Soluble sulfur-based copolymers prepared from elemental sulfur and alkenyl alcohol as positive active material for lithium-sulfur batteries

Publication date: 19 May 2017
Source:Polymer, Volume 117
Author(s): Kazuhiro Yamabuki, Kanae Itaoka, Takahiro Shinchi, Nobuko Yoshimoto, Kazuhide Ueno, Hiromori Tsutsumi
We prepared random copolymers from elemental sulfur (S) and alkenyl alcohol (10-undecen-1-ol, UDOL). The copolymers, poly(S-r-UDOL), have hydroxyl groups in their side chain and are soluble into the organic solvents, tetrahydrofuran (THF), N-methyl-2-pyrrolidone and chloroform. The Ketjen Black (KB) powder which included poly(S-r-UDOL) in its pores, poly(S-r-UDOL)@KB, was prepared by dipping KB powder into the THF solution with poly(S-r-UDOL). The poly(S-r-UDOL)@KB electrode showed the electrochemical responses based on the redox reaction of polysulfide chains in poly(S-r-UDOL). The assembled cells with the poly(S-r-UDOL)@KB as a positive active material and lithium as a negative active material showed high discharge capacity at 1st cycle and low cycle performance under constant current charge-discharge conditions. Treatment of the poly(S-r-UDOL)@KB with hexamethylene diisocyanate (HDI) was effective in retention of the cell capacity. Formation of crosslinked structure between poly(S-r-UDOL) molecules in the KB pores through urethane bonds improved capacity retention of the Li- poly(S-r-UDOL) electrode battery system.

Graphical abstract

http://ift.tt/2oBr9KM