Müller Henry A, Joshi Yug, Hadjixenophontos Efi, Peter Claudia, Csiszár Gábor, Richter Gunther, Schmitz Guido
Chair of Materials Physics, Institute of Materials Science, University of Stuttgart Heisenbergstraße 3 70569 Stuttgart Germany
Max-Planck-Institute for Intelligent Systems Heisenbergstraße 3 70569 Stuttgart Germany.
RSC Adv. 2020 Jan 22;10(7):3636-3645. doi: 10.1039/c9ra10125j.
Recent investigations of layered, rock salt and spinel-type manganese oxides in composite powder electrodes revealed the mutual stabilization of the Li-Mn-O compounds during electrochemical cycling. A novel approach of depositing such complex compounds as an active cathode material in thin-film battery electrodes is demonstrated in this work. It shows the maximum capacity of 226 mA h g which is superior in comparison to that of commercial LiMnO powder as well as thin films. Reactive ion beam sputtering is used to deposit films of a LiMnO composition. The method allows for tailoring of the active layer's crystal structure by controlling the oxygen partial pressure during deposition. Electron diffractometry reveals the presence of layered monoclinic and defect rock salt structures, the former transforms during cycling and results in thin films with extraordinary electrochemical properties. X-ray photoelectron spectroscopy shows that a large amount of disorder on the cation sub-lattices has been incorporated in the structure, which is beneficial for lithium migration and cycle stability.
近期对复合粉末电极中分层、岩盐型和尖晶石型锰氧化物的研究表明，在电化学循环过程中，锂锰氧化物化合物相互稳定。本文展示了一种将此类复杂化合物作为活性阴极材料沉积在薄膜电池电极中的新方法。其显示出226 mA h g的最大容量，与商业LiMnO粉末以及薄膜相比具有优势。采用反应离子束溅射法沉积LiMnO成分的薄膜。该方法可通过控制沉积过程中的氧分压来调整活性层的晶体结构。电子衍射测定表明存在层状单斜和缺陷岩盐结构，前者在循环过程中发生转变，从而产生具有非凡电化学性能的薄膜。X射线光电子能谱表明，结构中阳离子亚晶格上存在大量无序现象，这有利于锂的迁移和循环稳定性。
