Composite cathodes, electrochemical cells comprising novel composite cathodes, and processes for fabricating same

The present invention pertains to composite cathodes suitable for use in an electrochemical cell, said cathodes comprising: (a) an electroactive sulfur-containing cathode material, wherein said electroactive sulfur-containing cathode material, in its oxidized state, comprises a polysulfide moiety of the formula —S m —, wherein m is an integer equal to or greater than 3; and, (b) an electroactive transition metal chalcogenide composition, which encapsulates said electroactive sulfur-containing cathode material, and which retards the transport of anionic reduction products of said electroactive sulfur-containing cathode material, said electroactive transition metal chalcogenide composition comprising an electroactive transition metal chalcogenide having the formula M j Y k (OR) l wherein: M is a transition metal; Y is the same or different at each occurrence and is oxygen, sulfur, or selenium; R is an organic group and is the same or different at each occurrence; j is an integer ranging from 1 to 12; k is a number ranging from 0 to 72; and l is a number ranging from 0 to 72; with the proviso that k and l cannot both be 0. The present invention also pertains to methods of making such composite cathodes, cells comprising such composite cathodes, and methods of making such cells.