柔性全固态薄膜锂电池制备过程中退火作用机理研究

As an important part of all solid state battery, solid-thin-film lithium battery (STFLB) is of much potential in the field of micro and wearable electronic devices. However, the capacity of the initially commercialized STFLBs is low and their cost is too high, which are caused by the choices of rigid-ceramic substrate and noble metal current collector. In this project, low-cost stainless steel foil is used as the substrate and current collector of STFLBs, and several important issues in the annealing process are going to be studied, including: (1) formation and growth process of oxidation layer on the surface of the metallic substrate, (2) interface evolution and elements diffusion between the substrate and cathode film, (3) the physical and chemical properties of the cathode film influenced by preparation and annealing technical parameters, (4) the STFLBs’ electrochemical performance influenced by the factors above. This project aims to elucidate the mechanism of interaction between the cathode film and metallic substrate, and establish theoretical and technological foundation for solving the problems of substrate oxidation, elements diffusion and electrode interface stability.

固态薄膜锂电池作为全固态电池的一个重要分支，在微型设备和可穿戴电子产品等领域极具应用潜力。然而，目前国际上初步商品化的薄膜锂电池多以硬质陶瓷材料为基板，以贵金属为集流体，造成电池能量密度降低和成本偏高，从而制约了该类产品的商业应用。为了解决以上问题，本课题以廉价的不锈钢箔作为电池基板和集流体，对正极薄膜晶化热处理过程中涉及的主要问题开展基础性研究，具体内容包括：金属基板表面氧化层形成及生长过程研究；金属基板与正极薄膜间界面演变和元素扩散研究；薄膜沉积和热处理实验条件对正极薄膜理化性能的影响；以及上述因素对全电池性能的影响机理。本课题旨在揭示在热处理过程中，正极薄膜与金属基板间的作用规律，为金属基板氧化、薄膜间元素扩散和电极界面稳定性问题的有效解决奠定理论和技术基础。

全固态薄膜锂电池（以下简称“TFLB”） 作为全固态电池的一个重要分支，在微型设备和可穿戴电子产品等领域极具应用潜力。目前国际上初步商品化的薄膜锂电池多以硬质陶瓷材料为基板，以贵金属为集流体，造成电池能量密度降低和成本偏高，从而制约了该类产品的商业应用。为了解决以上问题，本课题以廉价的不锈钢箔作为电池基板和集流体，探索研究了柔性TFLB制备过程中的基础性和技术性问题，包括：金属基板热处理过程对表面氧化层粗糙度和基板金相状态的影响；金属基板与正极薄膜间界面演变和元素扩散研究；薄膜沉积和热处理实验条件对正极薄膜理化性能的影响；以及上述因素对全电池性能的影响机理；在以上工作的基础上进一步开展了柔性TFLB初步工程化制备探索研究，解决了大面积金属基板和正极薄膜热处理难题，并利用卷对卷真空镀膜设备和技术成功完成了平米级正极和电解质薄膜制备，开辟了一条新的金属基TFLB制备路径，为其工业化制备提供了有益探索。