Effect of Al[sub 2]O[sub 3]-Coated o-LiMnO[sub 2] Cathodes Prepared at Various Temperatures on the 55°C Cycling Behavior

The electrochemical cycling behavior of -coated orthorhombic cathodes prepared at various temperatures is reported. While the coated cathodes prepared at 600 and show that Al atoms are uniformly distributed throughout the particle, those prepared at 400 and show that Al atoms are mainly located at the surface region. This difference significantly affects both the discharge capacity and the cycle life of the electrodes, and lower temperature heat- treatment of the coated results in a higher capacity and a better cycle life during cycling. In particular, coated cathodes prepared at exhibit the best cycling performance, maintaining a maximum capacity of bare with a minimal capacity loss. Moreover, capacity fading is closely related to Mn dissolution from and phases appeared over the 3 and 4 V cycling, respectively. © 2001 The Electrochemical Society. All rights reserved.