论文总字数：20097字

摘 要

锂离子电池由于其能量密度高、重量轻、自放电率低等优点，在众多可充电电池中，被视为一种重要研究对象。锂电池主要由四个部分构成，正负极、电解液和隔膜。隔膜可以阻隔电池的正负极，防止电池短路，还可以吸收电解质，为锂离子的自由快速传输提供有效通道，是导电离子的有效传输通道，是锂离子电池重要的一个组成部分。另外，电池隔膜还会直接或间接地影响着锂离子电池的电池容量、循环性能以及电池性能。本课题主要有两个部分，一是熟悉、掌握隔膜材料的湿法制备工艺；二是测试分析不同有机纤维组成配比等对隔膜材料性能的影响规律。

文中以聚丙烯（PP）纤维和棉（花）纤维为主要研究对象，进行了不同纤维原料性能测试分析和棉纤维对改性PP纤维隔膜成型性能影响研究。对比分析了原始聚丙烯纤维、使用5%浓度高锰酸钾（KMnO₄）溶液酸蚀改性聚丙烯纤维和棉纤维电子显微镜（SEM）图片。并设计了五种不同的改性PP/棉纤维复合纤维-水质量配比，采用试验的方法，通过结构性能、力学性能、耐热性能和电化学相关性能等性能指标，研究不同有机纤维组成配比对隔膜性能的影响。分析对比不同复合纤维隔膜数据，发现当棉纤维含量占比为40%时，锂离子电池隔膜性能良好，各项性能指标中，抗张强度可达1.661KN/m，吸液率可达692%，吸液高度可达38mm，相应的保液率为103%，孔隙率为44.63%。从这些性能指标中可以看出，添加棉纤维作为PP纤维的复合增强纤维，可以改善隔膜的吸湿性能，而通过SEM图片可得知，在经过湿法打浆、成型和高温热压工艺，棉纤维和改性PP纤维相互交织形成网格结构，提高了隔膜的抗张强度。

关键词：锂离子电池隔膜 棉纤维 聚丙烯纤维 酸蚀改性

Research on Preparation and Performance of Lithium Battery Wet Process Separator Materials

ABSTRACT

Lithium ion batteries are regarded as the main research object of rechargeable batteries due to their advantages such as high energy density, light weight and low self-discharge rate. Lithium battery is constituted by positive and negative electrodes, electrolyte and separator. The separator can prevent the short circuit of the battery,and absorb the electrolyte and provide an effective channel for the free and fast transmission of lithium ions. Is an important part of lithium-ion batteries. The performance of the separator material can influence the performance of the battery. The purpose of this subject is to familiarize and master the principles and processes of the wet method (thermal induced phase separation (TIPS)) preparation of lithium ion battery separator materials, prepare lithium battery separator materials, test and analyze different organic fiber composition ratios, processes, etc. The influence law of material performance.

In this paper, polypropylene (PP) fiber and cotton (flower) fiber are the main research objects. On the one hand, a contrast study of the properties of diverse fiber raw materials was carried out, on the other hand, the effect of cotton fibers on the forming properties of the modified PP fiber separator. Comparative analysis of the original polypropylene fiber, using 5% concentration potassium permanganate (KMnO₄) solution acid etching modified polypropylene fiber and cotton fiber electron microscope (SEM) pictures. Five different modified PP / cotton fiber composite fiber-water quality ratios were designed, and the experimental method was used to study the effect of different cotton fiber addition on the performance of the battery separator. By studying the battery separator's structural performance, mechanical properties, heat resistance and electrochemical performance, the data of different composite fiber separators are analyzed and compared, and it is found that when the cotton fiber content is 40%, the tensile strength can be Up to 1.661KN / m, the liquid absorption rate can reach 692%, the liquid absorption height can reach 38mm, the corresponding liquid retention rate is 103%, the porosity is 44.63%, and a good performance lithium ion battery separator is obtained. Adding cotton fiber as a composite reinforcing fiber of PP fiber can improve the moisture absorption performance of the separator, and it can be seen according to the SEM pictures, after wet beating, forming and high temperature hot pressing process,, the cotton fiber and the modified PP fiber are interwoven to form a web The lattice structure improves the tensile strength of the diaphragm.

Key words: Lithium ion battery separator; Cotton fiber; Polypropylene fibers; Acid etching modification

目录

摘要 I

ABSTRACT II

第一章绪论 1

1.1背景与意义 1

1.2锂电池隔膜 2

1.3研究内容 4

1.4湿法隔膜材料制备工艺 5

第二章 材料制备及性能表征 6

2.1 实验材料和仪器 6

2.2 测试表征 9

第三章 实验结果与讨论 12

3.1 不同纤维原料性能测试分析 12

3.2 棉纤维对改性PP纤维隔膜性能影响 13

第四章 结论与展望 19

第五章 经济性分析 21

参考文献 22

致谢 25

第一章绪论

1.1背景与意义

锂离子电池由于其能量密度高、重量轻、自放电率低等优点，被视为一种重要电池研究对象。相较于传统的锰镍电池与铅酸电池，循环寿命更长的锂离子电池对环境的污染与危害也要小很多。在人类对能源的需求日益增长，环境污染与破坏却愈发严重的今天，由于迫切需要探索出先进的能源转换方式和储存媒介，导致新能源产业的发展越来越重要，锂离子电池作为可充电电池的一个重要研究对象，逐渐成为取代传统化石燃料的动力源之一。

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