Benzene-based polyorganodisulfide cathode materials for secondary lithium batteries

A novel kind of benzene-based organodisulfide, 5,8-dihydro-1H,4H-2,3,6,7-tetrathia-anthracene (DTTA) and its homopolymer, poly(5,8dihydro-1H,4H-2,3,6,7-tetr ithia-anthracene) (PDTTA) were designed, synthesized and presented as a cathode material for high-energy v secondary lithium batteries. The polyorganodisulfides were characterized by FT-IR, XPS and elemental analysis. The designed system has many advantages, such as high theoretical charge density (ca. 471 mAh/g), fast redox process and enhanced cycling stability, which are due to the intramolecular electrocatalytic effect of polyphenyl chain and the intramolecular cleavage-recombination of the S-S bond, respectively. The cyclic voltammetry test results proved the effect of this kind of electrocatalysis, and the charge-discharge experimental results showed that the polymer has the specific capacity of 422 mAh/g at 2nd cycle and 170 mAh/g at the 44th cycle. (c) 2005 Elsevier Ltd. All rights reserved.