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Golmon, Stephanie; Maute, Kurt; Dunn, Martin L. Numerical modeling of electrochemical-mechanical interactions in lithium polymer batteries //COMPUTERS & STRUCTURES Volume: 87 Issue: 23-24 Pages: 1567-1579 Published: DEC 2009 - Web of Science

This paper presents a multi-scale finite element approach for lithium batteries to study electrochemical-mechanical interaction phenomena at macro- and micro-scales. The battery model consists of a lithium foil anode, a separator, and a porous cathode that includes solid active materials and a liquid electrolyte. We develop a multi-scale approach to analyze the surface kinetics and electrochemical-mechanical phenomena within a single spherical particle of the active material. Homogenization techniques relate parameters in the micro-scale particle model to those in the macro-scale model describing the lithium ion transport, electric potentials and mechanical response based on porous electrode theory. (c) 2009 Elsevier Ltd. All rights reserved.

Guan, Hong-yan; Lian, Fang; Xi, Kai; et al. Polyvinyl formal based gel polymer electrolyte prepared using initiator free in-situ thermal polymerization method //JOURNAL OF POWER SOURCES Volume: 245 Pages: 95-100 Published: JAN

Novel polyvinyl formal (PVFM) based gel polymer electrolytes (GPEs) are developed using an initiator free thermal polymerization method. The polymerization mechanism during the cross-linking process is investigated by means of Fourier transform infrared (FTIR) spectroscopy measurements. With the prepared GPEs (containing 2 to 5 wt % PVFM), Li polymer batteries with LiFePO4 as the cathode are assembled, and the electrochemical properties such as interfacial impedance, electrochemical stability window and cycling performance are evaluated. The resulting PVFM based GPEs present a better thermal stability compared with the corresponding conventional liquid electrolyte and an acceptable conductivity of similar to 10(-3) S cm(-1) at ambient temperatures. Cyclic voltammetric (CV) curves reveal that the electrochemical stability window of PVFM based GPE is 1.5-5V vs. Li/Li+ and wider than that for the corresponding liquid electrolyte which is 1.8-4.4 V. The discharge capacity of the polymer Li/LiFePO4 battery is 145 mAh g(-1) over a voltage range of 2.5-4.25 V at 1/10 C rate after 80 cycles with a small capacity fade. (C) 2013 Elsevier B.V. All rights reserved.

Xiao, Meng; Choe, Song-Yul Theoretical and experimental analysis of heat generations of a pouch type LiMn2O4/carbon high power Li-polymer battery // JOURNAL OF POWER SOURCES Volume: 241 Pages: 46-55 Published: NOV 1 2013 - Web of Science

Charge transport and chemical reactions during charging and discharging of a battery produce heat that determines temperature behaviors. The elevated temperature causes undesired side reactions that accelerate degradation and potentially result in catastrophic operating conditions like a thermal runaway. The heat generated in an operating battery is generally approximated by the sum of the reversible and irreversible heat. The reversible heat is produced by the change of entropy. The irreversible heat is approximated by either the overpotential heating or Ohmic and reaction heating. Most studies have compared the surface temperature with tuned convection coefficients, but not investigated the heat generation directly. A study conveyed shows that two other heat source terms, enthalpy heating and heat of mixing, should be included to accurately and completely describe the heat generation. The first one is caused by diffusion of lithium ions in the solid phase and the second one by change of the gradient of ion concentrations. An electrochemical thermal model including these additional terms is experimentally validated against calorimetric measurements on a 15.7 Ah LiMn2O4/carbon pouch type power cell using a specially designed calorimeter. (C) 2013 Elsevier B.V. All rights reserved.

Ali, A. M. M.; Subban, R. H. Y.; Bahron, H.; et al. Investigation on modified natural rubber gel polymer electrolytes for lithium polymer battery // JOURNAL OF POWER SOURCES Volume: 244 Special Issue: SI Pages: 636-640 Published: DEC 15 2013 - Web of Science

Non-aqueous gel polymer electrolytes (GPEs) consisting of 30% poly(methyl methacrylate)-grafted natural rubber (MG30), lithium triflate (LiTf), and ethylene carbonate (EC) dissolved in tetrahydrofuran are examined as electrolytes for lithium polymer batteries. The AC impedance technique is employed at room and elevated temperatures in the frequency range between 0.1 kHz and 1.0 MHz to optimize the conductivity of MG30-LiTf samples. The membrane containing 35 wt.% of LiTf is found to exhibit the highest ionic conductivity. The introduction of EC resulted in increased ionic conductivity of up to 8.95 x 10(-3) S cm(-1) at room temperature for the composition MG30(15):LiTf(9):EC(76). The temperature dependence conductivity for all systems studied is of the Vogel-Tamman-Fulcher type. Attenuated total reflectance-Fourier transformed infrared spectroscopic analysis suggested that EC penetrated between the polymer chains without perturbing the complexation that occurred between the polymer and lithium salt. The Li/Li+ interface stability is established to withstand voltages greater than 4.2 V. A lithium polymer half-cell is successfully fabricated using MG30-based GPE and the cell with configuration of Li/MG30:LiTf:EC/LiCoO2 is found to show good cycling efficiency at room temperature. (C) 2013 Elsevier B.V. All rights reserved.

Corbo, P.; Migliardini, F.; Veneri, O. Lithium polymer batteries and proton exchange membrane fuel cells as energy sources in hydrogen electric vehicles //JOURNAL OF POWER SOURCES Volume: 195 Issue: 23 Pages: 7849-7854 Published: DEC 1 2010

This paper deals with the application of lithium ion polymer batteries as electric energy storage systems for hydrogen fuel cell power trains. The experimental study was firstly effected in steady state conditions, to evidence the basic features of these systems in view of their application in the automotive field, in particular charge-discharge experiments were carried at different rates (varying the current between 8 and 100 A). A comparison with conventional lead acid batteries evidenced the superior features of lithium systems in terms of both higher discharge rate capability and minor resistance in charge mode. Dynamic experiments were carried out on the overall power train equipped with PEM fuel cell stack (2 kW) and lithium batteries (47.5V, 40 Ah) on the European R47 driving cycle. The usage of lithium ion polymer batteries permitted to follow the high dynamic requirement of this cycle in hard hybrid configuration, with a hydrogen consumption reduction of about 6% with respect to the same power train equipped with lead acid batteries. (C) 2009 Elsevier B.V. All rights reserved.

Hanyu, Yuki; Ganbe, Yoshiyuki; Honma, Itaru Application of quinonic cathode compounds for quasi-solid lithium batteries //JOURNAL OF POWER SOURCES Volume: 221 Pages: 186-190 Published: JAN 1 2013

Solid-state cells are one of the strongest candidate designs for utilisation of renewable high-capacity organic cathode materials. Following our previous work on tetracyanoquinodimethane, further high-capacity quinonic compounds, namely dichlorodicyanobenzoquinone, tetrahydroxybenzoquinone and dihydroxybenzoquinone were investigated. Cell cycling experiments indicated that these compounds undergo reversible redox reaction with significantly less cyclic capacity decay. 3.4 V of cell voltage was attainable from DDQ cells and capacities exceeding 250 mAh g(-1) were obtained from THBQ and DHBQ. These results reassure that by adopting an appropriate battery design, cycleability of organic cathodes can be drastically improved and they can be exploited as low-cost environmentally friendly high energy-density cathode materials. (C) 2012 Elsevier B.V. All rights reserved.

Hashem, A. M. A.; Abdel-Ghany, A. E.; Eid, A. E.; et al. Study of the surface modification of LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion battery //JOURNAL OF POWER SOURCES Volume: 196 Issue: 20 Pages: 8632-8637 Published: OCT 15 2011 -Web of Science

anced by 20% for post-treated LNMCO particles at 600 degrees C for half-an-hour. (C) 2011 Elsevier B.V. All rights reserved. The surface of LiNi1/3Co1/3Mn1/3O2 (LNMCO) particles has been studied for material synthesized at 900 degrees C by a two-step process from a mixture of LiOH center dot H2O and metal oxalate [(Ni1/3Co1/3Mn1/3)C2O4] obtained by co-precipitation. Samples have been characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), Raman scattering (RS) spectroscopy, and magnetic measurements. We have investigated the effect of the heat treatment of particles at 600 degrees C with organic substances such as sucrose and starch. HRTEM images and RS spectra indicate that the surface of particles has been modified. The annealing does not lead to any carbon coating but it leads to the crystallization of the thin disordered layer on the surface of LiNi1/3Co1/3Mn1/3O2. The beneficial effect has been tested on the electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 cathode materials. The capacity at 10C-rate is enh

Huang, Qian; Cosimbescu, Lelia; Koech, Phillip; et al. Composite organic radical-inorganic hybrid cathode for lithium-ion batteries //JOURNAL OF POWER SOURCES Volume: 233 Pages: 69-73 Published: JUL 1 2013 - Web of Science

A new organic radical-inorganic hybrid cathode comprised of poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA)/LiFePO4 composite system was developed and reported for the first time. The hybrid electrodes' voltammetry contains three pairs of reversible redox peaks indicating the combination of electrochemical characteristics between LiFePO4 and PTMA electrodes and shows a decrease in voltage gap between oxidation and reduction that corresponds to an improvement in the rate and reversibility of the redox couples. Results from electrochemical impedance spectroscopy show lower charge-transfer resistance of cycled hybrid cathodes suggesting an enhanced electrode/electrolyte interface formed in hybrid systems which leads to faster migration of Li ions through the interface and longer cycle life capability when compared with pure LiFePO4 or PTMA cathode system. Optimizing the hybrid cathode's ratio of PTMA/LiFePO4 yields a significant improvement in high pulse power performance (30 mAh cm(-3)) over the pure PTMA (16 mAh cm(-3)) or LiFePO4 (3.0 mAh cm(-3)) cathode. Further characterization of the hybrid electrodes using SEM showed a more compact surface morphology after high rate pulse experiments. The demonstrated properties of hybrid cathodes are promising for transportation and other high pulse power applications that require long cycle life and low cost. (C) 2013 Published by Elsevier B.V.

Jin, En Mei; Jin, Bo; Jeon, Yeon-Su; et al. Electrochemical properties of LiMnO2 for lithium polymer battery //JOURNAL OF POWER SOURCES Volume: 189 Issue: 1 Special Issue: SI Pages: 620-623 Published: APR 1 2009

Well-defined o-LiMnO2 cathode materials were synthesized by quenching method at 1050 degrees C in an argon flow. The synthesized LiMnO2 particle was characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). LiMnO2/solid polymer electrolyte (SPE)/Li batteries were characterized electrochemically by charge/discharge experiments, cyclic voltammetry (CV) and ac impedance spectroscopy. The charge/discharge results show that the discharge capacities of LiMnO2 are 62 mAh g(-1) at the first cycle and 124 mAh g(-1) after 70 cycles, respectively. Moreover, we evaluated batteries using liquid electrolyte and SPE. From the charge/discharge results, the discharge capacity of LiMnO2/SPE/Li battery is greater than that of LiMnO2/Li battery with liquid electrolyte. (C) 2008 Published by Elsevier B.V.

Kaneko, Fuminari; Wada, Shinto; Nakayama, Masanobu; et al. Capacity Fading Mechanism in All Solid-State Lithium Polymer Secondary Batteries Using PEG-Borate/Aluminate Ester as Plasticizer for Polymer Electrolytes//ADVANCED FUNCTIONAL MATERIALS Volume: 19 Issue: 6 Pages: 918-925 - Web of Science

Solid-state lithium polymer secondary batteries (LPB) are fabricated with a two-electrode-type cell construction of Lilsolid-state polymer electrolyte (SPE)vertical bar LiFePO(4). 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 degrees C. However, a decrease of discharge capacities abruptly follows after tens of stablecycles. 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 aftercycling. 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

Kim, G. -T.; Jeong, S. S.; Xue, M. -Z.; et al. Development of ionic liquid-based lithium battery prototypes // JOURNAL OF POWER SOURCES Volume: 199 Pages: 239-246 Published: FEB 1 2012

The lab-scale manufacturing of Li/LiFePO(4) and Li(4)Ti(5)O(12)/LiFePO(4) stacked battery prototypes and their performance characterization are described here. The prototypes were realized in the frame of an European Project devoted to the development of greener and safer lithium batteries, based on ionic liquid electrolytes, for integration with photovoltaic panels. N-Butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR(14)TESI) and N-butyl-N-methylpyrrolidinium bis(fluoromethanesulfonyl)imide (PYR(14)FSI), selected as the ionic liquids (ILs), were used to formulate the poly(ethylene oxide)-LiN(SO(2)CF(3))(2)-PYR(14)TESI (PEO-LiTFSI-PYR(14)TFSI) polymer electrolyte and the LiTESI-PYR(14)FSI liquid electrolyte, which were employed to produce lithium metal and lithium-ion prototypes, respectively. The composite electrodes for the lithium metal and lithium-ion prototypes were prepared through, respectively, a solvent-free and a water-based procedure route. The performance of the lithium battery prototypes was evaluated in terms of specific capacity, energy, cycle life and coulombic efficiency at different current densities. The results have indicated high reproducibility and the feasibility of scaling-up solvent-free, lithium batteries based on ionic liquids for low and mid rate applications such as renewable energy storage. (C) 2011 Elsevier B.V. All rights reserved.

Kim, Jae-Kwang; Thebault, Frederic; Heo, Min-Yeong; et al. 2,3,6,7,10,11-Hexamethoxytriphenylene (HMTP): A new organic cathode material for lithium batteries //ELECTROCHEMISTRY COMMUNICATIONS Volume: 21 Pages: 50-53 Published: JUL 2012 - Web of Science

We propose a new organic cathode material for rechargeable lithium battery applications: 2,3,6,7,10,11-hexamethoxytriphenylene (HMTP). HMTP is composed of six methoxy functional groups substituted onto a central triphenylene moiety. The cell, incorporating 40 wt.% of organic cathode material, exhibits full specific capacity at current densities up to 3 C. The main advantage of HMTP as organic cathode material lies in a stable cell performance and negligible self discharge, even though the capacity is lower, similar to 66 mAh/g, compared to other organic cathode materials. Cells with the HMTP cathode showed >95% retention of the initial discharge capacity after 50 cycles at 1 C and self-discharge was not observed during a full month of open circuit voltage measurements. The latter is due to the fact that the nature of the HMTP radical is fundamentally different from other organic cathode materials' radicals. (C) 2012 Elsevier B.V. All rights reserved.

Kim, Ui Seong; Yi, Jaeshin; Shin, Chee Burm; et al. Modelling the thermal behaviour of a lithium-ion battery during charge //JOURNAL OF POWER SOURCES Volume: 196 Issue: 11 Special Issue: SI Pages: 5115-5121 Published: JUN 1 2011 -Web of Science

A method for modelling the thermal behaviour of a lithium-ion battery (LIB) during charge is presented. The effect of charge conditions on the thermal behaviour is examined by means of the finite element method. A comparison of the experimental charge curves with the modelling results validates the two-dimensional modelling of the potential and current density distribution on the electrodes of an LIB as a function of charge time during constant-current charge followed by constant-voltage charge. The heat generation rates as a function of the charge time and the position on the electrodes are calculated to predict the temperature distributions of the LIB based on the modelling results for potential and current density distributions. The temperature distributions obtained from the modelling are in good agreement with the experimental measurements. (C) 2011 Elsevier B.V. All rights reserved.

Li, Xianglin; Faghri, Amir Optimization of the Cathode Structure of Lithium-Air Batteries Based on a Two-Dimensional, Transient, Non-Isothermal Model //JOURNAL OF THE ELECTROCHEMICAL SOCIETY Volume: 159 Issue: 10 Pages: A1747-A1754 Published: 2012

A two-dimensional, transient, and non-isothermal model was developed in this work to study the mass transfer properties of the Li-air battery. Special attentions have been paid to the cathode carbon electrode and the distributions of oxygen, lithium ion, lithium peroxide, and temperature in the carbon electrode have been calculated in the model. The effects of discharge current, electrode thickness, porosity distribution in the electrode, and cathode open ratio on the discharge capacity of the battery have been investigated. Modeling results showed that the discharge capacity of a Li-air battery was primarily determined by the oxygen supply. Most of the available pores deep in the electrode were not utilized because Li2O2 accumulated at the electrode/air interface and blocked the oxygen. It was also found that the utilization rate of the electrode was lower when the electrode was thick, the cathode open ratio was low, and the discharge current was high. A unique design of the carbon electrode with a non-uniform porosity distribution was proposed, and the discharge capacity of the battery was increased by more than 25% after implementing the new electrode. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.043210jes] All rights reserved.

Li, Zhe; Huang, Jun; Liaw, Bor Yann; et al A review of lithium deposition in lithium-ion and lithium metal secondary batteries //JOURNAL OF POWER SOURCES Volume: 254 Pages: 168-182 Published: MAY 15 2014 - Web of Science

Major aspects related to lithium deposition in lithium-ion and lithium metal secondary batteries are reviewed. For lithium-ion batteries with carbonaceous anode, lithium deposition may occur under harsh charging conditions such as overcharging or charging at low temperatures. The major technical solutions include: (1) applying electrochemical models to predict the critical conditions for deposition initiation; (2) preventions by improved battery design and material modification; (3) applying adequate charging protocols to inhibit lithium deposition. For lithium metal secondary batteries, the lithium deposition is the inherent reaction during charging. The major technical solutions include: (1) the use of mechanistic models to elucidate and control dendrite initiation and growth; (2) engineering surface morphology of the lithium deposition to avoid dendrite formation via adjusting the composition and concentration of the electrolyte; (3) controlling battery working conditions. From a survey of the literature, the areas that require further study are proposed; e.g., refining the lithium deposition criteria, developing an effective AC self pre-heating method for low-temperature charging of lithium-ion batteries, and clarifying the role the solid electrolyte interphase (SEI) plays in determining the deposition morphology; to facilitate a refined control of the lithium deposition. (c) 2013 Elsevier B.V. All rights reserved.

Mahesh, K. C.; Suresh, G. S.; Bhattacharyya, A. J.; et al. Synthesis and Electrochemical Characterization of LiNi0.8Co0.2O2 as Cathode Material for Aqueous Rechargeable Lithium Batteries //JOURNAL OF THE ELECTROCHEMICAL SOCIETY Volume: 159 Issue: 5 Pages: A571-A578 Published: 2012

LiNi0.8Co0.2O2 cathode material for lithium ion batteries is synthesized by reaction under autogenic pressure at elevated temperature (RAPET) method. The simple synthesis procedure is time and energy saving, and thus is promising for commercial application. The structure and stability of the material have been characterized by means of XRD and TG-DTA. The electrochemical properties of the LiNi0.8Co0.2O2 cathode are investigated in 2 M Li2SO4 aqueous electrolyte and they are compared to that in an organic electrolyte. A battery cell consisting of LiNi0.8Co0.2O2 as cathode in 2 M Li2SO4 solution is constructed in combination with LiTi2 (PO4)(3) as anode. The cell retained almost constant discharge capacity over hundred cycles. The electrochemical impedance spectral ( EIS) studies in aqueous and nonaqueous electrolytes revealed that the mechanism of lithium ion intercalation and deintercalation processes in LiNi0.8Co0.2O2 electrode follow almost similar mechanism in both aqueous and nonaqueous electrolytes. The chemical diffusion coefficient was calculated from slow scan rate cyclic voltammetry and EIS. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.075205jes] All rights reserved.

Miao, Cui; Bai, Peifeng; Jiang, Qianqian; et al. A novel synthesis and characterization of LiFePO4 and LiFePO4/C as a cathode material for lithium-ion battery //JOURNAL OF POWER SOURCES Volume: 246 Pages: 232-238 Published: JAN 15 2014

A novel hydrothermal stripping technique is developed to synthesize pure LiFePO4 and LiFePO4/C cathode materials. The pure sample is directly synthesized by the cation exchange between the organic phase which is prepared with FeSO4 center dot 7H(2)O and naphthenic acid, and aqueous phase prepared with H3PO4 and LiOH. SEM exhibits that the primary sizes of the well-distributed LiFePO4 and LiFePO4/C particles are about 150 nm and 100 nm in diameter, respectively. TEM indicates the LiFePO4/C is uniformly coated with a carbon layer about 2.7 nm in size. The as-prepared LiFePO4 exhibits a high initial discharge capacity of 135.5 mAh g(-1) at 0.1 C, and the LiFePO4/C composite sintered at 650 degrees C for 4 h exhibits the best electrode properties with discharge capacities of 151.7, 154.8, 149.8 and 139.1 mAh g(-1) at 0.1 C, 0.2 C, 0.5 C and 1.0 C rates, respectively. In addition, the LiFePO4/C also shows excellent capacity retention and cycle performances. (C) 2013 Elsevier B.V. All rights reserved.

Nanda, Jagjit; Martha, Surendra K.; Porter, Wallace D.; et al. Thermophysical properties of LiFePO4 cathodes with carbonized pitch coatings and organic binders: Experiments and first-principles modeling // JOURNAL OF POWER SOURCES Volume: 251 Pages: 8-13 Published: APR 1 2014

We report heat capacity, thermogravimetry and thermal diffusivity data for carbonized mesophase pitch coated LiFePO4 (LFP) cathodes. The results are compared with the thermophysical properties of a conventional LFP-based electrode having a poly (vinylene) difluoride (PVDF) binder and conductive carbon diluents. The measured heat capacity of LFP as a function of temperature is in good agreement with model calculations based on first-principles methods. Thermal diffusivity data indicate that the mesophase pitch coated LFP compositions have a factor of two higher thermal diffusivity than the conventional electrode composition, suggesting that the coatings improve heat transfer. In the presence of an electrolyte mixture (1.2 M lithium hexa-fluorophosphate), differential scanning calorimetry (DSC) analysis of the LFP-pitch composite and LFP-PVDF-carbon composites showed similar onset temperature and heat evolution. (C) 2013 Published by Elsevier B.V.

Navarathinam, Nimal; Lee, Regina; Chesser, Hugh. Characterization of Lithium-Polymer batteries for CubeSat applications //ACTA ASTRONAUTICA Volume: 68 Issue: 11-12 Pages: 1752-1760 Published: JUN-JUL 2011 - Web of Science

With the development of several key technologies, nanosatellites are emerging as important vehicles for carrying out technology demonstrations and space science research. Nanosatellites are attractive for several reasons, the most important being that they do not involve the prohibitive costs of a conventional satellite launch. One key enabling technology is in the area of battery technology. In this paper, we focus on the characterization of battery technologies suitable for nanosatellites.

Navarra, M. A.; Manzi, J.; Lombardo, L.; et al. Ionic Liquid-Based Membranes as Electrolytes for Advanced Lithium Polymer Batteries // CHEMSUSCHEM Volume: 4 Issue: 1 Pages: 125-130 Published: 2011- Web of Science

Gel-type polymer electrolytes are formed by immobilizing a solution of lithium N,N-bis(trifluoromethanesulfonyl) imide (LiTFSI) in N-n-butyl-N-ethylpyrrolidinium N, N-bis(trifluoromethanesulfonyl) imide (Py(24)TFSI) ionic liquid (IL) with added mixtures of organic solvents, such as ethylene, propylene and dimethyl carbonates (EC, PC, and DMC, respectively), into a poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) matrix, and their properties investigated. The addition of the organic solvent mixtures results in an improvement of the ionic conductivity and in the stabilization of the interface with the lithium electrode. Conductivity values in the range of 10(-3)-10(-2) S cm(-1) are obtained in a wide temperature range. These unique properties allow the effective use of these membranes as electrolytes for the development of advanced polymer batteries based on a lithium metal anode and an olivine-type lithium iron phosphate cathode.

Prasanth, Raghavan; Shubha, Nageswaran; Hng, Effect of poly(ethylene oxide) on ionic conductivity and electrochemical properties of poly(vinylidenefluoride) based polymer gel electrolytes prepared by electrospinning for lithium ion batteries

Effect of poly(ethylene oxide) on the electrochemical properties of polymer electrolyte based on electrospun, non-woven membrane of PVdF is demonstrated. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, uniformly dispersed thin fibers with diameter in the range of 1.5-1.9 mu m. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents. The polymer gel electrolyte shows ionic conductivity of 4.9 x 10(-3) S cm(-1) at room temperature. Electrochemical performance of the polymer gel electrolyte is evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge-discharge cycling is demonstrated. (C) 2013 Elsevier B.V. All rights reserved.

Qin, Guohui; Wu, Quanping; Zhao, Jun; et al. C/LiFePO4/multi-walled carbon nanotube cathode material with enhanced electrochemical performance for lithium-ion batteries //JOURNAL OF POWER SOURCES Volume: 248 Pages: 588-595 Published: FEB 15 2014

C/LiFePO4/multi-walled carbon nanotubes composite is prepared by a hybrid of hydrothermal progress that involves an in-situ multi-walled carbon nanotubes embedding approach and a facile electro-polymerization polyaniline process. The designed material on nanosize with about 100-200 nm in length contains tridimensional networks and uniform-thickness carbon layer, which remarkably enhance its electronic conductivity. The synthesized LiFePO4 composite offers a discharge capacity of 169.8 mAh g(-1) at the C/2 rate and high capacity retention at the 5C rate. Meanwhile, the well-crystallized material composed of many densely aggregated nanoparticles and interconnected nanochannels presents a high tap density leading to excellent volumetric Li storage properties at high current rates (>135 mAh cm(-3) at 20C), and stable charge/discharge cycle ability (>95% capacity retention after 200 charge/discharge cycles). As such, the prepared material with controllable size and structure yields an enhanced electrochemical performance in terms of charming rate capability, cycling life and capacity retention as a cathode in lithium-ion batteries, this non-organic facile synthesize avenue can be promising to prepare high-power electrode materials. (C) 2013 Published by Elsevier B.V.

Rahimi-Eichi, Habiballah; Baronti, Federico; Chow, Mo-Yuen Online Adaptive Parameter Identification and State-of-Charge Coestimation for Lithium-Polymer Battery Cells //IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS Volume: 61 Issue: 4 Pages: 2053-2061 Published: APR 2014 - Web of Science

Real-time estimation of the state of charge (SOC) of the battery is a crucial need in the growing fields of plug-in hybrid electric vehicles and smart grid applications. The accuracy of the estimation algorithm directly depends on the accuracy of the model used to describe the characteristics of the battery. Considering a resistance-capacitance (RC)-equivalent circuit to model the battery dynamics, we use a piecewise linear approximation with varying coefficients to describe the inherently nonlinear relationship between the open-circuit voltage (V-OC) and the SOC of the battery. Several experimental test results on lithium (Li)-polymer batteries show that not only do the V-OC-SOC relationship coefficients vary with the SOC and charging/discharging rates but also the RC parameters vary with them as well. The moving window least squares parameter-identification technique was validated by both data obtained from a simulated battery model and experimental data. The necessity of updating the parameters is evaluated using observers with updating and nonupdating parameters. Finally, the SOC coestimation method is compared with the existing well-known SOC estimation approaches in terms of performance and accuracy of estimation.

Ramesh, S.; Arof, A. K. A study incorporating nano-sized silica into PVC-blend-based polymer electrolytes for lithium batteries //JOURNAL OF MATERIALS SCIENCE Volume: 44 Issue: 23 Pages: 6404-6407 Published: DEC 2009 - Web of Science

Blends of poly(vinyl chloride)-poly(methyl methacrylate) (PVC/PMMA) and poly(vinyl chloride)-poly(ethylene oxide) (PVC/PEO) with lithium triflate (LiCF(3)SO(3)) as salt, ethylene carbonate (EC), and dibuthyl phthalate (DBP) as plasticizers and nano-sized silica (SiO(2)) as filler, the first of its kind in such a study, were prepared using the solution-cast technique. This study affirmed that SiO(2) added PVC-PMMA and PVC-PEO-blend-based polymer electrolytes have the ability to retain their ionic conductivity and integrity even after 60 days of storage time at room temperature. The reduction of ionic conductivity values in PVC-PMMA-LiCF(3)SO(3)-DBP-EC:SiO(2)-based and SiO(2)-free membranes are 9 and 30%, respectively. When PVC-PEO-blend was used, the reduction of ionic conductivity values in PVC-PEO-LiCF(3)SO(3)-DBP-EC:SiO(2)-based and SiO(2)-free system was 16 and 40%, respectively, after 60 days of storage also at room temperature. The SiO(2)-based complexes were also found to maintain their conductivity at higher temperatures of 60 A degrees C and 90 A degrees C with progressive storage times. This clearly shows that the SiO(2)-induced stabilizing effect is maintained even at higher temperatures. Silica has brought the conductivity of polymer electrolytes into the useful realm for materials in lithium polymer battery applications.

Shi, Zhongqi; Huang, Ming; Huai, Yongjian; et al. Synthesis of LiFePO4/C cathode material from ferric oxide and organic lithium salts // ELECTROCHIMICA ACTA Volume: 56 Issue: 11 Pages: 4263-4267 Published: APR 15 2011 - Web of Science

LiFePO4/C cathode material has been simply synthesized via a modified in situ solid-state reaction route using the raw materials of Fe2O3, NH4H2PO4, Li2C2O4 and lithium polyacrylate (PAALi). The sintering temperature of LiFePO4/C precursor is studied by thermo-gravimetric (TG)/differential thermal analysis (DTA). The physical properties of LiFePO4/C are then investigated through analysis using by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and the electrochemical properties are investigated by electrochemical impedance spectra (EIS), cyclic voltammogram (CV) and constant current charge/discharge test. The LiFePO4/C composite with the particle size of similar to 200 nm shows better discharge capacity (156.4 mAh g(-1)) than bare LiFePO4 (52.3 mAh g(-1)) at 0.2 C due to the improved electronic conductivity which is demonstrated by EIS. The as-prepared LiFePO4/C through this method also shows excellent high-rate characteristic and cycle performance. The initial discharge capacity of the sample is 120.5 mAh g(-1) and the capacity retention rate is 100.6% after 50 cycles at 5 C rate. The results prove that the using of organic lithium salts can obtain a high performance LiFePO4/C composite. (C) 2011 Elsevier Ltd. All rights reserved.

Shimizu, Akihiro; Kuramoto, Hiroki; Tsujii, Yutaka; et al. Introduction of two lithiooxycarbonyl groups enhances cyclability of lithium batteries with organic cathode materials // JOURNAL OF POWER SOURCES Volume: 260 Pages: 211-217 Published: AUG 15 2014 - Web of Science

To increase the cyclability of lithium batteries using organic cathode materials of low molecular weights, two lithiooxycarbonyl (-CO2Li) groups was introduced to p- and o-quinones. The introduction of two -CO2Li groups does not strongly affect the redox potentials of quinones. Lithium batteries using p- and o-quinones with two -CO2Li groups as cathode materials exhibit excellent cyclability compared to their parent quinones. In particular, yrene-4,5,9,10-tetraone having two lithiooxycarbonyl groups (LCPYT) exhibited high energy density, high cyclability, and fast charge ability. These results indicate that introduction of two lithiooxycarbonyl groups to quinones serves as a simple and effective way to decrease the solubility of various quinones in electrolyte solutions without significant decrease in the voltage. (C) 2014 Elsevier B.V. All rights reserved.

Wang, Lishi; Yang, Wensheng; Li, Xingwang; et al. Nanocomposite Polymer Electrolyte Doped with Nanosized Li0.1Ca0.9TiO3 for Lithium Polymer Batteries //ELECTROCHEMICAL AND SOLID STATE LETTERS Volume: 13 Issue: 1 Pages: A7-A10 Published: 2010

A poly(ethylene oxide) (PEO)-based nanocomposite polymer electrolyte (NCPE) doped with nanosized Li0.1Ca0.9TiO3, a lithium fast ionic conductor, has been developed. The ionic conductivity and lithium ion transference number of PEO12-LiClO4-Li0.1Ca0.9TiO3 NCPE are both enhanced by the addition of nanosized Li0.1Ca0.9TiO3, with a maximum ionic conductivity of 1.02 X 10(-5) S cm(-1) at room temperature and a maximum lithium ion transference number of 0.533 at 70 degrees C when the Li0.1Ca0.9TiO3 content is 15 wt %. A broad electrochemical stability window suggests that the NCPE is a viable candidate for the electrolyte material in lithium polymer batteries. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3257593] All rights reserved.

Wu, Feng; Wu, Sheng Xian; Chen, Ren Jie; et al. Electrochemical performance of sulfur composite cathode materials for rechargeable lithium batteries //CHINESE CHEMICAL LETTERS Volume: 20 Issue: 10 Pages: 1255-1258 Published: OCT 2009

The structure and characteristic of carbon materials have a direct influence on the electrochemical performance of sulfur-carbon composite electrode materials for lithium-sulfur battery. In this paper, sulfur composite has been synthesized by heating a mixture of elemental sulfur and activated carbon, which is characterized as high specific surface area and microporous structure. The composite, contained 70% sulfur, as cathode in a lithium cell based on organic liquid electrolyte was tested at room temperature. It showed two reduction peaks at 2.05 V and 2.35 V, one oxidation peak at 2.4 V during cyclic voltammogram test. The initial discharge specific capacity was 1180.8 mAh g(-1) and the utilization of electrochemically active sulfur was about 70.6% assuming a complete reaction to the product of Li(2)S. The specific capacity still kept as high as 720.4 mAh g(-1) after 60 cycles retaining 61% of the initial discharge capacity. (C) 2009 Ren Jie Chen. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Wu, Hao-Yiang; Saikia, Diganta; Chao, Hung-Yu; et al. Synthesis and characterization of highly conductive plasticized double core organic-inorganic hybrid electrolytes for lithium polymer batteries //JOURNAL OF POWER SOURCES Volume: 238 Pages: 265-273 Published: SEP 15 2013 - Web of Science

A new highly ion conductive plasticized organic inorganic hybrid electrolyte membrane based on triblock co-polymer poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether) (ED2003), poly(ethylene glycol) diglycidyl ether (PEGDGE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), 2,4,6-trichloro-1,3,5-triazine (cyanuric chloride, CC) and 3-(glycidyloxypropyl)trimethoxysilane (GLYMO) has been synthesized by a sol-gel process and characterized by a variety of experimental techniques. FTIR and C-13 NMR measurements have been performed to study the molecular structure of the hybrid as well as the interactions among the constituents of the membrane. The hybrid membrane is plasticized with different electrolyte solvents and exhibits remarkable swelling ratios in the range of 670-800%. The ionic conductivity of the hybrid electrolyte membranes is varied with different electrolyte solvents and shows a maximum value of 6.9 x 10(-3) S cm(-1) for 1 M LiClO4 in EC/PC at 30 degrees C. The test cell carries initial discharge capacity of 115 mAh g(-1) at a current rate of 0.2 C and shows good cycling performance up to 100 cycles and coulombic efficiency of 98-99% for the entire cycles. The plasticized organic inorganic hybrid electrolyte membrane holds promise for applications in lithium polymer batteries. (C) 2013 Elsevier B.V. All rights reserved.

Xiao, Meng; Choe, Song-Yul Dynamic modeling and analysis of a pouch type LiMn2O4/Carbon high power Li-polymer battery based on electrochemical-thermal principles //JOURNAL OF POWER SOURCES Volume: 218 Pages: 357-367 Published: NOV 15 2012 - Web of Science

A dynamic model for a pouch type Li-polymer battery based on electrochemical and thermal principles is developed to analyze static and dynamic performances of a single cell. The model for the single cell is a quasi-three-dimensional, constructed by connecting one-dimensional models for micro cells using current collectors. The developed model can represent distributions of temperature, potentials, and current flows along with distribution of lithium ions through the plane. The model is coded using MATLAB and validated against a LiMn2O4/Carbon pouch type power cell. The static analysis includes responses of the terminal voltage at different current rates derived from the distribution of over-potentials in the micro cell as function of state of charge (SOC) as well as distribution of potentials and current flows in the single cell. Ion concentration in the electrodes and electrolyte of the micro cell are analyzed. The dynamic analysis includes voltage and temperature responses during charging and discharging processes. The results demonstrate effects of operation conditions on key variables of the cell performance that includes distribution of ions in the electrodes and electrolyte in micro cells as well as distribution of heat generation in single cell level during a charging and discharging process. (C) 2012 Elsevier B.V. All rights reserved.

Yoon, Mi Young; Hong, Sun Ki; Hwang, Hae Jin Fabrication of Li-polymer/silica aerogel nanocomposite electrolyte for an all-solid-state lithium battery // CERAMICS INTERNATIONAL Volume: 39 Issue: 8 Pages: 9659-9663 Published: DEC 2013- Web of Science

Nanocomposite solid-polymer electrolytes were fabricated using polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), LiClO4 and silica aerogel, with the aim of improving lithium ion conductivity and thermal stability. The effects of the PEO:PVDF ratio, polymer:Li-salt ratio, and silica aerogel content on the electrical conductivity of the solid-polymer electrolytes were examined. Highest lithium ion conductivity of 1.70 x 10(-4) S/cm was obtained at 30 degrees C in the SPE-2 sample with PEO:PVDF= 3:1 and polymer:Li-salt= 6:1. XRD and FT-IR analysis showed that the observed phenomenon could be explained by the degree of crystallinity of the polymer electrolyte and by the dissociation degree of Li-salt. 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Yun, Ye Sun; Kim, Jin Hee; Lee, Sang-Young; et al Cycling performance and thermal stability of lithium polymer cells assembled with ionic liquid-containing gel polymer electrolytes //JOURNAL OF POWER SOURCES Volume: 196 Issue: 16 Special Issue: SI Pages: 6750-6755 Published: AUG 15 2011

Gel polymer electrolytes containing 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and a small amount of additive (vinylene carbonate, fluoroethylene carbonate, and ethylene carbonate) are prepared, and their electrochemical properties are investigated. The cathodic limit of the gel polymer electrolytes can be extended to 0 V vs. Li by the formation of a protective solid electrolyte interphase on the electrode surface. Using these gel polymer electrolytes, lithium metal polymer cells composed of a lithium anode and a LiNi(1/3)Co(1/3)Mn(1/3)O(2) cathode are assembled, and their cycling performances are evaluated at room temperature. The cells show good cycling performance, comparable to that of a cell assembled with gel polymer electrolyte containing standard liquid electrolyte (1.0 M LiPF(6) in ethylene

Zeng, Rong-hua; Li, Xiao-ping; Qiu, Yong-cai; et al. Synthesis and properties of a lithium-organic coordination compound as lithium-inserted material for lithium ion batteries // ELECTROCHEMISTRY COMMUNICATIONS Volume: 12 Issue: 9 Pages: 1253-1256 Published: SEP 2010 - Web of Science

A lithium-organic coordination compound based on an aromatic carbonyl derivative, [Li(2)(C(14)H(6)O(4))], was synthesized by the dehydration of [Li(2)(C(14)H(6)O(4))center dot H(2)O], and used as a novel lithium-inserted material for lithium ion batteries. The synthesized material has initial discharge capacity of 126 and 115 mAh/g at current densities of 22 and 111 mAh/g, corresponding to the columbic efficiency of 99.2% and 983% at the first cycle, and its capacity fading is only 5% and 13% after 50 cycles, respectively, showing that this compound is a promising candidate as lithium-inserted material for lithium ion batteries. (C) 2010 Elsevier B.V. All rights reserved

Zhao, Taolin; Chen, Shi; Li, Li; et al. Synthesis, characterization, and electrochemistry of cathode material Li [Li0.2Co0.13Ni0.13Mn0.54]O-2 using organic chelating agents for lithium-ion batteries // JOURNAL OF POWER SOURCES Volume: 228 Pages: 206-213 Published: APR 15 2013 - Web of Science

Oxalic acid, tartaric acid (TA), and succinic acid (SA) are studied as chelating agents for sol gel synthesis of Li[Li0.2Co0.13Ni0.13Mn0.54]O-2 as a cathode material for lithium-ion batteries. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy show that the materials are single-phase compounds with good crystallinities and layered alpha-NaFeO2 structures. The TA-material has the smallest particles (0.2-0.3 mu m), with a smooth surface, and uniform distribution. Electrochemical studies indicate that the TA-material exhibits the highest initial discharge capacity (281.1 mAh g(-1) at 0.1 C, 192.8 mAh g(-1) at 2.0 C), the highest reversible capacity after 50 cycles (240.5 mAh g(-1) at 0.1 C, 167.4 mAh g(-1) at 0.5 C), and the best rate performance. The cycling stability of the SA-material is the best, with capacity retentions of 87.4% at 0.1 C and 80.1% at 0.5 C after 50 cycles. Mn4+/3+ reduction peaks appear at the first discharge process and become more evident with increasing cycle number, resulting in a spinel structure, as proved by cyclic voltammetry and differential capacity curves. Electrical impedance spectroscopy confirms that the low charge-transfer resistance of the TA-material is responsible for its superior discharge capacity and rate performance. (C) 2012 Elsevier B.V. All rights reserved

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