论文总字数：27048字

摘 要

随着社会科技的不断进步，智能手机的更新换代，以及电动汽车的诞生，人们对于高质量的电储能装置的需求日益增强，而锂电池作为现代社会广泛使用的新型清洁能源储能设备，再次获得了研究人员们的关注。传统锂电池因其电解质为液态，容易出现泄漏等状况，在安全性和环保性上存在缺陷，而且在高温高压等恶劣条件下容易发生爆炸。在此情况下，研究人员将目光投向了新型清洁能源全固态锂离子电池。较为典型的固态电解质包括氧化物固态电解质与硫化物固态电解质，而硫化物固态电解质因具有较低的硬度与很高的离子电导率，获得了研究人员们的广泛关注。即便如此，硫化物固态电解质依然存在很多弊端，例如其对水并不稳定，所含硫元素易产生有毒气体，其化学、电化学稳定性都较差，同时制作成本也偏高。在新型清洁能源全固态锂电池放电过程中，离子负极材料脱出来，进入到固态电解质，最后嵌入正极材料。因此，详细地研究固态电解质的力学性能尤为重要，为其组装到全固态电池中提供理论指导。本文以硫化物固态电解质材料Li₃PS₄,Li₁₀GeP₂S₁₂,Li₆PS₅X(X=Cl,Br,I)为例，通过Materials Studio 中Castep计算模拟软件进行对固态电解质进行相关的理论模型建立，并通过第一性原理密度泛函理论结构优化，获得最稳定的硫化物晶体结构。在此基础上，基于密度泛函理论，通过状态方程，详细考察固态电解质的弹性常数，进而通过方程拟合计算出杨氏模量，剪切模量等力学性能参数，确定各类硫化物电解质的力学性能。经过一系列建模以及计算，我们发现Li₁₀GeP₂S₁₂的弹性模量最小，其质地最软，最易于加工。最后研究硫化物固态电解质应力应变关系，进而确定材料本身固有的力学性能。

关键词：新型清洁能源,固态电解质,弹性常数,力学性能

Mechanical analysis of sulfide solid electrolyte of solid state battery

ABSTRACT

With the continuous progress of social science and technology, the upgrading of smart phones, and the birth of electric cars, people's demand for high-quality electric energy storage devices is increasing day by day, and lithium battery, as a widely used power storage device in modern society, has once again attracted researchers' attention.Traditional lithium battery is prone to leakage due to its liquid electrolyte, which has defects in safety and environmental protection. Moreover, it is easy to explode under harsh conditions such as high temperature and high pressure.In this case, the researchers looked at lithium batteries with solid electrolytes. Typical solid electrolytes include oxide solid electrolyte and sulfide solid electrolyte, and sulfide solid electrolyte is favored by researchers due to its low hardness, interface resistance and high ionic conductivity.Even so, there are still many disadvantages of sulfide solid electrolyte. For example, it is not stable to water, the sulfur contained in it is prone to produce toxic gas, its chemical and electrochemical stability is poor, and the production cost is also high.During the discharge process of an all-solid-state lithium battery, the ion anode material is removed and transferred to the solid electrolyte, and finally embedded into the anode material. Therefore, it is particularly important to study the mechanical properties of solid electrolytes in detail.The Li₃PS₄ of sulphide solid electrolyte Materials, Li₁₀GeP₂S₁₂, Li₆PS₅X(X=Cl,Br,I) as an example, through the Materials Studio castep calculation simulation software to carry on the related theory of solid electrolyte model, and optimized by first principles, to obtain the most stable sulphide crystal structure. On this basis, based on density functional theory, the elastic constant of solid electrolyte was investigated in detail through state equation, and then the mechanical properties parameters such as young's modulus and shear modulus were calculated through equation fitting, so as to determine the mechanical properties of various sulfide electrolytes. After a series of modeling and calculation, we found that the elastic modulus of Li₁₀GeP₂S₁₂ is the smallest, with the softest

texture and the easiest to process.At last, the stress-strain relationship of sulfide solid electrolyte is studied.

Key Words:Green Renewable Energy;Solid State Lithium Battery;The Elastic Constants; Mechanical Property

目 录

摘要 Ⅰ

ABSTRACT Ⅱ

第一章 绪论 1

1.1课题背景与意义 1

1.1.1固态锂电池的发展历程 1

1.1.2固态锂电池的工作原理 1

1.1.3固态锂电池的种类 2

1.1.4固态电解质的介绍 3

1.1.5全固态锂电池发展前景 3

1.2国内外研究进展 4

1.2.1研究进展 4

1.2.2综述小结 6

1.3研究目的 7

1.4研究方法 7

1.5本章小结 8

第二章 各类硫化物电解质建模与分析 9

2.1 建立各类硫化物模型 9

2.1.1 各类硫化物原子坐标 9

2.1.2 各类硫化物晶体结构 11

2.2 计算方法 13

2.2.1 参数设置 13

2.2.2 理论方法 15

2.3 优化各类硫化物晶体模型 15

2.3.1 能量收敛分析 15

2.3.2 优化各类硫化物结构 16

2.4 本章小结 18

第三章 各类硫化物弹性常数分析 19

3.1 计算参数设置 19

3.2 各类硫化物弹性矩阵计算 19

3.3各类硫化物固态电解质弹性矩阵分析 21

3.4本章小结 22

第四章 各类硫化物固态电解质力学性质分析 24

4.1 力学性质计算方法与方程 24

4.2 分析各类硫化物力学参数 25

4.3 对比分析各类硫化物力学参数 25

4.4 本章小结 28

第五章 结论与展望 30

5.1 文章总结 30

5.2 展望 32

参考文献 34

致谢 37

请支付后下载全文，论文总字数：27048字