DEVELOPMENT OF LITHIUM-MANGANESE COMPOSITE OXIDES AS CATHODE MATERIALS FOR LITHIUM-ION BATTERIES.

我们开发了熔融浸渍法制备锂离子电池正极材料（锂锰氧化物）的工艺。主要研究了尖晶石型Li_xMn_yO_4和Li_MnO_2两种材料<0.33>。主要研究结果如下：（1）建立了锂二次电池正极材料Li_xMn_yO_4的制备方法（熔融浸渍法）。我们发现，通过通入氮气可以很容易地控制尖晶石Li_xMn_yO_4的氧含量。B）初步阐明了Li_xMn_yO_4的尖晶石结构式与电池性能的关系。基于尖晶石式，尖晶石化合物分为两组，富氧尖晶石和富锂尖晶石。这些话让我们逐渐在电池研究人员中流行起来。（3）阐明了尖晶石Li_xMn_yO_4正极材料在室温和高温（50 ℃以上）下容量衰减的机理。（4）在400 ℃以下生成的锂锰氧化物是一种新材料Li_<0.33>MnO_2。确定了制备具有优良电池性能的高性能锂离子电池的最佳工艺条件。

We have developed the preparation procedures of cathode materials (Lithium-Manganese oxides) for lithium-ion batteries by melt-impregnation method developed us. Two types of material, 1) spinel Li_xMn_yO_4 and 2) Li_<0.33>MnO_2, were mainly studied. The obtained important results are as follows ; a) The preparation method (melt-impregnation method) for spinel Li_xMn_yO_4 excellent as cathode in lithium secondary batteries has been established. We found that the oxygen content of spinel Li_xMn_yO_4 was easily controlled by the introduction of nitrogen gas. b) The relation between the spinel formula of Li_xMn_yO_4 and its battery performance is initially clarified. Based on the spinel formula, spinel compounds are divided into two groups, oxygen rich and lithium rich spinel. These words proposed us become popular gradually among battery researchers. c) The mechanism of capacity fading in spinel Li_xMn_yO_4 cathode at room temperature and higher temperature (50>ﾟC) are clarified. d) Lithium-manganese oxide formed at less than 400ﾟC is proofed to be new material, Li_<0.33>MnO_2. The optimum condition for the preparation of it with excellent battery performance is determined.