WO2022001777A1

WO2022001777A1 - Electrolyte and electrochemical device containing electrolyte

Info

Publication number: WO2022001777A1
Application number: PCT/CN2021/101782
Authority: WO
Inventors: 刘建禹; 刘建; 郑建明; 管明明
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-06-29
Filing date: 2021-06-23
Publication date: 2022-01-06
Also published as: CN111740147A; CN111740147B

Abstract

The present application relates to an electrolyte, which contains bismaleimide compounds and propionate compounds, wherein on the basis of the total weight of the electrolyte, the content of the bismaleimide compounds is X, and the content of the propionate compounds is Y, where 0.002≤X/Y≤0.5.

Description

电解液和包含电解液的电化学装置Electrolyte and electrochemical device containing electrolyte

技术领域technical field

本申请涉及储能技术领域，尤其涉及一种电解液以及包括该电解液的电化学装置和电子装置。The present application relates to the technical field of energy storage, and in particular, to an electrolyte and an electrochemical device and an electronic device including the electrolyte.

背景技术Background technique

随着智能产品的普及和应用，人们对手机、笔记本、相机等电子产品的需求逐年增加。锂离子电池作为电子产品的工作电源，具有能量密度高、无记忆效应、工作电压高等特点，正逐步取代传统的Ni-Cd、MH-Ni电池。然而随着电子产品向轻薄化和便携化的发展，人们对锂离子电池的要求不断提高，开发循环稳定性好、阻抗小、自放电少、安全的锂离子电池是市场的主要需求之一。With the popularization and application of smart products, people's demand for electronic products such as mobile phones, notebooks, and cameras has increased year by year. As the working power supply of electronic products, lithium-ion batteries have the characteristics of high energy density, no memory effect and high working voltage, and are gradually replacing traditional Ni-Cd and MH-Ni batteries. However, with the development of thin and portable electronic products, people's requirements for lithium-ion batteries are constantly increasing. The development of lithium-ion batteries with good cycle stability, low impedance, less self-discharge and safety is one of the main needs of the market.

发明内容SUMMARY OF THE INVENTION

本申请通过提供一种电解液以解决至少一种存在于相关领域中的问题。特别地，本申请提供的电解液能够显著改善电化学装置的高温性能和浮充性能。本申请还涉及包含这种电解液的电化学装置和电子装置。The present application solves at least one problem existing in the related art by providing an electrolyte. In particular, the electrolyte provided by the present application can significantly improve the high temperature performance and float charge performance of the electrochemical device. The present application also relates to electrochemical devices and electronic devices comprising such electrolytes.

本申请提供一种电解液，其包含双马来酰亚胺化合物和丙酸酯化合物，其中所述双马来酰亚胺化合物包括：The application provides an electrolyte solution comprising a bismaleimide compound and a propionate compound, wherein the bismaleimide compound includes:

(III) 中的至少一种，其中，R ₁为 C ₁-C ₁₀亚烷基、C ₁-C ₁₀烷氧基、砜基、磺酰基、酯基、-O-、-O-O-、-S-、-S-S-或-O-S-O-，所述C ₁-C ₁₀亚烷基和所述C ₁-C ₁₀烷氧基任选地经卤素取代； At least one of (III), wherein R ₁ is a C ₁ -C ₁₀ alkylene group, a C ₁ -C ₁₀ alkoxy group, a sulfone group, a sulfonyl group, an ester group, -O-, -OO-, - S-, -SS- or -OSO-, said C ₁ -C ₁₀ alkylene and said C ₁ -C ₁₀ alkoxy optionally substituted with halogen;

其中，基于所述电解液的总重量，所述双马来酰亚胺化合物的含量为X，所述丙酸酯化合物的含量为Y，其中，0.002≤X/Y≤0.5。Wherein, based on the total weight of the electrolyte, the content of the bismaleimide compound is X, and the content of the propionate compound is Y, wherein 0.002≤X/Y≤0.5.

在一些实施例中，0.1％≤X≤5％，10％≤Y≤60％。In some embodiments, 0.1%≤X≤5%, 10%≤Y≤60%.

在一些实施例中，电解液中的式III化合物包括以下化合物中的至少一种：In some embodiments, the compound of formula III in the electrolyte includes at least one of the following compounds:

在一些实施例中，电解液中的丙酸酯化合物包含丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、丙酸戊酯、氟代丙酸甲酯、氟代丙酸乙酯、氟代丙酸丙酯、氟代丙酸丁酯或氟代丙酸戊酯中的至少一种，其中氟代表示化合物中至少一个氢原子被氟原子取代。In some embodiments, the propionate compound in the electrolyte comprises methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, methyl fluoropropionate, fluoropropionate At least one of ethyl ester, propyl fluoropropionate, butyl fluoropropionate or pentyl fluoropropionate, wherein fluorine represents that at least one hydrogen atom in the compound is replaced by a fluorine atom.

在一些实施例中，电解液中的丙酸酯化合物包括丙酸丙酯，并且所述丙酸丙酯的含量不低于所述丙酸酯总量的10％。In some embodiments, the propionate compound in the electrolyte includes propyl propionate, and the content of the propyl propionate is not less than 10% of the total amount of the propionate.

在一些实施例中，电解液还包含添加剂A，所述添加剂A包含偶氮二异丁腈、偶氮二异庚腈、过氧化二苯甲酰、过氧化苯甲酸叔丁酯或二叔丁基过氧化物中的至少一种；且基于所述电解液的总重量，所述添加剂A的含量为Z，且Z与X的关系满足0.001≤Z/X≤0.05。In some embodiments, the electrolyte further includes an additive A, the additive A includes azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, tert-butyl peroxybenzoate, or di-tert-butyl benzoate based on the total weight of the electrolyte, the content of the additive A is Z, and the relationship between Z and X satisfies 0.001≤Z/X≤0.05.

在一些实施例中，电解液还包含式IV表示的硫酰化合物，In some embodiments, the electrolyte further comprises a sulfuryl compound represented by formula IV,

其中，R ₂和R ₃各自独立地为C ₁-C ₈亚烷基并且任选地经卤素取代。 wherein R ₂ and R ₃ are each independently C ₁ -C ₈ alkylene and are optionally substituted with halogen.

在一些实施例中，电解液中的硫酰化合物包括硫酰二乙腈、硫酰二丙腈、硫酰二丁腈或硫酰二己腈中的至少一种，基于所述电解液总重量，所述硫酰化合物的含量为0.1％至5％。In some embodiments, the sulfuryl compound in the electrolyte includes at least one of sulfuryldiacetonitrile, sulfuryldipropionitrile, sulfuryldibutyronitrile, or sulfuryldicapronitrile, based on the total weight of the electrolyte, The content of the sulfuryl compound is 0.1% to 5%.

在一些实施例中，电解液还包含二腈化合物或三腈化合物中的至少一种；其中：In some embodiments, the electrolyte further comprises at least one of a dinitrile compound or a trinitrile compound; wherein:

二腈化合物包含丁二腈、戊二腈、己二腈、1,5-二氰基戊烷、1,6-二氰基己烷、1,7-二氰基庚烷、1,8-二氰基辛烷、1,9-二氰基壬烷、1,10-二氰基癸烷、1,12-二氰基十二烷、四甲基丁二腈、2-甲基戊二腈、2,4-二甲基戊二腈或2,2,4,4-四甲基戊二腈中的至少一种；Dinitrile compounds include succinonitrile, glutaronitrile, adiponitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, 1,7-dicyanoheptane, 1,8- Dicyanooctane, 1,9-dicyanononane, 1,10-dicyanodecane, 1,12-dicyanododecane, tetramethylsuccinonitrile, 2-methylpentanedi At least one of nitrile, 2,4-dimethylglutaronitrile or 2,2,4,4-tetramethylglutaronitrile;

三腈化合物包含1,3,5-戊三甲腈、1,2,3-丙三甲腈、1,3,6-己三甲腈、1,2,6-己三甲腈、1,2,3-三(2-氰基乙氧基)丙烷、1,2,4-三(2-氰基乙氧基)丁烷或1,2,5-三(氰基乙氧基)戊烷中的至少一种。Trinitrile compounds include 1,3,5-pentanetricarbonitrile, 1,2,3-propanetricarbonitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2,3-hexanetricarbonitrile At least one of tris(2-cyanoethoxy)propane, 1,2,4-tris(2-cyanoethoxy)butane or 1,2,5-tris(cyanoethoxy)pentane A sort of.

本申请还提供一种电化学装置，其包括正极、负极、设置于正极和负极之间的隔离膜、以及根据本申请的电解液。The present application also provides an electrochemical device including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution according to the present application.

在一些实施例中，电化学装置中的正极包含：In some embodiments, the positive electrode in the electrochemical device comprises:

正极集流体；positive current collector;

正极活性材料层；和a positive electrode active material layer; and

绝缘层，所述绝缘层设置于所述正极集流体上，所述绝缘层满足条件(a)至(c)中的至少一者：an insulating layer, the insulating layer is disposed on the positive electrode current collector, and the insulating layer satisfies at least one of the conditions (a) to (c):

(a)所述绝缘层与所述正极活性材料层间有空隙，所述空隙的宽度为小于等于2mm；(a) There is a gap between the insulating layer and the positive electrode active material layer, and the width of the gap is less than or equal to 2 mm;

(b)所述绝缘层包括无机粒子，所述无机粒子包括氧化铝、二氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、二氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种；(b) The insulating layer includes inorganic particles, and the inorganic particles include aluminum oxide, silicon dioxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, calcium oxide, at least one of zirconia, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate;

(c)所述绝缘层包括聚合物，所述聚合物包括偏氟乙烯的均聚物、偏氟乙烯的共聚物、六氟丙烯的共聚物、聚苯乙烯、聚苯乙炔、聚乙烯酸钠、聚乙烯酸钾、聚甲基丙烯酸甲酯、聚乙烯、聚丙烯或聚四氟乙烯中的至少一种。(c) The insulating layer includes a polymer, and the polymer includes a homopolymer of vinylidene fluoride, a copolymer of vinylidene fluoride, a copolymer of hexafluoropropylene, polystyrene, polyphenylene vinylene, sodium polyvinylidene , at least one of potassium polyvinate, polymethyl methacrylate, polyethylene, polypropylene or polytetrafluoroethylene.

本申请还提供一种电子装置，其包括根据本申请的电化学装置。The present application also provides an electronic device comprising the electrochemical device according to the present application.

附图说明Description of drawings

在下文中将简要地说明为了描述本申请实施例或现有技术所必要的附图以便于描述本申请的实施例。显而易见地，下文描述中的附图仅只是本申请中的部分实施例。对本领域技术人员而言，在不需要创造性劳动的前提下，依然可以根据这些附图中所例示的结构来获得其他实施例的附图。Hereinafter, drawings necessary to describe the embodiments of the present application or the related art will be briefly described in order to facilitate the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, the drawings of other embodiments can still be obtained according to the structures illustrated in these drawings without creative efforts.

图1示出根据本申请的正极，其中正极包含正极集流体(1)、第一表面正极活性物质层(2)、第二表面活性物质层(3)和绝缘层(4)。Figure 1 shows a positive electrode according to the present application, wherein the positive electrode comprises a positive electrode current collector (1), a first surface positive electrode active material layer (2), a second surface active material layer (3) and an insulating layer (4).

图2示出根据本申请的电化学装置经过化成之后，负极的傅里叶红外光谱。FIG. 2 shows the Fourier infrared spectrum of the negative electrode after the electrochemical device according to the present application is formed.

具体实施方式detailed description

为使本申请的目的、技术方案和优点更加清楚，下面将结合实施例对本申请的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。在此所描述的有关实施例为说明性质的且用于提供对本申请的基本理解。本申请的实施例不应该被解释为对本申请的限制。基于本申请提供的技术方案及所给出的实施例，本领域技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the implementations. example. The relevant embodiments described herein are illustrative in nature and are used to provide a basic understanding of the present application. The embodiments of the present application should not be construed as limitations of the present application. All other embodiments obtained by those skilled in the art without creative work based on the technical solutions provided in this application and the given embodiments fall within the protection scope of this application.

如本文中所使用，术语“约”用以描述及说明小的变化。当与事件或情形结合使用时，所述术语可指代其中事件或情形精确发生的例子以及其中事件或情形极近似地发生的例子。举例来说，当结合数值使用时，术语可指代小于或等于所述数值的±10％的变化范围，例如小于或等于±5％、小于或等于±4％、小于或等于±3％、小于或等于±2％、小于或等于±1％、小于或等于±0.5％、小于或等于±0.1％、或小于或等于±0.05％。举例来说，如果两个数值之间的差值小于或等于所述值的平均值的±10％(例如小于或等于±5％、小于或等于±4％、小于或等于±3％、小于或等于±2％、小于或等于±1％、小于或等于±0.5％、小于或等于±0.1％、或小于或等于±0.05％)，那么可认为所述两个数值“约”相同。As used herein, the term "about" is used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs proximately. For example, when used in conjunction with a numerical value, a term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, Less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, if the difference between two values is less than or equal to ±10% of the mean of the values (eg, less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%), then the two values are considered to be "about" the same.

另外，有时在本文中以范围格式呈现量、比率和其它数值。应理解，此类范围格式是用于便利及简洁起见，且应灵活地理解，不仅包含明确地指定为范围限制的数值，而且包含涵盖于所述范围内的所有个别数值或子范围，如同明确地指定每一数值及子范围一般。In addition, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity, and that it is to be understood flexibly to include not only the numerical values expressly designated as the limits of the range, but also all individual numerical values or subranges subsumed within the stated range, as if expressly Specify each numerical value and subrange generically.

在具体实施方式及权利要求书中，由术语“中的一者”、“中的一个”、“中的一种”或其他相似术语所连接的项目的列表可意味着所列项目中的任一者。例如，如果列出项目A及B，那么短语“A及B中的一者”意味着仅A或仅B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的一者”意味着仅A；仅B；或仅C。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。In the Detailed Description and the Claims, a list of items joined by the terms "one of," "one of," "one of," or other similar terms can mean that any of the listed items one. For example, if items A and B are listed, the phrase "one of A and B" means A only or B only. In another example, if the items A, B, and C are listed, the phrase "one of A, B, and C" means A only; B only; or C only. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

在具体实施方式及权利要求书中，由术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。In the Detailed Description and the Claims, a list of items joined by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean the listed items any combination of . For example, if items A and B are listed, the phrase "at least one of A and B" means A only; B only; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means A only; or B only; C only; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

本申请中使用下列定义(除非另外明确地说明)：The following definitions are used in this application (unless expressly stated otherwise):

为简单起见，“Cn-Cm”基团是指具有“n”至“m”个碳原子的基团，其中“n”和“m”是整数。例如，“C _1-C ₁₀”亚烷基是具有1至10个碳原子的亚烷基。 For simplicity, a "Cn-Cm" group refers to a group having "n" to "m" carbon atoms, where "n" and "m" are integers. For example, a "C1 _- _C10 " alkylene group is an alkylene group having 1 to 10 carbon atoms.

术语“烷基”预期是具有1至20个碳原子的直链饱和烃结构。“烷基”还预期是具有3至20个碳原子的支链或环状烃结构。例如，烷基可为1至20个碳原子的烷基、1至10个碳原子的烷基、1至5个碳原子的烷基、5至20个碳原子的烷基、5至15个碳原子的烷基或5至10个碳原子的烷基。当指定具有具体碳数的烷基时，预期涵盖具有该碳数的所有几何异构体；因此，例如，“丁基”意思是包括正丁基、仲丁基、异丁基、叔丁基和环丁基；“丙基”包括正丙基、异丙基和环丙基。烷基实例包括，但不限于甲基、乙基、正丙基、异丙基、环丙基、正丁基、异丁基、仲丁基、叔丁基、环丁基、正戊基、异戊基、新戊基、环戊基、甲基环戊基、乙基环戊基、正己基、异己基、环己基、正庚基、辛基、环丙基、环丁基、降冰片基等。另外，烷基可以是任选地被取代的。The term "alkyl" is intended to be a straight chain saturated hydrocarbon structure having from 1 to 20 carbon atoms. "Alkyl" is also contemplated to be a branched or cyclic hydrocarbon structure having 3 to 20 carbon atoms. For example, the alkyl group can be an alkyl group of 1 to 20 carbon atoms, an alkyl group of 1 to 10 carbon atoms, an alkyl group of 1 to 5 carbon atoms, an alkyl group of 5 to 20 carbon atoms, an alkyl group of 5 to 15 carbon atoms An alkyl group of carbon atoms or an alkyl group of 5 to 10 carbon atoms. When specifying an alkyl group having a specific carbon number, it is intended to encompass all geometric isomers having that carbon number; thus, for example, "butyl" is meant to include n-butyl, sec-butyl, isobutyl, tert-butyl and cyclobutyl; "propyl" includes n-propyl, isopropyl and cyclopropyl. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, octyl, cyclopropyl, cyclobutyl, norbornyl Base et al. Additionally, alkyl groups can be optionally substituted.

术语“烯基”是指可为直链或具支链且具有至少一个且通常1个、2个或3个碳碳双键的单价不饱和烃基团。除非另有定义，否则所述烯基通常含有2至20个碳原子，例如可以为2至20个碳原子的烯基、6至20个碳原子的烯基、2至10个碳原子的烯基或2至6个碳原子的烯基。代表性烯基包括(例如)乙烯基、正丙烯基、异丙烯基、正-丁-2-烯基、丁-3-烯基、正-己-3-烯基等。另外，烯基可以是任选地被取代的。The term "alkenyl" refers to a monovalent unsaturated hydrocarbon group which may be straight or branched and having at least one and usually 1, 2 or 3 carbon-carbon double bonds. Unless otherwise defined, the alkenyl group typically contains from 2 to 20 carbon atoms, for example, it may be alkenyl of 2 to 20 carbon atoms, alkenyl of 6 to 20 carbon atoms, alkenyl of 2 to 10 carbon atoms group or an alkenyl group of 2 to 6 carbon atoms. Representative alkenyl groups include, for example, vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but-3-enyl, n-hex-3-enyl, and the like. Additionally, alkenyl groups may be optionally substituted.

术语“炔基”是指可为直链或具支链且具有至少一个且通常具有1个、2个或3个碳碳三键的单价不饱和烃基团。除非另有定义，否则所述炔基通常含有2至20个碳原子，例如可以为2至20个碳原子的炔基、6至20个碳原子的炔基、2至10个碳原子的炔基或2至6个碳原子的炔基。代表性炔基包括(例如)乙炔基、丙-2-炔基(正-丙炔基)、正-丁-2-炔基、正-己-3-炔基等。另外，炔基可以是任选地被取代的。The term "alkynyl" refers to a monovalent unsaturated hydrocarbon group which may be straight or branched and having at least one and usually one, two or three carbon-carbon triple bonds. Unless otherwise defined, the alkynyl group typically contains from 2 to 20 carbon atoms, for example, it may be alkynyl of 2 to 20 carbon atoms, alkynyl of 6 to 20 carbon atoms, alkynyl of 2 to 10 carbon atoms alkynyl or alkynyl of 2 to 6 carbon atoms. Representative alkynyl groups include, for example, ethynyl, prop-2-ynyl (n-propynyl), n-but-2-ynyl, n-hex-3-ynyl, and the like. Additionally, alkynyl groups may be optionally substituted.

术语“亚烷基”意指可为直链或具支链的二价饱和烷基。除非另有定义，否则所述亚烷基通常含有1到10个、1至6个、1至4个或2至4个碳原子，且包括(例如)C ₂-C ₃亚烷基和C ₂-C ₆亚烷基-。代表性亚烷基包括(例如)亚甲基、乙烷-1,2-二基(“亚乙基”)、丙烷-1,2-二基、丙烷-1,3-二基、丁烷-1,4-二基、戊烷-1,5-二基等。 The term "alkylene" means a divalent saturated alkyl group which may be straight or branched. Unless otherwise defined, such alkylene groups typically contain the 1-10, 1-6, 1-4, or 2-4 carbon atoms, and include (for example) C ₂ -C ₃ alkylene and C _2- C ₆ alkylene-. Representative alkylene groups include, for example, methylene, ethane-1,2-diyl ("ethylene"), propane-1,2-diyl, propane-1,3-diyl, butane -1,4-diyl, pentane-1,5-diyl, etc.

术语“亚烯基”意指通过从上述定义的烯基中除去一个氢原子而获得的双官能团。优选的亚烯基包括但不限于-CH＝CH-、-C(CH ₃)＝CH-、-CH＝CHCH ₂–等。 The term "alkenylene" means a bifunctional group obtained by removing one hydrogen atom from an alkenyl group as defined above. Preferred alkenylene groups include, but are not limited to, -CH = CH -, - C ( CH 3) = CH -, - CH = CHCH 2 - and the like.

术语“芳基”意指具有单环(例如，苯基)或稠合环的单价芳香族烃。稠合环***包括那些完全不饱和的环***(例如，萘)以及那些部分不饱和的环***(例如，1,2,3,4-四氢萘)。除非另有定义，否则所述芳基通常含有6个到26个、6至20个、6至15个或6至10个碳环原子且包括(例如)C ₆-C ₁₀芳基。代表性芳基包括(例如)苯基、甲基苯基、丙基苯基、异丙基苯基、苯甲基和萘-1-基、萘-2-基等等。 The term "aryl" means a monovalent aromatic hydrocarbon having a single ring (eg, phenyl) or fused rings. Fused ring systems include those that are fully unsaturated (eg, naphthalene) as well as those that are partially unsaturated (eg, 1,2,3,4-tetrahydronaphthalene). Unless otherwise defined, such aryl groups typically contain from 6 to 26, 6 to 20, 6 to 15 or 6 to 10 ring carbon atoms and include (e.g.) C ₆ -C ₁₀ aryl group. Representative aryl groups include, for example, phenyl, methylphenyl, propylphenyl, isopropylphenyl, benzyl, and naphth-1-yl, naphth-2-yl, and the like.

术语“杂环”或“杂环基”意指取代或未取代的5至8元单或双环非芳族烃，其中1至3个碳原子被选自氮、氧或硫原子的杂原子替换。实例包括吡咯烷-2-基；吡咯烷-3-基；哌啶基；吗啉-4-基等，这些基团随后可被取代。“杂原子”是指选自N、O和S的原子。The term "heterocycle" or "heterocyclyl" means a substituted or unsubstituted 5 to 8 membered mono- or bicyclic non-aromatic hydrocarbon in which 1 to 3 carbon atoms are replaced by heteroatoms selected from nitrogen, oxygen or sulfur atoms . Examples include pyrrolidin-2-yl; pyrrolidin-3-yl; piperidinyl; morpholin-4-yl and the like, which groups may subsequently be substituted. "Heteroatom" refers to an atom selected from N, O and S.

如本文所用，术语“卤素”可为F、Cl、Br或I。As used herein, the term "halogen" may be F, Cl, Br or I.

如本文所用，术语“氰基”涵盖含有机基团-CN的有机物。As used herein, the term "cyano" encompasses organics containing the organic group -CN.

当上述取代基经取代时，取代基可选自由以下组成的群组：卤素、烷基、烯基、芳基和杂芳基。When the above substituents are substituted, the substituents may be selected from the group consisting of halogen, alkyl, alkenyl, aryl and heteroaryl.

一、电解液1. Electrolyte

1、双马来酰亚胺化合物和丙酸酯化合物1. Bismaleimide compound and propionate compound

本申请提供一种电解液，其包含双马来酰亚胺化合物和丙酸酯化合物，其中，双马来酰亚胺化合物包括：The present application provides an electrolyte solution comprising a bismaleimide compound and a propionate compound, wherein the bismaleimide compound includes:

(III) 中的至少一种，其中，R ₁为C ₁-C ₁₀亚烷基、C ₁-C ₁₀烷氧基、砜基、磺酰基、酯基、-O-、-O-O-、-S-、-S-S-或-O-S-O-，C ₁-C ₁₀亚烷基和C ₁-C ₁₀烷氧基任选地经卤素取代。 At least one of (III), wherein R ₁ is a C ₁ -C ₁₀ alkylene group, a C ₁ -C ₁₀ alkoxy group, a sulfone group, a sulfonyl group, an ester group, -O-, -OO-, - S-, -SS- or -OSO-, C ₁ -C ₁₀ alkylene and C ₁ -C ₁₀ alkoxy are optionally substituted with halogen.

在一些实施例中，电解液中的式III化合物具有对称结构，且N原子一定要与苯环相连，例如，式III化合物包括以下化合物中的至少一种：In some embodiments, the compound of formula III in the electrolyte has a symmetrical structure, and the N atom must be connected to the benzene ring. For example, the compound of formula III includes at least one of the following compounds:

在一些实施例中，电解液中的双马来酰亚胺化合物选自式I、式II或式III-1的化合物中的至少一种。In some embodiments, the bismaleimide compound in the electrolyte is selected from at least one of the compounds of formula I, formula II or formula III-1.

在一些实施例中，丙酸酯化合物包含丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、丙酸戊酯、氟代丙酸甲酯、氟代丙酸乙酯、氟代丙酸丙酯、氟代丙酸丁酯或氟代丙酸戊酯中的至少一种，其中氟代表示化合物中至少一个氢原子被氟原子取代。In some embodiments, the propionate compound comprises methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, methyl fluoropropionate, ethyl fluoropropionate, At least one of propyl fluoropropionate, butyl fluoropropionate or pentyl fluoropropionate, wherein fluorine represents that at least one hydrogen atom in the compound is replaced by a fluorine atom.

在一些实施例中，丙酸酯化合物包含丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯或丙酸戊酯中的至少一种。在一些实施例中，电解液中的丙酸酯化合物包括丙酸丙酯，并且，丙酸酯化合物占电解液整体重量的10％至60％，并且丙酸丙酯的含量不低于丙酸酯化合物总量的10％，例如，丙酸丙酯的含量可以为40％、50％、60％、70％、80％、90％、甚至可以高达100％。丙酸酯中丙酸丙酯的含量在10％以上可以保证较高的电导率，进而增强电池的动力学，并且可提升电解液溶剂的整体热稳定性。In some embodiments, the propionate compound comprises at least one of methyl propionate, ethyl propionate, propyl propionate, butyl propionate, or pentyl propionate. In some embodiments, the propionate compound in the electrolyte includes propyl propionate, and the propionate compound accounts for 10% to 60% of the total weight of the electrolyte, and the content of propyl propionate is not less than propionate 10% of the total amount of ester compounds, for example, propyl propionate may be present at 40%, 50%, 60%, 70%, 80%, 90%, and even as high as 100%. The content of propyl propionate in the propionate above 10% can ensure higher electrical conductivity, thereby enhancing the kinetics of the battery, and can improve the overall thermal stability of the electrolyte solvent.

在一些实施例中，丙酸酯化合物为丙酸乙酯和丙酸丙酯的组合。特别有利地，当丙酸酯化合物为丙酸乙酯和丙酸丙酯的组合时，本申请的电解液可以出人意料地实现优异的热箱性能和倍率性能。In some embodiments, the propionate compound is a combination of ethyl propionate and propyl propionate. Particularly advantageously, when the propionate compound is a combination of ethyl propionate and propyl propionate, the electrolyte of the present application can unexpectedly achieve excellent hot box performance and rate performance.

在一些实施例中，基于电解液的总重量，双马来酰亚胺化合物的含量为X，0.1％≤X≤5％，例如，X可以为0.1％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1.0％、2.0％、3.0％、4.0％或5.0％，或者为上述任意两个数值之间的范围。In some embodiments, based on the total weight of the electrolyte, the content of the bismaleimide compound is X, 0.1%≤X≤5%, for example, X can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 2.0%, 3.0%, 4.0% or 5.0%, or a range between any two of the above.

在一些实施例中，基于电解液的总重量，丙酸酯化合物的含量为Y，10％≤Y≤60％，例如，Y可以为10％、15％、18％、20％、25％、30％、35％、40％、45％、50％或60％，或者为上述任意两个数值之间的范围。In some embodiments, based on the total weight of the electrolyte, the content of the propionate compound is Y, 10%≤Y≤60%, for example, Y can be 10%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or 60%, or a range between any two of the above.

在一些实施例中，双马来酰亚胺化合物的含量为X，0.1％≤X≤5％，例如，X可以为0.1％、0.3％、0.5％、1％、2％、3％、4％、5％，或者为上述任意两个数值之间的范围。In some embodiments, the content of the bismaleimide compound is X, 0.1%≤X≤5%, for example, X can be 0.1%, 0.3%, 0.5%, 1%, 2%, 3%, 4% %, 5%, or a range between any two values above.

在一些实施例中，双马来酰亚胺化合物与丙酸酯化合物的含量的比X/Y为0.005至0.5，例如，X/Y可以为0.005、0.008、0.01、0.0125、0.0150、0.0167、0.0250、0.05、0.1、0.2、0.3、0.4、0.5，或者为上述任意两个数值之间的范围。In some embodiments, the ratio X/Y of the content of the bismaleimide compound to the propionate compound is 0.005 to 0.5, for example, X/Y may be 0.005, 0.008, 0.01, 0.0125, 0.0150, 0.0167, 0.0250 , 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, or a range between any two of the above values.

在一些实施例中，双马来酰亚胺化合物的含量X与丙酸酯化合物的含量Y满足0.002≤X/Y≤0.5。In some embodiments, the content X of the bismaleimide compound and the content Y of the propionate compound satisfy 0.002≤X/Y≤0.5.

在一些实施例中，双马来酰亚胺化合物的含量X与丙酸酯化合物的含量Y同时满足上述条件，即，0.1％≤X≤5％，10％≤Y≤60％，且0.002≤X/Y≤0.5。In some embodiments, the content X of the bismaleimide compound and the content Y of the propionate compound simultaneously satisfy the above conditions, that is, 0.1%≤X≤5%, 10%≤Y≤60%, and 0.002≤ X/Y≤0.5.

当双马来酰亚胺化合物与丙酸酯化合物的含量在上述范围内时，既可以实现安全性能的改善，又可保证电池较好的动力学性能。When the content of the bismaleimide compound and the propionate compound is within the above range, the safety performance can be improved, and the better kinetic performance of the battery can be ensured.

2、添加剂A2. Additive A

在一些实施例中，电解液还包含添加剂A，添加剂A包含偶氮二异丁腈、偶氮二异庚腈、过氧化二苯甲酰、过氧化苯甲酸叔丁酯或二叔丁基过氧化物中的至少一种。基于所述电解液的总重量，添加剂A的含量为Z，且添加剂A的含量Z与双马来酰亚胺化合物的含量X的关系满足0.001≤Z/X≤0.05。例如，Z/X的值可以为0.001、0.002、0.005、0.008、0.01、0.05，或者为上述任意两个数值之间的范围。上述添加剂A的添加可出人意料地避免式III化合物对电池倍率、循环、低温放电等电性能的恶化。In some embodiments, the electrolyte further includes an additive A, and the additive A includes azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, tert-butyl peroxybenzoate, or di-tert-butyl peroxybenzoate. at least one of the oxides. Based on the total weight of the electrolyte, the content of the additive A is Z, and the relationship between the content Z of the additive A and the content X of the bismaleimide compound satisfies 0.001≤Z/X≤0.05. For example, the value of Z/X can be 0.001, 0.002, 0.005, 0.008, 0.01, 0.05, or a range between any two of the above. The addition of the above-mentioned additive A can unexpectedly avoid the deterioration of the electrical properties of the compound of formula III on battery rate, cycle, low temperature discharge and the like.

3、硫酰化合物3. Sulfuryl compounds

在一些实施例中，电解液中的硫酰化合物包括硫酰二乙腈、硫酰二丙腈、硫酰二丁腈或硫酰二己腈中的至少一种，优选为硫酰二丙腈。In some embodiments, the sulfuryl compound in the electrolyte includes at least one of sulfuryldiacetonitrile, sulfuryldipropionitrile, sulfuryldibutyronitrile, or sulfuryldicapronitrile, preferably sulfuryldipropionitrile.

在一些实施例中，基于电解液总重量，硫酰化合物的含量为0.1％至5％，例如，其含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、0.9％、1％、2.5％、3％、5％，或者为上述任意两个数值之间的范围。In some embodiments, the content of the sulfuryl compound is 0.1% to 5% based on the total weight of the electrolyte, for example, the content thereof may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.9%, 1% , 2.5%, 3%, 5%, or a range between any two of the above values.

本申请中，式IV的硫酰化合物与式III化合物，特别是与式III-1化合物的组合使用可形成均匀且较薄的界面保护层，能够明显改善电池初始及循环过程中的阻抗增长，保证电池实现更好的循环稳定性。In this application, the combination of the sulfuryl compound of formula IV and the compound of formula III, especially the compound of formula III-1, can form a uniform and thinner interface protection layer, which can significantly improve the impedance growth of the battery during initial and cycle process, Ensure that the battery achieves better cycle stability.

4、腈类化合物4. Nitrile compounds

三腈化合物包含1,3,5-戊三甲腈、1,2,3-丙三甲腈、1,3,6-己烷三腈、1,2,6-己烷三腈、1,2,3-三(2-氰基乙氧基)丙烷、1,2,4-三(2-氰基乙氧基)丁烷或1,2,5-三(氰基乙氧基)戊烷中的至少一种。Trinitrile compounds include 1,3,5-pentanetricarbonitrile, 1,2,3-propanetricarbonitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2, In 3-tris(2-cyanoethoxy)propane, 1,2,4-tris(2-cyanoethoxy)butane or 1,2,5-tris(cyanoethoxy)pentane at least one of.

在一些实施例中，基于电解液总重量，二腈化合物的含量为0.1％至8％，例如，其含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、1％、3％、5％、8％，或者为上述任意两个数值之间的范围。In some embodiments, the content of the dinitrile compound is 0.1% to 8% based on the total weight of the electrolyte, for example, its content may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 3% , 5%, 8%, or a range between any two of the above values.

在一些实施例中，基于电解液总重量，三腈化合物的含量为0.1％至5％，例如，其含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、1％、3％、4％，或者为上述任意两个数值之间的范围。In some embodiments, the content of the trinitrile compound is 0.1% to 5% based on the total weight of the electrolyte, for example, its content may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 3% , 4%, or a range between any two of the above values.

在一些实施例中，电解液中二腈化合物的用量与三腈化合物的用量之比大于或等于1，这样可以避免对铜集流体的腐蚀。In some embodiments, the ratio of the amount of the dinitrile compound to the amount of the trinitrile compound in the electrolyte is greater than or equal to 1, so as to avoid corrosion of the copper current collector.

5.添加剂B5. Additive B

在一些实施例中，电解液还包含添加剂B，添加剂B包含氟代碳酸乙烯酯、碳酸亚乙烯酯、1,3-丙烷磺内酯中的至少一种。In some embodiments, the electrolyte further includes an additive B, and the additive B includes at least one of fluoroethylene carbonate, vinylene carbonate, and 1,3-propane sultone.

在一些实施例中，基于电解液总重量，添加剂B的含量为0.1％至12％，例如，其含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、1％、3％、4％、8％、10％、12％，或者为上述任意两个数值之间的范围。In some embodiments, the content of the additive B is 0.1% to 12% based on the total weight of the electrolyte, for example, its content may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 3%, 4%, 8%, 10%, 12%, or a range between any two values above.

二、电化学装置2. Electrochemical device

正极集流体；positive current collector;

正极活性材料层；和a positive electrode active material layer; and

绝缘层，其设置于所述正极集流体上并且满足条件(a)至(c)中的至少一者：an insulating layer disposed on the positive electrode current collector and satisfying at least one of the conditions (a) to (c):

(a)所述绝缘层与所述正极活性材料层间有空隙，所述空隙的宽度为0mm至2mm，例如，可以为0、0.5mm、1mm、1.5mm或2mm，或者为上述任意两个数值之间的范围；(a) There is a gap between the insulating layer and the positive electrode active material layer, and the width of the gap is 0 mm to 2 mm, for example, 0, 0.5 mm, 1 mm, 1.5 mm or 2 mm, or any two of the above the range between values;

在一些实施例中，绝缘层满足上述条件(a)。具体而言，如附图1中所示出的，正极片包含正极集流体(1)、第一表面正极活性物质层(2)、第二表面活性物质层(3)和绝缘层(4)。第一表面正极活性物质层(2)较第二表面活性物质层(3)短，绝缘层(4)位于相邻两个第一表面正极活性物质层之间，绝缘层两端与第一表面活性物质层之间有小于等于2mm的空隙。正极极片一般包括正极集流体、正极活性物质层等。其中，正极集流体上除了活性物质层覆盖的区域外，还包括没有活性物质层覆盖的区域(也称作空箔区域)。在热滥用测试中，铝集流体处于较高的电位，与电解液接触容易产生较多的热量，因此，通过在空箔区上设置一层绝缘层可以有效的保护正极极片中的正极集流体的空箔区域，减少其与电解液的直接接触，有利于减少产热量。满足条件(a)的正极与本申请所述的电解液结合，有利于提升电池的整体热稳定性，进一步提升热箱的通过温度。In some embodiments, the insulating layer satisfies condition (a) above. Specifically, as shown in FIG. 1, the positive electrode sheet comprises a positive electrode current collector (1), a first surface positive electrode active material layer (2), a second surface active material layer (3) and an insulating layer (4) . The first surface positive active material layer (2) is shorter than the second surface active material layer (3), the insulating layer (4) is located between two adjacent first surface positive active material layers, and both ends of the insulating layer are connected to the first surface There is a gap of 2 mm or less between the active material layers. The positive electrode sheet generally includes a positive electrode current collector, a positive electrode active material layer, and the like. Among them, in addition to the region covered by the active material layer, the positive electrode current collector also includes a region not covered by the active material layer (also referred to as an empty foil region). In the thermal abuse test, the aluminum current collector is at a high potential, and it is easy to generate more heat in contact with the electrolyte. Therefore, by setting an insulating layer on the empty foil area, the positive electrode collector in the positive electrode piece can be effectively protected. The empty foil area of the fluid reduces its direct contact with the electrolyte, which is beneficial to reduce heat generation. Combining the positive electrode that satisfies the condition (a) with the electrolyte described in this application is beneficial to improve the overall thermal stability of the battery and further increase the passing temperature of the hot box.

在本申请中，正极活性材料的具体种类不做特殊限制，可根据需求进行选择，具体地，可选自钴酸锂(LiCoO ₂)、锂镍钴锰(NCM)、锂镍钴铝(NCA)等三元材料、磷酸亚铁锂(LiFePO ₄)、锰酸锂(LiMn ₂O ₄)中的一种或几种。 In this application, the specific type of the positive electrode active material is not particularly limited, and can be selected according to needs, specifically, it can be selected from lithium cobalt oxide (LiCoO ₂ ), lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA) ) and other ternary materials, one or more of _{lithium iron phosphate (LiFePO 4} ) and lithium manganate (LiMn ₂ O _{4 ).}

在一些实施例中，负极包含负极集流体和负极活性材料层。在本申请中，负极活性材料的具体种类均不受到具体的限制，可根据需求进行选择。具体地，所述负极活性材料选自锂金属、结构化的锂金属、天然石墨、人造石墨、中间相微碳球(简称为MCMB)、硬碳、软碳、硅、硅-碳复合物、Li-Sn合金、Li-Sn-O合金、Sn、SnO、SnO ₂、尖晶石结构的锂化TiO ₂-Li ₄Ti ₅O ₁₂、Li-Al合金中的一种或几种。 In some embodiments, the negative electrode includes a negative electrode current collector and a negative electrode active material layer. In this application, the specific types of negative electrode active materials are not specifically limited, and can be selected according to requirements. Specifically, the negative electrode active material is selected from lithium metal, structured lithium metal, natural graphite, artificial graphite, mesophase micro-carbon spheres (abbreviated as MCMB), hard carbon, soft carbon, silicon, silicon-carbon composites, One or more of Li-Sn alloy, Li-Sn-O alloy, Sn, SnO, SnO ₂ , spinel structure lithiated TiO ₂ -Li ₄ Ti ₅ O ₁₂ , and Li-Al alloy.

在本申请中，隔离膜材料的具体种类均不受到具体的限制，可根据需求进行选择。具体地，隔离膜可选自聚乙烯膜、聚丙烯膜、聚偏氟乙烯膜以及他们的多层复合膜，也可根据实际需要在隔离膜基材表面涂覆无机或有机物质以增强电芯的硬度或提升隔离膜与阴阳极界面的粘结性。In this application, the specific types of isolation membrane materials are not specifically limited, and can be selected according to requirements. Specifically, the isolation film can be selected from polyethylene film, polypropylene film, polyvinylidene fluoride film and their multi-layer composite films, and inorganic or organic substances can also be coated on the surface of the isolation film substrate to strengthen the cell according to actual needs. The hardness of the separator may improve the adhesion between the separator and the anode and cathode interface.

在一些实施例中，在所述电化学装置经过化成(首次充电)之后，负极的傅里叶红外光谱具有在1770cm ^-1和1710cm ^-1处的两个特征峰，例如，如附图2中所示。该特征峰对应双马来酰亚胺化合物中五元环的特征峰，该五元环基团在负极表面生成有利于负极的热稳定性的提升。 In some embodiments, after the electrochemical device is formed (first charged), the FTIR spectrum of the negative electrode has ^{two characteristic peaks at 1770 cm -1} and 1710 cm ^-1 , eg, as shown in FIG. 2 shown. The characteristic peak corresponds to the characteristic peak of the five-membered ring in the bismaleimide compound, and the formation of the five-membered ring group on the surface of the negative electrode is beneficial to the improvement of the thermal stability of the negative electrode.

三、电子装置3. Electronic devices

本申请的电子装置的类型没有特别限定。在一些实施例中，本申请的电子学装置可以包括用于，但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。The type of the electronic device of the present application is not particularly limited. In some embodiments, the electronic devices of the present application may include, but are not limited to, notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, Headphones, VCRs, LCD TVs, Portable Cleaners, Portable CD Players, Mini Discs, Transceivers, Electronic Notepads, Calculators, Memory Cards, Portable Recorders, Radios, Backup Power, Motors, Automobiles, Motorcycles , Power-assisted bicycles, bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.

实施例Example

下面结合实施例，进一步阐述本申请。应理解，这些实施例仅用于说明本申请而不用于限制本申请的范围。The present application will be further described below with reference to the embodiments. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application.

1、制备方法1. Preparation method

实施例以及对比例中的锂离子电池均按照下述方法进行制备：The lithium ion batteries in the examples and comparative examples were prepared according to the following methods:

(1)电解液制备(1) Electrolyte preparation

在含水量小于10ppm的氩气气氛手套箱中，将碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二乙酯(DEC)按重量比1:1:1均匀混合，加入LiPF ₆搅拌均匀，形成基础电解液，其中LiPF ₆的浓度为1.15mol/L。在该基础电解液中，根据下文表格中提供的用量和种类分别添加其他添加剂以得到各个实施例和对比例的电解液。 In an argon atmosphere glove box with a water content of less than 10 ppm, ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) were uniformly mixed in a weight ratio of 1:1:1, and LiPF _{6 was} added to stir uniform, forming a base electrolyte with a LiPF ₆ concentration of 1.15 mol/L. In the base electrolyte, other additives were added according to the amounts and types provided in the table below to obtain the electrolytes of the respective examples and comparative examples.

(2)正极制备(2) Positive electrode preparation

将钴酸锂(LiCoO ₂)、碳纳米管(CNT)、聚偏二氟乙烯按照重量比95:2:3进行混合，加入N-甲基吡咯烷酮(NMP)，在真空搅拌机作用下搅拌直至体系形成均一的正极浆料，将此正极浆料均匀涂覆于正极集流体铝箔上。在85℃下烘干后经过冷压得到正极活性物质层，再经过裁片、分切、焊接极耳，然后在85℃的真空条件下干燥4h，得到正极。 Mix lithium cobalt oxide (LiCoO ₂ ), carbon nanotubes (CNT), and polyvinylidene fluoride in a weight ratio of 95:2:3, add N-methylpyrrolidone (NMP), and stir under the action of a vacuum mixer until the system is A uniform positive electrode slurry is formed, and the positive electrode slurry is uniformly coated on the aluminum foil of the positive electrode current collector. After drying at 85°C, the positive electrode active material layer was obtained by cold pressing, and then the tabs were cut, cut, welded, and then dried at 85°C under vacuum for 4 hours to obtain the positive electrode.

(3)负极制备(3) Preparation of negative electrode

将石墨、丁苯橡胶(SBR)、羧甲基纤维素钠(CMC)按照重量比95:2:3在适量的去离子水中充分搅拌混合，使其形成均匀的负极浆料；将此浆料涂覆于负极集流体铜箔上，烘干、冷压得到负极活性物质层，再经过裁片、分切、焊接极耳，然后在85℃的真空条件下干燥4h，得到负极。Fully stir and mix graphite, styrene-butadiene rubber (SBR), and sodium carboxymethyl cellulose (CMC) in an appropriate amount of deionized water at a weight ratio of 95:2:3 to form a uniform negative electrode slurry; this slurry It is coated on the negative electrode current collector copper foil, dried and cold pressed to obtain the negative electrode active material layer, and then sliced, cut, welded with tabs, and then dried under vacuum at 85°C for 4 hours to obtain the negative electrode.

(4)隔离膜制备(4) Preparation of isolation film

使用聚乙烯(PE)膜作为隔离膜。A polyethylene (PE) film was used as the separator.

(5)锂离子电池的制备(5) Preparation of lithium ion battery

将正极、隔离膜、负极按顺序叠好，使隔离膜处于正极和负极之间起到隔离的作用，然后卷绕，置于外包装箔中，将根据各个实施例和对比例制备的电解液注入到干燥后的电池中，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备。The positive electrode, the separator, and the negative electrode are stacked in sequence, so that the separator is placed between the positive electrode and the negative electrode to isolate the positive electrode and the negative electrode. Then, it is wound and placed in the outer packaging foil. After being injected into the dried battery, the preparation of the lithium ion battery is completed after the processes of vacuum packaging, standing, chemical formation, shaping, etc.

2、测试方法2. Test method

(1)锂离子电池的室温容量保持率的测试方法(1) Test method for the room temperature capacity retention rate of lithium ion batteries

在25℃下，将锂离子电池以0.7C恒流充电至4.45V，4.45V恒压充电至电流为0.05C，再用1C恒流放电至3.0V，此时完成首次循环，记录首次循环放电容量。按照上述条件使锂离子电池进行多次循环。以首次放电的容量为100％，反复进行充放电循环，至放电容量衰减至80％时，停止测试，记录循环圈数，将其作为评价锂离子电池循环性能的指标。At 25°C, the lithium-ion battery was charged to 4.45V with a constant current of 0.7C, charged with a constant voltage of 4.45V to a current of 0.05C, and then discharged with a constant current of 1C to 3.0V. At this time, the first cycle was completed, and the first cycle discharge was recorded. capacity. The lithium-ion battery was cycled a number of times under the above conditions. Taking the capacity of the first discharge as 100%, the charge-discharge cycle was repeated, and when the discharge capacity decreased to 80%, the test was stopped, and the number of cycles was recorded, which was used as an index to evaluate the cycle performance of lithium-ion batteries.

(2)倍率测试(2) Magnification test

在25℃下，将锂离子电池以0.7C恒流充电至4.45V，4.45V恒压充电至电流为0.05C，然后以不同倍率0.5C、1C、1.5C、2C、3C放电至3V，分别记录放电容量，以0.5C的放电容量作为基准(100％)，计算不同倍率下放电的容量保持率。本申请实施例中使用2C倍率下的容量保持率进行比对。2C容量保持率＝2C容量/0.5C容量×100％。At 25°C, the lithium-ion battery was charged to 4.45V with a constant current of 0.7C, charged to a current of 0.05C with a constant voltage of 4.45V, and then discharged to 3V at different rates of 0.5C, 1C, 1.5C, 2C, and 3C, respectively. The discharge capacity was recorded, and the discharge capacity at 0.5 C was used as a benchmark (100%) to calculate the capacity retention rate of discharge at different rates. In the examples of the present application, the capacity retention rate under 2C rate is used for comparison. 2C capacity retention rate=2C capacity/0.5C capacity×100%.

(3)热箱测试(3) Hot box test

在25℃下，将锂离子电池以0.7C恒流充电至4.45V，4.45V恒压充电至电流为0.05C。将电池放置在高温箱中，用5±2℃/分钟的温升速率加热到135℃，然后保持1h，记录电池的电压、温度以及热箱温度的变化。电池不起火、不***、不冒烟即为通过测试。每组测试10个电池，记录通过测试电池个数。At 25°C, the lithium-ion battery was charged to 4.45V with a constant current of 0.7C and a constant voltage of 4.45V to a current of 0.05C. Place the battery in a high temperature box, heat it to 135 °C with a temperature rise rate of 5 ± 2 °C/min, and then keep it for 1 h, record the voltage, temperature of the battery and changes in the temperature of the hot box. The test is passed if the battery does not catch fire, explode, or emit smoke. Test 10 batteries in each group, and record the number of batteries that pass the test.

(4)直流阻抗(DCR)测试(4) DC resistance (DCR) test

锂离子电池在25℃下静置1h，将锂离子电池以0.7C恒流充电至4.45V，4.45V恒压充电至电流为0.05C，之后0.1C放电至3.0V，得到电池的实际容量。然后，放电至指定容量后，分别用0.1C(即I ₁)放电10s，记录放电后的电压V ₁，1C(即I ₂)放电360s，记录放电后的电压V ₂。DCR＝(V ₂-V ₁)/(I ₂-I ₁)，每组各3只电池，按照DCR计算公式进行计算。本申请实施例中以20％SOC(State of Charge，荷电状态)的DCR作为比对。 The lithium-ion battery was left standing at 25°C for 1 hour, and the lithium-ion battery was charged to 4.45V at a constant current of 0.7C, charged to a current of 0.05C at a constant voltage of 4.45V, and then discharged to 3.0V at 0.1C to obtain the actual capacity of the battery. Then, after discharging to the specified capacity, discharge with 0.1C (ie I ₁ ) for 10 s, record the voltage V _{1 after discharge, and discharge at 1 C} (ie I ₂ ) for 360 s, and record the voltage V ₂ after discharge. DCR=(V ₂ -V ₁ )/(I ₂ -I ₁ ), there are 3 batteries in each group, and the calculation is performed according to the DCR calculation formula. In the examples of the present application, the DCR of 20% SOC (State of Charge, state of charge) is used as a comparison.

3、测试结果3. Test results

(1)双马来酰亚胺化合物和丙酸酯化合物对电池性能的影响(1) Influence of bismaleimide compound and propionate compound on battery performance

表1中提供实施例1-1至1-10和对比例1-1至1-9的数据以及测试结果。如表1中所示，本申请实施例中的丙酸酯化合物使用的是丙酸丙酯与丙酸乙酯。Table 1 provides data and test results for Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-9. As shown in Table 1, propyl propionate and ethyl propionate were used as propionate compounds in the examples of the present application.

表1.实施例1-1至1-18以及对比例1-1至1-9的测试结果Table 1. Test results of Examples 1-1 to 1-18 and Comparative Examples 1-1 to 1-9

如表1所示，从对比例1-1至对比例1-3的结果可以看出，在仅使用双马来酰亚胺化合物，而不包括丙酸酯化合物的情况下，随着双马来酰亚胺化合物用量的增加，电池的循环及倍率性能均逐渐恶化，这与负极成膜阻抗较大有直接关系，并且热箱性能也没有较大改善。As shown in Table 1, from the results of Comparative Examples 1-1 to 1-3, it can be seen that in the case of using only the bismaleimide compound without including the propionate compound, with the bismaleimide compound The cycle and rate performance of the battery gradually deteriorated with the increase of the amount of the imide compound, which was directly related to the larger film-forming resistance of the negative electrode, and the performance of the hot box was not greatly improved.

从对比例1-1、对比例1-4至对比例1-8的测试结果可以看出，在仅使用丙酸酯化合物，而不包括双马来酰亚胺化合物的情况下，随着丙酸酯化合物用量的增加，电池的动力学性略微得到提升，但是热稳定性变差并且热箱通过率显著降低，这主要与丙酸酯化合物易产气、对正负极反应活性较高有关。From the test results of Comparative Example 1-1, Comparative Example 1-4 to Comparative Example 1-8, it can be seen that in the case of using only the propionate compound without including the bismaleimide compound, with the propionate With the increase of the amount of the acid ester compound, the kinetics of the battery is slightly improved, but the thermal stability is deteriorated and the pass rate of the hot box is significantly reduced, which is mainly related to the easy gas production of the propionate compound and the high reactivity to the positive and negative electrodes. .

与对比例相比，实施例1-1至实施例1-18的结果表明：Compared with the comparative example, the results of Examples 1-1 to 1-18 show that:

(A)同时引入丙酸酯化合物与双马来酰亚胺化合物，能够使热箱性能及电性能均得到明显提升。对比例的基础电解液中仅包含碳酸酯，而没有添加丙酸酯化合物，在此条件下，单独添加双马来酰亚胺化合物(对比例1-2和对比例1-3)无法实现上述改善的效果。推测丙酸酯化合物的存在影响了双马来酰亚胺化合物在负极的成膜，两者共存可形成更加稳定的SEI，进而提升电池的热箱性能。(A) Simultaneously introducing a propionate compound and a bismaleimide compound can significantly improve both the thermal box performance and the electrical performance. The base electrolyte of the comparative example only contains carbonate, and no propionate compound is added. Under this condition, the addition of bismaleimide compound (comparative example 1-2 and comparative example 1-3) alone cannot achieve the above improved effect. It is speculated that the presence of the propionate compound affects the film formation of the bismaleimide compound on the negative electrode, and the coexistence of the two can form a more stable SEI, thereby improving the hot box performance of the battery.

(B)通过调整双马来酰亚胺化合物用量与丙酸酯化合物用量的比值(X/Y)及丙酸酯化合物中丙酸丙酯的含量，使得能够保证电池良好的安全性能，同时避免因使用双马来酰亚胺化合物而对电池动力学和循环性能导致的恶化。(B) By adjusting the ratio (X/Y) of the amount of the bismaleimide compound to the amount of the propionate compound and the content of propyl propionate in the propionate compound, it is possible to ensure the good safety performance of the battery while avoiding Deterioration of battery kinetics and cycling performance due to the use of bismaleimide compounds.

对比例1-9中使用等量的乙酸乙酯替换实施例1-18中的丙酸酯，由测试结果可以看出，根据本申请的丙酸酯化合物与双马来酰亚胺化合物的组合实现了改善热箱性能和电性能的协同效果，然而，对比例1-9中乙酸乙酯与双马来酰亚胺化合物的组合不能实现该协同作用。In Comparative Examples 1-9, the propionate in Example 1-18 was replaced with an equal amount of ethyl acetate, and it can be seen from the test results that the combination of the propionate compound and the bismaleimide compound according to the present application A synergistic effect of improving hot box performance and electrical performance was achieved, however, the combination of ethyl acetate and bismaleimide compound in Comparative Examples 1-9 could not achieve this synergistic effect.

(2)添加剂A对电池性能的影响(2) Influence of additive A on battery performance

本申请电解液中还可以进一步包含添加剂A，实施例2-1至2-5中使用偶氮二异丁腈、偶氮二异庚腈，其具体用量在以下表2中示出。The electrolyte solution of the present application may further contain additive A. In Examples 2-1 to 2-5, azobisisobutyronitrile and azobisisoheptanenitrile are used, and the specific amounts thereof are shown in Table 2 below.

表2.实施例1-3至1-5以及实施例2-1至2-4的测试结果Table 2. Test Results for Examples 1-3 to 1-5 and Examples 2-1 to 2-4

如表2所示，由于式III化合物具有双键，单纯通过电化学成膜对负极破坏较为严重，故本申请通过加入添加剂A使得在电池注液后高温静置阶段，通过热力学作用引发式III化合物优先聚合成膜。As shown in Table 2, since the compound of formula III has a double bond, it is more serious to damage the negative electrode simply by electrochemical film formation. Therefore, in the present application, by adding additive A, the formula III is induced by thermodynamics during the high temperature static stage after the battery is injected. The compounds preferentially polymerize to form films.

通过与实施例1-3至1-5相比较，出人意料地发现添加剂A的添加可避免式III化合物对于常温循环、放电倍率等电性能的恶化。该效果可能是通过以下两个方面实现：首先，热力学成膜更加均匀，阻抗更低，对负极的动力学破坏更小；其次，添加剂A的存在消耗了部分式III化合物，从而减少了式III通过电化学成膜对负极造成的破坏。此外，还可以看出，添加剂A的添加除了可以提升电性能之外，还避免了热箱能力的恶化，因此电池的实用性得到极大增强。By comparing with Examples 1-3 to 1-5, it is unexpectedly found that the addition of Additive A can avoid the deterioration of the electrical properties of the compound of formula III for normal temperature cycle, discharge rate and the like. This effect may be achieved through the following two aspects: first, the thermodynamic film formation is more uniform, the impedance is lower, and the kinetic damage to the negative electrode is smaller; second, the presence of additive A consumes part of the compound of formula III, thereby reducing the amount of formula III Destruction of the negative electrode by electrochemical film formation. In addition, it can also be seen that the addition of additive A can not only improve the electrical performance, but also avoid the deterioration of the hot box capability, so the practicability of the battery is greatly enhanced.

(3)硫酰基二腈对电池性能的影响(3) Influence of sulfuryl dinitrile on battery performance

本申请的电解液中还可以进一步包含硫酰基二腈化合物，其具体类型和含量在以下表3中示出。The electrolyte solution of the present application may further contain a sulfuryl dinitrile compound, the specific type and content of which are shown in Table 3 below.

表3.实施例1-4、2-2和实施例31-至3-10的测试结果Table 3. Test Results for Examples 1-4, 2-2 and Examples 31- to 3-10

对比实施例1-4与实施例3-1至3-3或对比实施例2-2与实施例3-6至3-8，可以看出，硫酰基二腈的引入均有利于DCR的降低，同时由于阻抗的降低，放电倍率亦略有改善。由此可见，在本申请中，不仅可以通过增加丙酸酯化合物的含量以提升电解液自身动力学来实现放电倍率的改善，通过调控电解液成份降低界面阻抗也可以实现该效果。Comparing Examples 1-4 and Examples 3-1 to 3-3 or Comparative Examples 2-2 and Examples 3-6 to 3-8, it can be seen that the introduction of sulfuryl dinitrile is beneficial to the reduction of DCR , and the discharge rate is also slightly improved due to the decrease in impedance. It can be seen that, in the present application, not only can the improvement of the discharge rate be achieved by increasing the content of the propionate compound to improve the kinetics of the electrolyte itself, but also by regulating the composition of the electrolyte to reduce the interface impedance.

(4)三腈对电池性能的影响(4) Influence of trinitrile on battery performance

本申请的电解液中还可以进一步包含三腈化合物，其具体类型和含量在以下表4中示出。The electrolyte solution of the present application may further contain trinitrile compounds, the specific types and contents of which are shown in Table 4 below.

表4.实施例1-4、2-2以及实施例4-1至4-10的测试结果Table 4. Test Results for Examples 1-4, 2-2 and Examples 4-1 to 4-10

由表4中的测试结果可以看出，三腈的引入可在双马来酰亚胺化合物的基础上进一步提升电池的热箱稳定性。这主要归因于三腈的存在使得正极界面的热稳定性更高，有利于改善高温高压下正极结构的稳定性，正极结构稳定性的改善进一步减少电解液在正极界面的氧化分解，从而减少反应热的产生。此外，在保证电池安全性能的基础上，通过引入三腈与双马来酰亚胺化合物组合使用，减少了双马来酰亚胺化合物的用量。It can be seen from the test results in Table 4 that the introduction of trinitrile can further improve the hot box stability of the battery on the basis of the bismaleimide compound. This is mainly due to the existence of trinitrile, which makes the thermal stability of the cathode interface higher, which is beneficial to improve the stability of the cathode structure under high temperature and high pressure. The improvement of the cathode structure stability further reduces the oxidative decomposition of the electrolyte at the cathode interface, thereby reducing the Generation of heat of reaction. In addition, on the basis of ensuring the safety performance of the battery, the amount of the bismaleimide compound is reduced by introducing the trinitrile and the bismaleimide compound for combined use.

(5)二腈和三腈化合物对电池性能的影响(5) Influence of dinitrile and trinitrile compounds on battery performance

本申请的电解液中还可以进一步包含二腈和三腈化合物，实施例5-1至5-5中举例说明己二腈和1,3,6己三甲腈实现的效果。The electrolytic solution of the present application may further contain dinitrile and trinitrile compounds. Examples 5-1 to 5-5 illustrate the effects achieved by adiponitrile and 1,3,6-hexanetricarbonitrile.

表5.实施例1-4、以及实施例5-1至5-5的测试结果Table 5. Test results for Examples 1-4, and Examples 5-1 to 5-5

由表5中的测试结果可以看出，三腈的含量过高会导致对铜箔的腐蚀，而将其与二腈进行组合并且调节二者的比例可以避免该现象的发生，此外，二腈和三腈化合物的组合使用对热箱性能也有一定改善。It can be seen from the test results in Table 5 that the excessive content of trinitrile will lead to corrosion of copper foil, and combining it with dinitrile and adjusting the ratio of the two can avoid this phenomenon. The combined use of trinitrile compounds also has a certain improvement in the performance of the hot box.

(6)正极绝缘层对电池性能的影响(6) Influence of positive insulating layer on battery performance

本申请的电化学装置中的正极可以包含绝缘层，以下表6中示出正极绝缘层对电池性能的影响。The positive electrode in the electrochemical device of the present application may include an insulating layer, and the effect of the positive electrode insulating layer on the battery performance is shown in Table 6 below.

表6Table 6

实施例6-1和6-2中的绝缘层位于相邻两个第一表面正极活性物质层之间，绝缘层两端与第一表面活性物质层之间有1mm的空隙，绝缘层无机材料为氧化铝，聚合物材料为聚偏氟乙烯，厚度为10μm。The insulating layers in Examples 6-1 and 6-2 are located between two adjacent first surface positive active material layers, there is a 1 mm gap between the two ends of the insulating layer and the first surface active material layer, and the insulating layer is made of inorganic materials. is aluminum oxide, the polymer material is polyvinylidene fluoride, and the thickness is 10 μm.

通过表6的数据意外地发现，绝缘层的存在可提升电池的热稳定性，同时对其他电性能无任何恶化。目前对于其作用机理尚不明确，推测绝缘层的存在，可减少金属铝基材的暴露，减少其与电解液的接触。由于满充状态电池正极处于高电位状态，相应的处于高电位的金属铝与电解液接触极易发生化学反应促进产热量的增大，通过减少基材的外露，在一定程度上或可减少产热提高热箱的通过率。Surprisingly, it was found from the data in Table 6 that the presence of the insulating layer can improve the thermal stability of the battery without any deterioration in other electrical properties. At present, its mechanism of action is still unclear. It is speculated that the existence of the insulating layer can reduce the exposure of the metal aluminum substrate and reduce its contact with the electrolyte. Since the positive electrode of the battery is in a high potential state in a fully charged state, the corresponding high-potential metal aluminum is easily contacted with the electrolyte to cause a chemical reaction to promote the increase of heat production. By reducing the exposure of the substrate, the production may be reduced to a certain extent. Heat increases the throughput of the hot box.

整个说明书中对“一些实施例”、“部分实施例”、“一个实施例”、“另一举例”、“举例”、“具体举例”或“部分举例”的引用，其所代表的意思是在本申请中的至少一个实施例或举例包含了该实施例或举例中所描述的特定特征、结构、材料或特性。因此，在整个说明书中的各处所出现的描述，例如：“在一些实施例中”、“在实施例中”、“在一个实施例中”、“在另一个举例中”，“在一个举例中”、“在特定举例中”或“举例”，其不必然是引用本申请中的相同的实施例或示例。此外，本文中的特定特征、结构、材料或特性可以以任何合适的方式在一个或多个实施例或举例中结合。Reference throughout the specification to "some embodiments," "some embodiments," "one embodiment," "another example," "example," "specific example," or "partial example" means that At least one embodiment or example in this application incorporates a particular feature, structure, material or characteristic described in the embodiment or example. Thus, descriptions such as: "in some embodiments", "in an embodiment", "in one embodiment", "in another example", "in an example", appearing in various places throughout the specification "in", "in a particular example", or "by way of example" is not necessarily a reference to the same embodiment or example in this application. Furthermore, the particular features, structures, materials or characteristics herein may be combined in any suitable manner in one or more embodiments or examples.

尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。Although illustrative embodiments have been shown and described, it should be understood by those skilled in the art that the above-described embodiments are not to be construed as limitations of the application, and changes may be made in the embodiments without departing from the spirit, principles and scope of the application , alternatives and modifications.

Claims

一种电解液，其包含双马来酰亚胺化合物和丙酸酯化合物，其中，所述双马来酰亚胺化合物包括：A kind of electrolyte, it comprises bismaleimide compound and propionate compound, wherein, described bismaleimide compound comprises:

至少一种，

at least one,

其中，R ₁为C ₁-C ₁₀亚烷基、C ₁-C ₁₀烷氧基、砜基、磺酰基、酯基、-O-、-O-O-、-S-、-S-S-或-O-S-O-，所述C ₁-C ₁₀亚烷基和所述C ₁-C ₁₀烷氧基任选地经卤素取代； Wherein, R ₁ is C ₁ -C ₁₀ alkylene, C ₁ -C ₁₀ alkoxy, sulfone, sulfonyl, ester, -O-, -OO-, -S-, -SS- or -OSO -, said C ₁ -C ₁₀ alkylene group and said C ₁ -C ₁₀ alkoxy group are optionally substituted with halogen;

其中，基于所述电解液的总重量，所述双马来酰亚胺化合物的含量为X，所述丙酸酯化合物的含量为Y，其中，0.002≤X/Y≤0.5。Wherein, based on the total weight of the electrolyte, the content of the bismaleimide compound is X, and the content of the propionate compound is Y, wherein 0.002≤X/Y≤0.5.
根据权利要求1所述的电解液，其中，0.1％≤X≤5％，10％≤Y≤60％。The electrolyte according to claim 1, wherein 0.1%≤X≤5%, and 10%≤Y≤60%.
根据权利要求1所述的电解液，其中，所述式III化合物包括The electrolyte of claim 1, wherein the compound of formula III comprises

中的至少一种；

at least one of;

所述丙酸酯化合物包含丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、丙酸戊酯、氟代丙酸甲酯、氟代丙酸乙酯、氟代丙酸丙酯、氟代丙酸丁酯或氟代丙酸戊酯中的至少一种，其中氟代表示化合物中至少一个氢原子被氟原子取代。The propionate compound comprises methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl propionate, methyl fluoropropionate, ethyl fluoropropionate, fluoropropionic acid At least one of propyl ester, butyl fluoropropionate or pentyl fluoropropionate, wherein fluorine represents that at least one hydrogen atom in the compound is replaced by a fluorine atom.
根据权利要求1所述的电解液，其中，所述丙酸酯化合物包括丙酸丙酯，并且所述丙酸丙酯化合物的含量不低于所述丙酸酯总量的10％。The electrolyte solution according to claim 1, wherein the propionate compound includes propyl propionate, and the content of the propyl propionate compound is not less than 10% of the total amount of the propionate.
根据权利要求1所述的电解液，其中，所述电解液还包含添加剂A，所述添加剂A包含偶氮二异丁腈、偶氮二异庚腈、过氧化二苯甲酰、过氧化苯甲酸叔丁酯或二叔丁基过氧化物中的至少一种；且The electrolyte according to claim 1, wherein the electrolyte further comprises an additive A, the additive A comprising azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, benzene peroxide at least one of tert-butyl formate or di-tert-butyl peroxide; and

基于所述电解液的总重量，所述添加剂A的含量为Z，且Z与X的关系满足0.001≤Z/X≤0.05。Based on the total weight of the electrolyte, the content of the additive A is Z, and the relationship between Z and X satisfies 0.001≤Z/X≤0.05.
根据权利要求1所述的电解液，其还包含式IV表示的硫酰化合物，The electrolyte according to claim 1, further comprising a sulfuryl compound represented by formula IV,

其中，R ₂和R ₃各自独立地为C ₁-C ₈亚烷基并且任选地经卤素取代。 wherein R ₂ and R ₃ are each independently C ₁ -C ₈ alkylene and are optionally substituted with halogen.
根据权利要求6所述的电解液，其中所述硫酰化合物包括硫酰二乙腈、硫酰二丙腈、硫酰二丁腈或硫酰二己腈中的至少一种，且，基于所述电解液总重量，所述硫酰化合物的含量为0.1％至5％。The electrolyte according to claim 6, wherein the sulfuryl compound comprises at least one of sulfuryldiacetonitrile, sulfuryldipropionitrile, sulfuryldibutyronitrile, or sulfuryldicapronitrile, and, based on the Based on the total weight of the electrolyte, the content of the sulfuryl compound is 0.1% to 5%.
根据权利要求1所述的电解液，其中：The electrolyte according to claim 1, wherein:

所述电解液还包含二腈化合物或三腈化合物中的至少一种；The electrolyte also contains at least one of a dinitrile compound or a trinitrile compound;

所述二腈化合物包含丁二腈、戊二腈、己二腈、1,5-二氰基戊烷、1,6-二氰基己烷、1,7-二氰基庚烷、1,8-二氰基辛烷、1,9-二氰基壬烷、1,10-二氰基癸烷、1,12-二氰基十二烷、四甲基丁二腈、2-甲基戊二腈、2,4-二甲基戊二腈或2,2,4,4-四甲基戊二腈中的至少一种；The dinitrile compound includes succinonitrile, glutaronitrile, adiponitrile, 1,5-dicyanopentane, 1,6-dicyanohexane, 1,7-dicyanoheptane, 1,5-dicyanopentane, 8-dicyanooctane, 1,9-dicyanononane, 1,10-dicyanodecane, 1,12-dicyanododecane, tetramethylsuccinonitrile, 2-methyl At least one of glutaronitrile, 2,4-dimethylglutaronitrile or 2,2,4,4-tetramethylglutaronitrile;

所述三腈化合物包含1,3,5-戊三甲腈、1,2,3-丙三甲腈、1,3,6-己三甲腈、1,2,6-己三甲腈、1,2,3-三(2-氰基乙氧基)丙烷、1,2,4-三(2-氰基乙氧基)丁烷或1,2,5-三(氰基乙氧基)戊烷中的至少一种。The trinitrile compound includes 1,3,5-pentanetricarbonitrile, 1,2,3-propanetricarbonitrile, 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile, 1,2, In 3-tris(2-cyanoethoxy)propane, 1,2,4-tris(2-cyanoethoxy)butane or 1,2,5-tris(cyanoethoxy)pentane at least one of.
一种电化学装置，其包括正极、负极、设置于所述正极和所述负极之间的隔离膜、以及权利要求1-8中任一项所述的电解液。An electrochemical device comprising a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and the electrolyte according to any one of claims 1-8.
根据权利要求9所述的电化学装置，其中，所述正极包含：The electrochemical device of claim 9, wherein the positive electrode comprises:

正极集流体；positive current collector;

正极活性材料层；和a positive electrode active material layer; and

绝缘层，所述绝缘层设置于所述正极集流体上，所述绝缘层满足条件(a)至(c)中的至少一者：an insulating layer, the insulating layer is disposed on the positive electrode current collector, and the insulating layer satisfies at least one of the conditions (a) to (c):

(a)所述绝缘层与所述正极活性材料层间有空隙，所述空隙的宽度小于等于2mm；(a) There is a gap between the insulating layer and the positive electrode active material layer, and the width of the gap is less than or equal to 2 mm;

(b)所述绝缘层包括无机粒子，所述无机粒子包括氧化铝、二氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、二氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种；(b) The insulating layer includes inorganic particles, and the inorganic particles include aluminum oxide, silicon dioxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, calcium oxide, at least one of zirconia, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate;

(c)所述绝缘层包括聚合物，所述聚合物包括偏氟乙烯的均聚物、偏氟乙烯的共聚物、六氟丙烯的共聚物、聚苯乙烯、聚苯乙炔、聚乙烯酸钠、聚乙烯酸钾、聚甲基丙烯酸甲酯、聚乙烯、聚丙烯或聚四氟乙烯中的至少一种。(c) The insulating layer includes a polymer, and the polymer includes a homopolymer of vinylidene fluoride, a copolymer of vinylidene fluoride, a copolymer of hexafluoropropylene, polystyrene, polyphenylene vinylene, sodium polyvinylidene , at least one of potassium polyvinate, polymethyl methacrylate, polyethylene, polypropylene or polytetrafluoroethylene.
一种电子装置，其包括权利要求9或10所述的电化学装置。An electronic device comprising the electrochemical device of claim 9 or 10.