Thin films of LiMn2O4 spinel were fabricated by RF magnetron sputtering. The as-deposited films were amorphous but could be crystallized into a spinel structure by rapid thermal annealing in an oxygen atmosphere. The electrochemical performance of 2000 Angstrom thick LiMn2O4 thin-film cathodes were tested in a LiMn2O4/1M LiC1O(4) in PC + DME/Li cell. LiMn2O4 spinel films prepared at 750 degrees C showed good intercalation kinetics and very promising cycling behavior. Room temperature cycling of these films had capacities of about 50 mu Ah/cm(2).mu m at 200 mu A/cm(2) and maintained more than 98% of their original capacity after more than 1000 cycles.