SULFUR–BASED LITHIUM-ORGANIC ELECTROLYTE SECONDARY BATTERIES

摘要

This program is aimed at developing a rechargeable organic-electrolyte lithium battery to operate over the range -40 to +160F, have an energy density approaching 100 Whr/lb, a cycle life in excess of 500, and high charge retention. The approach is to use positive electrodes based on higher sulfides of Nb, Ti and V. Nb and Ti disulfides and trisulfides were prepared thermally. They were characterized by scanning electron microscopy and by x-ray diffraction. All sulfides are electrochemically active and show similar overall behavior. The discharge mechanism involves a change in the valence of the transition metal, while maintaining the original layer structure, and compensation of the negative charge by intercalation of cations. Nature and concentration of the cations affect the discharge behavior. Non-metals such as S and I could either not be intercalated or were electrochemically inactive. Differences in the electrochemical behavior of the various sulfides and electrode structures are discussed.