Application of Dibenzo[c,e][1,2]dithiin, Phenanthro[4,5-cde][1,2]dithiin, Triphenyleno[1,12-cde][1,2]dithiin, and 6,7-Dithiodibenzo[c,e][1,2]dithiin as Cathode Active Materials for Lithium Secondary Batteries

Abstract

Dibenzo[c,e][1,2]dithiin (1), phenanthro[4,5-cde][1,2]dithiin (2), triphenyleno[l,12-cde][l,2]dithiin (3), and 6,7-dithiodibenzo[c,e][1,2]dithiin (4) were synthesized and the electrochemical properties of their compounds were investigated as cathode active materials in lithium secondary batteries. When solid polymer electrolyte (SPE) was used for making cells, the initial discharge capacity of the cell made of 2 (abbreviated as the cell 2 and so on) and the cell 3 were 177.4 mAh/g and 122.3 mAh/g at 60°C respectively. Furthermore, the cell 4, which has two disulfides in a molecule, showed the good initial discharge capacity of 264.1 mAh/g and the large rechargeable capacity, and the best electrochemical behaviors among 1, 2, 3, and 4.