WO2020119808A1

WO2020119808A1 - Electrolyte, battery and device

Info

Publication number: WO2020119808A1
Application number: PCT/CN2019/125328
Authority: WO
Inventors: 伊天成; ***; 钭舒适; 蒋耀; 梁成都
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2018-12-14
Filing date: 2019-12-13
Publication date: 2020-06-18
Also published as: CN111326791A; CN111326791B

Abstract

Disclosed are an electrolyte, a battery (5) and a device. The electrolyte contains an organic solvent and an electrolyte salt. The electrolyte also contains an additive A and an additive B. The additive A is a six-membered polycyano nitrogen heterocyclic compound with a lower oxidation potential, and the additive B is a dinitrile or polynitrile compound having an ether bond. The electrolyte can improve the cycle performance and storage performance of the battery (5), and especially improves the cycle performance and storage performance when the battery (5) is subjected to high temperatures and high voltages.

Description

电解液、电池及装置Electrolyte, battery and device

技术领域Technical field

本申请涉及储能材料领域，具体地讲，涉及一种电解液、电池及装置。This application relates to the field of energy storage materials, in particular, to an electrolyte, battery, and device.

背景技术Background technique

锂离子电池由于具备能量密度大、输出功率高、循环寿命长和环境污染小等优点而被广泛应用于电动汽车以及消费类电子产品中。目前对锂离子电池的需求是：高电压、高功率、长循环寿命、长存储寿命且安全性能优异。Lithium ion batteries are widely used in electric vehicles and consumer electronic products due to their advantages such as high energy density, high output power, long cycle life, and low environmental pollution. The current demand for lithium ion batteries is: high voltage, high power, long cycle life, long storage life and excellent safety performance.

锂离子电池目前广泛使用的是以六氟磷酸锂为导电锂盐以及以环状碳酸酯和/或链状碳酸酯为溶剂的电解液体系。然而上述电解液体系尚存在诸多不足，例如在高电压和高温情况下，上述电解液体系的循环性能和存储性能有待提高。Lithium ion batteries are currently widely used electrolyte systems using lithium hexafluorophosphate as a conductive lithium salt and cyclic carbonate and/or chain carbonate as a solvent. However, there are still many deficiencies in the above electrolyte system. For example, under high voltage and high temperature, the cycle performance and storage performance of the above electrolyte system need to be improved.

鉴于此，特提出本申请。In view of this, this application is hereby submitted.

发明内容Summary of the invention

鉴于背景技术中存在的问题，本申请的目的在于提供一种电解液、电池及装置，所述电解液能提高电池的循环性能和存储性能，尤其是提高电池高温高电压情况下的循环性能和存储性能。In view of the problems in the background art, the purpose of this application is to provide an electrolyte, a battery and a device, the electrolyte can improve the cycle performance and storage performance of the battery, especially improve the cycle performance and high-voltage cycle performance of the battery Storage performance.

为了达到上述目的，在本申请的第一方面，本申请提供了一种电解液，其含有有机溶剂以及电解质盐，所述电解液中还含有添加剂A以及添加剂B。In order to achieve the above object, in the first aspect of the present application, the present application provides an electrolytic solution, which contains an organic solvent and an electrolyte salt, and the electrolytic solution further contains additive A and additive B.

所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一种或几种。在式I-1、式I-2、式I-3中：R ₁、R ₂、R ₃、R ₄各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₁₂烷基、取代或未取代的C ₁～C ₁₂烷氧基、取代或未取代的C ₁～C ₁₂胺基、取代或未取代的C ₂～C ₁₂烯基、取代或未取代的C ₂～C ₁₂炔基、取代或未取代的C ₆～C ₂₆芳基、取代或未取代的C ₂～C ₁₂杂环基，其中，取代基选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数。 The additive A is selected from one or more of the compounds represented by Formula I-1, Formula I-2, and Formula I-3. In Formula I-1, Formula I-2, and Formula I-3: R ₁ , R ₂ , R ₃ , and R ₄ are each independently selected from a hydrogen atom, a halogen atom, and a substituted or unsubstituted C ₁ to C ₁₂ alkane Group, substituted or unsubstituted C ₁ -C ₁₂ alkoxy group, substituted or unsubstituted C ₁ -C ₁₂ amine group, substituted or unsubstituted C ₂ -C ₁₂ alkenyl group, substituted or unsubstituted C ₂ ～ C ₁₂ alkynyl, substituted or unsubstituted C ₆ to C ₂₆ aryl, substituted or unsubstituted C ₂ to C ₁₂ heterocyclic, wherein the substituent is selected from halogen atom, nitrile group, C ₁ to C ₆ alkane One or more of C ₂ to C ₆ alkenyl, C ₁ to C ₆ alkoxy; x, y, z are each independently selected from integers of 0 to 8; m, n, k are each independently An integer selected from 0 to 2.

所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种。在式II-1、式II-2中，a、b、c、d各自独立地选自1～5内的整数，R ₅、R ₆、R ₇、R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自取代或未取代的C ₁～C ₁₀亚烷基、取代或未取代的C ₂～C ₁₀亚烯基，其中，取代基选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种。 The additive B is selected from one or more of the compounds represented by Formula II-1 and Formula II-2. In Formula II-1 and Formula II-2, a, b, c, and d are each independently selected from integers within 1 to 5, R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from a substituted or unsubstituted C ₁ to C ₁₀ alkylene group, a substituted or unsubstituted C ₂ to C ₁₀ alkenylene group, wherein the substituent is selected from a halogen atom and a nitrile One or more of a group, a C ₁ -C ₆ alkyl group, a C ₂ -C ₆ alkenyl group, and a C ₁ -C ₆ alkoxy group.

在本申请的第二方面，本申请提供了一种电池，其包括本申请第一方面所述的电解液。In the second aspect of the present application, the present application provides a battery including the electrolyte described in the first aspect of the present application.

在本申请的第三方面，本申请提供了一种装置，其包括本申请的第二方面所述的电池。In a third aspect of the present application, the present application provides an apparatus including the battery described in the second aspect of the present application.

相对于现有技术，本申请至少包括如下所述的有益效果：本申请的电解液中含有氧化电位较低的多腈基六元氮杂环化合物，电池化成时便能在正极活性材料表面形成稳定的络合物层，有效钝化正极活性材料表面，抑制其对电解液的氧化作用、降低电池产气；本申请的电解液中还含有具有醚键的二腈或多腈类化合物，其能长久稳定地存在于电解液中，随时修补循环或高温存储过程中遭到破坏的络合物层(由添加剂A形成)，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏，该类分子醚基中的氧(-O-)会与电解液中痕量的PF ₅、HF发生反应，阻止PF ₅、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳；因此本申请的电解液能提高电池的循环性能和存储性能，尤其是能提高电池高温高电压情况下的循环性能和存储性能。本申请的装置包括所述的电池，因而至少具有与所述电池相同的优势。 Compared with the prior art, the present application includes at least the following beneficial effects: the electrolyte of the present application contains a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential, which can be formed on the surface of the positive electrode active material when the battery is formed The stable complex layer effectively deactivates the surface of the positive electrode active material, inhibits its oxidation of the electrolyte, and reduces battery gas production; the electrolyte of the present application also contains dinitrile or polynitrile compounds with ether bonds, which It can stably exist in the electrolyte for a long time, and it can repair the complex layer (formed by additive A) that is damaged during cycling or high-temperature storage at any time, reducing the dissolution of transition metal ions, greatly reducing the dissolution of the transition metal and depositing it on the negative electrode to SEI When the membrane is destroyed, the oxygen (-O-) in the molecular ether group will react with trace amounts of PF ₅ and HF in the electrolyte, preventing PF ₅ and HF from being directly exposed to the electrolyte without forming a complex layer. Corrosion of the surface of the positive electrode active material in the environment makes the surface of the positive electrode active material more durable during cycling and storage; therefore, the electrolyte of the present application can improve the cycle performance and storage performance of the battery, especially the high temperature and high temperature of the battery Cycle performance and storage performance under voltage. The device of the present application includes the aforementioned battery, and therefore has at least the same advantages as the aforementioned battery.

附图说明BRIEF DESCRIPTION

图1为A1化合物核磁共振碳谱。Figure 1 shows the NMR carbon spectrum of compound A1.

图2为A2化合物核磁共振碳谱。Figure 2 shows the NMR carbon spectrum of the A2 compound.

图3为A3化合物核磁共振碳谱。Figure 3 is the NMR carbon spectrum of A3 compound.

图4是电池的一实施方式的立体图。4 is a perspective view of an embodiment of a battery.

图5是电池模块的一实施方式的立体图。5 is a perspective view of an embodiment of a battery module.

图6是电池包的一实施方式的立体图。6 is a perspective view of an embodiment of a battery pack.

图7是图6的分解图。7 is an exploded view of FIG. 6.

图8是电池作为电源的装置的一实施方式的示意图。FIG. 8 is a schematic diagram of an embodiment of a device with a battery as a power source.

其中，附图标记说明如下：Among them, the reference signs are described as follows:

1电池包1 battery pack

2上箱体2 Upper cabinet

3下箱体3 Lower cabinet

4电池模块4 battery module

5电池5 batteries

具体实施方式detailed description

下面详细说明根据本申请的电解液、电池及装置。The electrolyte, battery and device according to the present application will be described in detail below.

首先说明根据本申请第一方面的电解液。First, the electrolyte according to the first aspect of the present application will be described.

根据本申请第一方面的电解液含有有机溶剂以及电解质盐，且所述电解液中还含有添加剂A以及添加剂B。The electrolytic solution according to the first aspect of the present application contains an organic solvent and an electrolyte salt, and the electrolytic solution further contains additive A and additive B.

〔添加剂A〕〔Additive A〕

在本申请第一方面的电解液中，所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一种或几种。在式I-1、式I-2、式I-3中：R ₁、R ₂、R ₃、R ₄各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₁₂烷基、取代或未取代的C ₁～C ₁₂烷氧基、取代或未取代的C ₁～C ₁₂胺基、取代或未取代的C ₂～C ₁₂烯基、取代或未取代的C ₂～C ₁₂炔基、取代或未取代的C ₆～C ₂₆芳基、取代或未取代的C ₂～C ₁₂杂环基，其中，取代基(这里表示“取代或未取代”中发生取代的情况)选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数。 In the electrolyte of the first aspect of the present application, the additive A is selected from one or more of the compounds represented by Formula I-1, Formula I-2, and Formula I-3. In Formula I-1, Formula I-2, and Formula I-3: R ₁ , R ₂ , R ₃ , and R ₄ are each independently selected from a hydrogen atom, a halogen atom, and a substituted or unsubstituted C ₁ to C ₁₂ alkane Group, substituted or unsubstituted C ₁ -C ₁₂ alkoxy group, substituted or unsubstituted C ₁ -C ₁₂ amine group, substituted or unsubstituted C ₂ -C ₁₂ alkenyl group, substituted or unsubstituted C ₂ ～ C ₁₂ alkynyl group, substituted or unsubstituted C ₆ to C ₂₆ aryl group, substituted or unsubstituted C ₂ to C ₁₂ heterocyclic group, wherein the substituent (here means substitution in “substituted or unsubstituted”) ) One or more selected from halogen atoms, nitrile groups, C ₁ ˜C ₆ alkyl groups, C ₂ ˜C ₆ alkenyl groups, C ₁ ˜C ₆ alkoxy groups; x, y, z are independently selected An integer from 0 to 8; m, n, and k are each independently selected from an integer of 0 to 2.

添加剂A为氧化电位较低的多腈基六元氮杂环化合物，腈基中的氮原子含有孤对电子，与正极活性材料中的过渡金属具有较强的络合作用，应用于电解液中后，可以在电池化成过程中吸附在正极活性材料表面生成一层疏松的多孔保护膜并有效钝化正极活性材料表面。该多孔保护膜不仅能在隔绝正极活性材料表面与电解液直接接触的同时不影响离子的正常传输，而且能在降低正极活性材料表面活性的同时抑制正极活性材料表面发生大量副反应，从而能达到减少副反应产物并降低产气的作用。Additive A is a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential. The nitrogen atom in the nitrile group contains a lone pair of electrons. It has a strong complexation with the transition metal in the positive electrode active material and is used in the electrolyte. After that, it can be adsorbed on the surface of the positive electrode active material during the formation of the battery to form a loose porous protective film and effectively passivate the surface of the positive electrode active material. The porous protective film not only can isolate the surface of the cathode active material from direct contact with the electrolyte without affecting the normal transmission of ions, but also can reduce the surface activity of the cathode active material while inhibiting a large number of side reactions on the surface of the cathode active material, thereby achieving Reduce the side reaction products and reduce the role of gas production.

添加剂A具有特殊的六元氮杂环结构，腈基与腈基的间距更接近正极活性材料表面过渡金属与过渡金属的间距，可以最大限度地发挥腈基的络合作用，且使更多数量的腈基发挥络合作用，因此与常规线性的腈基化合物相比，本申请的多腈基六元氮杂环化合物可具有更好的钝化效果。Additive A has a special six-membered nitrogen heterocyclic structure. The distance between the nitrile group and the nitrile group is closer to the distance between the transition metal and the transition metal on the surface of the positive electrode active material. It can maximize the complexation of the nitrile group and increase the number. The nitrile group has a complexing effect, so compared with the conventional linear nitrile compound, the polynitrile six-membered nitrogen heterocyclic compound of the present application can have a better passivation effect.

添加剂A特殊的六元氮杂环结构还能使分子的氧化电位较低，电池化成时便能在正极活性材料表面形成稳定的络合物层，改善整个电池体系的电化学性能，诸如降低产气、提高高温高电压下的循环寿命等。The special six-membered nitrogen heterocyclic structure of Additive A can also lower the oxidation potential of the molecule, and can form a stable complex layer on the surface of the positive electrode active material when the battery is formed, improving the electrochemical performance of the entire battery system, such as reducing production. Gas, improve the cycle life under high temperature and high voltage, etc.

在本申请第一方面的电解液中，优选地，所述添加剂A在所述电解液中的质量百分含量为0.1％～10％。如果添加剂A含量过低，则其对电解液的改善效果不明显；如果添加剂A含量过高，则其吸附在正极活性材料表面形成的络合物层过于厚和致密，影响离子的扩散迁移，正极阻抗大幅增高，同时还导致了电解液整体黏度提升、离子电导率下降，因此过高的含量反而影响了电池的性能。优选地，所述添加剂A含量范围的上限可任选自10％、9％、8％、7％、6％、5％、4.5％、4％、3.5％、3％、2.5％、2％、1.5％、1％、0.8％，所述添加剂A含量范围的下限可任选自0.1％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1.0％、1.2％。In the electrolyte of the first aspect of the present application, preferably, the mass percentage content of the additive A in the electrolyte is 0.1% to 10%. If the content of additive A is too low, the improvement effect on the electrolyte is not obvious; if the content of additive A is too high, the complex layer formed on the surface of the positive electrode active material adsorbed by it is too thick and dense, which affects the diffusion and migration of ions. The positive electrode impedance is greatly increased, and it also causes the overall viscosity of the electrolyte to increase and the ionic conductivity to decrease. Therefore, the excessively high content affects the performance of the battery. Preferably, the upper limit of the content range of the additive A may be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2% , 1.5%, 1%, 0.8%, the lower limit of the content range of the additive A can be optionally selected from 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0 %, 1.2%.

进一步优选地，所述添加剂A在所述电解液中的质量百分含量为0.1％～3.5％。Further preferably, the mass percentage content of the additive A in the electrolyte is 0.1% to 3.5%.

在本申请第一方面的电解液中，在式I-1、式I-2、式I-3所示的化合物中：In the electrolyte of the first aspect of the present application, in the compounds represented by Formula I-1, Formula I-2, and Formula I-3:

C ₁～C ₁₂烷基可为链状烷基，也可为环状烷基，链状烷基又可为直链烷基或支链烷基，位于环状烷基的环上的氢还可进一步被烷基取代。C ₁～C ₁₂烷基中碳原子数优选的下限值为1、2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C ₁～C ₁₀烷基；进一步优选地，选择C ₁～C ₆链状烷基、C ₃～C ₈环状烷基；更进一步优选地，选择C ₁～C ₄链状烷基、C ₅～C ₇环状烷基。作为C ₁～C ₁₂烷基的实例，具体可以举出：甲基、乙基、正丙基、异丙基、正丁基、异丁基、仲丁基、叔丁基、正戊基、异戊基、新戊基、己基、2-甲基-戊基、3-甲基-戊基、1,1,2-三甲基-丙基、3,3-二甲基-丁基、庚基、2-庚基、3-庚基、2-甲基己基、3-甲基己基、异庚基、辛基、壬基、癸基。 The C ₁ -C ₁₂ alkyl group may be a chain alkyl group or a cyclic alkyl group. The chain alkyl group may also be a linear or branched alkyl group. The hydrogen on the ring of the cyclic alkyl group is also It may be further substituted with alkyl. The preferred lower limit of the number of carbon atoms in the C ₁ to C ₁₂ alkyl group is 1, 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12. Preferably, C ₁ ˜C ₁₀ alkyl is selected; further preferably, C ₁ ˜C ₆ chain alkyl, C ₃ ˜C ₈ cyclic alkyl is selected; still more preferably, C ₁ ˜C ₄ chain is selected. Alkyl, C ₅ -C ₇ cyclic alkyl. Examples of the C ₁ to C ₁₂ alkyl group specifically include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, Isoamyl, neopentyl, hexyl, 2-methyl-pentyl, 3-methyl-pentyl, 1,1,2-trimethyl-propyl, 3,3-dimethyl-butyl, Heptyl, 2-heptyl, 3-heptyl, 2-methylhexyl, 3-methylhexyl, isoheptyl, octyl, nonyl, decyl.

当前述所提到的C ₁～C ₁₂烷基中含有氧原子时，可为C ₁～C ₁₂烷氧基。优选地，选择C ₁～C ₁₀烷氧基；进一步优选地，选择C ₁～C ₆烷氧基；更进一步优选地，选择C ₁～C ₄烷氧基。作为C ₁～C ₁₂烷氧基的实例，具体可以举出：甲氧基、乙氧基、正丙氧基、异丙氧基、正丁氧基、仲丁氧基、叔丁氧基、正戊氧基、异戊氧基、环戊氧基、环己氧基。 When the aforementioned C ₁ -C ₁₂ alkyl group contains an oxygen atom, it may be a C ₁ -C ₁₂ alkoxy group. Preferably, C ₁ -C ₁₀ alkoxy is selected; further preferably, C ₁ -C ₆ alkoxy is selected; still more preferably, C ₁ -C ₄ alkoxy is selected. Examples of C ₁ to C ₁₂ alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, t-butoxy, N-pentyloxy, isopentyloxy, cyclopentyloxy, cyclohexyloxy.

C ₂～C ₁₂烯基可为环状烯基，也可为链状烯基，链状烯基又可为直链烯基或支链烯基。另外，C ₂～C ₁₂烯基中双键的个数优选为1个。C ₂～C ₁₂烯基中碳原子数优选的下限值为2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C ₂～C ₁₀烯基；进一步优选地，选择C ₂～C ₆烯基；更进一步优选地，选择C ₂～C ₅烯基。作为C ₂～C ₁₂烯基的实例，具体可以举出：乙烯基、烯丙基、异丙烯基、戊烯基、环己烯基、环庚烯基、环辛烯基。 The C ₂ -C ₁₂ alkenyl group may be a cyclic alkenyl group or a chain alkenyl group, and the chain alkenyl group may be a linear alkenyl group or a branched alkenyl group. In addition, the number of double bonds in the C ₂ to C ₁₂ alkenyl group is preferably one. The preferred lower limit of the number of carbon atoms in the C ₂ to C ₁₂ alkenyl group is 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12. Preferably, C ₂ -C ₁₀ alkenyl is selected; further preferably, C ₂ -C ₆ alkenyl is selected; still more preferably, C ₂ -C ₅ alkenyl is selected. Examples of C ₂ to C ₁₂ alkenyl groups include vinyl, allyl, isopropenyl, pentenyl, cyclohexenyl, cycloheptenyl, and cyclooctenyl.

C ₂～C ₁₂炔基可为环状炔基，也可为链状炔基，链状炔基又可为直链炔基或支链炔基。另外，C ₂～C ₁₂炔基中三键的个数优选为1个。C ₂～C ₁₂炔基中碳原子数优选的下限值为2、3、4、5，优选的上限值为3、4、5、6、8、10、12。优选地，选择C ₂～C ₁₀炔基；进一步优选地，选择C ₂～C ₆炔基；更进一步优选地，选择C ₂～C ₅炔基。作为C ₂～C ₁₂炔基的实例，具体可以举出：乙炔基、炔丙基、异丙炔基、戊炔基、环己炔基、环庚炔基、环辛炔基。 The C ₂ -C ₁₂ alkynyl group may be a cyclic alkynyl group or a chain alkynyl group, and the chain alkynyl group may be a linear alkynyl group or a branched alkynyl group. In addition, the number of triple bonds in the C ₂ to C ₁₂ alkynyl group is preferably one. The preferred lower limit of the number of carbon atoms in the C ₂ to C ₁₂ alkynyl group is 2, 3, 4, and 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, and 12. Preferably, C ₂ to C ₁₀ alkynyl is selected; further preferably, C ₂ to C ₆ alkynyl is selected; still more preferably, C ₂ to C ₅ alkynyl is selected. Examples of C ₂ to C ₁₂ alkynyl groups include ethynyl, propargyl, isopropynyl, pentynyl, cyclohexynyl, cycloheptynyl, and cyclooctynyl groups.

C ₁～C ₁₂胺基可选自

其中R’、R”选自C ₁～C ₁₂烷基。 The C ₁ ～C ₁₂ amino group can be selected from

Wherein R ', R "is selected from C ₁ ~ C ₁₂ alkyl group.

C ₆～C ₂₆芳基可为苯基、苯烷基、联苯基、稠环芳烃基(例如萘基、蒽基、菲基)，联苯基和稠环芳烃基还可进一步被烷基或烯基取代。优选地，选择C ₆～C ₁₆芳基；进一步优选地，选择C ₆～C ₁₄芳基；更进一步优选地，选择C ₆～C ₉芳基。作为C ₆～C ₂₆芳基的实例，具体可以举出：苯基、苄基、联苯基、对甲苯基、邻甲苯基、间甲苯基、萘基、蒽基、菲基。 C ₆ ～C ₂₆ aryl groups can be phenyl, phenalkyl, biphenyl, fused ring aromatic hydrocarbon groups (such as naphthyl, anthracenyl, phenanthrenyl), biphenyl and fused ring aromatic hydrocarbon groups can be further alkyl Or alkenyl substitution. Preferably, a C ₆ -C ₁₆ aryl group is selected; further preferably, a C ₆ -C ₁₄ aryl group is selected; still more preferably, a C ₆ -C ₉ aryl group is selected. Examples of the C ₆ -C ₂₆ aryl group include phenyl, benzyl, biphenyl, p-tolyl, o-tolyl, m-tolyl, naphthyl, anthryl, and phenanthryl.

C ₂～C ₁₂杂环基中杂原子可选自氧、氮、硫、磷、硼中的一种或几种，杂环可为脂杂环或芳杂环。优选地，选择C ₂～C ₁₀杂环基；进一步优选地，选择C ₂～C ₇杂环基；更进一步优选地，选择五元芳杂环、六元芳杂环以及苯并杂环。作为C ₂～C ₁₂杂环基的实例，具体可以举出：环氧乙烷基、环氧丙烷基、环硫乙烷基、氮杂环丙烷基、β-丙内酯基、呋喃基、噻吩基、吡咯基、噻唑基、咪唑基、吡啶基、吡嗪基、嘧啶基、哒嗪基、吲哚基、喹啉基。 The hetero atom in the C ₂ -C ₁₂ heterocyclic group may be selected from one or more of oxygen, nitrogen, sulfur, phosphorus, and boron, and the hetero ring may be an aliphatic hetero ring or an aromatic hetero ring. Preferably, a C ₂ -C ₁₀ heterocyclic group is selected; further preferably, a C ₂ -C ₇ heterocyclic group is selected; still more preferably, a five-membered aromatic heterocyclic ring, a six-membered aromatic heterocyclic ring, and a benzo heterocyclic ring are selected. As examples of the C ₂ to C ₁₂ heterocyclic group, specific examples include ethylene oxide, propylene oxide, ethylene sulfide, aziridine, β-propiolactone, furyl, Thienyl, pyrrolyl, thiazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl.

作为取代基的卤素原子可选自氟原子、氯原子、溴原子中的一种或几种，优选为氟原子。The halogen atom as a substituent may be one or more selected from a fluorine atom, a chlorine atom, and a bromine atom, preferably a fluorine atom.

(1)具体地，式I-1所示的化合物为多腈基嘧啶类化合物。(1) Specifically, the compound represented by Formula I-1 is a polycyanopyrimidine compound.

在式I-1中：In formula I-1:

优选地，R ₁、R ₂、R ₃、R ₄各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₆直链或支链烷基、取代或未取代的C ₅～C ₉环状烷基、取代或未取代的C ₁～C ₆烷氧基、取代或未取代的C ₁～C ₆胺基、取代或未取代的C ₂～C ₆烯基、取代或未取代的C ₂～C ₆炔基、取代或未取代的C ₆～C ₁₂芳基、取代或未取代的C ₂～C ₁₂杂环基；进一步优选地，R ₁、R ₂、R ₃、R ₄各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₃直链或支链烷基、取代或未取代的C ₅～C ₇环状烷基、取代或未取代的C ₁～C ₃烷氧基、取代或未取代的C ₁～C ₃胺基、取代或未取代的C ₂～C ₃烯基、取代或未取代的C ₂～C ₃炔基、取代或未取代的C ₆～C ₈芳基、取代或未取代的C ₂～C ₇杂环基。其中，取代基选自卤素原子中的一种或几种。 Preferably, R ₁ , R ₂ , R ₃ , and R ₄ are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C ₁ to C ₆ linear or branched alkyl group, and a substitution Or unsubstituted C ₅ ～C ₉ cyclic alkyl, substituted or unsubstituted C ₁ ～C ₆ alkoxy, substituted or unsubstituted C ₁ ～C ₆ amino, substituted or unsubstituted C ₂ ～C ₆ alkenyl, substituted or unsubstituted C ₂ -C ₆ alkynyl, substituted or unsubstituted C ₆ -C ₁₂ aryl, substituted or unsubstituted C ₂ -C ₁₂ heterocyclyl; further preferably, R ₁ , R ₂ , R ₃ , and R ₄ are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C ₁ to C ₃ linear or branched alkyl group, a substituted or unsubstituted C ₅ to C ₇ cyclic alkyl, substituted or unsubstituted C ₁ to C ₃ alkoxy, substituted or unsubstituted C ₁ to C ₃ amine, substituted or unsubstituted C ₂ to C ₃ alkenyl, substituted Or unsubstituted C ₂ -C ₃ alkynyl, substituted or unsubstituted C ₆ -C ₈ aryl, substituted or unsubstituted C ₂ -C ₇ heterocyclic. Among them, the substituent is selected from one or more of halogen atoms.

x优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。y优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。x is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1, or 2. y is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.

m优选地选自1或2。n优选地选自1或2。m is preferably selected from 1 or 2. n is preferably selected from 1 or 2.

优选地，R ₁、R ₃为相同的基团；进一步优选地，R ₁、R ₃、R ₄均为相同的基团。 Preferably, R ₁ and R ₃ are the same group; further preferably, R ₁ , R ₃ and R ₄ are all the same group.

优选地，R ₁、R ₃均为氢原子；进一步优选地，R ₁、R ₃、R ₄均为氢原子。 Preferably, R ₁ and R ₃ are all hydrogen atoms; further preferably, R ₁ , R ₃ and R ₄ are all hydrogen atoms.

优选地，R ₁、R ₂、R ₃、R ₄均为氢原子，或者R ₁、R ₃、R ₄均为氢原子而R ₂选自氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₆直链或支链烷基、取代或未取代的C ₁～C ₆烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。 Preferably, R ₁ , R ₂ , R ₃ and R ₄ are all hydrogen atoms, or R ₁ , R ₃ and R ₄ are all hydrogen atoms and R _{2 is} selected from fluorine atom, chlorine atom, bromine atom, substituted or unsubstituted C ₁ -C ₆ linear or branched alkyl, substituted or unsubstituted C ₁ -C ₆ alkoxy. Wherein, the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.

优选地，式I-1所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the compound represented by Formula I-1 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

(2)具体地，式I-2所示的化合物为多腈基哌嗪类化合物。(2) Specifically, the compound represented by Formula I-2 is a polynitrile piperazine compound.

在式I-2中：In formula I-2:

优选地，R ₁、R ₂、R ₃、R ₄中至少有两个为相同的基团，进一步优选地，R ₁、R ₂、R ₃、R ₄中至少有三个为相同的基团。 Preferably, at least two of R ₁ , R ₂ , R ₃ , and R ₄ are the same group, and further preferably, at least three of R ₁ , R ₂ , R ₃ , and R ₄ are the same group.

优选地，R ₁、R ₂、R ₃、R ₄中至少有两个为氢原子；进一步优选地，R ₁、R ₂、R ₃、R ₄中至少有三个为氢原子。 Preferably, at least two of R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen atoms; further preferably, at least three of R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen atoms.

优选地，R ₁、R ₂、R ₃、R ₄均为氢原子，或者R ₁、R ₂、R ₃、R ₄中有三个为氢原子且剩余一个选自氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₆直链或支链烷基、取代或未取代的C ₁～C ₆烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。 Preferably, R ₁ , R ₂ , R ₃ and R ₄ are all hydrogen atoms, or three of R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atoms and the remaining one is selected from fluorine atom, chlorine atom and bromine atom , Substituted or unsubstituted C ₁ -C ₆ linear or branched alkyl, substituted or unsubstituted C ₁ -C ₆ alkoxy. Wherein, the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.

优选地，式I-2所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the compound represented by Formula I-2 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

(3)具体地，式I-3所示的化合物为多腈基均三嗪类化合物。(3) Specifically, the compound represented by Formula I-3 is a polynitrile mesitazine compound.

在式I-3中：In formula I-3:

优选地，R ₁、R ₂、R ₃各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₆直链或支链烷基、取代或未取代的C ₅～C ₉环状烷基、取代或未取代的C ₁～C ₆烷氧基、取代或未取代的C ₁～C ₆胺基、取代或未取代的C ₂～C ₆烯基、取代或未取代的C ₂～C ₆炔基、取代或未取代的C ₆～C ₁₂芳基、取代或未取代的C ₂～C ₁₂杂环基；进一步优选地，R ₁、R ₂、R ₃各自独立地选自氢原子、氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₃直链或支链烷基、取代或未取代的C ₅～C ₇环状烷基、取代或未取代的C ₁～C ₃烷氧基、取代或未取代的C ₁～C ₃胺基、取代或未取代的C ₂～C ₃烯基、取代或未取代的C ₂～C ₃炔基、取代或未取代的C ₆～C ₈芳基、取代或未取代的C ₂～C ₇杂环基。其中，取代基选自卤素原子中的一种或几种。 Preferably, R ₁ , R ₂ and R ₃ are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C ₁ to C ₆ linear or branched alkyl group, a substituted or unsubstituted C ₅ ～C ₉ cyclic alkyl, substituted or unsubstituted C ₁ ～C ₆ alkoxy, substituted or unsubstituted C ₁ ～C ₆ amino, substituted or unsubstituted C ₂ ～C ₆ alkenyl , Substituted or unsubstituted C ₂ -C ₆ alkynyl, substituted or unsubstituted C ₆ -C ₁₂ aryl, substituted or unsubstituted C ₂ -C ₁₂ heterocyclyl; further preferably, R ₁ , R ₂ And R ₃ are each independently selected from a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a substituted or unsubstituted C ₁ to C ₃ linear or branched alkyl group, and a substituted or unsubstituted C ₅ to C ₇ cyclic Alkyl, substituted or unsubstituted C ₁ -C ₃ alkoxy, substituted or unsubstituted C ₁ -C ₃ amine, substituted or unsubstituted C ₂ -C ₃ alkenyl, substituted or unsubstituted C ₂ ~C ₃ alkynyl, substituted or unsubstituted C ₆ -C ₈ aryl, substituted or unsubstituted C ₂ -C ₇ heterocyclyl. Among them, the substituent is selected from one or more of halogen atoms.

x优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。y优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。z优选地选自0～6的整数，进一步优选地选自0～4的整数，更进一步优选地选自0、1或2。x is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1, or 2. y is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2. z is preferably selected from integers of 0 to 6, further preferably selected from integers of 0 to 4, even more preferably selected from 0, 1 or 2.

m优选地选自1或2。n优选地选自1或2。k优选地选自1或2。m is preferably selected from 1 or 2. n is preferably selected from 1 or 2. k is preferably selected from 1 or 2.

优选地，R ₁、R ₂、R ₃中至少有两个为相同的基团。 Preferably, at least two of R ₁ , R ₂ and R ₃ are the same group.

优选地，R ₁、R ₂、R ₃中至少有两个为氢原子。 Preferably, at least two of R ₁ , R ₂ and R ₃ are hydrogen atoms.

优选地，R ₁、R ₂、R ₃均为氢原子，或者R ₁、R ₂、R ₃中有两个为氢原子且剩余一个选自氟原子、氯原子、溴原子、取代或未取代的C ₁～C ₆直链或支链烷基、取代或未取代的C ₁～C ₆烷氧基。其中，取代基选自卤素原子中的一种或几种，优选地，取代基选自氟原子。 Preferably, R ₁ , R ₂ and R ₃ are all hydrogen atoms, or two of R ₁ , R ₂ and R ₃ are hydrogen atoms and the remaining one is selected from fluorine atom, chlorine atom, bromine atom, substituted or unsubstituted C ₁ -C ₆ linear or branched alkyl, substituted or unsubstituted C ₁ -C ₆ alkoxy. Wherein, the substituent is selected from one or more of halogen atoms, preferably, the substituent is selected from fluorine atoms.

优选地，式I-3所示的化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the compound represented by Formula I-3 may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

〔添加剂B〕〔Additive B〕

在本申请第一方面的电解液中，所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种。在式II-1、式II-2中，a、b、c、d各自独立地选自1～5内的整数，R ₅、R ₆、R ₇、R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自取代或未取代的C ₁～C ₁₀亚烷基、取代或未取代的C ₂～C ₁₀亚烯基，其中，取代基(这里表示“取代或未取代”中发生取代的情况)选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种。 In the electrolyte of the first aspect of the present application, the additive B is selected from one or more of the compounds represented by Formula II-1 and Formula II-2. In Formula II-1 and Formula II-2, a, b, c, and d are each independently selected from integers within 1 to 5, R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from a substituted or unsubstituted C ₁ to C ₁₀ alkylene group, a substituted or unsubstituted C ₂ to C ₁₀ alkenylene group, wherein the substituent (here means “substituted or In the case of unsubstituted, substitution occurs) one or more selected from halogen atoms, nitrile groups, C ₁ to C ₆ alkyl groups, C ₂ to C ₆ alkenyl groups, and C ₁ to C ₆ alkoxy groups.

添加剂B为具有醚键的二腈或多腈类化合物，该类分子中的氮原子含有孤对电子，与正极活性材料中的过渡金属具有较强的络合作用，可随时修补循环或高温存储过程中遭到破坏的络合物层(由添加剂A形成)，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏；该类分子醚基中的氧(-O-)还会与电解液中痕量的PF ₅、HF发生反应，阻止PF ₅、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳。因此当添加剂B应用于电解液后，电池能具有较好的高温高压循环性能和存储性能。 Additive B is a dinitrile or polynitrile compound with an ether bond. The nitrogen atom in this molecule contains a lone pair of electrons. It has a strong complexation with the transition metal in the positive electrode active material, and can be repaired at any time or stored at high temperature. The complex layer (formed by additive A) that is destroyed during the process reduces the dissolution of transition metal ions and greatly reduces the damage to the SEI film deposited on the negative electrode after the transition metal dissolves; the oxygen (-O- ) It will also react with trace amounts of PF ₅ and HF in the electrolyte to prevent the PF ₅ and HF from corroding the surface of the cathode active material that is directly exposed to the electrolyte environment without forming a complex layer, so that the surface of the cathode active material Better durability during cycling and storage. Therefore, when the additive B is applied to the electrolyte, the battery can have better high-temperature and high-pressure cycle performance and storage performance.

在本申请第一方面的电解液中，优选地，所述添加剂B在所述电解液中的质量百分含量为0.1％～10％。如果添加剂B含量过低，则其吸收PF ₅、HF的作用不明显，无络合物层覆盖的裸露正极活性材料表面依然会遭到腐蚀；如果添加剂B含量过高，则正极活性材料表面形成的络合物层过于厚和致密，正负极阻抗大幅增高，反而影响了电池的性能。优选地，所述添加剂B含量范围的上限可任选自10％、9％、8％、7％、6％、5％、4.5％、4％、3.5％、3％、2.5％、2％、1.5％、1％、0.8％，所述添加剂B含量范围的下限可任选自0.1％、0.2％、0.3％、0.4％、0.5％、0.6％。 In the electrolyte of the first aspect of the present application, preferably, the mass percentage content of the additive B in the electrolyte is 0.1% to 10%. If the content of additive B is too low, the effect of PF ₅ and HF absorption is not obvious, and the surface of the bare positive electrode active material covered by the complex layer will still be corroded; if the content of additive B is too high, the surface of the positive electrode active material will form The complex layer is too thick and dense, and the impedance of the positive and negative electrodes is greatly increased, which affects the performance of the battery. Preferably, the upper limit of the content range of the additive B can be selected from 10%, 9%, 8%, 7%, 6%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2% , 1.5%, 1%, 0.8%, the lower limit of the content range of the additive B can be optionally selected from 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%.

进一步优选地，所述添加剂B在所述电解液中的质量百分含量为0.1％～5％。Further preferably, the mass percentage content of the additive B in the electrolyte is 0.1% to 5%.

在本申请第一方面的电解液中，在式II-1、式II-2所示的化合物中：In the electrolyte of the first aspect of the present application, in the compounds represented by Formula II-1 and Formula II-2:

C ₁～C ₁₀亚烷基可为直链亚烷基，也可为支链亚烷基，C ₁～C ₁₀亚烷基中碳原子数优选的下限值为1、2、3，优选的上限值为4、5、6、7、8、9、10。优选地，选择C ₁～C ₆亚烷基；进一步优选地，选择C ₂～C ₄亚烷基。作为C ₁～C ₁₀亚烷基的实例，具体可以举出：亚甲基、亚乙基、亚丙基、亚异丙基、亚丁基、亚异丁基、亚仲丁基、亚戊基、亚己基。 The C ₁ -C ₁₀ alkylene group may be a linear alkylene group or a branched chain alkylene group. The preferred lower limit of the number of carbon atoms in the C ₁ -C ₁₀ alkylene group is 1, 2, 3, preferably The upper limit of is 4, 5, 6, 7, 8, 9, 10. Preferably, C ₁ to C ₆ alkylene is selected; further preferably, C ₂ to C ₄ alkylene is selected. Examples of C ₁ to C ₁₀ alkylene groups include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, and pentylene. , Akilidene.

C ₂～C ₁₀亚烯基可为直链亚烯基，也可为支链亚烯基，C ₂～C ₁₀亚烯基中双键的个数优选为1个。C ₂～C ₁₂亚烯基中碳原子数优选的下限值为2、3、4、5，优选的上限值为4、5、6、7、8、9、10。优选地，选择C ₂～C ₆亚烯基。作为C ₂～C ₁₀亚烯基的实例，具体可以举出：亚乙烯基、亚烯丙基、亚异丙烯基、亚烯丁基、亚烯戊基。 The C ₂ to C ₁₀ alkenylene group may be a straight chain alkenylene group or a branched alkenylene group, and the number of double bonds in the C ₂ to C ₁₀ alkenylene group is preferably one. The preferable lower limit of the number of carbon atoms in C ₂ to C ₁₂ alkenylene is 2, 3, 4, and 5, and the preferable upper limit is 4, 5, 6, 7, 8, 9, and 10. Preferably, C ₂ to C ₆ alkenylene is selected. As examples of the C ₂ to C ₁₀ alkenylene group, specific examples include vinylidene group, allylene group, isopropenylene group, allylene group, and alkenylene group.

(1)具体地，式II-1所示的化合物为具有醚键的二腈类化合物。(1) Specifically, the compound represented by Formula II-1 is a dinitrile compound having an ether bond.

在式II-1中：In formula II-1:

优选地，a选自1或2。Preferably, a is selected from 1 or 2.

优选地，R ₅、R ₆、R ₇各自独立地选自取代或未取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆亚烯基，其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R ₅、R ₆、R ₇各自独立地选自C ₁～C ₆亚烷基、C ₂～C ₆亚烯基。更进一步优选地，R ₅、R ₆、R ₇各自独立地选自C ₂～C ₄亚烷基。 Preferably, R ₅ , R ₆ , and R ₇ are each independently selected from substituted or unsubstituted C ₁ -C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, wherein the substituent is selected from The halogen atom is preferably a fluorine atom. More preferably, R ₅ , R ₆ , and R ₇ are each independently selected from C ₁ to C ₆ alkylene and C ₂ to C ₆ alkenylene. Even more preferably, R ₅ , R ₆ , and R ₇ are each independently selected from C ₂ to C ₄ alkylene.

优选地，式II-1所示的化合物可选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,2-二(氰丁氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,3-二(氰丙氧基)丙烷、1,3-二(氰丁氧基)丙烷、1,4-二(氰乙氧基)丁烷、1,4-二(氰丙氧基)丁烷、1,4-二(氰丁氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷中的一种或几种。Preferably, the compound represented by Formula II-1 may be selected from 1,2-bis(cyanoethoxy)ethane, 1,2-bis(cyanopropoxy)ethane, 1,2-bis(cyanobutyl) Oxy)ethane, 1,3-bis(cyanoethoxy)propane, 1,3-bis(cyanopropoxy)propane, 1,3-bis(cyanobutoxy)propane, 1,4-bis (Cyanoethoxy)butane, 1,4-bis(cyanopropoxy)butane, 1,4-bis(cyanobutoxy)butane, 1,5-bis(cyanopropoxy)pentane , 1,6-bis (cyanopropyloxy) hexane in one or more.

进一步优选地，式II-1所示的化合物可选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,4-二(氰丙氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷中的一种或几种，具体结构如下：Further preferably, the compound represented by Formula II-1 may be selected from 1,2-bis(cyanoethoxy)ethane, 1,2-bis(cyanopropoxy)ethane, 1,3-bis(cyano Ethoxy) propane, 1,4-bis(cyanopropoxy)butane, 1,5-bis(cyanopropoxy)pentane, 1,6-bis(cyanopropoxy)hexane Species or several species, the specific structure is as follows:

(2)具体地，式II-2所示的化合物为具有醚键的多腈类化合物。(2) Specifically, the compound represented by Formula II-2 is a polynitrile compound having an ether bond.

在式II-2中：In formula II-2:

优选地，b、c、d各自独立地选自1或2。Preferably, b, c, and d are each independently selected from 1 or 2.

优选地，R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自取代或未取代的C ₁～C ₁₆亚烷基、取代或未取代的C ₂～C ₆亚烯基；其中，取代基选自卤素原子，优选为氟原子。进一步优选地，R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自C ₁～C ₆亚烷基、C ₂～C ₆亚烯基。更进一步优选地，R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自C ₂～C ₄亚烷基。 Preferably, R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from substituted or unsubstituted C ₁ ˜C ₁₆ alkylene, substituted or unsubstituted C ₂ ˜C ₆ sub Alkenyl; wherein, the substituent is selected from halogen atoms, preferably fluorine atoms. More preferably, R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from C ₁ to C ₆ alkylene and C ₂ to C ₆ alkenylene. Even more preferably, R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from C ₂ to C ₄ alkylene.

优选地，式II-2所示的化合物可选自1,2,3-三(氰乙氧基)丙烷、1,2,3-三(氰丙氧基)丙烷、1,3,5-三(氰乙氧基)戊烷、1,3,5-三(氰丙氧基)戊烷、1,2,6-三(氰乙氧基)己烷、1,4,7-三(氰乙氧基)庚烷中的一种或几种，具体结构如下：Preferably, the compound represented by Formula II-2 may be selected from 1,2,3-tris(cyanoethoxy)propane, 1,2,3-tris(cyanopropoxy)propane, 1,3,5- Tris(cyanoethoxy)pentane, 1,3,5-tris(cyanopropoxy)pentane, 1,2,6-tris(cyanoethoxy)hexane, 1,4,7-tri( One or more of cyanoethoxy) heptane, the specific structure is as follows:

〔添加剂C〕〔Additive C〕

在本申请第一方面的电解液中，所述电解液还可含有添加剂C。添加剂C可选自含有碳碳不饱和键的环状碳酸酯化合物、卤素取代的环状碳酸酯化合物、硫酸酯化合物、磺酸内酯化合物、二磺酸酯化合物、亚硫酸酯化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物中的一种或几种。In the electrolyte of the first aspect of the present application, the electrolyte may further contain additive C. The additive C may be selected from cyclic carbonate compounds containing carbon-carbon unsaturated bonds, halogen-substituted cyclic carbonate compounds, sulfate compounds, sultone compounds, disulfonate compounds, sulfite compounds, aromatic compounds , Isocyanate compound, phosphazene compound, acid anhydride compound, phosphite compound, phosphate compound, borate compound one or more.

在本申请第一方面的电解液中，优选地，所述添加剂C在所述电解液中的质量百分含量为0.01％～30％。In the electrolyte of the first aspect of the present application, preferably, the mass percentage content of the additive C in the electrolyte is 0.01% to 30%.

(a)含有碳碳不饱和键的环状碳酸酯化合物(a) Cyclic carbonate compounds containing carbon-carbon unsaturated bonds

含有碳碳不饱和键的环状碳酸酯化合物可选自式III-0所示的化合物中的一种或几种。在式III-0中，R ₂₀选自支链上有烯基或炔基取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆直链亚烯基，其中，取代基选自卤素原子、C ₁～C ₆烷基、C ₂～C ₆烯基中的一种或几种。 The cyclic carbonate compound containing a carbon-carbon unsaturated bond may be selected from one or more of the compounds represented by Formula III-0. In formula III-0, R _{20 is} selected from C ₁ -C ₆ alkylene substituted with alkenyl or alkynyl on the branch, substituted or unsubstituted C ₂ -C ₆ linear alkenylene, wherein The group is selected from one or more of halogen atoms, C ₁ to C ₆ alkyl groups, and C ₂ to C ₆ alkenyl groups.

优选地，含有碳碳不饱和键的环状碳酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the cyclic carbonate compound containing a carbon-carbon unsaturated bond may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

(b)卤素取代的环状碳酸酯化合物(b) Halogen substituted cyclic carbonate compounds

卤素取代的环状碳酸酯化合物可选自式III-1所示的化合物中的一种或几种。在式III-1中，R ₂₁选自卤素取代的C ₁～C ₆亚烷基、卤素取代的C ₂～C ₆亚烯基。 The halogen-substituted cyclic carbonate compound may be selected from one or more of the compounds represented by Formula III-1. In formula III-1, R _{21 is} selected from halogen-substituted C ₁ -C ₆ alkylene and halogen-substituted C ₂ -C ₆ alkenylene.

具体地，卤素取代的环状碳酸酯化合物可选自氟代碳酸乙烯酯(简称为FEC)、氟代碳酸丙烯酯(简称为FPC)、三氟代碳酸丙烯酯(简称为TFPC)、反式或顺式-4,5-二氟-1,3-二氧杂环戊烷-2-酮(以下将两者统称为“DFEC”)中的一种或几种。Specifically, the halogen-substituted cyclic carbonate compound may be selected from fluoroethylene carbonate (abbreviated as FEC), fluoropropylene carbonate (abbreviated as FPC), trifluoropropylene carbonate (abbreviated as TFPC), trans Or one or more of cis-4,5-difluoro-1,3-dioxolane-2-one (hereinafter both are collectively referred to as "DFEC").

(c)硫酸酯化合物(c) Sulfate compounds

硫酸酯化合物优选为环状硫酸酯化合物，环状硫酸酯化合物可选自式III-2所示的化合物中的一种或几种。在式III-2中，R ₂₂选自取代或未取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 The sulfate compound is preferably a cyclic sulfate compound, and the cyclic sulfate compound may be selected from one or more of the compounds represented by Formula III-2. In Formula III-2, R _{22 is} selected from substituted or unsubstituted C ₁ -C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, wherein the substituent is selected from halogen atom, C ₁ One or more of -C ₃ alkyl and C ₂ -C ₄ alkenyl.

在式III-2中，优选地，R ₂₂选自取代或未取代的C ₁～C ₄亚烷基、取代或未取代的C ₂～C ₄亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 In formula III-2, preferably, R _{22 is} selected from a substituted or unsubstituted C ₁ to C ₄ alkylene group, a substituted or unsubstituted C ₂ to C ₄ alkenylene group, wherein the substituent is selected from a halogen atom , C ₁ ～C ₃ alkyl, C ₂ ～C ₄ alkenyl one or more.

优选地，硫酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the sulfate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

进一步优选地，硫酸酯化合物选自硫酸乙烯酯(简称为DTD)、硫酸丙烯酯(简称为TMS)、4-甲基硫酸亚乙酯(简称为PLS)中的一种或几种，具体结构如下：Further preferably, the sulfate compound is selected from one or more of vinyl sulfate (abbreviated as DTD), propylene sulfate (abbreviated as TMS), 4-methylethylene sulfate (abbreviated as PLS), specific structure as follows:

(d)磺酸内酯化合物(d) Sultone compound

磺酸内酯化合物可选自式III-3所示的化合物中的一种或几种。在式III-3中，R ₂₃选自取代或未取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 The sultone compound can be selected from one or more of the compounds represented by formula III-3. In formula III-3, R _{23 is} selected from substituted or unsubstituted C ₁ -C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, wherein the substituent is selected from halogen atom, C ₁ One or more of -C ₃ alkyl and C ₂ -C ₄ alkenyl.

在式III-3中，优选地，R ₂₃选自取代或未取代的C ₁～C ₄亚烷基、取代或未取代的C ₂～C ₄亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 In formula III-3, preferably, R _{23 is} selected from substituted or unsubstituted C ₁ -C ₄ alkylene, substituted or unsubstituted C ₂ -C ₄ alkenylene, wherein the substituent is selected from halogen atoms , C ₁ ～C ₃ alkyl, C ₂ ～C ₄ alkenyl one or more.

优选地，磺酸内酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the sultone compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

进一步优选地，磺酸内酯化合物可选自1,3-丙烷磺酸内酯(简称为PS)、1,3-丙烯磺酸内酯(简称为PES)中的一种或几种，具体结构如下：Further preferably, the sultone compound may be selected from one or more of 1,3-propane sultone (abbreviated as PS) and 1,3-propene sultone (abbreviated as PES), specifically The structure is as follows:

(e)二磺酸酯化合物(e) Disulfonate compound

二磺酸酯化合物为含有两个磺酸基(-S(＝O) ₂O-)的化合物，优选选自二磺酸亚甲酯化合物，二磺酸亚甲酯化合物可选自式III-4所示的化合物中的一种或几种。在式III-4中，R ₂₄、R ₂₅、R ₂₆、R ₂₇各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₁₀烷基、取代或未取代的C ₂～C ₁₀烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 The disulfonate compound is a compound containing two sulfonic acid groups (-S(=O) ₂ O-), preferably selected from methylene disulfonate compounds, and the methylene disulfonate compound may be selected from formula III- One or more of the compounds shown in 4. In Formula III-4, R ₂₄ , R ₂₅ , R ₂₆ , and R ₂₇ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ to C ₁₀ alkyl group, and a substituted or unsubstituted C ₂ to C ₁₀ alkenyl, wherein the substituent is one or more selected from halogen atoms, C ₁ to C ₃ alkyl, and C ₂ to C ₄ alkenyl.

在式III-4中，优选地，R ₂₄、R ₂₅、R ₂₆、R ₂₇各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₄烷基、取代或未取代的C ₂～C ₆烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 In formula III-4, preferably, R ₂₄ , R ₂₅ , R ₂₆ , and R ₂₇ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ to C ₄ alkyl group, a substituted or unsubstituted C ₂ -C ₆ alkenyl group, wherein the substituent is one or more selected from halogen atom, C ₁ -C ₃ alkyl group, C ₂ -C ₄ alkenyl group.

优选地，二磺酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the disulfonate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

进一步优选地，二磺酸酯化合物可选自甲烷二磺酸亚甲酯(简称为MMDS)，具体结构如下：Further preferably, the disulfonate compound may be selected from methylene disulfonate (abbreviated as MMDS), and the specific structure is as follows:

(f)亚硫酸酯化合物(f) Sulfite compounds

亚硫酸酯化合物优选为环状亚硫酸酯化合物，具体可选自式III-5所示的化合物中的一种或几种。在式III-5中，R ₂₈选自取代或未取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 The sulfite compound is preferably a cyclic sulfite compound, and specifically can be selected from one or more of the compounds represented by Formula III-5. In formula III-5, R _{28 is} selected from substituted or unsubstituted C ₁ -C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, wherein the substituent is selected from halogen atom, C ₁ One or more of -C ₃ alkyl and C ₂ -C ₄ alkenyl.

在式III-5中，优选地，R ₂₈选自取代或未取代的C ₁～C ₄亚烷基、取代或未取代的C ₂～C ₄亚烯基，其中，取代基选自卤素原子、C ₁～C ₃烷基、C ₂～C ₄烯基中的一种或几种。 In formula III-5, preferably, R _{28 is} selected from substituted or unsubstituted C ₁ -C ₄ alkylene, substituted or unsubstituted C ₂ -C ₄ alkenylene, wherein the substituent is selected from halogen atoms , C ₁ ～C ₃ alkyl, C ₂ ～C ₄ alkenyl one or more.

优选地，亚硫酸酯化合物可选自亚硫酸乙烯酯(简称为ES)、亚硫酸丙烯酯(简称为PS)、亚硫酸丁烯酯(简称为BS)中的一种或几种。Preferably, the sulfite compound may be selected from one or more of vinyl sulfite (abbreviated as ES), propylene sulfite (abbreviated as PS), and butylene sulfite (abbreviated as BS).

(g)芳香化合物(g) Aromatic compounds

芳香化合物可选自环己基苯、氟代环己基苯化合物(1-氟-2-环己基苯、1-氟-3-环己基苯、1-氟-4-环己基苯)、叔丁基苯、叔戊基苯、1-氟-4-叔丁基苯、联苯、三联苯(邻位体、间位体、对位体)、二苯基醚、氟苯、二氟苯(邻位体、间位体、对位体)、茴香醚、2,4-二氟茴香醚、三联苯的部分氢化物(1,2-二环己基苯、2-苯基双环己基、1,2-二苯基环己烷、邻环己基联苯)中的一种或几种。The aromatic compound may be selected from cyclohexylbenzene, fluorocyclohexylbenzene compound (1-fluoro-2-cyclohexylbenzene, 1-fluoro-3-cyclohexylbenzene, 1-fluoro-4-cyclohexylbenzene), tert-butyl Benzene, tert-amylbenzene, 1-fluoro-4-tert-butylbenzene, biphenyl, terphenyl (ortho, meta, para), diphenyl ether, fluorobenzene, difluorobenzene (ortho Position, meta position, para position), anisole, 2,4-difluoroanisole, partial hydride of terphenyl (1,2-dicyclohexylbenzene, 2-phenylbicyclohexyl, 1,2 -One or more of diphenylcyclohexane and o-cyclohexylbiphenyl).

优选地，芳香化合物可选自联苯、三联苯(邻位体、间位体、对位体)、氟苯、环己基苯、叔丁基苯、叔戊基苯中的一种或几种，进一步优选地，芳香化合物可选自联苯、邻三联苯、氟苯、环己基苯、叔戊基苯中的一种或几种。Preferably, the aromatic compound may be selected from one or more of biphenyl, terphenyl (ortho, meta, para), fluorobenzene, cyclohexylbenzene, t-butylbenzene, t-pentylbenzene Further preferably, the aromatic compound may be selected from one or more of biphenyl, o-terphenyl, fluorobenzene, cyclohexylbenzene, and tert-amylbenzene.

(h)异氰酸酯化合物(h) Isocyanate compounds

异氰酸酯化合物可选自甲基异氰酸酯、乙基异氰酸酯、丁基异氰酸酯、苯基异氰酸酯、四亚甲基二异氰酸酯、六亚甲基二异氰酸酯、八亚甲基二异氰酸酯、1,4-亚苯基二异氰酸酯、丙烯酸2-异氰酸根合乙酯、甲基丙烯酸2-异氰酸根合乙酯中的一种或几种。The isocyanate compound may be selected from methyl isocyanate, ethyl isocyanate, butyl isocyanate, phenyl isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 1,4-phenylene diisocyanate One or more of isocyanate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate.

优选地，异氰酸酯化合物可选自六亚甲基二异氰酸酯、八亚甲基二异氰酸酯、丙烯酸2-异氰酸根合乙酯、甲基丙烯酸2-异氰酸根合乙酯中的一种或几种。Preferably, the isocyanate compound may be selected from one or more of hexamethylene diisocyanate, octamethylene diisocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate .

(i)磷腈化合物(i) Phosphazene compounds

磷腈化合物优选为环状磷腈化合物。环状磷腈化合物可选自甲氧基五氟环三磷腈、乙氧基五氟环三磷腈、苯氧基五氟环三磷腈、乙氧基七氟环四磷腈中的一种或几种。The phosphazene compound is preferably a cyclic phosphazene compound. The cyclic phosphazene compound can be selected from one of methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazene Kind or several.

优选地，环状磷腈化合物可选自甲氧基五氟环三磷腈、乙氧基五氟环三磷腈、苯氧基五氟环三磷腈中的一种或几种。Preferably, the cyclic phosphazene compound may be selected from one or more of methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, and phenoxypentafluorocyclotriphosphazene.

进一步优选地，环状磷腈化合物可选自甲氧基五氟环三磷腈或乙氧基五氟环三磷腈。Further preferably, the cyclic phosphazene compound may be selected from methoxypentafluorocyclotriphosphazene or ethoxypentafluorocyclotriphosphazene.

(j)酸酐化合物(j) Anhydride compound

酸酐化合物可为链状酸酐或环状酸酐。具体地，酸酐化合物可选自乙酸酐、丙酸酐、琥珀酸酐、马来酸酐、2-烯丙基琥珀酸酐、戊二酸酐、衣康酸酐、3-磺基-丙酸酐中的一种或几种。The acid anhydride compound may be a linear acid anhydride or a cyclic acid anhydride. Specifically, the acid anhydride compound may be selected from one or more of acetic anhydride, propionic anhydride, succinic anhydride, maleic anhydride, 2-allyl succinic anhydride, glutaric anhydride, itaconic anhydride, 3-sulfo-propionic anhydride Species.

优选地，酸酐化合物可选自琥珀酸酐、马来酸酐、2-烯丙基琥珀酸酐中的一种或几种。进一步优选地，酸酐化合物可选自琥珀酸酐、2-烯丙基琥珀酸酐中的一种或两种。Preferably, the acid anhydride compound may be selected from one or more of succinic anhydride, maleic anhydride, and 2-allyl succinic anhydride. Further preferably, the acid anhydride compound may be selected from one or both of succinic anhydride and 2-allyl succinic anhydride.

(k)亚磷酸酯化合物(k) Phosphite compounds

亚磷酸酯化合物可选自硅烷亚磷酸酯化合物，具体可选自式III-6所示的化合物中的一种或几种。在式III-6中，R ₃₁、R ₃₂、R ₃₃、R ₃₄、R ₃₅、R ₃₆、R ₃₇、R ₃₈、R ₃₉各自独立地选自卤素取代或未取代的C ₁～C ₆烷基。 The phosphite compound may be selected from silane phosphite compounds, and specifically may be selected from one or more of the compounds represented by Formula III-6. In formula III-6, R ₃₁ , R ₃₂ , R ₃₃ , R ₃₄ , R ₃₅ , R ₃₆ , R ₃₇ , R ₃₈ , and R ₃₉ are each independently selected from halogen-substituted or unsubstituted C ₁ -C ₆ alkane base.

优选地，硅烷亚磷酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the silane phosphite compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

(l)磷酸酯化合物(l) Phosphate compounds

磷酸酯化合物可选自硅烷磷酸酯化合物，具体可选自式III-7所示的化合物中的一种或几种。在式III-7中，R ₄₁、R ₄₂、R ₄₃、R ₄₄、R ₄₅、R ₄₆、R ₄₇、R ₄₈、R ₄₉各自独立地选自卤素取代或未取代的C ₁～C ₆烷基。 The phosphate compound may be selected from silane phosphate compounds, specifically one or more of the compounds represented by Formula III-7. In Formula III-7, R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ , R ₄₈ , and R ₄₉ are each independently selected from halogen-substituted or unsubstituted C ₁ to C ₆ alkyl base.

优选地，硅烷磷酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the silane phosphate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

(m)硼酸酯化合物(m) Borate compound

硼酸酯化合物可选自硅烷硼酸酯化合物，具体可选自式III-8所示的化合物中的一种或几种。在式III-8中，R ₅₁、R ₅₂、R ₅₃、R ₅₄、R ₅₅、R ₅₆、R ₅₇、R ₅₈、R ₅₉各自独立地选自卤素取代或未取代的C ₁～C ₆烷基。 The borate compound may be selected from silane borate compounds, specifically one or more of the compounds represented by Formula III-8. In Formula III-8, R ₅₁ , R ₅₂ , R ₅₃ , R ₅₄ , R ₅₅ , R ₅₆ , R ₅₇ , R ₅₈ , and R ₅₉ are each independently selected from halogen-substituted or unsubstituted C ₁ to C ₆ alkane base.

优选地，硅烷硼酸酯化合物可具体选自以下化合物中的一种或几种，但本申请不限于此：Preferably, the silane borate compound may be specifically selected from one or more of the following compounds, but the application is not limited thereto:

〔有机溶剂〕〔Organic solvents〕

在本申请第一方面的电解液中，作为本申请实施例的电解液中使用的有机溶剂优选为非水有机溶剂。In the electrolyte of the first aspect of the present application, the organic solvent used as the electrolyte in the embodiments of the present application is preferably a non-aqueous organic solvent.

优选地，作为本申请实施例的电解液中使用的有机溶剂可包括环状碳酸酯以及链状碳酸酯，其可进一步提高高温高电压情况下的循环性能和存储性能，且易于将电解液的电导率调节至合适的范围，从而更有利于各添加剂达到更好的成膜效果。Preferably, the organic solvent used in the electrolyte as an embodiment of the present application may include cyclic carbonate and chain carbonate, which can further improve the cycle performance and storage performance under high temperature and high voltage, and it is easy to The electrical conductivity is adjusted to a suitable range, which is more conducive to each additive to achieve a better film-forming effect.

作为本申请实施例的电解液中使用的有机溶剂还可进一步包括羧酸酯，即根据本申请的有机溶剂可包括环状碳酸酯、链状碳酸酯以及羧酸酯的混合物。羧酸酯具有介电常数大且粘度低的特点，可有效防止离子和电解液中阴离子的缔合，同时在离子传导方面比环状碳酸酯和链状碳酸酯更有优势，尤其是在低温下，能可保证电解液具有良好的离子传导特性。The organic solvent used in the electrolyte as an example of the present application may further include a carboxylic acid ester, that is, the organic solvent according to the present application may include a mixture of cyclic carbonate, chain carbonate, and carboxylic acid ester. Carboxylic acid esters have the characteristics of large dielectric constant and low viscosity, which can effectively prevent the association of ions and anions in the electrolyte, and at the same time have more advantages in ion conduction than cyclic carbonates and chain carbonates, especially at low temperatures The following can ensure that the electrolyte has good ion conduction characteristics.

其中，基于有机溶剂的总质量计：环状碳酸酯的质量百分含量可为15％～55％，优选为25％～50％；链状碳酸酯的质量百分含量可为15％～74％，优选为25％～70％；羧酸酯的质量百分含量可为0.1％～70％，优选为5％～50％。Among them, based on the total mass of the organic solvent: the mass percentage content of the cyclic carbonate can be 15% to 55%, preferably 25% to 50%; the mass percentage content of the chain carbonate can be 15% to 74 %, preferably 25% to 70%; the mass percentage content of the carboxylic acid ester may be 0.1% to 70%, preferably 5% to 50%.

具体地，环状碳酸酯可选自碳酸乙烯酯、碳酸丙烯酯、碳酸1,2-丁烯酯、碳酸-2,3-丁二醇酯中的一种或几种。进一步优选地，环状碳酸酯可选自碳酸乙烯酯、碳酸丙烯酯中的一种或几种。Specifically, the cyclic carbonate may be selected from one or more of ethylene carbonate, propylene carbonate, 1,2-butene carbonate, and 2,3-butanediol carbonate. Further preferably, the cyclic carbonate may be one or more selected from ethylene carbonate and propylene carbonate.

具体地，链状碳酸酯可选自碳酸甲乙酯、碳酸甲丙酯、碳酸甲基异丙酯、碳酸甲丁酯、碳酸乙丙酯中的一种或几种的非对称链状碳酸酯；链状碳酸酯还可选自碳酸二甲酯、碳酸二乙酯、碳酸二丙酯、碳酸二丁酯中的一种或几种的对称链状碳酸酯；链状碳酸酯还可为上述非对称链状碳酸酯和对称链状碳酸酯的混合物。Specifically, the chain carbonate may be one or more asymmetric chain carbonates selected from ethyl methyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, methyl butyl carbonate, and ethyl propyl carbonate. ; The chain carbonate can also be selected from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, one or more symmetric chain carbonate; the chain carbonate can also be the above A mixture of asymmetric chain carbonates and symmetric chain carbonates.

具体地，羧酸酯可选自新戊酸甲酯、新戊酸乙酯、新戊酸丙酯、新戊酸丁酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸丁酯中的一种或几种。Specifically, the carboxylic acid ester may be selected from methyl pivalate, ethyl pivalate, propyl pivalate, butyl pivalate, methyl butyrate, ethyl butyrate, propyl butyrate, butyric acid One or more of butyl ester, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate.

〔电解质盐〕〔Electrolyte salt〕

在本申请第一方面的电解液中，作为本申请中使用的电解质盐，可以合适地列举出下述的锂盐。In the electrolytic solution of the first aspect of the present application, as the electrolyte salt used in the present application, the following lithium salts can be suitably cited.

〔Li盐－1类〕：可以合适地列举出选自LiPF ₆、LiBF ₄、LiAsF ₆、LiSbF ₆、LiPF ₄(CF ₃) ₂、LiPF ₃(C ₂F ₅) ₃、LiPF ₃(CF ₃) ₃、LiPF ₃(异-C ₃F ₇) ₃和LiPF ₅(异-C ₃F ₇)中的一种或几种的“路易斯酸与LiF的络盐”，其中优选选自LiPF ₆、LiBF ₄、LiAsF ₆，更优选选自LiPF ₆、LiBF ₄。 [Li salt-1]: LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiPF ₄ (CF ₃ ) ₂ , LiPF ₃ (C ₂ F ₅ ) ₃ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ (iso-C ₃ F ₇ ) ₃ and LiPF ₅ (iso-C ₃ F ₇ ) one or more of "Lewis acid and LiF complex salt", which is preferably selected from LiPF ₆ , LiBF ₄ and LiAsF _{6 are} more preferably selected from LiPF ₆ and LiBF ₄ .

〔Li盐－2类〕：可以合适地列举出选自(CF ₂) ₂(SO ₂) ₂NLi(环状)、(CF ₂) ₃(SO ₂) ₂NLi(环状)和LiC(SO ₂CF ₃) ₃中的一种或几种的“亚胺或甲基化锂盐”。 [Li salts-2]: suitably selected from (CF ₂ ) ₂ (SO ₂ ) ₂ NLi (cyclic), (CF ₂ ) ₃ (SO ₂ ) ₂ NLi (cyclic) and LiC (SO one or more of the ₂ CF _{₃₎ 3} "methyl imide or lithium salts."

〔Li盐－3类〕：可以合适地列举出选自LiSO ₃F、LiCF ₃SO ₃、CH ₃SO ₄Li、C ₂H ₅SO ₄Li、C ₃H ₇SO ₄Li、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、五氟((甲磺酰)氧基)磷酸锂(LiPFMSP)中的一种或几种的“含有S(＝O) ₂O结构的锂盐”，其中更优选选自LiSO ₃F、CH ₃SO ₄Li、C ₂H ₅SO ₄Li或LiTFMSB。 [Li salt-3 types]: suitably selected from LiSO ₃ F, LiCF ₃ SO ₃ , CH ₃ SO ₄ Li, C ₂ H ₅ SO ₄ Li, C ₃ H ₇ SO ₄ Li, trifluoro(( One or more of "methanesulfonyl)oxy) lithium borate (LiTFMSB), pentafluoro((methanesulfonyl)oxy) lithium phosphate (LiPFMSP)" lithium salt containing S(=O) ₂ O structure ", wherein it is more preferably selected from LiSO ₃ F, CH ₃ SO ₄ Li, C ₂ H ₅ SO ₄ Li or LiTFMSB.

〔Li盐－4类〕：可以合适地列举出选自LiPO ₂F ₂、Li ₂PO ₃F和LiClO ₄中的一种或几种的“含有P＝O或Cl＝O结构的锂盐”，其中优选选自LiPO ₂F ₂、Li ₂PO ₃F。 [Li salts-4]: One or more "Lithium salts containing P=O or Cl=O structure" selected from one or more of LiPO ₂ F ₂ , Li ₂ PO ₃ F, and LiClO ₄ can be suitably cited , Wherein it is preferably selected from LiPO ₂ F ₂ and Li ₂ PO ₃ F.

〔Li盐－5类〕：可以合适地列举出选自双[草酸根-O,O’]硼酸锂(LiBOB)、二氟[草酸根-O,O’]硼酸锂、二氟双[草酸根-O,O’]磷酸锂(LiPFO)和四氟[草酸根-O,O’]磷酸锂中的一种或几种的“以草酸盐配位体为正离子的锂盐”，其中更优选选自LiBOB、LiPFO。[Li salt-5]: suitably selected from bis[oxalate-O,O'] lithium borate (LiBOB), difluoro[oxalate-O,O'] lithium borate, difluorobis[oxalic acid Root-O,O']Lithium Phosphate (LiPFO) and tetrafluoro[oxalate-O,O']Lithium Phosphate, one or more "lithium salt with oxalate ligand as positive ion", Among them, it is more preferably selected from LiBOB and LiPFO.

上述锂盐可以单独使用或混合使用。其中，优选地，锂盐选自LiPF ₆、LiPO ₂F ₂、Li ₂PO ₃F、LiBF ₄、LiSO ₃F、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、双[草酸根-O,O’]硼酸锂(LiBOB)、二氟双[草酸根-O,O’]磷酸锂(LiPFO)和四氟[草酸根-O,O’]磷酸锂中的一种或几种。进一步优选地，锂盐选自LiPF ₆、LiBF ₄、LiSO ₃F、三氟((甲磺酰)氧基)硼酸锂(LiTFMSB)、LiPO ₂F ₂、双[草酸根-O,O’]硼酸锂(LiBOB)和二氟双[草酸根-O,O’]磷酸锂(LiPFO)中的一种或几种。更进一步优选地，锂盐为LiPF ₆。 The above lithium salts can be used alone or in combination. Among them, preferably, the lithium salt is selected from LiPF ₆ , LiPO ₂ F ₂ , Li ₂ PO ₃ F, LiBF ₄ , LiSO ₃ F, trifluoro((methanesulfonyl)oxy) lithium borate (LiTFMSB), bis[oxalic acid One or more of lithium-O,O'] lithium borate (LiBOB), difluorobis[oxalate-O,O'] lithium phosphate (LiPFO) and tetrafluoro[oxalate-O,O'] lithium phosphate Species. Further preferably, the lithium salt is selected from LiPF ₆ , LiBF ₄ , LiSO ₃ F, trifluoro((methanesulfonyl)oxy) lithium borate (LiTFMSB), LiPO ₂ F ₂ , bis[oxalate-O,O'] One or more of lithium borate (LiBOB) and difluorobis[oxalate-O,O'] lithium phosphate (LiPFO). Even more preferably, the lithium salt is LiPF ₆ .

在本申请第一方面的电解液中，所述电解液的制备方法不受限制，可按照常规电解液的方法制备。In the electrolyte of the first aspect of the present application, the preparation method of the electrolyte is not limited, and can be prepared according to a conventional electrolyte method.

在本申请第一方面的电解液中，优选地，所述电解液25℃的电导率为4mS/cm～12mS/cm。In the electrolyte of the first aspect of the present application, preferably, the electrolyte has a conductivity of 4 mS/cm to 12 mS/cm at 25°C.

在本申请第一方面的电解液中，所述添加剂A可通过下述方法合成。In the electrolyte of the first aspect of the present application, the additive A can be synthesized by the following method.

(1)式I-1所示的化合物的制备(1) Preparation of compound represented by formula I-1

反应方程式为：The reaction equation is:

具体制备工艺为：The specific preparation process is:

在20min～60min内向原料P-1中滴加浓度为30％～40％的P-2水溶液并快速搅拌，滴加完毕后快速搅拌15h～30h，于70℃～90℃油浴回流搅拌3h～5h，得到无色发烟粘稠状液体中间产物I-1-1；继续加入K ₂CO ₃、KI、无水乙腈，快速搅拌成固液混合相，于40℃～60℃下快速加入原料P-3，继续搅拌10h～20h后冷却至室温，分离提纯得到式I-1所示的化合物。 P20 aqueous solution with a concentration of 30% to 40% is added dropwise to the raw material P-1 within 20min to 60min and quickly stirred. After the completion of the dropwise addition, the solution is rapidly stirred for 15h to 30h, and stirred at 70°C to 90°C in an oil bath under reflux for 3h. 5h, to obtain colorless fuming viscous liquid intermediate product I-1-1; continue to add K ₂ CO ₃ , KI, anhydrous acetonitrile, quickly stir to form a solid-liquid mixed phase, quickly add raw materials at 40 ℃ ~ 60 ℃ P-3, continue to stir for 10h-20h, then cool to room temperature, and separate and purify to obtain the compound represented by Formula I-1.

(2)式I-2所示的化合物的制备(2) Preparation of the compound represented by formula I-2

反应方程式为：The reaction equation is:

具体制备工艺为：The specific preparation process is:

将无水碳酸钠、原料P-4与原料P-3在无水乙醇中混合，反应搅拌2h～5h；热乙醇反复多次冲洗得到粗产物，重结晶得到式I-2所示的化合物。The anhydrous sodium carbonate, the raw material P-4 and the raw material P-3 are mixed in absolute ethanol, and the reaction is stirred for 2h to 5h; the hot ethanol is repeatedly washed several times to obtain a crude product, and the compound represented by the formula I-2 is obtained by recrystallization.

(3)式I-3所示的化合物的制备(3) Preparation of the compound represented by formula I-3

反应方程式为：The reaction equation is:

具体制备工艺为：The specific preparation process is:

将无水碳酸钠、原料P-5与原料P-3在无水乙醇中混合，反应搅拌2h～5h；热乙醇反复多次冲洗得到粗产物，重结晶得到式I-3所示的化合物。The anhydrous sodium carbonate, the raw material P-5 and the raw material P-3 are mixed in absolute ethanol, and the reaction is stirred for 2h to 5h; the hot ethanol is repeatedly washed many times to obtain a crude product, and the compound represented by formula I-3 is obtained by recrystallization.

其次说明根据本申请第二方面的电池。Next, the battery according to the second aspect of the present application will be described.

根据本申请第二方面的电池包括电极组件以及根据本申请第一方面所述的电解液，所述电极组件包括正极极片、负极极片以及隔离膜。需要说明的是，根据本申请第二方面的电池可为锂离子电池、钠离子电池或镁离子电池。The battery according to the second aspect of the present application includes an electrode assembly and the electrolyte according to the first aspect of the present application, the electrode assembly includes a positive pole piece, a negative pole piece, and a separator. It should be noted that the battery according to the second aspect of the present application may be a lithium ion battery, a sodium ion battery, or a magnesium ion battery.

当电池为锂离子电池时，正极极片包含能脱出、嵌入锂离子的正极活性材料，负极极片包含能嵌入、脱出锂离子的负极活性材料。When the battery is a lithium ion battery, the positive pole piece contains a positive electrode active material capable of detaching and intercalating lithium ions, and the negative pole piece contains a negative electrode active material capable of intercalating and detaching lithium ions.

具体的，当电池为锂离子电池时，正极活性材料包括Li _x1Co _y1M _1-y1O _2-z1Q _z1，0.5≤x1≤1.2，0.8≤y1<1.0，0≤z1≤0.1，M选自Al、Ti、Zr、Y、Mg中的一种或几种，Q选自F、Cl、S中的一种或几种。当使用包含金属离子M掺杂的钴酸锂材料Li _x1Co _y1M _1-y1O _2-z1Q _z1的正极活性材料时，掺杂元素M在钴酸锂材料中充当骨架，可以减小钴酸锂材料深度脱锂过程中的晶格形变量，延缓钴酸锂材料体相结构的退化，改善锂离子电池在大于4.2V高电压下使用时的结构稳定性。正极活性材料还可包括锂镍氧化物、锂锰氧化物、锂镍锰氧化物、锂镍钴锰氧化物、锂镍钴铝氧化物、前述这些氧化物添加其他过渡金属或非过渡金属得到的化合物中的一种或几种。 Specifically, when the battery is a lithium ion battery, the positive electrode active material includes Li _x1 Co _y1 M _1-y1 O _2-z1 Q _z1 , 0.5≤x1≤1.2, 0.8≤y1<1.0, 0≤z1≤0.1, M is selected From one or more of Al, Ti, Zr, Y, and Mg, Q is selected from one or more of F, Cl, and S. When a positive electrode active material containing lithium cobalt oxide material Li _x1 Co _y1 M _1-y1 O _2-z1 Q _z1 doped with metal ion M is used, the doping element M acts as a skeleton in the lithium cobalt oxide material, which can reduce cobalt The lattice shape variation during the deep delithiation of the lithium acid material delays the degradation of the bulk structure of the lithium cobaltate material and improves the structural stability of the lithium ion battery when it is used at a high voltage greater than 4.2V. The positive electrode active material may also include lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, the foregoing oxides obtained by adding other transition metals or non-transition metals One or more of the compounds.

具体的，当电池为锂离子电池时，负极活性材料包括软碳、硬碳、人造石墨、天然石墨、Si、SiO _x2、Si/C复合材料、Si合金、钛酸锂、能与锂形成合金的金属中的一种或几种，0<x2≤2。 Specifically, when the battery is a lithium ion battery, the negative electrode active material includes soft carbon, hard carbon, artificial graphite, natural graphite, Si, SiO _x2 , Si/C composite material, Si alloy, lithium titanate, and can form an alloy with lithium One or more of the metals, 0<x2≤2.

当电池为钠离子电池时，正极极片包含能脱出、嵌入钠离子的正极活性材料，负极极片包含能嵌入、脱出钠离子的负极活性材料。When the battery is a sodium ion battery, the positive pole piece contains a positive active material that can be extracted and inserted into sodium ions, and the negative pole piece contains a negative active material that can be inserted and extracted from sodium ions.

具体地，正极活性材料可以选自钠铁复合氧化物(NaFeO ₂)、钠钴复合氧化物(NaCoO ₂)、钠铬复合氧化物(NaCrO ₂)、钠锰复合氧化物(NaMnO ₂)、钠镍复合氧化物(NaNiO ₂)、钠镍钛复合氧化物(NaNi _1/2Ti _1/2O ₂)、钠镍锰复合氧化物(NaNi _1/2Mn _1/2O ₂)、钠铁锰复合氧化物(Na _2/3Fe _1/3Mn _2/3O ₂)、钠镍钴锰复合氧化物(NaNi _1/3Co _1/3Mn _1/3O ₂)、钠铁磷酸化合物(NaFePO ₄)、钠锰磷酸化合物(NaMnPO ₄)、钠钴磷酸化合物(NaCoPO ₄)等。但本申请并不限定于这些材料，本申请还可以使用其他可被用作钠离子电池正极活性材料的传统公知的材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。 Specifically, the positive electrode active material may be selected from sodium iron composite oxide (NaFeO ₂ ), sodium cobalt composite oxide (NaCoO ₂ ), sodium chromium composite oxide (NaCrO ₂ ), sodium manganese composite oxide (NaMnO ₂ ), sodium Nickel composite oxide (NaNiO ₂ ), sodium nickel titanium composite oxide (NaNi _1/2 Ti _1/2 O ₂ ), sodium nickel manganese composite oxide (NaNi _1/2 Mn _1/2 O ₂ ), sodium iron manganese Composite oxide (Na _2/3 Fe _1/3 Mn _2/3 O ₂ ), sodium nickel cobalt manganese composite oxide (NaNi _1/3 Co _1/3 Mn _1/3 O ₂ ), sodium iron phosphate compound (NaFePO ₄ ), sodium manganese phosphate compound (NaMnPO ₄ ), sodium cobalt phosphate compound (NaCoPO ₄ ), etc. However, this application is not limited to these materials, and this application may also use other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination.

具体地，负极活性材料可以选自硬碳、天然石墨、人造石墨、软碳、炭黑、乙炔黑、碳纳米管、石墨烯、碳纳米纤维等碳材料。此外，作为其他负极活性材料，还可以列举出例如Si、Ge、Pb、In、Zn、H、Ca、Sr、Ba、Ru、Rh等与钠发生合金化的元素的单质、含这些元素的氧化物以及碳化物等。但并不限定于这些材料，本申请还可以使用其他可被用作钠离子电池负极活性材料的传统公知的材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。Specifically, the negative electrode active material may be selected from hard carbon, natural graphite, artificial graphite, soft carbon, carbon black, acetylene black, carbon nanotubes, graphene, carbon nanofibers, and other carbon materials. In addition, examples of other negative electrode active materials include elements such as Si, Ge, Pb, In, Zn, H, Ca, Sr, Ba, Ru, and Rh which are alloyed with sodium, and oxidation containing these elements And carbides. However, it is not limited to these materials, and other conventionally known materials that can be used as negative electrode active materials for sodium ion batteries can also be used in this application. Only one type of these negative electrode active materials may be used alone, or two or more types may be used in combination.

当电池为镁离子电池时，正极极片包含能脱出、嵌入镁离子的正极活性材料，负极极片包含能嵌入、脱出镁离子的负极活性材料。例如，正极活性材料可以选自V ₂O ₅、MoO ₃、MnO ₂、TiS ₂、MoS ₂等，负极活性材料可以选自金属镁、镁合金、石墨等。但并不限定于这些材料，本申请还可以使用其他可被用作镁离子电池正负极活性材料的传统公知的材料。这些正负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。 When the battery is a magnesium ion battery, the positive pole piece contains a positive active material that can be extracted and inserted into magnesium ions, and the negative pole piece contains a negative active material that can be inserted and extracted from magnesium ions. For example, the positive electrode active material may be selected from V ₂ O ₅ , MoO ₃ , MnO ₂ , TiS ₂ , MoS ₂ and the like, and the negative electrode active material may be selected from metal magnesium, magnesium alloy, graphite and the like. However, it is not limited to these materials, and other conventionally known materials that can be used as positive and negative electrode active materials for magnesium ion batteries can also be used in this application. Only one type of these positive and negative electrode active materials may be used alone, or two or more types may be used in combination.

在本申请第二方面的电池中，所述隔离膜设置在正极极片和负极极片之间，起到隔离作用。所述隔离膜的具体种类并不受到具体的限制，可以是现有电池中使用的任何隔离膜材料，例如聚乙烯、聚丙烯、聚偏氟乙烯以及它们的多层复合膜，但不仅限于这些。In the battery of the second aspect of the present application, the separator is provided between the positive pole piece and the negative pole piece to play a role of isolation. The specific type of the separator is not specifically limited, and may be any separator material used in existing batteries, such as polyethylene, polypropylene, polyvinylidene fluoride, and their multilayer composite films, but not limited to these .

在本申请第二方面的电池中，所述正极极片还包括粘结剂和导电剂。将包含有正极活性材料、粘结剂和导电剂的正极浆料涂覆在正极集流体上，待正极浆料干燥后获得正极极片。导电剂以及粘结剂的种类和含量不受具体的限制，可根据实际需求进行选择。正极集流体的种类也不受具体的限制，可根据实际需求进行选择。In the battery of the second aspect of the present application, the positive pole piece further includes a binder and a conductive agent. The positive electrode slurry containing the positive electrode active material, the binder and the conductive agent is coated on the positive electrode current collector, and the positive electrode sheet is obtained after the positive electrode slurry is dried. The types and contents of conductive agent and binder are not specifically limited, and can be selected according to actual needs. The type of positive electrode current collector is also not subject to specific restrictions, and can be selected according to actual needs.

同样的，所述负极极片还包括粘结剂和导电剂。将包含有负极活性材料、粘结剂和导电剂的负极浆料涂覆在负极集流体上，待负极浆料干燥后获得负极极片。导电剂以及粘结剂的种类和含量不受具体的限制，可根据实际需求进行选择。负极集流体的种类也不受具体的限制，可根据实际需求进行选择。Similarly, the negative pole piece further includes a binder and a conductive agent. The negative electrode slurry containing the negative electrode active material, the binder and the conductive agent is coated on the negative electrode current collector, and the negative electrode sheet is obtained after the negative electrode slurry is dried. The types and contents of conductive agent and binder are not specifically limited, and can be selected according to actual needs. The type of negative electrode current collector is not subject to specific restrictions, and can be selected according to actual needs.

在本申请第二方面的电池中，电池的充电截止电压可不小于4.2V，即电池可在不小于4.2V的高电压状态下使用。在高电压状态下，正极活性材料表面过渡金属的价态越高，与添加剂A中腈基的库仑相互作用便越强，也即添加剂A能够越大程度地发挥相应的保护作用。优选地，电池可在4.2V～4.9V范围内工作，进一步优选地，电池可在4.3V～4.8V范围内工作。In the battery of the second aspect of the present application, the charge cut-off voltage of the battery may be not less than 4.2V, that is, the battery may be used in a high voltage state not less than 4.2V. In the high-voltage state, the higher the valence state of the transition metal on the surface of the positive electrode active material, the stronger the Coulomb interaction with the nitrile group in the additive A, that is, the greater the degree of additive A's corresponding protection. Preferably, the battery can operate in the range of 4.2V to 4.9V, and further preferably, the battery can operate in the range of 4.3V to 4.8V.

本申请第二方面的电池可以包括外包装，用于封装正极极片、负极极片和电解液。作为一个示例，正极极片、负极极片和隔离膜可经叠片或卷绕形成叠片结构电极组件或卷绕结构电极组件，电极组件封装在外包装内；电解液浸润于电极组件中。电池中电极组件的数量可以为一个或几个，可以根据需求来调节。The battery of the second aspect of the present application may include an outer package for encapsulating the positive pole piece, the negative pole piece and the electrolyte. As an example, the positive electrode sheet, the negative electrode sheet, and the separator may be laminated or wound to form a laminated structure electrode assembly or a wound structure electrode assembly. The electrode assembly is packaged in an outer package; the electrolyte is infiltrated into the electrode assembly. The number of electrode assemblies in the battery can be one or several, which can be adjusted according to requirements.

本申请第二方面的电池既可为硬壳外包装，也可为软包装。硬壳外包装优选使用金属材质的硬壳(例如铝壳、钢壳等)。软包装优选使用包装袋作为电池外包装，所述包装袋通常包括容纳部和密封部，其中容纳部用于容纳电极组件和电解液，而密封部用于将电极组件和电解液密封。The battery of the second aspect of the present application may be either a hard case outer package or a flexible package. It is preferable to use a metal hard shell (for example, aluminum shell, steel shell, etc.) for the hard shell outer packaging. The flexible packaging preferably uses a packaging bag as the battery outer packaging. The packaging bag generally includes an accommodating portion and a sealing portion, wherein the accommodating portion is used to accommodate the electrode assembly and the electrolyte, and the sealing portion is used to seal the electrode assembly and the electrolyte.

本申请第一方面所述的电解液对于软包装电池性能的改善更明显，原因在于软包装电池在使用时很容易发生鼓胀，而本申请可以极大降低电池产气量，避免软包装电池鼓胀造成寿命缩短。The electrolyte described in the first aspect of the present application improves the performance of the flexible package battery more obviously, because the flexible package battery is prone to swell when in use, and this application can greatly reduce the gas production of the battery and avoid the shortening of the life of the flexible package battery.

本申请对电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。如图4是作为一个示例的方形结构的电池5。There is no particular limitation on the shape of the battery in this application, and it may be cylindrical, square, or any other shape. FIG. 4 is a battery 5 of a square structure as an example.

在一些实施例中，电池可以组装成电池模块，电池模块所含电池的数量可以为多个，具体数量可根据电池模块的应用和容量来调节。In some embodiments, the battery may be assembled into a battery module, and the number of batteries contained in the battery module may be multiple, and the specific number may be adjusted according to the application and capacity of the battery module.

图5是作为一个示例的电池模块4。参照图5，在电池模块4中，多个电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个电池5进行固定。FIG. 5 is a battery module 4 as an example. Referring to FIG. 5, in the battery module 4, a plurality of batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, it can also be arranged in any other way. Further, the plurality of batteries 5 can be fixed by fasteners.

可选地，电池模块4还可以包括具有容纳空间的壳体，多个电池5容纳于该容纳空间。Optionally, the battery module 4 may further include a housing having an accommodating space, and a plurality of batteries 5 are accommodated in the accommodating space.

在一些实施例中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以根据电池包的应用和容量进行调节。In some embodiments, the above battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.

图6和图7是作为一个示例的电池包1。参照图6和图7，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。6 and 7 are battery packs 1 as an example. 6 and 7, the battery pack 1 may include a battery box and a plurality of battery modules 4 provided in the battery box. The battery case includes an upper case 2 and a lower case 3. The upper case 2 can be covered on the lower case 3 and forms an enclosed space for accommodating the battery module 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.

接下来说明本申请第三方面的装置。Next, the device of the third aspect of the present application will be described.

在本申请第三方面提供一种装置，所述装置包括本申请第二方面的电池，所述电池为所述装置提供电源。所述装置可以但不限于是移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能***等。In a third aspect of the present application, an apparatus is provided. The apparatus includes the battery of the second aspect of the present application, and the battery provides power for the apparatus. The device may be, but not limited to, mobile equipment (such as mobile phones, notebook computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf balls) Vehicles, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

所述装置可以根据其使用需求来选择电池、电池模块或电池包。The device can select a battery, battery module or battery pack according to its usage requirements.

图8是作为一个示例的装置。该装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该装置对电池的高功率和高能量密度的需求，可以采用电池包或电池模块。FIG. 8 is a device as an example. The device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. In order to meet the requirements of the device for high power and high energy density of the battery, a battery pack or battery module may be used.

作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用电池作为电源。As another example, the device may be a mobile phone, a tablet computer, a notebook computer, or the like. The device is usually required to be thin and light, and a battery can be used as a power source.

为了使本申请的目的、技术方案和有益技术效果更加清晰，以下结合实施例，对本申请进行进一步详细说明。应当理解的是，本说明书中描述的实施例仅仅是为了解释本申请，并非为了限定本申请，实施例的配方、比例等可因地制宜做出选择而对结果并无实质性影响。In order to make the purpose, technical solutions and beneficial technical effects of the present application clearer, the following describes the present application in further detail with reference to the embodiments. It should be understood that the embodiments described in this specification are only for explaining the application, not for limiting the application. The formulations, proportions, etc. of the embodiments can be selected according to local conditions and have no substantial effect on the results.

在本申请的下述具体实施例中，仅示出电池为锂离子电池的实施例，但本申请不限于此。在实施例、对比例中，所使用到的试剂、材料以及仪器如没有特殊的说明，均可商购获得。其中添加剂A1、A2、A3的具体合成过程如下，其它种类的添加剂A均可根据类似的方法合成。In the following specific embodiments of the present application, only embodiments in which the battery is a lithium ion battery are shown, but the present application is not limited to this. In the examples and comparative examples, the reagents, materials and instruments used are commercially available unless otherwise specified. The specific synthesis process of additives A1, A2, and A3 is as follows. Other types of additives A can be synthesized according to similar methods.

添加剂A1的合成：Synthesis of additive A1:

在0.5h内向1,3-丙二胺中滴加37％甲醛水溶液并快速搅拌，滴加完毕后继续快速搅拌20h，之后于80℃油浴回流搅拌4h，得到无色发烟粘稠状液体中间产物六氢嘧啶；继续加入K ₂CO ₃、KI、无水乙腈，快速搅拌成固液混合相，之后于60℃下0.5h内加入β-氯丙腈，继续搅拌17h后冷却至室温，分离提纯得到A1。核磁共振碳谱如图1所示。 Add dropwise 37% formaldehyde aqueous solution to 1,3-propanediamine within 0.5h and quickly stir. After the addition is complete, continue to stir rapidly for 20h, then stir at 80°C oil bath under reflux for 4h, to obtain a colorless fuming viscous liquid Intermediate product hexahydropyrimidine; continue to add K ₂ CO ₃ , KI, anhydrous acetonitrile, and quickly stir to form a solid-liquid mixed phase, then add β-chloropropionitrile within 0.5 h at 60°C, continue stirring for 17 h, then cool to room temperature, Separation and purification to obtain A1. The NMR carbon spectrum is shown in Figure 1.

添加剂A2的合成：Synthesis of Additive A2:

将无水碳酸钠、哌嗪与β-氯丙腈在无水乙醇中混合，反应搅拌4h；热乙醇反复多次冲洗得到粗产物，重结晶得到A2。核磁共振碳谱如图2所示。Anhydrous sodium carbonate, piperazine and β-chloropropionitrile were mixed in absolute ethanol, and the reaction was stirred for 4h; the hot ethanol was repeatedly washed many times to obtain the crude product, and recrystallized to obtain A2. The NMR carbon spectrum is shown in Figure 2.

添加剂A3的合成：Synthesis of Additive A3:

将无水碳酸钠、1,3,5-均三嗪与氯乙腈在无水乙醇中混合，反应搅拌4h；热乙醇反复多次冲洗得到粗产物，重结晶得到A3。核磁共振碳谱如图3所示。Anhydrous sodium carbonate, 1,3,5-s-triazine and chloroacetonitrile were mixed in absolute ethanol, and the reaction was stirred for 4h; the hot ethanol was washed repeatedly for many times to obtain the crude product, and A3 was obtained by recrystallization. The NMR carbon spectrum is shown in Figure 3.

在实施例1-24和对比例1-2中，电池均按照下述方法制备。In Examples 1-24 and Comparative Examples 1-2, batteries were prepared according to the following methods.

(1)电解液的制备(1) Preparation of electrolyte

采用碳酸乙烯酯(简称为EC)、碳酸甲乙酯(简称为EMC)和碳酸二乙酯(简称为DEC)的混合液为有机溶剂，其中，EC、EMC和DEC的质量比为1:1:1。锂盐为LiPF ₆，LiPF ₆的含量为电解液总质量的12.5％。按照如表1所示的电解液组成加入各添加剂，其中各添加剂组分的含量均为相对于电解液的总质量计算得到。 A mixed solution of ethylene carbonate (abbreviated as EC), ethyl methyl carbonate (abbreviated as EMC) and diethyl carbonate (abbreviated as DEC) is used as an organic solvent, wherein the mass ratio of EC, EMC and DEC is 1:1 :1. The lithium salt is LiPF ₆ , and the content of LiPF ₆ is 12.5% of the total mass of the electrolyte. Each additive is added according to the electrolyte composition shown in Table 1, wherein the content of each additive component is calculated relative to the total mass of the electrolyte.

其中，在实施例和对比例中所使用的添加剂A和添加剂B分别简写为：Among them, the additives A and B used in the examples and comparative examples are abbreviated as:

(2)正极极片的制备(2) Preparation of positive pole pieces

将表1所示的正极活性材料、粘结剂PVDF、导电剂乙炔黑按照质量比98:1:1混合，加入N-甲基吡咯烷酮，在真空搅拌机作用下搅拌至稳定均一，获得正极浆料；将正极浆料均匀涂覆于铝箔上；将铝箔在室温晾干后转移至120℃的鼓风烘箱中干燥1h，然后经过冷压、分切得到正极极片。The positive electrode active material shown in Table 1, the binder PVDF, and the conductive agent acetylene black were mixed according to a mass ratio of 98:1:1, N-methylpyrrolidone was added, and stirred under the action of a vacuum mixer until stable and uniform, to obtain a positive electrode slurry ; Evenly coat the positive electrode slurry on the aluminum foil; dry the aluminum foil at room temperature and transfer to a 120°C blast oven to dry for 1h, and then cold press and cut to obtain the positive pole piece.

(3)负极极片的制备(3) Preparation of negative pole pieces

将负极活性材料石墨、导电剂乙炔黑、增稠剂羧甲基纤维素钠溶液、粘结剂丁苯橡胶乳液按照质量比97:1:1:1混合，加入去离子水，在真空搅拌机作用下搅拌至稳定均一，获得负极浆料；将负极浆料均匀涂覆于铜箔上；将铜箔在室温晾干后转移至120℃的鼓风烘箱中干燥1h，然后经过冷压、分切得到负极极片。Mix the negative electrode active material graphite, the conductive agent acetylene black, the thickener sodium carboxymethyl cellulose solution, the binder styrene-butadiene rubber emulsion according to the mass ratio of 97:1:1:1, add deionized water, and act in a vacuum mixer Stir under stirring until it is stable and uniform to obtain the negative electrode slurry; apply the negative electrode slurry evenly on the copper foil; dry the copper foil at room temperature and transfer to a 120°C blast oven for 1 hour, and then cold press and cut A negative pole piece is obtained.

(4)锂离子电池的制备(4) Preparation of lithium ion batteries

将正极极片、负极极片以及PP/PE/PP隔离膜进行卷绕得到电极组件，将电极组件放入包装袋铝塑膜中，之后注入电解液，再依次经过封口、静置、热冷压、化成、排气、测试容量等工序，获得锂离子电池。Wind the positive pole piece, the negative pole piece and the PP/PE/PP separator to obtain the electrode assembly, put the electrode assembly into the aluminum-plastic film of the packaging bag, then inject the electrolyte, and then pass through sealing, standing, hot cooling Pressure, formation, exhaust, test capacity and other processes to obtain lithium-ion batteries.

表1 实施例1-24和对比例1-2的电解液参数Table 1 Electrolyte parameters of Examples 1-24 and Comparative Examples 1-2

下面说明锂离子电池的测试过程。The test procedure of the lithium ion battery is explained below.

(1)锂离子电池在常温、高电压情况下的循环性能测试(1) Cycling performance test of lithium-ion battery at normal temperature and high voltage

在25℃下，将锂离子电池先以1C恒流充电至电压为4.35V，进一步以4.35V恒压充电至电流为0.05C，然后以1C恒流放电至电压为3.0V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。将锂离子电池按照上述方法进行200次循环充电/放电测试，检测得到第200次循环的放电容量。At 25 ℃, the lithium ion battery is first charged with a constant current of 1C to a voltage of 4.35V, further charged with a constant voltage of 4.35V to a current of 0.05C, and then discharged with a constant current of 1C to a voltage of 3.0V, which is a charge During the discharge cycle, the current discharge capacity is the first cycle discharge capacity. The lithium-ion battery was subjected to 200 cycles of charge/discharge test according to the above method, and the discharge capacity at the 200th cycle was detected.

锂离子电池循环200次后的容量保持率(％)＝(锂离子电池循环200次的放电容量/锂离子电池首次循环的放电容量)×100％。Capacity retention rate (%) after 200 cycles of the lithium ion battery = (discharge capacity of the lithium ion battery after 200 cycles/discharge capacity of the first cycle of the lithium ion battery)×100%.

(2)锂离子电池在高温、高电压情况下的循环性能测试(2) Cycling performance test of lithium ion battery under high temperature and high voltage

在45℃下，将锂离子电池先以1C恒流充电至电压为4.35V，进一步以4.35V恒压充电至电流为0.05C，然后以1C恒流放电至电压为3.0V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。将锂离子电池按照上述方法进行200次循环充电/放电测试，检测得到第200次循环的放电容量。At 45 ℃, the lithium ion battery is first charged with a constant current of 1C to a voltage of 4.35V, further charged with a constant voltage of 4.35V to a current of 0.05C, and then discharged with a constant current of 1C to a voltage of 3.0V, which is a charge During the discharge cycle, the current discharge capacity is the first cycle discharge capacity. The lithium-ion battery was subjected to 200 cycles of charge/discharge test according to the above method, and the discharge capacity at the 200th cycle was detected.

(3)锂离子电池在高温情况下的存储性能测试(3) Storage performance test of lithium ion battery under high temperature

在25℃下，将锂离子电池以0.5C恒流充电至电压为4.35V，然后以4.35V恒压充电至电流为0.05C，此时测试锂离子电池的厚度并记为h ₀；之后将锂离子电池放入85℃的恒温箱，存储24h后取出，测试此时锂离子电池的厚度并记为h ₁。 At 25°C, charge the lithium ion battery at a constant current of 0.5C to a voltage of 4.35V, and then charge it at a constant voltage of 4.35V to a current of 0.05C. At this time, test the thickness of the lithium ion battery and record it as h ₀ ; The lithium-ion battery is placed in a constant temperature box at 85°C, and is taken out after storing for 24 hours. At this time, the thickness of the lithium-ion battery is tested and recorded as h ₁ .

锂离子电池85℃存储24h后的厚度膨胀率(％)＝[(h ₁-h ₀)/h ₀]×100％。 Lithium-ion battery thickness expansion rate (%) after storage at 85°C for 24 hours = [(h ₁ -h ₀ )/h ₀ ]×100%.

表2 实施例1-24和对比例1-2的性能测试结果Table 2 Performance test results of Examples 1-24 and Comparative Examples 1-2

从实施例1-24和对比例1-2的对比中可以看出：在电解液中加入本申请的组合添加剂后可显著提高锂离子电池在高温高电压情况下的循环性能和存储性能。It can be seen from the comparison between Examples 1-24 and Comparative Examples 1-2 that the combination performance of the lithium ion battery under high temperature and high voltage can be significantly improved by adding the combined additive of the present application to the electrolyte.

与对比例1未加入添加剂相比，本申请的电解液包含添加剂A和添加剂B的组合添加剂。其中，添加剂A为氧化电位较低的多腈基六元氮杂环化合物，其在电池化成时便能在正极活性材料表面形成稳定的络合物层，有效钝化正极活性材料表面，降低正极活性材料表面活性，隔绝电解液与正极活性材料表面的直接接触，使得表面副反应大大减少，副反应中消耗的锂离子也就相应减少，也就是可逆锂离子的消耗速度大大减慢，最终显现出来的实际效果是锂离子电池循环容量保持率大幅提升；部分表面副反应可产生气体，表面副反应的减少还意味着电池产气量减少，最终显现出来的实际效果是高温下锂离子电池厚度膨胀明显减轻。添加剂B为具有醚键的二腈或多腈类化合物，其能长久稳定地存在于电解液中，随时修补循环或高温存储过程中遭到破坏的络合物层(由添加剂A形成)，减少过渡金属离子溶出，大大降低过渡金属溶出后沉积在负极对SEI膜的破坏；该类分子醚基中的氧(-O-)会与电解液中痕量的PF ₅、HF发生反应，阻止PF ₅、HF对未形成络合物层而直接暴露于电解液环境中的正极活性材料表面的腐蚀，使正极活性材料表面在循环和存储过程中的耐久度更佳。由此，本申请的电解液能显著提高锂离子电池在高温高电压情况下的循环性能和存储性能。 Compared with Comparative Example 1 in which no additives are added, the electrolyte of the present application contains the combined additive of additive A and additive B. Among them, the additive A is a polynitrile six-membered nitrogen heterocyclic compound with a low oxidation potential, which can form a stable complex layer on the surface of the positive electrode active material when the battery is formed, effectively passivating the surface of the positive electrode active material and reducing the positive electrode The surface activity of the active material isolates the direct contact between the electrolyte and the surface of the positive electrode active material, which greatly reduces the surface side reactions, and the lithium ions consumed in the side reactions are correspondingly reduced, that is, the consumption rate of reversible lithium ions is greatly reduced, and finally appears The actual effect is that the lithium-ion battery cycle capacity retention rate has been greatly improved; some surface side reactions can produce gas, and the reduction of surface side reactions also means that the battery gas production is reduced. The actual effect finally revealed is the thickness expansion of the lithium-ion battery at high temperature. Significantly reduced. Additive B is a dinitrile or polynitrile compound with an ether bond, which can stably exist in the electrolyte for a long time, and can repair the complex layer (formed by additive A) that is damaged during cycling or high-temperature storage at any time, reducing The dissolution of transition metal ions greatly reduces the damage of the SEI film deposited on the negative electrode after the transition metal dissolution; the oxygen (-O-) in this type of molecular ether group will react with trace amounts of PF ₅ and HF in the electrolyte to prevent PF _5. Corrosion of the surface of the positive electrode active material that is directly exposed to the electrolyte environment without forming a complex layer by HF makes the surface of the positive electrode active material more durable during cycling and storage. Therefore, the electrolyte of the present application can significantly improve the cycle performance and storage performance of the lithium ion battery under high temperature and high voltage.

而与对比例2仅采用线性的腈基化合物相比，本申请的多腈基六元氮杂环化合物具有特殊的六元氮杂环结构，腈基与腈基的间距更接近正极活性材料表面过渡金属与过渡金属的间距，可以最大限度地发挥腈基的络合作用，且使更多数量的腈基发挥络合作用。因此本申请的多腈基六元氮杂环化合物对正极活性材料表面过渡金属的覆盖作用更强，对正极活性材料表面具有更好的钝化效果，对锂离子电池循环性能和存储性能的改善效果也更加出众。Compared with the linear nitrile compound in Comparative Example 2, the polynitrile six-membered nitrogen heterocyclic compound of the present application has a special six-membered nitrogen heterocyclic structure, and the distance between the nitrile group and the nitrile group is closer to the surface of the positive electrode active material The distance between the transition metal and the transition metal can maximize the complexation of the nitrile group, and allow a greater number of nitrile groups to exert the complexation. Therefore, the polynitrile six-membered nitrogen heterocyclic compound of the present application has a stronger covering effect on the transition metal on the surface of the positive electrode active material, has a better passivation effect on the surface of the positive electrode active material, and improves the cycle performance and storage performance of the lithium ion battery The effect is also more outstanding.

与对比例1和对比例2相比，本申请的实施例还使用了金属离子M掺杂的钴酸锂材料Li _x1Co _y1M _1-y1O _2-z1Q _z1作为正极活性材料，掺杂元素M在正极活性材料中充当骨架，可以减小正极活性材料深度脱锂过程中的晶格形变量，延缓正极活性材料体相结构的退化，大大改善锂离子电池在高电压情况下使用时的结构稳定性。 Compared with Comparative Example 1 and Comparative Example 2, the examples of the present application also use metal ion M-doped lithium cobaltate material Li _x1 Co _y1 M _1-y1 O _2-z1 Q _z1 as the positive electrode active material, doped Element M serves as a skeleton in the positive electrode active material, which can reduce the lattice deformation of the positive electrode active material during the deep delithiation process, delay the degradation of the bulk structure of the positive electrode active material, and greatly improve the lithium ion battery when used at high voltage Structural stability.

从实施例1-7可以看出，随着添加剂A加入量的增加(0.1％增至10.0％)，在充电截止电压固定为4.35V的情况下，锂离子电池在25℃和45℃时的循环容量保持率达到最佳后又出现了下降的趋势，85℃存储24h厚度膨胀率一直减小。这充电截当添加剂A的加入量较多时，首先添加剂A吸附在正极活性材料表面形成的络合物层容易更厚和致密，影响锂离子的扩散迁移，正极阻抗大幅增高；其次添加剂A在形成络合物层的同时会消耗锂离子，导致可用于循环的锂离子减少；最后添加剂A较高的加入量会引起电解液整体黏度提升、离子电导率下降，最终锂离子电池在25℃和45℃时的循环容量保持率达到最佳后出现了下降的趋势。因此，添加剂A的加入量需要适量，优选为0.1％～10.0％，更优选为0.1％～3.5％。It can be seen from Examples 1-7 that with the increase in the amount of additive A added (0.1% to 10.0%), when the charge cut-off voltage is fixed at 4.35V, the lithium ion battery at 25 ℃ and 45 ℃ After the cycle capacity retention rate reached the optimal level, there was a downward trend again, and the thickness expansion rate at 85°C for 24 hours kept decreasing. When the addition amount of additive A is large, first, the complex layer formed by additive A adsorbed on the surface of the positive electrode active material is easy to be thicker and denser, which affects the diffusion and migration of lithium ions, and the impedance of the positive electrode is greatly increased; secondly, additive A is formed At the same time, the complex layer will consume lithium ions, resulting in the reduction of lithium ions that can be used for recycling. Finally, the higher amount of additive A will cause the overall viscosity of the electrolyte to increase and the ion conductivity to decrease. Finally, the lithium ion battery is at 25 ℃ and 45 The cycle capacity retention rate at ℃ showed a downward trend after reaching the best. Therefore, an appropriate amount of the additive A needs to be added, preferably 0.1% to 10.0%, and more preferably 0.1% to 3.5%.

从实施例8-14可以看出，随着添加剂B加入量的增加(0.1％增至10.0％)，在充电截止电压固定为4.35V的情况下，锂离子电池在25℃和45℃时的循环容量保持率达到最佳后又出现了下降的趋势，85℃存储24h厚度膨胀率一直减小。这是由于添加剂B的加入量较多时，其对正极活性材料表面的络合物层的修补作用较强烈，最终正极活性材料表面形成的络合物层容易更厚和致密，正负极阻抗大幅增高，从而锂离子电池在25℃和45℃时的循环容量保持率达到最佳后出现了下降的趋势。因此，添加剂B的加入量也需要适量，添加为0.1％～10.0％，更优选为0.1％～5.0％。It can be seen from Examples 8-14 that with the increase in the amount of additive B added (0.1% to 10.0%), when the charge cut-off voltage is fixed at 4.35V, the lithium ion battery at 25 ℃ and 45 ℃ After the cycle capacity retention rate reached the optimal level, there was a downward trend again, and the thickness expansion rate at 85°C for 24 hours kept decreasing. This is because when the additive amount of additive B is large, the repairing effect on the complex layer on the surface of the positive electrode active material is strong, and finally the complex layer formed on the surface of the positive electrode active material tends to be thicker and denser, and the impedance of the positive and negative electrodes is large Increased, so that the cycle capacity retention rate of lithium-ion batteries at 25 ℃ and 45 ℃ reached the optimal after a downward trend. Therefore, an appropriate amount of the additive B needs to be added, and the addition is 0.1% to 10.0%, and more preferably 0.1% to 5.0%.

根据上述说明书的揭示和教导，本申请所属领域的技术人员还可以对上述实施方式进行适当的变更和修改。因此，本申请并不局限于上面揭示和描述的具体实施方式，对本申请的一些修改和变更也应当落入本申请的权利要求的保护范围内。此外，尽管本说明书中使用了一些特定的术语，但这些术语只是为了方便说明，并不对本申请构成任何限制。According to the disclosure and teaching of the above description, those skilled in the art to which this application belongs can also make appropriate changes and modifications to the above-mentioned embodiments. Therefore, the application is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the application should also fall within the protection scope of the claims of the application. In addition, although some specific terms are used in this specification, these terms are only for convenience of description, and do not constitute any limitation to this application.

Claims

一种电解液，含有有机溶剂以及电解质盐；An electrolyte containing organic solvents and electrolyte salts;

其特征在于，It is characterized by,

所述电解液中还含有添加剂A以及添加剂B；The electrolyte also contains additive A and additive B;

所述添加剂A选自式I-1、式I-2、式I-3所示的化合物中的一种或几种；The additive A is selected from one or more of the compounds represented by Formula I-1, Formula I-2, and Formula I-3;

在式I-1、式I-2、式I-3中：R ₁、R ₂、R ₃、R ₄各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₁₂烷基、取代或未取代的C ₁～C ₁₂烷氧基、取代或未取代的C ₁～C ₁₂胺基、取代或未取代的C ₂～C ₁₂烯基、取代或未取代的C ₂～C ₁₂炔基、取代或未取代的C ₆～C ₂₆芳基、取代或未取代的C ₂～C ₁₂杂环基，其中，取代基选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种；x、y、z各自独立地选自0～8的整数；m、n、k各自独立地选自0～2的整数； In Formula I-1, Formula I-2, and Formula I-3: R ₁ , R ₂ , R ₃ , and R ₄ are each independently selected from a hydrogen atom, a halogen atom, and a substituted or unsubstituted C ₁ to C ₁₂ alkane Group, substituted or unsubstituted C ₁ -C ₁₂ alkoxy group, substituted or unsubstituted C ₁ -C ₁₂ amine group, substituted or unsubstituted C ₂ -C ₁₂ alkenyl group, substituted or unsubstituted C ₂ ～ C ₁₂ alkynyl, substituted or unsubstituted C ₆ to C ₂₆ aryl, substituted or unsubstituted C ₂ to C ₁₂ heterocyclic, wherein the substituent is selected from halogen atom, nitrile group, C ₁ to C ₆ alkane One or more of C ₂ to C ₆ alkenyl, C ₁ to C ₆ alkoxy; x, y, z are each independently selected from integers of 0 to 8; m, n, k are each independently An integer selected from 0 to 2;

所述添加剂B选自式II-1、式II-2所示的化合物中的一种或几种；The additive B is selected from one or more of the compounds represented by Formula II-1 and Formula II-2;

在式II-1、式II-2中，a、b、c、d各自独立地选自1～5内的整数，R ₅、R ₆、R ₇、R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自取代或未取代的C ₁～C ₁₀亚烷基、取代或未取代的C ₂～C ₁₀亚烯基，其中，取代基选自卤素原子、腈基、C ₁～C ₆烷基、C ₂～C ₆烯基、C ₁～C ₆烷氧基中的一种或几种。 In Formula II-1 and Formula II-2, a, b, c, and d are each independently selected from integers within 1 to 5, R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from a substituted or unsubstituted C ₁ to C ₁₀ alkylene group, a substituted or unsubstituted C ₂ to C ₁₀ alkenylene group, wherein the substituent is selected from a halogen atom and a nitrile One or more of a group, a C ₁ -C ₆ alkyl group, a C ₂ -C ₆ alkenyl group, and a C ₁ -C ₆ alkoxy group.
根据权利要求1所述的电解液，其特征在于，The electrolyte according to claim 1, characterized in that

在式I-1、式I-2、式I-3中：R ₁、R ₂、R ₃和R ₄各自独立地选自氢原子、卤素原子、取代或未取代的C ₁～C ₃直链或支链烷基、取代或未取代的C ₅～C ₇环状烷基、取代或未取代的C ₁～C ₃烷氧基、取代或未取代的C ₁～C ₃胺基、取代或未取代的C ₂～C ₃烯基、取代或未取代的C ₂～C ₃炔基、取代或未取代的C ₆～C ₈芳基、取代或未取代的C ₂～C ₇杂环基，其中，取代基选自卤素原子；x、y、z各自独立地选自0、1或2；m、n、k各自独立地选自1或2；和/或， In Formula I-1, Formula I-2, and Formula I-3: R ₁ , R ₂ , R ₃ and R ₄ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ to C ₃ straight Chain or branched alkyl, substituted or unsubstituted C ₅ -C ₇ cyclic alkyl, substituted or unsubstituted C ₁ -C ₃ alkoxy, substituted or unsubstituted C ₁ -C ₃ amine, substituted Or unsubstituted C ₂ -C ₃ alkenyl, substituted or unsubstituted C ₂ -C ₃ alkynyl, substituted or unsubstituted C ₆ -C ₈ aryl, substituted or unsubstituted C ₂ -C ₇ heterocyclic Group, wherein the substituent is selected from halogen atoms; x, y, z are each independently selected from 0, 1 or 2; m, n, k are each independently selected from 1 or 2; and/or,

在式II-1、式II-2中：R ₅、R ₆、R ₇、R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自取代或未取代的C ₁～C ₆亚烷基、取代或未取代的C ₂～C ₆亚烯基，其中，取代基选自卤素原子；a、b、c、d各自独立地选自1或2。 In Formula II-1 and Formula II-2: R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from substituted or unsubstituted C ₁ ~C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, wherein the substituent is selected from halogen atoms; a, b, c, d are each independently selected from 1 or 2.
根据权利要求1所述的电解液，其特征在于，The electrolyte according to claim 1, characterized in that

在式I-1中，R ₁、R ₃均为氢原子；优选地，R ₁、R ₃、R ₄均为氢原子； In formula I-1, R ₁ and R ₃ are all hydrogen atoms; preferably, R ₁ , R ₃ and R ₄ are all hydrogen atoms;

在式I-2中，R ₁、R ₂、R ₃、R ₄中至少有两个为氢原子；优选地，R ₁、R ₂、R ₃、R ₄中至少有三个为氢原子； In formula I-2, at least two of R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen atoms; preferably, at least three of R ₁ , R ₂ , R ₃ , and R ₄ are hydrogen atoms;

在式I-3中，R ₁、R ₂、R ₃中至少有两个为氢原子。 In formula I-3, at least two of R ₁ , R ₂ and R ₃ are hydrogen atoms.
根据权利要求1所述的电解液，其特征在于，The electrolyte according to claim 1, characterized in that

在式II-1中，R ₅、R ₆、R ₇各自独立地选自C ₁～C ₆亚烷基、C ₂～C ₆亚烯基，优选地，R ₅、R ₆、R ₇各自独立地选自C ₂～C ₄亚烷基； In formula II-1, R ₅ , R ₆ , and R ₇ are each independently selected from C ₁ to C ₆ alkylene, C ₂ to C ₆ alkenylene, preferably, R ₅ , R ₆ , and R ₇ are each Independently selected from C ₂ to C ₄ alkylene;

在式II-2中，R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自C ₁～C ₆亚烷基、C ₂～C ₆亚烯基，优选地，R ₈、R ₉、R ₁₀、R ₁₁、R ₁₂、R ₁₃各自独立地选自C ₂～C ₄亚烷基。 In formula II-2, R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , and R ₁₃ are each independently selected from C ₁ to C ₆ alkylene, C ₂ to C ₆ alkenylene, preferably, R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each independently selected from C ₂ to C ₄ alkylene.
根据权利要求1所述的电解液，其特征在于，所述添加剂A选自如下化合物中的一种或几种：The electrolyte according to claim 1, wherein the additive A is selected from one or more of the following compounds:
根据权利要求1所述的电解液，其特征在于，The electrolyte according to claim 1, characterized in that

所述添加剂B选自1,2-二(氰乙氧基)乙烷、1,2-二(氰丙氧基)乙烷、1,2-二(氰丁氧基)乙烷、1,3-二(氰乙氧基)丙烷、1,3-二(氰丙氧基)丙烷、1,3-二(氰丁氧基)丙烷、1,4-二(氰乙氧基)丁烷、1,4-二(氰丙氧基)丁烷、1,4-二(氰丁氧基)丁烷、1,5-二(氰丙氧基)戊烷、1,6-二(氰丙氧基)己烷、1,2,3-三(氰乙氧基)丙烷、1,2,3-三(氰丙氧基)丙烷、1,3,5-三(氰乙氧基)戊烷、1,3,5-三(氰丙氧基)戊烷、1,2,6-三(氰乙氧基)己烷、1,4,7-三(氰乙氧基)庚烷中的一种或几种。The additive B is selected from 1,2-di(cyanoethoxy)ethane, 1,2-di(cyanopropoxy)ethane, 1,2-di(cyanobutoxy)ethane, 1, 3-bis(cyanoethoxy)propane, 1,3-bis(cyanopropoxy)propane, 1,3-bis(cyanobutoxy)propane, 1,4-bis(cyanoethoxy)butane , 1,4-bis(cyanopropoxy)butane, 1,4-bis(cyanobutoxy)butane, 1,5-bis(cyanopropoxy)pentane, 1,6-bis(cyano Propoxy) hexane, 1,2,3-tris (cyanoethoxy) propane, 1,2,3-tris (cyanopropoxy) propane, 1,3,5-tris (cyanoethoxy) Pentane, 1,3,5-tris(cyanopropoxy)pentane, 1,2,6-tris(cyanoethoxy)hexane, 1,4,7-tris(cyanoethoxy)heptane One or more of them.
根据权利要求1所述的电解液，其特征在于，The electrolyte according to claim 1, characterized in that

所述添加剂A在所述电解液中的质量百分含量为0.1％～10％，优选为0.1％～3.5％；和/或，The mass percentage content of the additive A in the electrolyte is 0.1% to 10%, preferably 0.1% to 3.5%; and/or,

所述添加剂B在所述电解液中的质量百分含量为0.1％～10％，优选为0.1％～5％。The mass percentage content of the additive B in the electrolyte is 0.1% to 10%, preferably 0.1% to 5%.
根据权利要求1所述的电解液，其特征在于，所述电解液中还含有添加剂C，所述添加剂C选自含有碳碳不饱和键的环状碳酸酯化合物、卤素取代的环状碳酸酯化合物、硫酸酯化合物、磺酸内酯化合物、二磺酸酯化合物、亚硫酸酯化合物、芳香化合物、异氰酸酯化合物、磷腈化合物、酸酐化合物、亚磷酸酯化合物、磷酸酯化合物、硼酸酯化合物中的一种或几种。The electrolyte according to claim 1, wherein the electrolyte further contains an additive C selected from a cyclic carbonate compound containing a carbon-carbon unsaturated bond, a halogen-substituted cyclic carbonate Compounds, sulfate compounds, sultone compounds, disulfonate compounds, sulfite compounds, aromatic compounds, isocyanate compounds, phosphazene compounds, anhydride compounds, phosphite compounds, phosphate compounds, borate compounds One or more.
一种电池，包括电极组件以及电解液，所述电极组件包括正极极片、负极极片以及隔离膜；A battery includes an electrode assembly and an electrolyte, the electrode assembly includes a positive pole piece, a negative pole piece, and a separator;

其特征在于，It is characterized by,

所述电解液为根据权利要求1-8中任一项所述的电解液。The electrolyte is the electrolyte according to any one of claims 1-8.
根据权利要求9所述的电池，其特征在于，所述正极极片中的正极活性材料包括Li _x1Co _y1M _1-y1O _2-z1Q _z1，0.5≤x1≤1.2，0.8≤y1<1.0，0≤z1≤0.1，M选自Al、Ti、Zr、Y、Mg中的一种或几种，Q选自F、Cl、S中的一种或几种。 The battery according to claim 9, wherein the positive electrode active material in the positive electrode sheet comprises Li _x1 Co _y1 M _1-y1 O _2-z1 Q _z1 , 0.5≤x1≤1.2, 0.8≤y1<1.0 , 0≤z1≤0.1, M is selected from one or more of Al, Ti, Zr, Y, and Mg, and Q is selected from one or more of F, Cl, and S.
一种装置，其特征在于，包括根据权利要求9或10所述的电池。An apparatus characterized by comprising the battery according to claim 9 or 10.