Electrochemical studies of low-temperature processed nano-crystalline LiMn2O4 thin film cathode at 55°C

LiMn2O4 thin films with nano-crystals less than 100 nm were successfully grown on polished stainless steel substrates at 400 degrees C and 200 m Torr of oxygen by pulsed laser deposition. A maximum discharge capacity of 62.4 mu Ah cm(-2) mu m(-1) cycled between 3.0 and 4.5 V with a current density of 20 mu Ah cm(-2) was achieved. The effect of several overdischarge cycles was negligible, and both the effect of Jahn-Teller distortion at low potentials on capacity loss and structure instability at high potentials were effectively inhibited in this nano-crystalline film, resulting in an excellent cycling stability with a very low fading rate of capacity up to 500 cycles at 55 degrees C. (c) 2006 Elsevier B.V. All rights reserved.