6×10−7 S cm−1 which is a factor three lower than that for the PS complex. The Ea and log10(σ0) values of the composite polymer electrolytes consistently decrease with increasing x. The mechanical properties are enhanced with Filler addition, a maximum tensile strength of 22.8 MPa, is obtained at x=7.5–10 wt.%, a value which is three times higher than that for the PS complex.

  • studies on plasticized peo lithium triflate Ceramic Filler composite electrolyte system
    Solid State Ionics, 2002
    Co-Authors: C. J. Leo, G Subba V Rao, B. V. R. Chowdari
    Abstract:

    Composite polymer electrolytes (CPEs), polyethylene oxide (PEO)+Li triflate with Li Nasicompound [Li1.4(Al0.4Ge1.6)(PO4)3] as the Ceramic Filler and EC+PC as the plasticizer, have been studied as thin films. Their crystallinity, thermal behaviour, mechanical strength, ionic conductivity, interfacial stability and Li(1s) XPS binding energies (BEs) have been examined. Changes in Tg, melting temperatures (Tm1 and Tm2), tensile strength (TS) and maximum elongation at break of the CPE films have been studied as a function of different wt.% plasticizer. With the addition of plasticizer, an order of magnitude increase in the ionic conductivity was obtained for temperature T<60 °C. The σ−T data of the CPEs have been fitted to either Arrhenius-type or Vogel–Tamman–Fulcher (VTF)-type behaviour depending on the T range and plasticizer content. Interfacial stability was found to be enhanced with the addition of plasticizer. The variation in the Li(1s) binding energies correlates well with that of σ values. Present study shows that CPEs with 5–10 wt.% plasticizer exhibit the optimum performance.

  • Studies on plasticized PEO–lithium triflate–Ceramic Filler composite electrolyte system ☆
    Solid State Ionics, 2002
    Co-Authors: C. J. Leo, G. V. Subba Rao, B. V. R. Chowdari
    Abstract:

    Composite polymer electrolytes (CPEs), polyethylene oxide (PEO)+Li triflate with Li Nasicompound [Li1.4(Al0.4Ge1.6)(PO4)3] as the Ceramic Filler and EC+PC as the plasticizer, have been studied as thin films. Their crystallinity, thermal behaviour, mechanical strength, ionic conductivity, interfacial stability and Li(1s) XPS binding energies (BEs) have been examined. Changes in Tg, melting temperatures (Tm1 and Tm2), tensile strength (TS) and maximum elongation at break of the CPE films have been studied as a function of different wt.% plasticizer. With the addition of plasticizer, an order of magnitude increase in the ionic conductivity was obtained for temperature T