Effect of Fuel Content and Temperature on Spinel LiMn2O4 Prepared by Solid-State Combustion Synthesis

Spinel LiMn2O4 powders were prepared by solid-state combustion synthesis using the manganese carbonate and the lithium carbonate as raw materials and the starch as fuel. The effects of the temperature (500, 600, and 700 degrees C) and fuel content (0 similar to 30%, mass fraction) on products were studied. The results indicated that high purity or single phase LiMn2O4 could be prepared quickly by solid state combustion method in 1 h. At 500, 600, and 700 degrees C, products with the main phase of LiMn2O4 could be obtained. At 600 degrees C, the products were better. Single phase LiMn2O4 could be prepared at 600 degrees C with the starch content of 20%. At 500 and 700 degrees C, impurity phase was Mn2O3 when the starch content <= 10%, and was Mn3O4 when the starch content >= 20%. At 600 degrees C, little impurity phase of Mn3O4 could appear when the starch content reached 30%. Mn2O3 could be generated easily at lower temperature, and Mn3O4 could be generated easily at higher temperature. At the same temperature, the effect of the starch content on the crystallinity of products was not obvious. With the same starch content, the crystallinity of products increased with the increasing temperature. The above experimental phenomena were explained through thermodynamic analysis.