Morphology and electrochemical properties of LiMn 2 O 4 powders derived from the sol-gel route

Spinel-lithium manganese oxide (LiMn 2 O 4 ) powders are prepared by the sol-gel method using polyvinyl alcohol (PVA) in this study, and evaluated as a positive electrode material for Li-ion batteries. PVA helps to maintain the homogeneity of the system in the precursors and thereby facilitates the formation of monophasic powders. The average primary particle size of the calcined LiMn 2 O 4 powders decreases with an increase in the amount of PVA used in solution. Increasing the amount of PVA also results in a rise in the discharge capacity at 25 ¢XC because of the large interface area of small particles. On the other hand, the discharge capacity of the small LiMn 2 O 4 particles suffers markedly capacity fading when the batteries are operated at elevated temperatures. ? 2001 Elsevier Science B.V.