TY - JOUR
T1 - Suppression of polysulfide dissolution by polypyrrole modification of sulfur-based cathodes in lithium secondary batteries
AU - Nakamura, Natsuki
AU - Yokoshima, Tokihiko
AU - Nara, Hiroki
AU - Momma, Toshiyuki
AU - Osaka, Tetsuya
N1 - Funding Information:
This work was partly supported by a Grant-in-Aid for specially promoted research “Establishment of electrochemical device engineering” from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) , Japan, “Advanced Low Carbon Technology Research and Development Program, Specially Promoted Research for Innovative Next Generation Batteries (ALCA Spring)” from Japan Science and Technology Agency (JST) , Japan.
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2015/1/15
Y1 - 2015/1/15
N2 - In order to solve the problem of polysulfide dissolution into the electrolyte on sulfur-based cathodes, we propose a novel method of modifying the S cathode by coating it with a polypyrrole (PPy) film, which is prepared by oxidative electropolymerization using a solution consisting of, 1-methyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and pyrrole. The PPy film demonstrates a high Li+ transport number. The film also exhibits a superior ability to inhibit polysulfide dissolution into the electrolyte during the charge-discharge cycles. Furthermore, the charge-discharge properties of the coated cathode is evaluated using an electrolyte consisting of 1.0 M LiTFSI in a mixture of 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL), which is known to easily dissolve polysulfides. Because of the surface modification with the PPy film, the cathode exhibits excellent specific capacities of 823 and 354 mAh g-1 at C-rates of 0.1 and 1.0 C, respectively, with high coulombic efficiency. Thus, the strategy of coating the S cathode with PPy is successful in inhibiting the polysulfides dissolution even in electrolytes known to easily dissolve polysulfides, besides allowing high C-rate operation. Further, the modification of the S cathode allows the selection of a suitable electrolyte based on the anode, rather than being limited by the cathode.
AB - In order to solve the problem of polysulfide dissolution into the electrolyte on sulfur-based cathodes, we propose a novel method of modifying the S cathode by coating it with a polypyrrole (PPy) film, which is prepared by oxidative electropolymerization using a solution consisting of, 1-methyl-1-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and pyrrole. The PPy film demonstrates a high Li+ transport number. The film also exhibits a superior ability to inhibit polysulfide dissolution into the electrolyte during the charge-discharge cycles. Furthermore, the charge-discharge properties of the coated cathode is evaluated using an electrolyte consisting of 1.0 M LiTFSI in a mixture of 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL), which is known to easily dissolve polysulfides. Because of the surface modification with the PPy film, the cathode exhibits excellent specific capacities of 823 and 354 mAh g-1 at C-rates of 0.1 and 1.0 C, respectively, with high coulombic efficiency. Thus, the strategy of coating the S cathode with PPy is successful in inhibiting the polysulfides dissolution even in electrolytes known to easily dissolve polysulfides, besides allowing high C-rate operation. Further, the modification of the S cathode allows the selection of a suitable electrolyte based on the anode, rather than being limited by the cathode.
KW - Electropolymerizing
KW - Li-ion permselectivity
KW - Polypyrrole
KW - Polysulfide dissolution
KW - Sulfur-based cathode
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U2 - 10.1016/j.jpowsour.2014.10.192
DO - 10.1016/j.jpowsour.2014.10.192
M3 - Article
AN - SCOPUS:84910046931
SN - 0378-7753
VL - 274
SP - 1263
EP - 1266
JO - Journal of Power Sources
JF - Journal of Power Sources
ER -