Direct Fabrication of Lithium Double Oxides Films by Solution Processes

LiCoO_2、LiNiO_2等锂复合氧化物是锂电池研究最多的电极材料。采用溶胶-凝胶法、喷雾热解法、CVD法和PVD法（包括溅射法和真空激光烧蚀法）制备了它们的薄膜。这些方法将通过在>800 ℃下加热/烧制、产生高能物质和/或保持真空来消耗大量能量。为了减少能源和材料的消耗，我们提出了“软溶液工艺”来制备高性能的陶瓷薄膜，如LiCoO_2和/或LiNiO_2薄膜，在本研究中，我们成功地在室温至200℃的低温水溶液中直接制备了LiCoO_2和/或LiNiO_2薄膜。开发的水热/电化学方法使我们能够在Pt，Ni，石墨以及Co衬底上的Ni上制备这些薄膜。它们结晶良好且具有电化学活性。我们还可以证明在任何基底上陶瓷膜的可能的直接图案化，包括有机多孔材料，如纸/布/聚合物。

Lithiuun double oxides like LiCoO_2, LiNiO_2, etc. are most extensively studied for electrode materials for lithium batteries. Their films have been fabricated by sol-gel, spray-pyrolysis, CVD and PVD including sputtering and laser ablation methods in vacuum. Those methods would consume huge amount of energies by heating/firing at >800 ℃, creating highly energetic species, and/or keeping vacuum. To minimize the consumption of energies and materials, we are proposing "Soft Solution Processing" to fabricate highly functional ceramics film like lithium double oxides.In the present study, we have succeeded to fabricate the films of LiCoO_2 and/or LiNiO_2 directly in aqueous solutions at low temperatures at RT-200℃ without any post-firing. The developed hydrothermal/electrochemical methods enable us to fabricate those films on Pt, Ni, Graphite, as well as Ni on Co substrates. They are well-crystallized and electrochemically active. We could also demonstrate a possible a possible direct patterning of ceramic films on any substrate including organic porous materials like paper/cloth/polymers.