Preparation and evaluation of lithium secondary batteries by using thin film technology

从2005年到2006年对氧化锰膜的制备工艺进行了研究。在开始这项研究之前，我们发现已经用反应蒸发法制备了锂二次电池用的锰氧化物(Mn3O4)薄膜。由于金属锰在氧气气氛中蒸发，所以坩埚中的金属锰受到氧化。因此，沉积速度随着沉积次数的增加而恶化。本研究提出了一种在反应蒸发过程中阻止锰蒸发剂与氧气气氛接触的技术。通过我们的研究，我们已经开发出三种类型的分离器：钼分离器、不锈钢电池(SUS电池)和石英瓶。它们已经安装在锰质坩埚的底部。在对Mn3O4薄膜进行评价时，发现需要制备含Li的锰氧化物薄膜。2006年开始采用溅射法制备LiMn2O4薄膜。结果表明，即使在室温(R.T.)的衬底温度下也能制备出LiMn2O4薄膜。用这种方法。该材料在性价比上优于其他材料，且无毒。经过快速热退火(RTA)处理后，样品的结晶性能得到改善。通过这项研究，制备程序已经很复杂了。这项研究正在进行中。

The preparation procedure of manganese oxide films have been investigated from 2005 through 2006. Before starting this research, it was found that manganese oxide (Mn_3O_4) films for lithium secondary batteries have been prepared using a reactive evaporation method. The metallic Mn in the crucible suffers oxidation since it is evaporated in the oxygen atmosphere. So the deposition rate is deteriorated with increasing deposition run.This research shows a technique which keeps off the Mn evaporant from oxygen atmosphere during the reactive evaporation process. Three types of separators have been developed through our studies: a Mo separator, a stainless steel cell (SUS cell), and a quartz ampoule. They have been installed in the bottom of the Mn crucible. The Mn_3O_4 films could be prepared with high reproducibility with these devices.During the evaluation of Mn_3O_4 films, it was found that manganese oxide films which involve Li have to be prepared. Preparation of LiMn_2O_4 thin films using a sputtering method was started on 2006. It was found that LiMn_2O_4 thin films could be prepared even at the substrate temperature of room temperature (R.T.) by this method. This material is superior to other materials in the cost performance as well as non-toxic. The crystal properties could be improved after a rapid thermal annealing (RTA) process. The preparation procedure has been sophisticated through this study. The study is now under way.