Transference Number (transference + number)

Distribution by Scientific Domains

Kinds of Transference Number

  • ion transference number


  • Selected Abstracts


    Solid Composite Polymer Electrolytes with High Cation Transference Number

    ISRAEL JOURNAL OF CHEMISTRY, Issue 3-4 2008
    Hadar Mazor
    This work presents the electrochemical and structural study of the dual modified composite LiBOB-based polymer electrolyte. Modification has been carried out by calix[6]pyrrole (CP) anion trap and nanosize silica filler. The main advantage of the use of LiBOB salt is the high ionic conductivity at near-ambient temperatures and low solid-electrolyte interphase (SEI) resistance. The conductivity of LiBOB:PEO20:CP0.125 with SiO2 is slightly lower than 10,5 Scm,1 at 30 °C, a value higher by about two orders of magnitude than that of the semi-crystalline LiCF3SO3 (LiTf)-PEO system. At 75 to 90 °C the bulk ionic conductivity of modified LiBOB polymer electrolyte approaches 1 mScm,1. The transference number of dual-modified LiBOB-polymer electrolyte is about 0.8 at 75 °C. Cyclic voltammetry tests showed a wide electrochemical stability window of the composite polymer electrolyte. The peak power of Li/MoOxSy cell with the polymer electrolyte film containing CP and SiO2 reaches 2.2 mW/cm2 and 3.0 mW/cm2 at 90 and 110 °C, respectively. [source]


    ChemInform Abstract: Determination of the Sodium Ion Transference Number of the Dion,Jacobson-Type Layered Perovskite NaCa2Nb3O10 Using ac Impedance and dc Methods.

    CHEMINFORM, Issue 24 2002
    V. Thangadurai
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Capacity Fading Mechanism in All Solid-State Lithium Polymer Secondary Batteries Using PEG-Borate/Aluminate Ester as Plasticizer for Polymer Electrolytes

    ADVANCED FUNCTIONAL MATERIALS, Issue 6 2009
    Fuminari Kaneko
    Abstract Solid-state lithium polymer secondary batteries (LPB) are fabricated with a two-electrode-type cell construction of Li|solid-state polymer electrolyte (SPE)|LiFePO4. Plasticizers of poly(ethylene glycol) (PEG)-borate ester (B-PEG) or PEG-aluminate ester (Al-PEG) are added into lithium-conducting SPEs in order to enhance their ionic conductivity, and lithium bis-trifluoromethansulfonimide (LiTFSI) is used as the lithium salt. An improvement of the electrochemical properties is observed upon addition of the plasticizers at an operation temperature of 60,°C. However, a decrease of discharge capacities abruptly follows after tens of stable cycles. To understand the origin of the capacity fading, electrochemical impedance techniques, ex-situ NMR and scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) techniques are adopted. Alternating current (AC) impedance measurements indicate that the decrease of capacity retention in the LPB is related to a severe increase of the interfacial resistance between the SPE and cathode. In addition, the bulk resistance of the SPE film is observed to accompany the capacity decay. Ex situ NMR studies combined with AC impedance measurements reveal a decrease of Li salt concentration in the SPE film after cycling. Ex situ SEM/EDS observations show an increase of concentration of anions on the electrode surface after cycling. Accordingly, the anions may decompose on the cathode surface, which leads to a reduction of the cycle life of the LPB. The present study suggests that a choice of Li salt and an increase of transference number is crucial for the realization of lithium polymer batteries. [source]


    Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium-ion battery

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010
    Xiaoyuan Yu
    Abstract The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium-ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the Tg and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10,3 S cm,1 at room temperature and 1.42 × 10,2 S cm,1 at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3O2 cell were evaluated at a current rate of 0.1C and in voltage range of 2.8,4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3 O2 cell is 115.3 mAh g,1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


    Lewis acid,base property of P(VDF- co -HFP) measured by inverse gas chromatography

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008
    Baoli Shi
    Abstract Poly (vinylidene fluoride- co -hexafluoropropylene) P(VDF- co -HFP) is an excellent material for polymer electrolytes of lithium ion battery. To enhance the lithium ion transference number, some metal oxides were often embedded into P(VDF- co -HFP). The promising mechanism for the increase in lithium ionic conductivity was Lewis acid-base theory. In this experiment, the Lewis acid,base properties of P(VDF- co -HFP) were measured by inverse gas chromatography (IGC). The Lewis acid constant Ka of P(VDF- co -HFP) is 0.254, and the base constant Kb is 1.199. Compared with other polymers characterized by IGC, P(VDF- co -HFP) is the strongest Lewis basic polymers. Except aluminum ion, lithium ion is the strongest Lewis acidic ion according to their , value of Lewis acids. Therefore, a strong Lewis acid,base interaction will exist between lithium ion and P(VDF- co -HFP). This will restrict the transference of lithium ion in P(VDF- co -HFP). To enhance the lithium ion transference by blending other metal ions into P(VDF- co -HFP), it is suggested that the preferential ions should be Al3+, Mg2+, Na+, and Ca2+ because these metal ions have relative large , values. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


    Structure, electrical and optical properties of (PVA/LiAsF6) polymer composite electrolyte films

    POLYMER ENGINEERING & SCIENCE, Issue 5 2010
    Madhu Mohan Varishetty
    In this work, Li+ ion conducting polymer composite electrolyte films (PECs) were prepared based on poly (vinyl alcohol) (PVA), lithium hexafluoro arsenate (LiAsF6), and ceramic filler TiO2 using solution cast technique. The XRD and FTIR spectra were used to determine the complexation of the PVA polymer with LiAsF6 salt. The ionic conductivities of the (PVA + LiAsF6) and (PVA + LiAsF6 + TiO2) films have been determined by the A.C. impedance measurements in the temperature range 320,440 K. The maximum conductivity was found to be 5.10 × 10,4 S cm,1 for PVA:LiAsF6 (75:25) + 5 wt% TiO2 polymer composite film at 320 K. The calculation of Li+ ion transference number was carried out by the combination of A.C. impedance and D.C. polarization methods and is found to be 0.52 for PVA:LiAsF6 (75:25) + 5 wt% TiO2 film. Optical properties such as direct energy gap, indirect energy gap, and optical absorption edge values were investigated in pure PVA and salt complexed PVA films from their optical absorption spectra in the wavelength range of 200,600 nm. The absorption edge was found at 5.76 eV for undoped film, while it is observed at 4.87 and 4.70 eV for 20 and 25 wt% LiAsF6 doped films, respectively. The direct band gaps for these undoped and salt doped PVA films were found to be 5.40, 5.12, and 4.87 eV, respectively, whereas the indirect band gaps were determined as 4.75, 4.45, and 4.30 eV. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers [source]


    Crystallinity, thermal properties, morphology and conductivity of quaternary plasticized PEO-based polymer electrolytes

    POLYMER INTERNATIONAL, Issue 3 2007
    Yan-Jie Wang
    Abstract Quaternary plasticized solid polymer electrolyte (SPE) films composed of poly(ethylene oxide), LiClO4, Li1.3Al0.3Ti1.7(PO4)3, and either ethylene carbonate or propylene carbonate as plasticizer (over a range of 10,40 wt%) were prepared by a solution-cast technique. X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) indicated that components such as LiClO4 and Li1.3Al0.3Ti1.7(PO4)3 and the plasticizers exerted important effects on the plasticized quaternary SPE systems. XRD analysis revealed the influence from each component on the crystalline phase. DSC results demonstrated the greater flexibility of the polymer chains, which favored ionic conduction. SEM examination revealed the smooth and homogeneous surface morphology of the plasticized polymer electrolyte films. EIS suggested that the temperature dependence of the films' ionic conductivity obeyed the Vogel,Tamman,Fulcher (VTF) relation, and that the segmental movement of the polymer chains was closely related to ionic conduction with increasing temperature. The pre-exponential factor and pseudo activation energy both increased with increasing plasticizer content and were maximized at 40 wt% plasticizer content. The charge transport in all polymer electrolyte films was predominantly reliant on lithium ions. All transference numbers were less than 0.5. Copyright © 2006 Society of Chemical Industry [source]


    Theory of Ion Transport in Electrochemically Switchable Nanoporous Metallized Membranes

    CHEMPHYSCHEM, Issue 1 2009
    Christian Amatore Dr.
    Abstract A physicomathematical model of ion transport through a synthetic electrochemically switchable membrane with nanometric metal-plated pores is presented. Due to the extremely small size of the cylindrical pores, electrical double layers formed inside overlap, and thus, strong electrostatic fields whose intensities vary across the cross-sections of the nanopores are created. Based on the proposed model a relationship between the relative electrostatic energies experienced by ions in the nanopores and the potential applied to the membrane is established. This allows the prediction of transference numbers and explains quantitatively the ion-transport switching capability of such synthetic membranes. The predictions of this model agree satisfactorily with previous experimental data obtained for this type of devices by Martin and co-workers. [source]