The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers

LaFemina, Nikki H.; Chen, Quan; Colby, Ralph H.; Mueller, Karl T.

doi:10.1063/1.4962743

Cited by 19 publications

(32 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…c) High shear modulus of the electrolyte, where elastic-plastic deformation of both lithium and electrolyte occurs. Lithium Poisson's ratio --0.42 [23] Yield strength of lithium 0.4 [47,49] Hardening modulus of lithium 1.9 [47,49] Hardening exponent of lithium --0.4 [47,49] PEO Yield strength of PEO polymer 0.77 [12,48] Hardening modulus of PEO polymer 3.5 [12] Hardening exponent of lithium --0.4 [12] Partial molar volume of lithium 1.3x10 -5 [23] Partial molar volume of electrolyte salt 1.674x10 -4 [23] Lithium diffusion coefficient 1x10 -12 [65,66] Lithium transference number --0.3 [23,35] Thermodynamic factor --1. [31,55] Amplitude 400.0 [31,55] Anodic and cathodic reaction rate constants 9.832x10 -6 [23,35] Anodic and cathodic transfer coefficients --0.5 [23,35] Domain length [23] Universal which concentration and potential distributions were calculated.…”

mentioning

confidence: 99%

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Barai

Higa

Srinivasan

2017

Phys. Chem. Chem. Phys.

279

259

View full text Add to dashboard Cite

Future lithium-ion batteries must use lithium metal anodes to fulfill the demands of high energy density applications with the potential to enable affordable electric cars with 350-mile range. However, dendrite growth during charging prevents the commercialization of this technology. It has been demonstrated that the presence of a compressive mechanical stress field around a dendritic protrusion prevents growth. Several techniques based on this concept, such as protective layers, externally applied pressure and solid electrolytes have been investigated by other researchers. Because of the low coulombic efficiencies associated with the stiff protective layers and high-pressure conditions, implementation of these techniques in commercial cells is complicated. Polymer-based solid electrolytes demonstrate better efficiency and capacity retention capabilities. However, dendrite growth is still possible in polymer electrolytes at higher current densities. The simulations described in this article provide guidance on the conditions under which dendrite growth is possible in polymer cells and targets for material properties needed for dendrite prevention. Increasing the elastic modulus of the electrolyte prevents the growth of dendritic protrusions in two ways: (i) higher compressive mechanical stress leads to reduced exchange current density at the protrusion peak compared to the valley, and (ii) plastic deformation of lithium metal results in reduction of the height of the dendritic protrusion. A phase map is constructed, showing the range of operation (applied current) and design (electrolyte elastic modulus) parameters that corresponds to stable lithium deposition. It is found that increasing the yield strength of the polymer electrolyte plays a significant role in preventing dendrite growth in lithium metal anodes, providing a new avenue for further exploration.

show abstract

mentioning

confidence: 99%

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Barai

Higa

Srinivasan

2017

Phys. Chem. Chem. Phys.

279

259

View full text Add to dashboard Cite

show abstract

“…Significant enhancements of conductivity relative to Nernst-Einstein predictions have been observed 154 , but the intrinsically slow dynamics of polymeric materials has made it difficult to obtain materials with values comparable to small molecule fluids. Recently, it has been suggested that lowering the dielectric constant of the polymer matrix 155 should greatly improve the situation and other strategies are actively being pursued.…”

Section: Discussionmentioning

confidence: 99%

Superionic UO₂: A model anharmonic crystalline material

et al. 2019

View full text Add to dashboard Cite

Crystalline materials at elevated temperatures and pressures can exhibit properties more reminiscent of simple liquids than ideal crystalline materials. Superionic crystalline materials having a liquid-like conductivity  are particularly interesting for battery, fuel cell, and other energy applications, and we study UO2 as a prototypical superionic material since this material is widely studied given its commercial importance as reactor fuel. Using molecular dynamics, we first investigate basic thermodynamic and structural properties. We then quantify structural relaxation, dynamic heterogeneity, and average ions mobility. We find that the non-Arrhenius diffusion and structural relaxation time of this prototypical superionic material can be quantitatively described in terms of a generalized activated transport model ('string model') in which the activation energy varies in direct proportion to the average string length. Our transport data can also be described equally well by an Adam-Gibbs model in which the excess entropy density of the crystalline material is estimated from specific heat and thermal expansion data, consistent with the average scale of string-like collective motion scaling inversely with the excess entropy of the crystal. Strong differences in the temperature dependence of the interfacial mobility from non-ionic materials are observed, and we suggest that this difference is due to the relatively high cohesive interaction of ionic materials. In summary, the study of superionic UO2 provides insight into the role of cooperative motion in enhancing ion mobility in ionic materials and offers design principles for the development of new superionic materials for use in diverse energy applications. † Corresponding authors: hao.zhang@ualberta.ca; jack.douglas@nist.gov *Official work of the US government-Not subject to copyright in the United States.

show abstract

“…Using the unpaired cation fraction of −23% for Li + as determined from Raman spectroscopy and a measured density of 1.28 g/mL, we estimate the Li + diffusivity in PEG 31 DA-x-STFSILi as 6 × 10 −24 cm 2 /s at 20 • C. Na + and K + diffusivities at 20 • C are estimated as 5 × 10 −25 and 3 × 10 −25 cm 2 /s, respectively, for PEG 31 DA-x-STFSINa and PEG 31 DA-x-STFSIK. The Li + diffusivity value estimated here should in the future be compared to the 7 Li self-diffusion coefficient as measured via pulse-field gradient nuclear magnetic resonance spectroscopy (PFG-NMR) [55]. While several other works have used Raman spectroscopy to estimate the degree of TFSI anion coordination in electrolytes such as ionic liquids, we believe that this is the first effort to apply this approach to single-ion conducting polymers with tethered STFSI anions.…”

Section: Introductionmentioning

confidence: 92%

Ion Transport in Solvent-Free, Crosslinked, Single-Ion Conducting Polymer Electrolytes for Post-Lithium Ion Batteries

et al. 2018

View full text Add to dashboard Cite

Solvent-free, single-ion conducting electrolytes are sought after for use in electrochemical energy storage devices. Here, we investigate the ionic conductivity and how this property is influenced by segmental mobility and conducting ion number in crosslinked single-ion conducting polyether-based electrolytes with varying tethered anion and counter-cation types. Crosslinked electrolytes are prepared by the polymerization of poly(ethylene glycol) diacrylate (PEGDA), poly(ethylene glycol) methyl ether acrylate, and ionic monomers. The ionic conductivity of the electrolytes is measured and interpreted in the context of differential scanning calorimetry and Raman spectroscopy measurements. A lithiated crosslinked electrolyte prepared with PEG 31 DA and (4-styrenesulfonyl)(trifluoromethanesulfonyl)imide (STFSI) monomers is found to have a lithium ion conductivity of 3.2 × 10 −6 and 1.8 × 10 −5 S/cm at 55 and 100 • C, respectively. The percentage of unpaired anions for this electrolyte was estimated at about 23% via Raman spectroscopy. Despite the large variances in metal cation-STFSI binding energies as predicted via density functional theory (DFT) and large variations in ionic conductivity, STFSI-based crosslinked electrolytes with the same charge density and varying cations (Li, Na, K, Mg, and Ca) were estimated to all have unpaired anion populations in the range of 19 to 29%.

show abstract

The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers

Cited by 19 publications

References 49 publications

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Superionic UO₂: A model anharmonic crystalline material

Ion Transport in Solvent-Free, Crosslinked, Single-Ion Conducting Polymer Electrolytes for Post-Lithium Ion Batteries

Contact Info

Product

Resources

About

The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers

Cited by 19 publications

References 49 publications

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Lithium dendrite growth mechanisms in polymer electrolytes and prevention strategies

Superionic UO2: A model anharmonic crystalline material

Ion Transport in Solvent-Free, Crosslinked, Single-Ion Conducting Polymer Electrolytes for Post-Lithium Ion Batteries

Contact Info

Product

Resources

About

Superionic UO₂: A model anharmonic crystalline material