THIN-FILM CATHODES FOR SECONDARY LITHIUM BATTERIES

We have prepared thin films of the active cathode materials LiCoO2 and LiMn2O4 by chemical techniques. Low pressure chemical vapor depositio n was successful at readily preparing LiCoO2 at temperatures ranging f rom 450 to 650 degrees C; however, in order to prepare the spinel phas e LiMn2O4 temperatures greater than 600 degrees C were required. The u se of a spray pyrolysis technique was successful in preparing both LiC oO2 and LiMn2O4 at substrates heated to temperatures as low as 400 deg rees C. This temperature was probably not the actual synthesis tempera ture since thermal gravimetric experiments tend to indicate that our s ol was capable of combustion synthesis.