Open circuit voltage for solid polymer electrolyte/salt systems in lithium batteries

Pai, Sung Jin; Bae, Young Chan

doi:10.1007/s10800-004-6708-4

Cited by 4 publications

(5 citation statements)

References 38 publications

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“…These PEO-lithium triflate films cast from solution onto Teflon substrates were found to have an inherent potential of around 0.2 V and a discharge capacity of 80 nF cm −2 . Again, this potential can be attributed to different salt concentration at the two surfaces and matches theoretical predictions by Pai and Bae for PEO-LiTf films [14]. The spherulites at each surface were found to have different morphologies that can be associated with PEO electrolyte having different concentrations of complexed salt.…”

Section: Discussionsupporting

confidence: 85%

“…Computations predict concentration ratios from approximately 10 to 33 should exist for this voltage range. The approximate ratio of surface concentrations, based upon ATR IR data (13)(14)(15)(16)(17)(18)(19)(20), falls within this range. Thus, the inherent voltage observed matches well with theoretical values calculated with approximate concentrations obtained from this work's IR data.…”

Section: Resultsmentioning

confidence: 65%

“…The IR data allows interesting comparisons to be made with open circuit voltages calculated by Pai and Bae for PEOLiTf films [14]. They have made theoretical calculations of the open circuit voltage for PEO electrolyte films of different concentrations being brought in contact with each other.…”

Section: Resultsmentioning

confidence: 99%

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Investigation of the inherent electrical potential of PEO electrolyte films

Johnson¹,

Kennedy²,

Smith³

et al. 2007

Electrochimica Acta

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Section: Discussionsupporting

confidence: 85%

Section: Resultsmentioning

confidence: 65%

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Investigation of the inherent electrical potential of PEO electrolyte films

Johnson¹,

Kennedy²,

Smith³

et al. 2007

Electrochimica Acta

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“…15 However, no theoretical consideration concerning the long-range electrostatic forces between ions was taken into account in those models. Chen and co-workers 16 proposed a local-composition model for aqueous electrolyte systems.…”

mentioning

confidence: 99%

“…Using the phase diagram, progress in modeling of the solid polymer electrolyte system has been made to show the relationship between the activity of the electrolyte and the open-circuit voltage ͑OCV͒ of the concentration cell in our previous work. 15 However, no theoretical consideration concerning the long-range electrostatic forces between ions was taken into account in those models. Chen and co-workers 16 proposed a local-composition model for aqueous electrolyte systems.…”

mentioning

confidence: 99%

Electrochemical Properties for Solid Polymer Electrolyte/Salt Systems in Lithium Secondary Batteries

Pai

Bae

Sun

2005

J. Electrochem. Soc.

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We establish a new thermodynamic framework to describe the electrochemical properties of solid polymer electrolyte/salt systems. The Pitzer-Debye-Hückel expression is introduced to the modified double lattice-nonrandom model to take into account longrange electrostatic forces between molecules. After developing full descriptions for the electrochemical properties of a poly͑eth-ylene oxide͒ ͑PEO͒/NaCF 3 SO 3 system, the open-circuit voltage ͑OCV͒, diffusion coefficient, and ionic conductivity are calculated and compared with experimental data. We predict OCVs and diffusion coefficients of PEO/ZnBr 2 and PEO/ZnI 2 systems with the parameters obtained from phase diagrams and ionic conductivity data. The quantitative description according to the proposed model is in good agreement with the experimental data.Ionically conducting polymers were first discovered nearly three decades ago and were subsequently used as electrolytes in solidstate batteries. These polymers are solutions of salts in polymers in which a macroscopically solid state is achieved by entanglement. Microscopically they behave as liquids. The polymer electrolytes are generally composites of poly͑ethylene oxide͒ ͑PEO͒ and a salt such as LiClO 4 , LiAsF 6 , LiCF 3 SO 3 , and LiPF 6 . These materials show a common characteristic, namely the interdependence between measured properties and the nature and proportion of the phases present in the polymer electrolytes. It is believed that the ionic conduction is a property of the amorphous phase and that ion association, ionpolymer interactions, and local relaxations of the polymer strongly influence the ionic mobility. 1 Phase diagram studies of PEO-based electrolyte systems were initiated mainly as a consequence of previous ionic conductivity studies which showed significant variations of the ionic conductivity as a function of different experimental parameters, thermal history being one of the most important. Robitaille et al. 2 and Bésner and Prud'homme 3 reported complete phase diagrams for PEO/NaSCN and PEO/KSCN. Stainer et al. 4 constructed the phase diagram for PEO/NH 4 SCN. Lee and Crist 5 reported the phase behavior for PEO/NaSCN mixtures, which shows a eutectic point. Robitaille and Fauteux, 6 Fauteux, 7 and Fauteux and McCabe 8 studied extensively the phase behaviors of binary solid polymer electrolyte/salt systems such as PEO/LiX͑X = CF 3 SO 3 − , ClO 4 − , AsF 6 − , N͑CF 3 SO 2 ͒ 2 − , N͑CF 3 SO 3 ͒ 3 − ͒, and PEO/NaI. Gorecki et al. 9 described a phase diagram of PEO/Li͓͑CF 3 SO 2 ͒ 2 N͔ from the physics point of view. Labrèche et al. 10 also reported a partial phase diagram for PEO/Li͓͑CF 3 SO 2 ͒ 2 N͔ and employed tetraethylenesulfamide as a plasticizer for the same system. Recently Bae's group 11-14 has investigated this subject, introducing various thermodynamic models that describe phase behaviors of solid polymer electrolyte/salt systems. These theories consider various factors such as specific interaction, pressure, and local composition and agree with experimental data remarkably.Using t...

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Effect of Lithium Iodide Addition on Poly(ethylene oxide)−Poly(vinylidene fluoride) Polymer-Blend Electrolyte for Dye-Sensitized Nanocrystalline Solar Cell

et al. 2008

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The effect of lithium iodide concentration on the conduction behavior of poly(ethylene oxide)-poly(vinylidene fluoride) (PEO-PVDF) polymer-blend electrolyte and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. The conduction behavior of these electrolytes was investigated with varying LiI concentration (10-60 wt % in polymer blend) by impedance spectroscopy. A "polymer-in-salt" like conduction behavior has been observed in the high salt concentration region. The transition from "salt-in-polymer" to "polymer-in-salt" conduction behavior happened at the salt content of 23.4 wt %, which is much lower than 50 wt % as generally reported. The electrolyte shows the highest ionic conductivity (approximately 10(-3) S cm(-1)) at the salt concentration above 23.4 wt %. From the evaluation of salt effect on the performances of corresponding DSSC, we find that increasing LiI concentration leads to increased short-circuit photocurrent density (Jsc) caused by enhanced I3(-) diffusion up to an LiI content of 28.9 wt %. Above this limitation, the Jsc decreases as a result of increased charge recombination caused by the further increased I3(-) concentration. The open-circuit voltage (Voc) increases gradually with LiI concentration owing to the enhanced I(-) content in DSSC. The optimized conversion efficiency is obtained at a salt content of 28.9 wt % in the "polymer-in-salt" region, with high ionic conductivity (1.06 x 10(-3) S cm(-1)). Based on these facts, we suggest that the changes of conduction behavior and the changes of I3(-) and I(-) concentrations in the electrolytes contribute to the final performance variation of the corresponding DSSC with varying LiI concentration.

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Open circuit voltage for solid polymer electrolyte/salt systems in lithium batteries

Cited by 4 publications

References 38 publications

Investigation of the inherent electrical potential of PEO electrolyte films

Investigation of the inherent electrical potential of PEO electrolyte films

Electrochemical Properties for Solid Polymer Electrolyte/Salt Systems in Lithium Secondary Batteries

Effect of Lithium Iodide Addition on Poly(ethylene oxide)−Poly(vinylidene fluoride) Polymer-Blend Electrolyte for Dye-Sensitized Nanocrystalline Solar Cell

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