原子层沉积技术对锂离子电池电极材料的表面处理研究

Lithium-ion battery (LIB) technology is a very important technology in the reasearch area of energy materials. The battery electrodes are the key components of LIBs, and the surface treatment of the electrodes plays a significant role in determining their electrochemical properties. Atomic layer deposition (ALD) technology is a novel and advanced thin film deposition technology. The films grown by ALD are normally uniform, dense, and conformal, so ALD is very suitable for uniformly coating films on porous materials. As many LIB electrode materials are indeed porous, ALD should be particularly beneficial for treating their surface. This project aims at applying this advanced technology of ALD in the surface treatment of LIB cathods and anodes, focusing on realizing the ALD process of new materials, through careful structural and electrical charaterizations, to investigate, in great detail, the effects of ALD treatment on the electrochemical properties of the electrodes, such as cyclability, charging rate, stability, etc. Thereafter, a model will be proposed to explain the experimentally observed changes that ALD introduces. Applying this advanced technology of ALD in the study of LIBs will not only promote the properties of the electrodes, but also advance the development of the ALD technology itself. Therefore, this project is of great value in both fundamental study and practical applications.

锂离子电池技术是能源研究领域的一个非常重要内容。其中，电极是锂离子电池最关键的核心部件，而电极的表面处理对其电化学性能的影响巨大。原子层沉积（ALD）镀膜技术作为新颖先进的薄膜制备技术，其所制备的薄膜具有均匀、致密、高保形性等特点，尤其适合在多孔材料表面均匀成膜，因此，它在处理介观多孔电极材料表面时就具有特别的优势。本拟将ALD应用于对锂离子电池正负电极材料的表面处理研究中，侧重于引入新型ALD材料，通过大量表面薄膜材料的表征和电化学的表征，深入系统地研究ALD处理对电极材料的充放电循环性、倍率性、稳定性等方面的影响机制，并提出理论模型，以解释实验中ALD引起的性能变化。本研究将最先进的ALD技术应用在锂离子电池研究中，不仅可以帮助获得高性能的电极材料，也可以进一步推动ALD技术本身的发展，因此本项目具有基础研究价值和重要的潜在应用价值。

锂离子电池技术是当今能源存储技术中的一种重要技术。锂离子电池的性能在很大程度上取决于其电极材料的性能。本项目研究了一种基于新颖的原子层沉积（ALD）技术来对锂离子电池的电极材料进行表面处理，从而提升电极材料性能。本项目以锂电池锂镍锰钴氧化物（三元材料）为例，研究开发了针对这种三元材料的ALD包覆技术，实现了对电极材料的可控均匀一致的ALD包覆，同时也开发了多种新材料的ALD工艺。进一步的电池性能表征表明，只需要5层原子层的ALD氧化铝包覆，就可以在很大程度上提升三元材料的循环稳定性。以此为基础，通过深入细致的机理研究，进一步发现ALD薄膜对电极材料最大的作用是在高电位条件下，阻止三元材料的表面形成锂离子扩散较为困难的岩盐相NiO。这项机理研究阐明了ALD薄膜在锂电池电极材料中所起的作用，具有一定的普适性，为今后ALD技术在锂电池领域中的产业化应用提供了理论基础。