Deng Shiwei, Zhu Huilin, Zheng Zhiyuan, Kong Zixiang, Wang Zixing, Zhou Wang, Tang Rui, Wu Jian-Fang, Liu Jilei
College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha 410082, China.
Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, China.
Nano Lett. 2024 Aug 14;24(32):9801-9807. doi: 10.1021/acs.nanolett.4c01266. Epub 2024 Aug 1.
Cation-doped cubic LiLaZrO is regarded as a promising solid electrolyte for safe and energy-dense solid-state lithium batteries. However, it suffers from the formation of LiCO and high electronic conductivity, which give rise to an unconformable Li/LiLaZrO interface and lithium dendrites. Herein, composite AlF-LiLaZrTaO solid electrolytes were created based on thermal AlF decomposition and F/O displacement reactions under a high-temperature sintering process. When the AlF is thermally decomposed, it leaves AlO/AlF meliorating the grain boundaries and F ions partially displacing O ions in the grains. Due to the higher electronegativity of F in the grains and the grain-boundary modification, these AlF-LiLaZrTaO deliver optimized electronic conduction and chemical stability against the formation of LiCO. The Li/AlF-LiLaZrTaO/Li cell exhibits a low interfacial resistance of ∼16 Ω cm and an ultrastable long-term cycling behavior for 800 h under a current density of 200 μA/cm, leading to Li//LiCoO solid-state batteries with good rate performance and cycling stability.
阳离子掺杂的立方相LiLaZrO被认为是用于安全且能量密集型固态锂电池的一种很有前景的固体电解质。然而，它存在LiCO的形成以及高电子电导率的问题，这会导致Li/LiLaZrO界面不协调以及锂枝晶的产生。在此，基于高温烧结过程中的AlF热分解和F/O置换反应，制备了复合AlF-LiLaZrTaO固体电解质。当AlF热分解时，会留下AlO/AlF改善晶界，并且F离子部分取代晶粒中的O离子。由于晶粒中F的电负性较高以及晶界改性，这些AlF-LiLaZrTaO具有优化的电子传导性以及对LiCO形成的化学稳定性。Li/AlF-LiLaZrTaO/Li电池在200 μA/cm的电流密度下表现出约16 Ω cm的低界面电阻以及800 h的超稳定长期循环行为，从而实现了具有良好倍率性能和循环稳定性的Li//LiCoO固态电池。
