Preparation and characterization of partially substituted LiMyMn2-yO4 (M = Ni, Co, Fe) spinel cathodes for Li-ion batteries

The electrochemical and thermal behaviors of the spinels-LiMn2O4, LiCo1/6Mn11/6O4, LiFe1/6Mn11/6O4, and LiNi1/6Mn11/6O4 were studied using electrochemical and thermochernical techniques. The electrochemical techniques included cyclic voltammetry, charge-discharge cycling of 2016 coin cells and diffusion coefficient measurements using Galvanostatic Intermittent Titration Technique. Better capacity retention was observed for the substituted spinels (0.11% loss percycle for LiCo1/6Mn11/6O4; 0.3% loss per cycle for LiFe1/6Mn11/6O4; and 0.2% loss per cycle for LiNi1/6Mn11/6O4) than for the lithium manganese dioxide spinel (1.6% loss per cycle for first ten cycles, 0.9% loss per cycle for 33 cycles) during 33 cycled. The Differential Scanning Calorimetry results showed that the cobalt substituted spinel has better thermal stability than the lithium manganese oxide and other substituted spinels. (C) 2002 Elsevier Science Ltd. All rights reserved.