Structure and Ionic Conductivity of Polystyrene-block-poly(ethylene oxide) Electrolytes in the High Salt Concentration Limit

Mahati Chintapalli; Thao N.P. Le; Naveen R. Venkatesan; Nikolaus G. Mackay; Adriana A. Rojas; Jacob L. Thelen; X. Chelsea Chen; Didier Devaux; Nitash P. Balsara

doi:10.1021/acs.macromol.5b02620

Structure and Ionic Conductivity of Polystyrene-block-poly(ethylene oxide) Electrolytes in the High Salt Concentration Limit

Mahati Chintapalli, Thao N.P. Le, Naveen R. Venkatesan, Nikolaus G. Mackay, Adriana A. Rojas, Jacob L. Thelen, X. Chelsea Chen, Didier Devaux, Nitash P. Balsara

Research output: Contribution to journal › Article › peer-review

136 Scopus citations

Abstract

We explore the relationship between the morphology and ionic conductivity of block copolymer electrolytes over a wide range of salt concentrations for the system polystyrene-block-poly(ethylene oxide) (PS-b-PEO, SEO) mixed with lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI). Two SEO polymers were studied, SEO(16-16) and SEO(4.9-5.5), over the salt concentration range r = 0.03-0.55. The numbers x and y in SEO(x-y) are the molecular weights of the blocks in kg mol^-1, and the r value is the molar ratio of salt to ethylene oxide moieties. Small-angle X-ray scattering was used to characterize morphology and grain size at 120 °C, differential scanning calorimetry was used to study the crystallinity and the glass transition temperature of the PEO-rich microphase, and ac impedance spectroscopy was used to measure ionic conductivity as a function of temperature. The most surprising observation of our study is that ionic conductivity in the concentration regime 0.11 ≤ r ≤ 0.21 increases in SEO electrolytes but decreases in PEO electrolytes. The maximum in ionic conductivity with salt concentration occurs at about twice the salt concentration in SEO (r = 0.21) as in PEO (r = 0.11). We propose that these observations are due to the effect of salt concentration on the grain structure in SEO electrolytes.

Original language	English
Pages (from-to)	1770-1780
Number of pages	11
Journal	Macromolecules
Volume	49
Issue number	5
DOIs	https://doi.org/10.1021/acs.macromol.5b02620
State	Published - Mar 9 2016
Externally published	Yes

Funding

The primary support for this research is by the National Science Foundation (Division of Materials Research), Grant No. 1505444. Small-angle X-ray spectroscopy was performed at beamline 7.3.3 at the Advanced Light Source synchrotron in Berkeley, CA. Beamline 7.3.3 is supported by the Director of the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract DE-AC02-05CH11231. Electron microscopy was supported by the Soft Matter Electron Microscopy and Scattering program from the Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the U.S. Department of Energy, under Contract DE-AC02-05CH11231. M.C. was supported by the National Science Foundation Graduate Research Fellowship under Grant GE1106400.

Funders	Funder number
Office of Basic Energy Sciences
National Science Foundation
U.S. Department of Energy	DE-AC02-05CH11231
Division of Materials Research	1505444
Office of Science
Division of Materials Sciences and Engineering	GE1106400

Access to Document

10.1021/acs.macromol.5b02620

Cite this

@article{f12b58aa1bf044c59c31f99df1ad5aeb,

title = "Structure and Ionic Conductivity of Polystyrene-block-poly(ethylene oxide) Electrolytes in the High Salt Concentration Limit",

abstract = "We explore the relationship between the morphology and ionic conductivity of block copolymer electrolytes over a wide range of salt concentrations for the system polystyrene-block-poly(ethylene oxide) (PS-b-PEO, SEO) mixed with lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI). Two SEO polymers were studied, SEO(16-16) and SEO(4.9-5.5), over the salt concentration range r = 0.03-0.55. The numbers x and y in SEO(x-y) are the molecular weights of the blocks in kg mol-1, and the r value is the molar ratio of salt to ethylene oxide moieties. Small-angle X-ray scattering was used to characterize morphology and grain size at 120 °C, differential scanning calorimetry was used to study the crystallinity and the glass transition temperature of the PEO-rich microphase, and ac impedance spectroscopy was used to measure ionic conductivity as a function of temperature. The most surprising observation of our study is that ionic conductivity in the concentration regime 0.11 ≤ r ≤ 0.21 increases in SEO electrolytes but decreases in PEO electrolytes. The maximum in ionic conductivity with salt concentration occurs at about twice the salt concentration in SEO (r = 0.21) as in PEO (r = 0.11). We propose that these observations are due to the effect of salt concentration on the grain structure in SEO electrolytes.",

author = "Mahati Chintapalli and Le, {Thao N.P.} and Venkatesan, {Naveen R.} and Mackay, {Nikolaus G.} and Rojas, {Adriana A.} and Thelen, {Jacob L.} and Chen, {X. Chelsea} and Didier Devaux and Balsara, {Nitash P.}",

note = "Publisher Copyright: {\textcopyright} 2016 American Chemical Society.",

year = "2016",

month = mar,

day = "9",

doi = "10.1021/acs.macromol.5b02620",

language = "English",

volume = "49",

pages = "1770--1780",

journal = "Macromolecules",

issn = "0024-9297",

publisher = "American Chemical Society",

number = "5",

}

TY - JOUR

T1 - Structure and Ionic Conductivity of Polystyrene-block-poly(ethylene oxide) Electrolytes in the High Salt Concentration Limit

AU - Chintapalli, Mahati

AU - Le, Thao N.P.

AU - Venkatesan, Naveen R.

AU - Mackay, Nikolaus G.

AU - Rojas, Adriana A.

AU - Thelen, Jacob L.

AU - Chen, X. Chelsea

AU - Devaux, Didier

AU - Balsara, Nitash P.

PY - 2016/3/9

Y1 - 2016/3/9

N2 - We explore the relationship between the morphology and ionic conductivity of block copolymer electrolytes over a wide range of salt concentrations for the system polystyrene-block-poly(ethylene oxide) (PS-b-PEO, SEO) mixed with lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI). Two SEO polymers were studied, SEO(16-16) and SEO(4.9-5.5), over the salt concentration range r = 0.03-0.55. The numbers x and y in SEO(x-y) are the molecular weights of the blocks in kg mol-1, and the r value is the molar ratio of salt to ethylene oxide moieties. Small-angle X-ray scattering was used to characterize morphology and grain size at 120 °C, differential scanning calorimetry was used to study the crystallinity and the glass transition temperature of the PEO-rich microphase, and ac impedance spectroscopy was used to measure ionic conductivity as a function of temperature. The most surprising observation of our study is that ionic conductivity in the concentration regime 0.11 ≤ r ≤ 0.21 increases in SEO electrolytes but decreases in PEO electrolytes. The maximum in ionic conductivity with salt concentration occurs at about twice the salt concentration in SEO (r = 0.21) as in PEO (r = 0.11). We propose that these observations are due to the effect of salt concentration on the grain structure in SEO electrolytes.

AB - We explore the relationship between the morphology and ionic conductivity of block copolymer electrolytes over a wide range of salt concentrations for the system polystyrene-block-poly(ethylene oxide) (PS-b-PEO, SEO) mixed with lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI). Two SEO polymers were studied, SEO(16-16) and SEO(4.9-5.5), over the salt concentration range r = 0.03-0.55. The numbers x and y in SEO(x-y) are the molecular weights of the blocks in kg mol-1, and the r value is the molar ratio of salt to ethylene oxide moieties. Small-angle X-ray scattering was used to characterize morphology and grain size at 120 °C, differential scanning calorimetry was used to study the crystallinity and the glass transition temperature of the PEO-rich microphase, and ac impedance spectroscopy was used to measure ionic conductivity as a function of temperature. The most surprising observation of our study is that ionic conductivity in the concentration regime 0.11 ≤ r ≤ 0.21 increases in SEO electrolytes but decreases in PEO electrolytes. The maximum in ionic conductivity with salt concentration occurs at about twice the salt concentration in SEO (r = 0.21) as in PEO (r = 0.11). We propose that these observations are due to the effect of salt concentration on the grain structure in SEO electrolytes.

UR - http://www.scopus.com/inward/record.url?scp=84960449436&partnerID=8YFLogxK

U2 - 10.1021/acs.macromol.5b02620

DO - 10.1021/acs.macromol.5b02620

M3 - Article

AN - SCOPUS:84960449436

SN - 0024-9297

VL - 49

SP - 1770

EP - 1780

JO - Macromolecules

JF - Macromolecules

IS - 5

ER -

Structure and Ionic Conductivity of Polystyrene-block-poly(ethylene oxide) Electrolytes in the High Salt Concentration Limit

Abstract

Funding

Access to Document

Other files and links

Fingerprint

Cite this