NEW ORGANODISULFIDE POLYANILINE COMPOSITE CATHODE FOR SECONDARY LITHIUM BATTERY

A new composite cathode used for high-energy density secondary lithium batteries is developed, which consists of 2,5-dimercapto-1,3,4-thiadiazole (organodisulfide), polyaniline, and gel electrolyte. Polyaniline works to promote the redox reaction of the organodisulfide in the composite electrode, providing the cyclic voltammogram showing a narrower peak-potential separation of 0.5V between cathode and anode peaks. The lithium cell using the composite cathode and gel electrolyte based on acrylonitrile-methylacrylate copolymer has over 3.OV cell voltage with 303 Wh kg-1 cathode energy density at a current density of 0.1 mA cm-2 at room temperature. In practice, a model cell with 80-mu-m thick lithium anode, 50-mu-m thick gel electrolyte, and 170-mu-m thick composite cathode is expected to deliver 220 Wh kg-1 cell energy density at 0.1 mA cm-2.