基于宣纸的锂离子电池关键材料制备及表征

发布时间：2018-08-04 16:06

【摘要】：锂离子电池是目前最为广泛应用的便携式电源系统,而且正往多功能化及大型化方向发展以应用于动力电池系统及能源储能系统,如何进一步提高锂离子电池能量密度成为当前该领域重要的研究课题。同时,相较于其他电池,锂离子电池原料成本较高,加工工艺复杂,电池中多个关键组件为非可再生资源或具备一定的毒性,因此导致锂离子电池成本居高不下,也不利于环境保护。本论文针对以上两个问题,尝试采用生物材料制成品(宣纸薄膜)来全部或部分取代锂离子电池中的某些关键组件,以实现降低锂离子电池生产成本,同时提高锂离子电池能量密度,改善其环境相容性的目的。在第一章中,我们将简要介绍人类认识及发明使用电池的历史,分析介绍锂离子电池中各关键组件及其各自功能性,同时还将对生物材料在锂离子电池中的应用及宣纸薄膜进行简要的介绍。第二章重点介绍本论文中主要使用的药品、试剂及主要检测、表征手段。宣纸薄膜是一种由特殊植物纤维(青檀树皮与长秆籼稻草纤维)为原料,通过湿法抄造工艺制备而来的无纺布型薄膜材料。独特的原料纤维与湿法抄造的工艺赋予了宣纸独特的功能性,如润墨性、耐久性、变形性以及抗虫性等,其中润墨性反映了该材料的强亲水浸润性。而在锂离子电池关键组件中,隔离膜的最基本功能要求即为具备强浸润性,能够与电解液发生优良浸润保证锂离子在隔离膜中的顺畅传输。因此,在第三章中我们从宣纸薄膜的功能性出发,尝试采用宣纸薄膜作为隔离膜应用于锂离子电池中,通过对宣纸薄膜进行形貌、结构、化学组成、热稳定性、电化学稳定性等方面进行检测分析,从理论上展示了可行性。再通过多种电极材料与宣纸薄膜进行匹配,从实验上验证了其作为电池隔膜材料的可行性。在第四章中,我们采用压烧工艺,以宣纸薄膜为原料制备了具有三维多孔网状结构的自支撑碳膜材料,这种由生物纤维制备而来的自支撑碳膜具有高比表面积,可作为负极应用于锂离子电池当中。在第五章至第七章中,基于压烧工艺制备三维多孔碳膜的工作基础,我们将多种电极材料,包括磷酸铁锂、磷酸钒锂以及钛酸锂等与宣纸薄膜进行复合。通过固相法制备电极材料前驱体,并将其制备成浆料涂覆于宣纸薄膜之上,通过一步共烧工艺,同时实现电极材料的高温成相与宣纸薄膜的高温碳化,制备了三维多孔碳膜支撑的磷酸铁锂和磷酸钒锂薄膜正极、以及钛酸锂薄膜负极。由于该方法以固相合成法为基础,并采用生物材料,因此可降低原料及生产成本。基于宣纸薄膜材料,我们制备了锂离子电池的三种关键组件,即正极材料、隔离膜和负极材料。因此,在第八章中,我们尝试设计并组装了一个主要基于宣纸材料的全电池LiFePO4/C并验证了其可行性。在第九章中,我们通过采用1,2-丙二醇作为溶剂,通过溶胶凝胶法制备了锂离子电池无机固体陶瓷电解质Li1.3Al0.3Ti1.7(PO4)3。该合成路线简化了实验工艺,制备了组成均匀的前驱体,降低了高温烧结温度,在850℃烧结所得样品锂离子电导率较高,在50℃下为3.0×10-4S cm-1。第十章是对本论文的创新之处和不足之处进行简要总结,并对今后可能的工作方向进行展望。
[Abstract]:Lithium ion battery is the most widely used portable power supply system, and it is developing in the direction of multi-function and large scale to apply to power battery system and energy storage system. How to further improve the energy density of lithium ion battery has become an important research topic in this field. The cost of the raw material is high, the processing technology is complex, the key components in the battery are non renewable resources or have certain toxicity. Therefore, the cost of lithium ion battery is high, and it is not conducive to environmental protection. In this paper, we try to use the biological material (Xuan paper film) to replace the lithium ion in all or part of the two problems. Some key components of the battery can reduce the production cost of lithium-ion batteries, increase the energy density of lithium-ion batteries and improve their environmental compatibility.
In the first chapter, we will briefly introduce the history of human knowledge and invention of the use of batteries, analyze the key components and their respective functions in lithium ion batteries, and introduce briefly the application of biological materials in lithium ion batteries and the film of Xuan paper. The second chapter focuses on the main drugs used in this paper. Agents and main detection and characterization methods.
The paper film is a non-woven film material made from special plant fiber (Tsing sandalwood bark and long straw indica straw fiber) by wet processing. The unique raw material fiber and wet process technology give the unique function of Xuan paper, such as ink wetting, durability, deformability and insect resistance, including ink wetting property. In the key component of lithium ion batteries, the most basic functional requirements of the isolation membrane are the strong infiltration and the excellent infiltration with the electrolyte to ensure the smooth transmission of the lithium ion in the isolation membrane. Therefore, in the third chapter, we try to use the Xuan paper from the function of the paper film. The thin film is applied to the lithium ion battery as an isolating membrane. Through the detection and analysis of the morphology, structure, chemical composition, thermal stability and electrochemical stability of the paper film, the feasibility is demonstrated in theory. Then the film is matched with a variety of electrode materials and the film is tested as a battery diaphragm material. Feasibility.
In the fourth chapter, we have prepared a self supporting carbon film material with a three-dimensional porous network structure using the padding process. The self supporting carbon film produced by the biological fiber has a high surface area and can be used as a negative electrode in lithium ion batteries.
In the fifth chapter to the seventh chapter, the working basis of a three-dimensional porous carbon film is prepared based on the pressing process. We compounded a variety of electrode materials, including lithium iron phosphate, lithium phosphate, and lithium titanate. The precursor of electrode materials was prepared by solid phase method, and the slurry was coated on a Xuan paper film by a step. The co firing process and high temperature carbonization of the high temperature phase and paper film of the electrode materials have been realized. The cathode of lithium iron phosphate and lithium vanadium phosphate film supported by three dimensional porous carbon membrane and lithium titanate film anode are prepared. The method is based on the solid phase synthesis and uses biological materials, thus reducing the cost of raw materials and production.
Based on the paper film material, we have prepared three key components of the lithium ion battery, the cathode material, the isolation film and the negative electrode. Therefore, in the eighth chapter, we try to design and assemble a full battery LiFePO4/C, which is mainly based on the paper material, and verify its feasibility.
In the ninth chapter, by using 1,2- propanediol as a solvent, the inorganic solid ceramic electrolyte Li1.3Al0.3Ti1.7 (PO4) 3. of lithium ion battery was prepared by sol-gel method. The synthetic route was simplified, and the homogeneous precursor was prepared, the sintering temperature of high temperature was reduced, and the lithium ion conductivity was obtained at 850 C. Higher, 3 x 10-4S cm-1. at 50 C
The tenth chapter briefly summarizes the innovations and shortcomings of this paper, and looks into the possible direction of future work.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM912

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