【摘要】 以碳酸锰和碳酸锂为原料、淀粉为燃料,研究了温度(500,600,700℃)和燃料量(0～30%,质量分数)对固相燃烧合成尖晶石型LiMn2O4的影响。实验结果表明,通过固相燃烧合成方法在1h可快速制备高纯度或单相的尖晶石型LiMn2O4产物。在500,600,700℃添加10%～30%淀粉时,可得到主晶相为LiMn2O4的产物,但600℃时最好。在600℃添加20%淀粉时,固相燃烧合成可得到单相尖晶石型LiMn2O4产物;在500和700℃淀粉量≤10%时,产物中杂相为Mn2O3,而淀粉量≥20%为Mn3O4。在600℃时,淀粉量达到30%产物中才有极少Mn3O4出现。温度较低时易生成Mn2O3,高温时易生成Mn3O4;加热温度相同时淀粉量对产物晶粒的结晶度影响不大,而淀粉量相同时,产物晶粒的结晶度随加热温度而增加。从化学热力学原理的角度探讨了不同温度和燃料量对固相燃烧合成产物组成的影响。更多还原

【Abstract】 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 oC) and fuel content (0～30%,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 oC,products with the main phase of LiMn2O4 could be obtained. At 600 oC,the products were better. Single phase LiMn2O4 could be prepared at 600 oC with the starch content of 20%. At 500 and 700 oC,impurity phase was Mn2O3 when the starch content ≤10%,and was Mn3O4 when the starch content ≥20%. At 600 oC,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.更多还原