微管式中空纤维膜全固态锂离子电池的设计与研究

There are still many difficulties for the application of all solid state lithium ion battery considered as potential power sources, such as the regulation and reaction mechanisms of two phase interface regulation of electrode/electrolyte solid-solid, structure design, and so on. In this study, an optimization design of total battery with asymmetric hollow fiber structured electrolyte microtube will be adopted to improve the stability of the interface between the electrode and electrolyte, and alleviate the phase interfacial effect of solid-solid. Based on the principle of phase separation induction in polymer solution, self-supported asymmetric hollow fibers of solid electrolyte with high specific surface area will be prepared by a phase-inversion method, combining with technology of self-supported microtubule solid oxide fuel cell. The battery electrode will be prepared, depositing on the surface of the electrolyte fiber by atomic layer deposition and vacuum-assisted impregnation, then a single total battery is build. To develop an efficient method to control the interface of the solid-solid phase, the developing mechanism of the hollow fiber and the effect of the electrode layer synthesized by different routes. Mostly, the novelty structure of all solid state lithium ion battery can be applied in lithium sulfur batteries and lithium air batteries, and make a significant contribution to the promotion and implementation of all solid state lithium ion batteries.

全固态锂离子电池作为一种有潜力的化学电源仍面临着电极/电解质固固两相界面调控与反应机制、全电池结构设计等诸多难题。结合前期工作，申请者提出一种基于非对称的中空纤维管的电池结构优化设计，结合不同的电极层/电解质层制备手段，提高电极与电解质之间的界面稳定性，缓和固固两相界面效应，以获得高性能全固态锂离子全电池为目的。为实现以上目标，本项目依据聚合物溶液相分离诱导原理，结合固体氧化物燃料电池的微管式自支撑技术，利用相转换法-烧结法，采用原子层沉积/真空灌注等技术制备高度非对称中空纤维管式的全固态锂离子电池。探讨中空纤维管结构的形成机制，分析电极制备方案对界面效应的影响规律，确定调控电极/电解质层界面的有效手段。该项目所涉及的技术成果还可以运用到锂硫电池、锂空电池领域中，最重要的是可获得具有知识产权的全固态锂离子电池制备技术，为实现全固态锂离子电池的成熟与推广做出有意义的贡献。

全固态锂离子电池作为一种有潜力的化学电源仍面临着电极/电解质固固两相界面调控与反应机制、全电池结构设计等诸多难题。本项目基于聚合物溶液相分离诱导原理，采用相转化纺丝技术设计并可控制备了新型微管式全固态锂离子电池单体。首先，我们设计了符合要求的锂离子电池正极材料，通过引入高导电性的TaC改性LFP正极材料。经过改性后，TaC-LFP的首次放电比容量达到了159.0 mAh g-1，经过200圈循环后，容量保持在94.5%（2C），展现了优异的电化学稳定性。探究了中空纤维膜的结构参数与相转化纺丝技术参数之间的演变规律，研究了中空纤维膜在高温焙烧过程中的收缩规律，设计了由致密表皮层与疏松多孔层的非对称中空纤维膜。开发了微管式全固态锂离子电池单体，首次放电比容量达到0.12 mAh，经过100次循环后，容量衰减到0.027mAh。此外，本项目提出了局部非溶剂诱导相转化法概念，设计了PVA基新型隔膜，实现了对隔膜微观结构的调控。本项目的研究工作将为设计并可控制备高性能微管式锂离子电池提供试验和理论基础。