WO2013097596A1

WO2013097596A1 - Lithium ion secondary battery and electrolyte therefor and use of amide compound therein

Info

Publication number: WO2013097596A1
Application number: PCT/CN2012/086325
Authority: WO
Inventors: 李利民; 石桥
Original assignee: 深圳新宙邦科技股份有限公司
Priority date: 2011-12-31
Filing date: 2012-12-11
Publication date: 2013-07-04
Also published as: CN102569880A; CN102569880B

Abstract

The present invention provides a non-aqueous electrolyte for a lithium ion battery, able to control the acidity of the electrolyte, inhibit the dissolution of Mn²⁺, and thus increase the cycle life and storage performance at high temperatures of a lithium permanganate battery, and a lithium ion battery based on the electrolyte, and provides the use of an amide compound in a lithium ion battery. In order to achieve the above-mentioned purpose, the present invention provides a non-aqueous electrolyte for a lithium ion battery. The electrolyte contains a solvent, a lithium salt, and an amide compound as shown by formula I, wherein R₁ is selected from an alkyl group having 4-20 carbon atoms, and R₂ and R₃ are independently selected from a methyl or ethyl group respectively.

Description

锂离子二次电池及其电解液以及酰胺类化合物的应用技术领域 Application of lithium ion secondary battery and electrolyte thereof and amide compound

本发明涉及一种锂离子电池与锂离子电池电解液，尤其涉及一种锰酸锂电池及其电解液，并涉及酰胺类化合物在其中的应用。背景技术 The present invention relates to a lithium ion battery and a lithium ion battery electrolyte, and more particularly to a lithium manganate battery and an electrolyte thereof, and to the use of an amide compound therein. Background technique

目前普遍使用的二次电池有四种：铅酸电池，镍镉电池，镍氢电池和锂离子电池。锂离子电池因为其具有工作电压高、体积小、质量轻、比能量高、无记忆效应、自放电小、循环寿命长、环境友好等优点，而被称为性能最优越的二次电池，号称 "终极电池"。锂离子电池的市场需求一直保持相当高的增长速度，同时其在电动车上的应用也成为现实。目前锂离子动力电池已经在电动自行车中得到大力的推广使用，随着锂离子动力电池技术水平的不断提高，锂离子动力电池在汽车等大型动力运载工具的应用也会越来越广泛。 There are four types of secondary batteries commonly used at present: lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries and lithium ion batteries. Lithium-ion batteries are called the most superior secondary batteries because of their high operating voltage, small size, light weight, high specific energy, no memory effect, low self-discharge, long cycle life and environmental friendliness. "The ultimate battery." The market demand for lithium-ion batteries has maintained a relatively high growth rate, and its application in electric vehicles has become a reality. At present, lithium-ion power batteries have been widely promoted in electric bicycles. With the continuous improvement of the technical level of lithium-ion power batteries, the application of lithium ion power batteries in large-scale power vehicles such as automobiles will become more and more widespread.

锰酸锂具有三维隧道结构和较好的脱嵌锂性质，同时其资源丰富、价格低廉、安全性好、环境友好，因此，被广泛地用作锂离子电池正极材料。但是，锰酸锂电池存在严重的容量衰减问题，尤其是在高温条件下。其容量衰减原因主要有：锰的溶解、 Jahn-Te l ler效应和电解液分解等，其中电解液对锰酸锂的腐蚀是导致容量衰减和循环性能恶化的直接原因。 Lithium manganate has a three-dimensional tunnel structure and good deintercalation of lithium. At the same time, it is rich in resources, low in cost, safe in safety and environmentally friendly. Therefore, it is widely used as a positive electrode material for lithium ion batteries. However, lithium manganate batteries have serious capacity degradation problems, especially at high temperatures. The main reasons for the capacity decay are: dissolution of manganese, Jahn-Teler effect and decomposition of electrolyte. The corrosion of lithium manganate by electrolyte is the direct cause of capacity degradation and deterioration of cycle performance.

在含有锂盐的电解液中，锰酸锂会发生以下两种的溶解： In an electrolyte containing a lithium salt, lithium manganate dissolves in two ways:

第一，酸的作用直接溶解。存在的痕量水会导致锂盐分解产生氢离子，氢离子与锰酸锂发生如下反应： First, the action of the acid dissolves directly. The presence of traces of water causes the lithium salt to decompose to produce hydrogen ions, which react with lithium manganate as follows:

LiMn₂0₄+4H⁺→Li⁺+ λ— Μη0₂+Μη²⁺+2Η₂0。 LiMn ₂ 0 ₄ + 4H ⁺ → Li ⁺ + λ - Μη0 ₂ + Μ η ⁺ ₂ + ² Η ₂ 0.

第二，固体颗粒表面三价锰离子的歧化溶解，发生以下的反应： Second, the disproportionation of trivalent manganese ions on the surface of the solid particles dissolves, and the following reactions occur:

2 Mn³⁺ (sol id) →Mn⁴⁺ (sol id) +Mn²⁺ (solut ion) 。 2 Mn ³⁺ (sol id) → Mn ⁴⁺ (sol id) + Mn ²⁺ (solut ion).

生成的 Mn²⁺溶解在电解液中，锰的溶解不仅使 LiMn₂0₄活性物质的绝对量减少，还会引发 LiMn₂0₄晶格结构的转变，使 LiMnA丧失或部分丧失电化学活性，降低其稳定性能，影响电池的循环寿命。 The generated Mn ^{2+ is} dissolved in the electrolyte. The dissolution of manganese not only reduces the absolute amount of the LiMn ₂ ₄ active material, but also causes the transformation of the LiMn ₂ 0 ₄ lattice structure, which causes the loss or partial loss of electrochemical activity of LiMnA. Reduce its stability and affect the cycle life of the battery.

另外，在高温时，由于高温的催化，会导致固体颗粒表面三价锰离子的歧化溶解更加剧烈，从而造成 L iMn₂0₄在循环过程中容量衰减更加严重。发明内容 Further, at high temperatures, due to the high temperature catalyst, disproportionation leads to surface of solid particles of trivalent manganese ions dissolved more severe, resulting in L iMn ₂ 0 ₄ capacity fade during cycling more serious. Summary of the invention

本发明的目的在于提供一种能控制电解液的酸度，抑制 Mn²⁺的溶出，从而提高锰酸锂电池的循环寿命和高温储存性能的锂离子电池用非水电解液，以及基于该电解液的锂离子电池，并提供了一种酰胺类化合物在锂离子电池中的应用。 An object of the present invention is to provide a nonaqueous electrolyte for a lithium ion battery capable of controlling the acidity of an electrolyte, suppressing the elution of Mn ²⁺ , thereby improving the cycle life and high temperature storage performance of a lithium manganate battery, and based on the electrolyte Lithium-ion batteries and the use of an amide compound in lithium-ion batteries.

为实现上述发明目的，本发明提供了一种锂离子电池用非水电解液，所述电解液中含有： In order to achieve the above object, the present invention provides a nonaqueous electrolyte for a lithium ion battery, wherein the electrolyte contains:

溶剂； Solvent

锂盐； Lithium salt

如结构式 1所示的酰胺类化合物，

An amide compound as shown in Structural Formula 1,

结构式 1 Structural formula 1

其中选自碳原子数为 4~20的烃基， R₂,R₃分别独立地选自甲基或者乙基。在某些实施例中，所述可以选自链烃基，例如直链的烷基、带不饱和键的烃基、具有支链的烷基或具有支链且带不饱和键的烃基等；也可以选自带有环烷基的烃基或带有芳香环的烃基等。 It is selected from a hydrocarbon group having 4 to 20 carbon atoms, and R ₂ and R ₃ are each independently selected from a methyl group or an ethyl group. In certain embodiments, the one may be selected from a chain hydrocarbon group, such as a linear alkyl group, a hydrocarbon group having an unsaturated bond, a branched alkyl group, or a branched chain hydrocarbon group having an unsaturated bond, etc. It is selected from a hydrocarbon group having a cycloalkyl group or a hydrocarbon group having an aromatic ring or the like.

作为优选方案，上述技术方案中，所述结构式 1所示的酰胺类化合物为下列结构式中的一种或多种： Preferably, in the above technical solution, the amide compound represented by the structural formula 1 is one or more of the following structural formulas:

N，N -二甲基丁酰胺， N，N -二乙基丁酰胺， N，N -二甲基戊酰胺， N，N_二乙基戊酰胺， N，N -二甲基己酰胺， N，N -二乙基己酰胺， N，N -二甲基庚酰胺， N，N -二乙基庚酰胺， N，N -二甲基辛酰胺， N，N -二乙基辛酰胺， N，N -甲乙基辛酰胺， Ν, Ν- 二甲基壬酰胺， Ν，Ν -二乙基壬酰胺， Ν，Ν -甲乙基壬酰胺， Ν，Ν -二甲基癸酰胺， Ν，Ν_二乙基癸酰胺， Ν，Ν_甲乙基癸酰胺， Ν，Ν -二甲基月桂酰胺， Ν，Ν_二乙基月桂酰胺， N，N -甲乙基月桂酰胺。 N,N-dimethylbutyramide, N,N-diethylbutanamide, N,N-dimethylpentanamide, N,N-diethylpentanamide, N,N-dimethylhexanamide, N,N-diethylhexanamide, N,N-dimethylheptanamide, N,N-diethylheptanamide, N,N-dimethyloctanoamide, N,N-diethyloctylamide, N,N-methylethyl octamide, hydrazine, hydrazine-dimethyl phthalamide, hydrazine, hydrazine - diethyl hydrazide, hydrazine, hydrazine - methyl ethyl amide, hydrazine, hydrazine - dimethyl amide, hydrazine, Ν_Diethyl amide, hydrazine, hydrazine _ methyl ethyl amide, hydrazine, hydrazine - dimethyl lauramide, hydrazine, hydrazine _ diethyl ethyl Cinnamamide, N,N-methylethyl lauramide.

进一步而言，上述技术方案中，所述非水电解液中的溶剂优选自如下的至少一种或几种：碳酸乙烯酯（EC)、碳酸丙烯酯（PC)、碳酸亚丁酯（BC)、碳酸二乙酯（DEC)、碳酸二甲酯（DMC)、碳酸甲乙酯（EMC)、 γ _丁内酯（GBL)、环丁砜、乙酸甲酯（ΜΑ)、乙酸乙酯（ΕΑ)、丙酸甲酯（MP)及丙酸乙酯（ΕΡ)。 Further, in the above technical solution, the solvent in the non-aqueous electrolyte solution is preferably at least one or more of the following: ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), Diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), γ-butyrolactone (GBL), sulfolane, methyl acetate (ΜΑ), ethyl acetate (ΕΑ), C Methyl ester (MP) and ethyl propionate (ΕΡ).

进一步而言，上述技术方案中，所述非水电解液中的锂盐优选自如下的至少一种或几种： LiC10₄、 L 1 CF3SO3 , LiC₄F₉S0₃、 LiPF₆、 LiBF₄、 LiAsF₆、 LiN (C₂F₅S0₂) ₂ 及 L iN (CF₃S0₂) ₂。 Further, in the above technical solution, the lithium salt in the nonaqueous electrolytic solution is preferably at least one or more of the following: LiC10 ₄ , L 1 CF ₃ SO ₃ , LiC ₄ F ₉ S0 ₃ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiN (C ₂ F ₅ S0 ₂ ) ₂ and L iN (CF ₃ S0 ₂ ) ₂ .

在优选方案中，所述锂盐包括 LiPF₆与辅助锂盐，所述辅助锂盐选自：双草酸硼酸锂 ( LiBOB ), 二氟草酸硼酸锂 ( LiODFB )及四氟硼酸锂 ( LiBF4 ) 中的一种或多种，所述辅助锂盐的含量按电解液的总重量计为 0. 1% ~ 3%。 In a preferred embodiment, the lithium salt comprises LiPF ₆ and an auxiliary lithium salt selected from the group consisting of lithium bis(oxalate)borate (LiBOB), lithium difluorooxalate borate (LiODFB) and lithium tetrafluoroborate (LiBF4). 1%〜3%。 The total weight of the electrolyte is 0.1% ~ 3%.

在上一方案基础上进行改进，所述锂盐总浓度为 0. 6 ~ 1. 5 M (即 mol/L )。进一步的优选方案中，所述非水电解液中还包含以下添加剂的一种或多种：碳酸亚乙烯酯（VC ), 乙烯基碳酸乙烯酯（VEC ), 卤代碳酸乙烯酯，环状磺酸酯，环状亚硫酸酯，环状硫酸酯。 The improvement of the total concentration of the lithium salt is 0.6 to 1.5 M (ie, mol/L). In a further preferred embodiment, the non-aqueous electrolyte further comprises one or more of the following additives: vinylene carbonate (VC), vinyl ethylene carbonate (VEC), halogenated ethylene carbonate, cyclic sulfonate Acid ester, cyclic sulfite, cyclic sulfate.

由于采用了以上技术方案，本发明具备的有益效果在于： Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

本锂电池非水电解液中，由于含有酰胺类化合物添加剂，在电池化成时，能够在正极表面形成稳定的耐高温钝化膜（SEI膜），能够有效地抑制电池正极 (锰酸锂）与电解液的反应，减少锰离子的溶解，同时，酰胺类化合物添加剂还能控制电解液酸度，进一步降低锰的溶解，从而减緩电池在循环过程中容量的衰减，保证电池具有良好的高温存储性能。具体实施方式 In the non-aqueous electrolyte of the lithium battery, since the amide-based compound additive is contained, a stable high-temperature-resistant passivation film (SEI film) can be formed on the surface of the positive electrode during the formation of the battery, and the positive electrode of the battery (lithium manganate) can be effectively suppressed. The reaction of the electrolyte reduces the dissolution of manganese ions. At the same time, the amide compound additive can also control the acidity of the electrolyte, further reduce the dissolution of manganese, thereby slowing down the capacity decay of the battery during the cycle, and ensuring good high-temperature storage performance of the battery. . detailed description

为详细说明本发明的技术内容、构造特征、所实现目的及效果，以下结合实施方式详予说明。 The technical contents, structural features, objects and effects achieved by the present invention will be described in detail below with reference to the embodiments.

对比例 1: Comparative 1:

所述电解液按以下方法制备：在 Ar气氛的手套箱中，将碳酸乙烯酯（EC )、碳酸丙烯酯（PC )、碳酸甲乙酯（EMC ) 与碳酸二乙酯（DEC ) 按重量比为 EC:PC:EMC:DEC=25:5:50:20进行混合，之后加入六氟磷酸锂配制成 1M ( M即 mol/L )的电解液；并向其中加入 1% (按质量计，下同）的碳酸亚乙烯酯（VC ), 1.5% (按质量计，下同）的 1 , 3-丙烷磺酸内酯（1,3-PS )和 1% (按质量计，下同）的氟代碳酸乙烯酯（FEC )。 The electrolyte was prepared as follows: In an Ar atmosphere glove box, ethylene carbonate (EC), Propylene carbonate (PC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are mixed by weight ratio EC:PC:EMC=DEC=25:5:50:20, and then added with lithium hexafluorophosphate to make 1M (M is mol/L) of electrolyte; and added 1% (by mass, the same below) of vinylene carbonate (VC), 1.5% (by mass, the same below) of 1,3-propane Sulfonic acid lactone (1,3-PS) and 1% by mass of the same fluoroethylene carbonate (FEC).

对比例 2 Comparative example 2

电解液制备方法与对比例 1 的相同，不同的是电解液中没有加入任何添加剂。 The electrolyte preparation method was the same as in Comparative Example 1, except that no additive was added to the electrolyte.

对比例 3 Comparative example 3

电解液制备方法与对比例 1 的相同，不同的是电解液中不添加氟代碳酸乙烯酯（ FEC )。 The electrolyte preparation method was the same as in Comparative Example 1, except that no fluoroethylene carbonate (FEC) was added to the electrolyte.

实施例 2 Example 2

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.2%的 Ν,Ν-二甲基辛醜胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.2% of hydrazine, hydrazine-dimethyl octylamine was added to the electrolyte.

实施例 3 Example 3

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.2%的 Ν,Ν-二乙基辛酰胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.2% of hydrazine, hydrazine-diethyloctylamide was added to the electrolytic solution.

实施例 4 Example 4

电解液制备方法与对比例 1 的相同，不同的是电解液中加入 0.2%的 Ν,Ν- 二甲基月桂酰胺。 The electrolyte was prepared in the same manner as in Comparative Example 1, except that 0.2% of hydrazine, hydrazine-dimethyl lauramide was added to the electrolyte.

实施例 5 Example 5

电解液制备方法与对比例 1 的相同，不同的是电解液中加入 0.2%的 Ν,Ν- 二乙基月桂酰胺。 The electrolyte was prepared in the same manner as in Comparative Example 1, except that 0.2% of hydrazine, hydrazine-diethyl lauramide was added to the electrolyte.

实施例 6 Example 6

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.1%的 Ν,Ν-二甲基辛醜胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.1% of hydrazine, hydrazine-dimethyl octylamine was added to the electrolyte.

实施例 7 电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.1%的 Ν,Ν-二乙基辛酰胺。 Example 7 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.1% of hydrazine, hydrazine-diethyl octylamide was added to the electrolytic solution.

实施例 8 Example 8

电解液制备方法与对比例 1 的相同, 不同的是电解液中加入 0.1%的 Ν,Ν- 二甲基月桂酰胺。 The electrolyte was prepared in the same manner as in Comparative Example 1, except that 0.1% of hydrazine, hydrazine-dimethyl lauramide was added to the electrolyte.

实施例 9 Example 9

电解液制备方法与对比例 1 的相同, 不同的是电解液中加入 0.1%的 Ν,Ν- 二乙基月桂酰胺。 The electrolyte was prepared in the same manner as in Comparative Example 1, except that 0.1% of hydrazine, hydrazine-diethyl lauramide was added to the electrolyte.

实施例 10 Example 10

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.05%的 Ν,Ν- 二甲基辛酰胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.05% of hydrazine, hydrazine-dimethyloctanoamide was added to the electrolytic solution.

实施例 11 Example 11

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.05%的 Ν,Ν- 二乙基辛酰胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.05% of hydrazine, hydrazine-diethyl octylamide was added to the electrolytic solution.

实施例 12 Example 12

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.05%的 Ν,Ν- 二甲基月桂酰胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.05% of hydrazine, hydrazine-dimethyl lauramide was added to the electrolytic solution.

实施例 13 Example 13

电解液制备方法与对比例 1的相同，不同的是电解液中加入 0.05%的 Ν,Ν- 二乙基月桂酰胺。 The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 0.05% of hydrazine, hydrazine-diethyl lauramide was added to the electrolytic solution.

实施例 14 Example 14

电解液制备方法与对比例 1 的相同, 不同的是电解液中加入 2.0%的 Ν,Ν- 二甲基二十一酰胺。 The electrolyte was prepared in the same manner as in Comparative Example 1, except that 2.0% of hydrazine, hydrazine-dimethyl twenty-amide was added to the electrolyte.

实施例 15 Example 15

电解液制备方法与对比例 1 的相同, 不同的是电解液中加入 1.0%的 Ν,Ν- 甲乙基戊酰胺。电解液制备方法与对比例 1的相同，不同的是电解液中锂盐组分为 0. 5M的 LiC 解液中加入 0. 1%的:

(以下简称 A1 ) The electrolytic solution was prepared in the same manner as in Comparative Example 1, except that 1.0% of hydrazine, hydrazine-methylethyl pentamide was added to the electrolytic solution. 1% of the LiC solution: 0% of the LiC solution was added to the solution:

(hereinafter referred to as A1)

实施例 17 Example 17

电解液制备方法与对比例 1的相同，不同的是电解液中锂盐组分为 0. 8M的 5的的。 The electrolyte composition of the same as the first example, the difference is that the lithium salt component of the electrolyte is 0. 8M

LiC₄F₉S0₃; 且在电解液中加入 0. 05%的: 05%的添加: LiC ₄ F ₉ S0 ₃ ;

o o

(以下简称 A2 ) (hereinafter referred to as A2)

实施例 18 Example 18

电解液制备方法与对比例 1的相同，不同的是电解液中锂盐组分为 1. 5M的 LiB 解液中加入 0. 1%的：

(以下简称 A3 ) 1%的: The LiB solution was added to the solution.

(hereinafter referred to as A3)

实施例 19 Example 19

电解液制备方法与对比例 1 的相同，不同的是电解液中溶剂为 EC/DMC/GBL/EA=1: 1: 3: 5 ;锂盐组分为 0. 6M的 LiN (C₂F₅S0₂) ₂与 0. 4MLiN (CF₃S0₂) ₂；不加入其它添加剂；且在电解液中加入 0. 2%的：

(以下简称 A4 ) 实施例 20 The electrolyte solution was prepared in the same manner as in Comparative Example 1, except that the solvent in the electrolyte was EC/DMC/GBL/EA=1: 1:3:5; the lithium salt component was 0. 6M LiN (C ₂ F ₅ S0 _{₂₎ 2} and _{_{0. 4MLiN (CF 3 S0 2)}} 2; without addition of further additives; and a solution of 0.2% in the electrolytic solution:

(hereinafter referred to as A4) Example 20

电解液制备方法与对比例 1 的相同，不同的是电解液中溶剂为 MA: DMC: EA=30: 30: 40; 锂盐组分为 1M的 LiAsF₆; 不加入其它添加剂；且在电解液

(以下简称 A5 ) The electrolyte preparation method is the same as that of Comparative Example 1, except that the solvent in the electrolyte is MA: DMC: EA=30: 30: 40; the lithium salt component is 1M LiAsF ₆ ; no other additives are added;

(hereinafter referred to as A5)

实施例 21 : 电解液制备方法与实施例 10的相同，不同的是电解液中不加入其它添加剂 , 只加入 0.05%的 N，N-二曱基辛酰胺； Example 21: The electrolyte preparation method is the same as that of the embodiment 10, except that no other additives are added to the electrolyte, and only 0.05% of N,N-didecyloctylamide is added;

实施例 22: Example 22

电解液制备方法与实施例 11的相同，不同的是电解液中不加入其它添加剂，只加入 0.05%的 Ν,Ν-二乙基辛酰胺； The preparation method of the electrolyte was the same as that of Example 11, except that no other additives were added to the electrolyte, and only 0.05% of hydrazine, hydrazine-diethyl octylamide was added;

实施例 23: Example 23

电解液制备方法与实施例 12的相同，不同的是电解液中不加入其它添加剂，只加入 0.05%的 Ν，Ν-二曱基月桂酰胺； The preparation method of the electrolyte was the same as that of Example 12 except that no other additives were added to the electrolyte, and only 0.05% of hydrazine, hydrazine-didecyl laurate was added;

实施例 24: Example 24

电解液制备方法与实施例 13的相同，不同的是电解液中不加入其它添加剂，只加入 0.05%的 Ν，Ν-二乙基月桂酰胺； The electrolyte preparation method was the same as that of Example 13, except that no other additives were added to the electrolyte, and only 0.05% of hydrazine, hydrazine-diethyl lauramide was added;

实施例 25: Example 25:

电解液制备方法与实施例 10的相同，不同的是电解液中还加入双草酸硼酸锂（ LiBOB ) 0.1%, 同时调整 LiPF₆的量使锂盐总浓度为 1M; The electrolyte preparation method is the same as that of the embodiment 10, except that the electrolyte is further added with lithium oxalate borate (LiBOB) 0.1%, and the amount of LiPF ₆ is adjusted so that the total concentration of the lithium salt is 1M;

实施例 26: Example 26

电解液制备方法与实施例 11的相同，不同的是电解液中还加入双草酸硼酸锂（ LiBOB ) 1%, 同时调整 LiPF₆的量使裡盐总浓度为 1M; The electrolyte preparation method is the same as that of the embodiment 11, except that the electrolyte is further added with lithium oxalate borate (LiBOB) 1%, and the amount of LiPF ₆ is adjusted so that the total concentration of the salt is 1M;

实施例 27: Example 27

电解液制备方法与实施例 12的相同，不同的是电解液中还加入四氟硼酸锂 (L1BF4 ) 3%, 同时调整 LiPF₆的量使锂盐总浓度为 1M; The preparation method of the electrolyte is the same as that of the embodiment 12, except that the electrolyte is further added with 3% of lithium tetrafluoroborate (L1BF4), and the amount of LiPF ₆ is adjusted so that the total concentration of the lithium salt is 1M;

实施例 28: Example 28

电解液制备方法与实施例 13的相同，不同的是电解液中还加入双草酸硼酸锂（LiBOB )0.1%,二氟草酸硼酸锂（LiODFB)O.05%及四氟硼酸锂（ LiBF₄ ) 0.05%, 同时调整 LiPF₆的量使裡盐总浓度为 1M; 表 1: 各实施例、对比例配方列表 The electrolyte preparation method is the same as that of the embodiment 13, except that lithium bis(oxalate) borate (LiBOB) 0.1%, lithium difluorooxalate borate (LiODFB) 0.50% and lithium tetrafluoroborate (LiBF ₄ ) are further added to the electrolyte. 0.05%, while adjusting the amount of LiPF ₆ to make the total concentration of salt in the 1M; Table 1: List of examples, comparative formula

编号锂盐 (M) 辅助锂盐（质量《溶剂（比例为质量比）酰胺类化合物（质量％) 添加剂〔质量％) 对比例 1 LiPF₆ 1.0M EC:PC:EMC:DEC=25:5:50:20 —— VC 1.0%； (1， 3-PS) 1.5%； No. Lithium salt (M) Auxiliary lithium salt (mass "solvent (proportion to mass ratio) amide compound (% by mass) Additive [% by mass) Comparative Example 1 LiPF ₆ 1.0M EC: PC: EMC: DEC = 25: 5: 50:20 —— VC 1.0%; (1, 3-PS) 1.5%;

SZC980/ZT0ZN3/X3d 96S.60/CT0Z OAV 20 SZC980/ZT0ZN3/X3d 96S.60/CT0Z OAV 20

实施例 0.05%的 N，N-二甲基辛酰 Example 0.05% N,N-dimethyloctanoyl

LiPF₆ 1.0M EC:PC:EMC:DEC=25:5:50:20 —— LiPF ₆ 1.0M EC: PC: EMC: DEC=25:5:50:20 ——

21 胺 21 amine

实施例 0.05%的 N，N-二乙基辛酰 Example 0.05% N,N-diethyloctanoyl

LiPFe 1.0M EC:PC:EMC:DEC=25:5:50:20 —— LiPFe 1.0M EC: PC: EMC: DEC=25:5:50:20 ——

22 胺 22 amine

实施例 0.05%的 N，N-二甲基月桂 Example 0.05% N,N-Dimethyl Laurel

23 酰胺 23 amide

实施例 0.05%的 N，N-二乙基月桂 Example 0.05% N,N-Diethyl Laurel

24 酰胺 24 amide

实施例 LiPF₆ (锂盐总双草酸硼酸锂（LiBOB) 0.05%的 N， N-二甲基辛酰 VC 1.0% ； (1,3-PS) 1.5% ； Example LiPF ₆ (lithium salt total lithium bis(oxalate) borate (LiBOB) 0.05% N,N-dimethyloctanoyl VC 1.0%; (1,3-PS) 1.5%;

EC:PC:EMC:DEC=25:5:50:20 EC: PC: EMC: DEC=25:5:50:20

25 浓度 1. OM) 0.1% 胺 FEC 1.0% 实施例 LiPF₆ (锂盐总二氟草酸硼酸锂 0.05%的 N， N-二乙基辛酰 VC 1.0% ； (1,3-PS) 1.5% ； 25 Concentration 1. OM) 0.1% Amine FEC 1.0% Example LiPF ₆ (lithium salt total lithium difluorooxalate borate 0.05% N, N-diethyloctanoyl VC 1.0%; (1,3-PS) 1.5% ;

EC:PC:EMC:DEC=25:5:50:20 EC: PC: EMC: DEC=25:5:50:20

26 浓度 1. OM) (LiODFB) 1% 胺 FEC 1.0% 实施例 LiPF₆ (锂盐总 0.05%的 N， N-二甲基月桂 VC 1.0% ； (1， 3-PS) 1.5% ；四氟硼酸锂 (LiBF₄) 3% EC:PC:EMC:DEC=25:5:50:20 26 Concentration 1. OM) (LiODFB) 1% Amine FEC 1.0% Example LiPF ₆ (Lithium salt total 0.05% N, N-dimethyl Laurel VC 1.0%; (1, 3-PS) 1.5%; Tetrafluorocarbon Lithium borate (LiBF ₄ ) 3% EC: PC: EMC: DEC=25:5:50:20

27 浓度 1. OM) 酰胺 FEC 1.0% 27 Concentration 1. OM) Amide FEC 1.0%

双草酸硼酸锂（LiBOB) Lithium bis(oxalate) borate (LiBOB)

实施例 LiPF₆ (锂盐总 0.1%, 二氟草酸硼酸锂 0.05%的 N， N-二乙基月桂 VC 1.0% ； (1,3-PS) 1.5% ； Example LiPF ₆ (total lithium salt 0.1%, lithium difluorooxalate borate 0.05% N,N-diethyllauric VC 1.0%; (1,3-PS) 1.5%;

EC:PC:EMC:DEC=25:5:50:20 EC: PC: EMC: DEC=25:5:50:20

28 浓度 1.0M) (LiODFB) 0.05%及四氟酰胺 FEC 1.0% 28 Concentration 1.0M) (LiODFB) 0.05% and tetrafluoroamide FEC 1.0%

硼酸锂 (LiBF₄) 0.05% 常温循环性能测试 Lithium borate (LiBF ₄ ) 0.05% normal temperature cycle performance test

在常温（25°C ) 下，将根据实施例 2~28和对比例 1~3制备的电池用 1C恒流恒压充至 4.2V,然后用 1C恒流放电至 3.0V。充 /放电 500次循环后计算第 500 次循环容量的保持率。 The battery prepared according to Examples 2 to 28 and Comparative Examples 1 to 3 was charged to 4.2 V with a constant current of 1 C at a normal temperature (25 ° C), and then discharged to 3.0 V with a constant current of 1 C. After the 500 cycles of charging/discharging, the retention rate of the 500th cycle capacity was calculated.

第 500次循环容量保持率（％ ) = (第 500次循环放电容量 /首次循环放电容量 ) χ100 500th cycle capacity retention rate (%) = (500th cycle discharge capacity / first cycle discharge capacity) χ100

高温 45 °C循环性能测试 High temperature 45 °C cycle performance test

在 45°C下，将根据实施例 2~13和对比例 1~3制备的电池用 1C恒流恒压充至 4.2V, 然后用 1C恒流放电至 3.0V。充 /放电 500次循环后计算第 500次循环容量的保持率。 The batteries prepared according to Examples 2 to 13 and Comparative Examples 1 to 3 were charged to 4.2 V with a constant current of 1 C at 45 ° C, and then discharged to 3.0 V with a constant current of 1 C. After the 500 cycles of charging/discharging, the retention rate of the 500th cycle capacity was calculated.

第 500次循环容量保持率（％ ) = (第 500次循环放电容量 /首次循环放电容量 ) χ100% 500th cycle capacity retention rate (%) = (500th cycle discharge capacity / first cycle discharge capacity) χ100%

高温 60 °C保存性能测试 High temperature 60 °C preservation performance test

在常温（25°C ) 下进行一次 1C充电和放电（放电容量为 F。），再 1C恒流恒压充至 4.2V, 将电池放入 60°C的高温箱保存 1个月，再常温（25°C ) 下 1C 放电（放电容量为再常温（25°C ) 下 1C充电和放电（放电容量为 F₂)计算其容量保持率和容量恢复率。 1C charging and discharging at a normal temperature (25 ° C) (discharge capacity is F.), then 1 C constant current The constant pressure is charged to 4.2V, the battery is placed in a high temperature box at 60 ° C for 1 month, and the 1C discharge is performed at normal temperature (25 ° C) (discharge capacity is 1C charge and discharge at normal temperature (25 ° C)). The capacity is F ₂ ) and its capacity retention rate and capacity recovery rate are calculated.

容量保持率（％) =F₁/F_Qxl00% Capacity retention rate (%) = F ₁ /F _Q xl00%

容量恢复率（％ ) = F₂/ F_oxl00% Capacity recovery rate (%) = F ₂ / F _o xl00%

电池的最终性能 Final performance of the battery

上述各实施例与对比例的电解液各项电化学性能见下表 1 The electrochemical properties of the electrolytes of the above respective examples and comparative examples are shown in the following Table 1

实施例 16 75.8 57 58.0 69.0 实施例 17 75.5 56.5 57.5 68.5

Example 16 75.8 57 58.0 69.0 Example 17 75.5 56.5 57.5 68.5

实施例 18 54.5 45.6 40.5 50.1 Example 18 54.5 45.6 40.5 50.1

实施例 19 54.2 45.2 40.1 49.5 Example 19 54.2 45.2 40.1 49.5

实施例 20 53.5 44.6 39.5 48.0 Example 20 53.5 44.6 39.5 48.0

实施例 21 59.1 49.1 46.5 54.6 Example 21 59.1 49.1 46.5 54.6

实施例 22 60.1 50.2 47.6 55.5 Example 22 60.1 50.2 47.6 55.5

实施例 23 57.5 46.5 49.5 57.1 Example 23 57.5 46.5 49.5 57.1

实施例 24 58.2 48.0 50.2 58.2 Example 24 58.2 48.0 50.2 58.2

实施例 25 78.5 61.5 61.0 71.5 Example 25 78.5 61.5 61.0 71.5

实施例 26 79.5 62.2 62.1 72.6 Example 26 79.5 62.2 62.1 72.6

实施例 27 77.5 59.8 67.2 76.6 Example 27 77.5 59.8 67.2 76.6

实施例 28 78.7 60.7 68.0 77.5 Example 28 78.7 60.7 68.0 77.5

通过实施例 18~24和对比例 2的比较，可知本发明所选择结构式 1所示的酰胺化合物的加入，明显提高了电池的综合性能；通过实施例 2~17 和对比例 3 和对比例 1 的比较，酰胺化合物与其它添加剂联合使用，电池的综合性能进一步提高，其中，辛酰胺具有较好的常温循环和高温循环性能，而月桂酰胺具有较好的高温保存性能，添加量为 0.05%时，效果最佳；同时，从实施例 25~28 可以看出，辅助锂盐的加入，进一步提高电池的综合性能。 By comparison of Examples 18 to 24 and Comparative Example 2, it was found that the addition of the amide compound of the selected structural formula 1 of the present invention significantly improved the overall performance of the battery; by Examples 2-17 and Comparative Example 3 and Comparative Example 1 In comparison, the amide compound is used in combination with other additives, and the overall performance of the battery is further improved. Among them, octanamide has better normal temperature cycle and high temperature cycle performance, while lauramide has better high temperature storage performance when the addition amount is 0.05%. At the same time, it can be seen from Examples 25 to 28 that the addition of the auxiliary lithium salt further improves the overall performance of the battery.

以上所述仅为本发明的实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本发明的专利保护范围内。 The above is only the embodiment of the present invention, and thus does not limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied to other related technical fields, The same is included in the scope of patent protection of the present invention.

Claims

权利要求书 Claim

1、一种锂离子电池用非水电解液，其特征在于，所述电解液中含有：溶剂； A nonaqueous electrolyte for a lithium ion battery, characterized in that the electrolyte contains: a solvent;

锂盐； Lithium salt

如结构式 1所示的酰胺类化合物，

An amide compound as shown in Structural Formula 1,

结构式 1 Structural formula 1

其中选自碳原子数为 4~20的烃基， R₂,R₃分别独立地选自甲基或者乙基。It is selected from a hydrocarbon group having 4 to 20 carbon atoms, and R ₂ and R ₃ are each independently selected from a methyl group or an ethyl group.

2、根据权利要求 1所述的锂离子电池用非水电解液，其特征在于，所述如结构式 1所示的酰胺类化合物的含量按电解液的总重量计为 0. 001% ~ 2%。 001%〜 2% The total weight of the electrolyte is from 0.001% to 2%, based on the total weight of the electrolyte. .

3、根据权利要求 1或 2所述的锂离子电池用非水电解液，其特征在于，所述锂盐选自以下成分中的一种或多种： LiC10₄、 LiCF₃S0₃、 LiC₄F₉S0₃、 LiPF₆、 LiBF₄、 L iAsF₆、 L iN (C₂F₅S0₂) ₂、 LiN (CF₃S0₂) _{2 o} The nonaqueous electrolytic solution for a lithium ion battery according to claim 1 or 2, wherein the lithium salt is one or more selected from the group consisting of LiC10 ₄ , LiCF ₃ S0 ₃ , LiC ₄ F ₉ S0 ₃ , LiPF ₆ , LiBF ₄ , L iAsF ₆ , L iN (C ₂ F ₅ S0 ₂ ) ₂ , LiN (CF ₃ S0 ₂ ) _{2 o}

4、根据权利要求 1或 2所述的锂离子电池用非水电解液，其特征在于，所述锂盐包括 Li PF₆与辅助锂盐，所述辅助锂盐选自：双草酸硼酸锂，二氟草酸硼酸锂及四氟硼酸锂中的一种或多种，所述辅助锂盐的含量按电解液的总重量计为 0. 1% ~ 3%。 The nonaqueous electrolyte for a lithium ion battery according to claim 1 or 2, wherein the lithium salt comprises Li PF ₆ and an auxiliary lithium salt, and the auxiliary lithium salt is selected from the group consisting of lithium bis(oxalate) borate, 1%〜3%。 The content of the total weight of the electrolyte is 0.1% ~ 3%.

5、根据权利要求 1或 2所述的锂离子电池用非水电解液，其特征在于，所述溶剂选自以下成分中的一种或多种： The nonaqueous electrolytic solution for a lithium ion battery according to claim 1 or 2, wherein the solvent is one or more selected from the group consisting of:

碳酸乙烯酯、碳酸丙烯酯、碳酸亚丁酯、碳酸二乙酯、碳酸二甲酯、碳酸甲乙酯、 γ -丁内酯、环丁砜、乙酸甲酯、乙酸乙酯、丙酸甲酯及丙酸乙酯。 Ethylene carbonate, propylene carbonate, butylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, sulfolane, methyl acetate, ethyl acetate, methyl propionate and propionic acid Ethyl ester.

6、根据权利要求 1或 2所述的锂离子电池用非水电解液，其特征在于，其中的非水电解液还含有以下添加剂的一种或多种： The nonaqueous electrolytic solution for a lithium ion battery according to claim 1 or 2, wherein the nonaqueous electrolytic solution further contains one or more of the following additives:

碳酸亚乙烯酯，乙烯基碳酸乙烯酯，代碳酸乙烯酯，环状磺酸酯，环状亚硫酸酯，环状硫酸酯。 Vinylene carbonate, vinyl ethylene carbonate, ethylene carbonate, cyclic sulfonate, cyclic sulfite, cyclic sulfate.

7、一种锂离子二次电池，其特征在于： 7. A lithium ion secondary battery, characterized in that:

活性物质为 LiMnA的阴极；活性物质为石墨的阳极； The active material is a cathode of LiMnA; The active material is an anode of graphite;

置于阴极与阳极之间的多孔隔板； a porous separator disposed between the cathode and the anode;

以及权利要求 1至 5任意一项所述的锂离子电池用非水电解液。 The nonaqueous electrolytic solution for a lithium ion battery according to any one of claims 1 to 5.

8、如结构式 1所示的酰胺类化合物，在锰酸锂电池电解液中的应用；

8. The use of an amide compound of the formula 1 in an electrolyte of a lithium manganate battery;

结构式 1 Structural formula 1

其中选自碳原子数为 4~20的烃基， R₂,R₃分别独立地选自甲基或者乙基。 It is selected from a hydrocarbon group having 4 to 20 carbon atoms, and R ₂ and R ₃ are each independently selected from a methyl group or an ethyl group.