Cation and anion diffusion in the amorphous phase of the polymer electrolyte (PEO) 8LiCF3SO3

Bhattacharja, Sankar; Smoot, S.W.; Whitmore, D. H.

doi:10.1016/0167-2738(86)90132-3

Cited by 111 publications

(61 citation statements)

References 8 publications

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“…Through the use of 19 F NMR and the commonly employed counterion CF 3 SO3", anion transport can be measured as well. These measurements were first applied to polymer electrolytes by Mali and coworkers [12] and later by Bhattacharja and co-workers [13]. An important conclusion of the latter study was that cation and anion mobilities are comparable, a result which has been verified by other "direct" techniques such as radiotracer diffusion [10(a)] or electrochemical transference number measurements.…”

Section: Review Of Experimental Resultssupporting

confidence: 51%

NMR studies of ion mobility and association in polyether‐based polymer electrolytes

Greenbaum

1993

Polymers for Advanced Techs

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The results of several investigations of polyether‐based polymer electrolytes by nuclear magnetic resonance (NMR) spectroscopy conducted in the author's laboratory and by other groups are reviewed. For both 7Li and 23Na NMR, the onset of motional line‐narrowing occurs at about the glass transition temperature, illustrating the importance of polymer segmental motion to ion transport. Examples of the ability of NMR to probe cationanion interactions are discussed. These include chemical shift variations corresponding to different Li+ environments and nuclear quadrupole coupling and relaxation behavior as a probe of Na+ environment.

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Section: Review Of Experimental Resultssupporting

confidence: 51%

NMR studies of ion mobility and association in polyether‐based polymer electrolytes

Greenbaum

1993

Polymers for Advanced Techs

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“…[34][35][36] Nevertheless, the majority of reports for t + in polymer electrolytes fall between zero and one. [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] In contrast, all reports of t + in non-aqueous liquid electrolytes containing lithium salts fall between zero and one, including those that followed the techniques outlined by Ma and coworkers. [52][53][54][55][56] Zugmann and coworkers presented a comparative study using four different methods for measuring t + in nonaqueous liquid electrolytes.…”

mentioning

confidence: 99%

Negative Transference Numbers in Poly(ethylene oxide)-Based Electrolytes

Pesko

Timachova

Bhattacharya

et al. 2017

J. Electrochem. Soc.

192

367

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The performance of battery electrolytes depends on three independent transport properties: ionic conductivity, diffusion coefficient, and transference number. While rigorous experimental techniques for measuring conductivity and diffusion coefficients are well-established, popular techniques for measuring the transference number rely on the assumption of ideal solutions. We employ three independent techniques for measuring transference number, t + , in mixtures of polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt. Transference numbers obtained using the steady-state current method pioneered by Bruce and Vincent, t +,SS , and those obtained by pulsed-field gradient NMR, t +,NMR , are compared against a new approach detailed by Newman and coworkers, t +,Ne , for a range of salt concentrations. The latter approach is rigorous and based on concentrated solution theory, while the other two approaches only yield the true transference number in ideal solutions. Not surprisingly, we find that t +,SS and t +,NMR are positive throughout the entire salt concentration range, and decrease monotonically with increasing salt concentration. In contrast, t +,Ne has a non-monotonic dependence on salt concentration and is negative in the highly-concentrated regime. Our work implies that ion transport in PEO/LiTFSI electrolytes at high salt concentrations is dominated by the transport of ionic clusters. Energy density and safety of conventional lithium-ion batteries is limited by the use of liquid electrolytes comprising mixtures of flammable organic solvents and lithium salts. Polymer electrolytes have the potential to address both limitations. However, the power and lifetime of batteries containing solvent-free polymer electrolytes remain inadequate for most applications. The performance of electrolytes in batteries depends on three independent transport properties: ionic conductivity, σ, salt diffusion coefficient, D, and cation transference number, t + .1 The poor performance of batteries with polymer electrolytes is generally attributed to low conductivity, which is on the order of 10 −3 S/cm at 90• C for mixtures of polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt, 2,3 compared to that of liquid electrolytes which is 10 −2 S/cm at ambient temperatures. 4 Much of the literature in this field has been devoted to increasing the ionic conductivity of these materials.5-32 The purpose of our work is to shed light on another transport property of polymer electrolytes, the transference number.In a pioneering study, Ma and coworkers showed that the transference number of a mixture of PEO and a sodium salt is negative. 33Following this approach, others have obtained t + <0 in polymers containing lithium or sodium salts. [34][35][36] Nevertheless, the majority of reports for t + in polymer electrolytes fall between zero and one. [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] In contrast, all reports of t + in non-aqueous liquid electrolytes containi...

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“…Furthermore, previous structural studies by Dehas et al 23 on the sodium cobalt bronzes indicate that interchange between the P2 and other phases occurs with difficulty and only at temperatures above 700OC.…”

Section: Nal~pbnao~cooz Cellsmentioning

confidence: 99%

“…studied materials are -lithium-intercalating titanium disulfide, vanadium oxides, manganese oxides, 10-15 and cobalt and nickel oxides 16-20 for lithium cells, and the sodium analogues of these for sodium cells. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Lithium and sodium batteries are attractive not only for their potential high energy density but also because a battery assembly that is completely solid state is possible using solid-state lithium or-sodium ion conducting electrolytes. Solid-state polymer electrolytes were proposed by Armand in 1979 for lithium battery use, 37 and have attracted great attention since then.…”

Section: -9mentioning

confidence: 99%

Solid-state sodium batteries using polymer electrolytes and sodium intercalation electrode materials

Yun

1996

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Cation and anion diffusion in the amorphous phase of the polymer electrolyte (PEO) 8LiCF3SO3

Cited by 111 publications

References 8 publications

NMR studies of ion mobility and association in polyether‐based polymer electrolytes

NMR studies of ion mobility and association in polyether‐based polymer electrolytes

Negative Transference Numbers in Poly(ethylene oxide)-Based Electrolytes

Solid-state sodium batteries using polymer electrolytes and sodium intercalation electrode materials

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