2025-09-08 九州大学
図1 従来電極材と独自電極材における焼結時の現象を模式化したイメージ図
＜関連情報＞
- https://www.kyushu-u.ac.jp/ja/researches/view/1325
- https://www.kyushu-u.ac.jp/f/63199/25_0908_01.pdf
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/advs.202512219
バルク型全固体電池製造のためのCo焼結における高Ni正極材料（NMC622）とLi7La3Zr2O12間の反応抑制：新規手法とそのメカニズム Reaction Suppression Between a High-Ni Cathode Material (NMC622) and Li7La3Zr2O12 on Co-Sintering for Manufacturing Bulk-Type All-Solid-State Batteries: A New Method and Its Mechanism
Naohiro Hayashi, Ken Watanabe
Advanced Science Published: 29 August 2025
DOI:https://doi.org/10.1002/advs.202512219
Abstract
Co-sintering cathode materials with Li7La3Zr2O12 (LLZ) is a promising strategy for fabricating bulk-type all-solid-state batteries (ASSBs). However, preventing reactions between different materials, which is difficult with high-capacity cathode materials such as LiNi0.6Mn0.2Co0.2O2 (NMC622), is a pre-requisite for applying this strategy. To overcome this issue, Li1+xNi0.6Mn0.2Co0.2O2 (x = 0.01–0.2), which intentionally deviates from the stoichiometric NMC622 composition, is synthesized here. The formation of impurity phases in the co-sintering process can be controlled by adjusting the co-sintering temperature and x. Impurity phases are not formed on co-sintering with x = 0.075 at 800 °C because reduced cation mixing in NMC622 and the presence of a self-formed Li2CO3 layer on the particle surface, ensured by adjusting x, effectively suppresses reactions. Furthermore, good results are observed at sintering temperatures where the proportions of Ni2+ and Co2+, which promote cation mixing, are low. This study clarifies relevant reaction mechanisms using various analytical methods (such as temperature-rise X-ray absorption fine structure analysis and scanning transmission electron microscopy-electron energy loss spectroscopy), and confirms the repetitive operation of bulk-type ASSBs assembled using co-sintered Li1+xNi0.6Mn0.2Co0.2O2 (x = 0.075)/LLZ electrolyte systems. The method reported herein can be potentially adopted for cost-effective and high-energy-capacity ASSB production.
