论文总字数：19628字

摘 要

全钒液流电池中，电解液是电化学反应的活性物质，同时也是能量存储的介质。但是其正负极电解液之间存在钒离子交叉污染以及水迁移，一方面是由于隔膜的原因，另一方面是由于充放电过程中，隔膜两侧存在渗透压差，导致正负极电解液之间的渗透压不平衡从而导致钒离子的渗透和水迁移。本论文从平衡隔膜两侧的渗透压出发，在负极电解液中分别引入添加剂Al₂(SO₄)₃和2-甲基咪唑，来减小隔膜两侧存在的渗透压差，进而使钒电池的性能得到提高。主要内容如下：

1、添加剂Al₂(SO₄)₃对负极电解液以及钒电池性能的影响。加入无机盐Al₂(SO₄)₃添加剂之后，提高了电解液的导电性，可以提高电解液的活性。通过循环伏安曲线可知，Al₂(SO₄)₃的加入提高了氧化还原的峰电流，同时确定Al₂(SO₄)₃的最佳添加量为1.5wt%。钒离子渗透以及体积变化的曲线分析，均表明Al₂(SO₄)₃的加入可以减小电解液中钒离子的渗透和水迁移，这主要是由于负极加入Al₂(SO₄)₃，给负极补偿了一定的渗透压，减小了隔膜两侧的渗透压差，有效地平衡了正负极电解液之间的渗透压。表明添加剂Al₂(SO₄)₃的加入，可以促进电池整体性能的提高。

2、添加剂2-甲基咪唑对负极电解液以及钒电池性能的影响。通过循环伏安曲线可知，2-甲基咪唑的加入影响了氧化还原峰电流，但是增加了反应的可逆性，最终确定2-甲基咪唑的最佳添加量为1wt%。钒离子渗透以及体积变化的曲线分析，均表明2-甲基咪唑的加入大大减小了电解液中钒离子的渗透速率和水迁移，这主要是由于负极加入2-甲基咪唑，补偿了负极的渗透压，减小了隔膜两侧的渗透压差，有效地平衡了正负极电解液之间的渗透压。表明2-甲基咪唑的加入，可以提高电池的整体性能。

关键词： 全钒液流电池 电解液 Al₂(SO₄)₃ 2-甲基咪唑 渗透压

ABSTRACT

In all vanadium flow battery, the electrolyte is an electrochemical reaction of the active substance, but also the energy storage medium. The main problems arise vanadium battery vanadium ions is cross-contamination, and water migration between the positive and negative electrolytes, studies show that on the one hand is due to the diaphragm caused partly because the charge and discharge process, the osmotic pressure difference exists on both sides of the diaphragm resulting in positive and negative osmotic electrolyte imbalance between vanadium ions permeability and water migration. In this paper, from both sides of the membrane osmotic balance point of view, the negative electrode electrolyte additives were introduced into the Al₂(SO₄)₃ and 2-methylimidazole, to reduce the presence of the osmotic pressure difference on both sides of the membrane, thereby enabling the vanadium battery performance improved. The main contents are as follows:

1、The additive Al₂(SO₄)₃ on the negative electrode and the electrolyte of vanadium battery. Inorganic salt Al₂(SO₄)₃ After additives to improve the conductivity of the electrolyte, the electrolyte can be improved activity. Curve indicated by cyclic voltammetry, Al₂(SO₄)₃ is added to raise the redox peak current, while determining Al₂(SO₄)₃ is preferred dosage 1.5wt%. Curve analysis of vanadium ion permeability and volume change, show that Al₂(SO₄)₃ can be added to reduce water infiltration and migration of vanadium ions in the electrolyte, which is mainly due to the negative added Al₂(SO₄)₃, to compensate for certain negative the osmotic pressure, the osmotic pressure difference is reduced on both sides of the membrane, effective osmotic balance between the positive and negative electrolyte. It showed that the additive Al₂(SO₄)₃ is added, can contribute to improve the overall performance of the battery.

2、 2-methylimidazole additive effect on the negative electrode and the electrolyte of vanadium battery. By cyclic voltammetry curves shows that the addition of 2-methylimidazole influence the redox peak current, but increases the reversibility of the reaction, and ultimately determine the optimal dosage 2- methylimidazole 1wt%. Curve analysis and vanadium ions permeate volume change, show that the addition of 2-methylimidazole greatly reduces the permeation rate of the electrolyte and water transport vanadium ions, a negative electrode mainly due to the added 2-methylimidazole, the negative compensation the osmotic pressure, the osmotic pressure difference is reduced on both sides of the membrane, effective osmotic balance between the positive and negative electrolyte. It showed that the addition of 2-methylimidazole, can improve the overall performance of the battery.

KEYWORDS: all vanadium flow battery ; Electrolyte ； Al₂(SO₄)₃ ；2-methylimidazole ; Osmotic pressure

目录

摘 要 I

ABSTRACT II

目录 I

第一章 绪论 1

1.1 引言 1

1.2 全钒氧化还原液流电池 1

1.2.1 工作原理 1

1.2.2 基本结构和特点 2

1.3 全钒氧化还原液流电池的关键材料 2

1.3.1 电极材料 2

1.3.2 隔膜 3

1.4 电解液研究进展 3

1.4.1 电解液的制备 3

1.4.2 电解液的分析 4

1.4.3 电解液的优化 4

1.5 本课题研究的意义及内容 4

第二章 硫酸铝对负极电解液以及钒电池性能的影响 5

2.1 引言 5

2.2 实验部分 5

2.2.1 实验仪器 5

2.2.2 实验试剂 5

2.3 实验方法 6

2.3.1 钒离子渗透速率测试 6

2.3.2 循环伏安测试 7

2.3.3 电解液体积变化测试 7

2.3.4 电池充放电测试 7

2.4 结果与讨论 8

2.4.1 循环伏安分析 8

2.4.2 添加剂对钒离子渗透性能的影响 8

2.4.3 添加剂对电解液的体积变化的影响 9

2.4.4 添加剂对电池充放电性能的影响 10

2.5 本章小结 11

第三章 2-甲基咪唑对负极电解液以及钒电池性能的影响 12

3.1 前言 12

3.2 实验部分 12

3.2.1 实验仪器 12

3.2.2 实验试剂 12

3.3 实验方法 13

3.3.1 钒离子渗透速率测试 13

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