The effect of the coexistence of anion species in imidazolium cation-based molten salt systems

Minato Egashira, Shigeto Okada, Jun ichi Yamaki

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Wider application of imidazolium cation-based room temperature molten salts in batteries and electrochemical capacitors will require an improvement of their cathodic and anodic stability. In this study, the authors found that a certain combination of anions can change the anodic stability and other properties of molten salt systems. A 1:1 (in moles) mixture of 1-ethyl-3-methyl imidazolium (EMI) tetrafluoroborate and EMI bis(tetrafluoromethanesulfonyl)imide (TFSI) exhibited an anodic stability similar to that of EMITFSI, the most anodically stable single-anion molten salt among the molten salts used in this study. This anion also altered other characteristics of the salt, such as ionic conductivity and thermal stability, compared to those seen by a simple combination of each of these single-anion salts. In contrast, coexistence of the TFSI anion and trifluoromethanesulfonyl (triflate) anion provided no significant change in any characteristics of the molten salt described above. The 1H-NMR study of these molten salts revealed that the coexistence of tetrafluoroborate anions and TFSI anions lowered the degree of hydrogen bonding from that in each individual molten salt, while the coexistence of the TFSI anion and triflate anion provided no changes in hydrogen bonding. The coexistence of anions, such as tetrafluoroborate and TFSI, is expected to change the manner of cation-anion association, which inhibits hydrogen bonding. Based on these results, the authors suggest the possibility of controlling the electrochemical stability of a molten salt by varying the manner of its cation-anion association.

Original languageEnglish
Pages (from-to)457-461
Number of pages5
JournalSolid State Ionics
Volume148
Issue number3-4
DOIs
Publication statusPublished - Jun 1 2002

Fingerprint

molten salts
Anions
Cations
Molten materials
Negative ions
Salts
Positive ions
anions
cations
Imides
imides
Hydrogen bonds
hydrogen
Association reactions
salts
electrochemical capacitors
Ionic conductivity
ion currents
electric batteries
capacitors

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

The effect of the coexistence of anion species in imidazolium cation-based molten salt systems. / Egashira, Minato; Okada, Shigeto; Yamaki, Jun ichi.

In: Solid State Ionics, Vol. 148, No. 3-4, 01.06.2002, p. 457-461.

Research output: Contribution to journalArticle

@article{f74c91f610ca4f188a9b44106e666442,
title = "The effect of the coexistence of anion species in imidazolium cation-based molten salt systems",
abstract = "Wider application of imidazolium cation-based room temperature molten salts in batteries and electrochemical capacitors will require an improvement of their cathodic and anodic stability. In this study, the authors found that a certain combination of anions can change the anodic stability and other properties of molten salt systems. A 1:1 (in moles) mixture of 1-ethyl-3-methyl imidazolium (EMI) tetrafluoroborate and EMI bis(tetrafluoromethanesulfonyl)imide (TFSI) exhibited an anodic stability similar to that of EMITFSI, the most anodically stable single-anion molten salt among the molten salts used in this study. This anion also altered other characteristics of the salt, such as ionic conductivity and thermal stability, compared to those seen by a simple combination of each of these single-anion salts. In contrast, coexistence of the TFSI anion and trifluoromethanesulfonyl (triflate) anion provided no significant change in any characteristics of the molten salt described above. The 1H-NMR study of these molten salts revealed that the coexistence of tetrafluoroborate anions and TFSI anions lowered the degree of hydrogen bonding from that in each individual molten salt, while the coexistence of the TFSI anion and triflate anion provided no changes in hydrogen bonding. The coexistence of anions, such as tetrafluoroborate and TFSI, is expected to change the manner of cation-anion association, which inhibits hydrogen bonding. Based on these results, the authors suggest the possibility of controlling the electrochemical stability of a molten salt by varying the manner of its cation-anion association.",
author = "Minato Egashira and Shigeto Okada and Yamaki, {Jun ichi}",
year = "2002",
month = "6",
day = "1",
doi = "10.1016/S0167-2738(02)00087-5",
language = "English",
volume = "148",
pages = "457--461",
journal = "Solid State Ionics",
issn = "0167-2738",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - The effect of the coexistence of anion species in imidazolium cation-based molten salt systems

AU - Egashira, Minato

AU - Okada, Shigeto

AU - Yamaki, Jun ichi

PY - 2002/6/1

Y1 - 2002/6/1

N2 - Wider application of imidazolium cation-based room temperature molten salts in batteries and electrochemical capacitors will require an improvement of their cathodic and anodic stability. In this study, the authors found that a certain combination of anions can change the anodic stability and other properties of molten salt systems. A 1:1 (in moles) mixture of 1-ethyl-3-methyl imidazolium (EMI) tetrafluoroborate and EMI bis(tetrafluoromethanesulfonyl)imide (TFSI) exhibited an anodic stability similar to that of EMITFSI, the most anodically stable single-anion molten salt among the molten salts used in this study. This anion also altered other characteristics of the salt, such as ionic conductivity and thermal stability, compared to those seen by a simple combination of each of these single-anion salts. In contrast, coexistence of the TFSI anion and trifluoromethanesulfonyl (triflate) anion provided no significant change in any characteristics of the molten salt described above. The 1H-NMR study of these molten salts revealed that the coexistence of tetrafluoroborate anions and TFSI anions lowered the degree of hydrogen bonding from that in each individual molten salt, while the coexistence of the TFSI anion and triflate anion provided no changes in hydrogen bonding. The coexistence of anions, such as tetrafluoroborate and TFSI, is expected to change the manner of cation-anion association, which inhibits hydrogen bonding. Based on these results, the authors suggest the possibility of controlling the electrochemical stability of a molten salt by varying the manner of its cation-anion association.

AB - Wider application of imidazolium cation-based room temperature molten salts in batteries and electrochemical capacitors will require an improvement of their cathodic and anodic stability. In this study, the authors found that a certain combination of anions can change the anodic stability and other properties of molten salt systems. A 1:1 (in moles) mixture of 1-ethyl-3-methyl imidazolium (EMI) tetrafluoroborate and EMI bis(tetrafluoromethanesulfonyl)imide (TFSI) exhibited an anodic stability similar to that of EMITFSI, the most anodically stable single-anion molten salt among the molten salts used in this study. This anion also altered other characteristics of the salt, such as ionic conductivity and thermal stability, compared to those seen by a simple combination of each of these single-anion salts. In contrast, coexistence of the TFSI anion and trifluoromethanesulfonyl (triflate) anion provided no significant change in any characteristics of the molten salt described above. The 1H-NMR study of these molten salts revealed that the coexistence of tetrafluoroborate anions and TFSI anions lowered the degree of hydrogen bonding from that in each individual molten salt, while the coexistence of the TFSI anion and triflate anion provided no changes in hydrogen bonding. The coexistence of anions, such as tetrafluoroborate and TFSI, is expected to change the manner of cation-anion association, which inhibits hydrogen bonding. Based on these results, the authors suggest the possibility of controlling the electrochemical stability of a molten salt by varying the manner of its cation-anion association.

UR - http://www.scopus.com/inward/record.url?scp=0036604437&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036604437&partnerID=8YFLogxK

U2 - 10.1016/S0167-2738(02)00087-5

DO - 10.1016/S0167-2738(02)00087-5

M3 - Article

AN - SCOPUS:0036604437

VL - 148

SP - 457

EP - 461

JO - Solid State Ionics

JF - Solid State Ionics

SN - 0167-2738

IS - 3-4

ER -