Sulfides organic polymer: Novel cathode active material for rechargeable lithium batteries

Two novel sulfide polymers, poly(2-phenyl-1,3-dithiolane) and poly[ 1,4-di(1,3-dithiolan-2-yl)benzene], were prepared via facile oxidative-coupling polymerization under ambient conditions, characterized by FT-IR, XRD, TGA and elemental analysis, and were tested as cathode materials in rechargeable lithium battery. The charge-discharge tests showed that the specific capacity of poly[ 1,4-di(1,3-dithiolan-2-yl)benzene)] was 378 mAh g(-1) at the third cycle, and retained at 300 mAh g(-1) after 20 cycles. The specific capacity of poly(2-phenyl-1,3-dithiolane) was 117 mAh g(-1) at the second cycle, and retained at 100 mAh g(-1) after 20 cycles. The results indicated that thiolane group could be used as cathode active function group for lithium secondary batteries and the novel electrode reaction is proposed tentatively. (C) 2007 Elsevier B.V. All rights reserved.