The Chemistry of TiS3 and NbSe3 Cathodes

The cell discharge reactions of and cathodes in nonaqueous lithium cells have been shown to involve three lithiums per . Using reaction with as a model for cell discharge we show that cell discharge involves topochemical reactions in which the basic strucutre of the is maintained. Both and are chain structures containing X‒X bonds. The groups are reducible as well as the M 4+ ion, accounting for the stoichiometry. The cell reaction is reversible for , but only partially reversible for . Irreversibility in is suggested to be due to a change in coordination geometry of Ti 4+ from trigonal prismatic to octahedral.