Microstructure Analysis and Characterization of Li(NiCoMn)O2 Thin Film for Cathode Application Prepared by Li Diffusion on the Ni-Co-Mn Alloy Substrates
The currently used cathode material for secondary batteries such as LiCoO2 exhibited limit to further improve the functionality of the batteries, since the screen printing method cannot reduce the thickness of the battery further with the solid state reacted powder which has the size of several micrometer. In this study, we have synthesized Li(NiCoMn)O2 thin film to replace LiCoO2 thick film by employing Li-diffusion reaction on the surface of the textured Ni-Co-Mn alloy. The cube-textured Ni-Mn alloy was prepared by cold-isostatic pressing of mixed Ni-Mn powder, sintering, repeated rolling process, and annealing heat treatment for texture development. After thin layer of metallic Li was deposited on the surface of Ni-Co-Mn template using thermal evaporation method in the glove box or pulsed laser deposition, the Li/Ni-Co-Mn composite tape were heat treated at 800~900°C for 1~2hrs in oxidizing atmosphere to induce Li diffusion into the Ni-Co-Mn template and Li(NiCoMn)O2 phase formation. The Li(NiCoMn)O2 phase evolution was confirmed by XRD and microstructural characteristics such as grain size and surface morphology were analyzed by scanning electron microscopy and atomic force microscopy. Also the charge and discharge test was conducted to confirm the electrical characteristics of Li(NiCoMn)O2/Ni-Co-Mn thin film for the cathode application.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
J. S. Tak et al., "Microstructure Analysis and Characterization of Li(NiCoMn)O2 Thin Film for Cathode Application Prepared by Li Diffusion on the Ni-Co-Mn Alloy Substrates", Solid State Phenomena, Vols. 124-126, pp. 979-982, 2007