Characterization of Sputter‐Deposited LiMn2 O 4 Thin Films for Rechargeable Microbatteries

Abstract

Thin films of 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 Å thick thin‐film cathodes were tested in a in cell. spinel films prepared at 750°C showed good intercalation kinetics and very promising cycling behavior. Room temperature cycling of these films had capacities of about 50 μAh/cm²·μm at 200 μA/cm² and maintained more than 98% of their original capacity after more than 1000 cycles.