WO2022061582A1

WO2022061582A1 - Electrolyte, electrochemical device, and electronic device

Info

Publication number: WO2022061582A1
Application number: PCT/CN2020/117118
Authority: WO
Inventors: 彭谢学; 郑建明; 刘俊飞; 唐超
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2022-03-31
Also published as: CN113366687B; CN113366687A

Abstract

The present application provides an electrolyte, an electrochemical device, and an electronic device. The electrolyte comprises a compound A. The compound A comprises at least one of compounds represented by formula (I-A) and formula (I-B). The electrochemical device comprises a positive plate, a negative plate, an isolation film, and the electrolyte. The electronic device comprises the electrochemical device. The compound represented by formula I is added to the electrolyte, so that cycle performance and high-temperature storage performance of the electronic device comprising the electrochemical device using the electrolyte can be improved.

Description

电解液、电化学装置及电子装置Electrolyte, electrochemical device and electronic device

技术领域technical field

本申请涉及一种电解液、电化学装置及电子装置。The present application relates to an electrolyte, an electrochemical device and an electronic device.

背景技术Background technique

电化学装置(例如锂离子电池)由于具有高能量密度、低维护、相对较低的自放电、长循环寿命、无记忆效应、工作电压稳定和环境友好等特性受到人们的广泛关注，并因此被广泛地运用。随着技术的快速发展以及市场需求的多样性，人们对锂离子电池提出了更多要求，例如更薄、更轻、更多样化的外形、更高的安全性、更高的能量密度等。Electrochemical devices, such as Li-ion batteries, have received extensive attention due to their high energy density, low maintenance, relatively low self-discharge, long cycle life, no memory effect, stable operating voltage, and environmental friendliness, and are therefore widely used. widely used. With the rapid development of technology and the diversity of market demands, people have put forward more requirements for lithium-ion batteries, such as thinner, lighter, more diverse shapes, higher safety, higher energy density, etc. .

发明内容SUMMARY OF THE INVENTION

在一些实施例中，本申请提供了一种电解液，所述电解液包括化合物A，所述化合物A包括式(I-A)和式(I-B)表示的化合物中的至少一种；In some embodiments, the present application provides an electrolyte solution, the electrolyte solution includes compound A, and the compound A includes at least one of the compounds represented by formula (I-A) and formula (I-B);

在式(I-A)和式(I-B)中，In formula (I-A) and formula (I-B),

n选自1-6的整数；n is selected from an integer of 1-6;

R ¹选自式(I-C)、式(I-D)、式(I-E)、式(I-F)表示的结构式中的任意一种， R ¹ is selected from any one of the structural formulas represented by formula (IC), formula (ID), formula (IE) and formula (IF),

表示与相邻原子的结合位点；

represents the binding site with adjacent atoms;

R ¹¹选自氢、经取代或未经取代的C ₁-C ₁₀烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀连烯基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₂-C ₁₀杂环基、经取代或未经取代的含杂原子的官能团，并且，当经取代时，取代基为卤素； R ¹¹ is selected from hydrogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₂ -C ₁₀ alkynyl , substituted or unsubstituted C ₃ -C ₁₀ alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic hydrocarbon group, substituted or unsubstituted C2 _- _C10 heterocyclyl, substituted or unsubstituted heteroatom-containing functional groups, and, when substituted, the substituent is halogen;

R ¹⁷、R ¹⁹、R ^1c各自独立地选自经取代或未经取代的C ₁-C ₁₀亚烷基、经取代或未经取代的C ₂-C ₁₀亚烯基、经取代或未经取代的C ₂-C ₁₀亚炔基、经取代或未经取代的C ₃-C ₁₀亚连烯基、经取代或未经取代的C ₆-C ₁₀亚芳基、经取代或未经取代的C ₃-C ₁₀亚脂环烃基、经取代或未经取代的C ₂-C ₁₀亚杂环基，并且，当经取代时，取代基为卤素； R ¹⁷ , R ¹⁹ , R ^1c are each independently selected from substituted or unsubstituted C ₁ -C ₁₀ alkylene, substituted or unsubstituted C ₂ -C ₁₀ alkenylene, substituted or unsubstituted Substituted C ₂ -C ₁₀ alkynylene, substituted or unsubstituted C ₃ -C ₁₀ alkenylene, substituted or unsubstituted C ₆ -C ₁₀ arylene, substituted or unsubstituted C ₃ -C ₁₀ alicyclic alkylene, substituted or unsubstituted C ₂ -C ₁₀ heterocyclylene, and, when substituted, the substituent is halogen;

R ¹⁴、R ¹⁵、R ¹⁶、R ^1a、R ^1b各自独立地选自经取代或未经取代的C ₁-C ₁₀烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀连烯基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₂-C ₁₀杂环基，并且，当经取代时，取代基为卤素，其中，R ¹⁴和R ¹⁵之间可以键合而形成环结构； R ¹⁴ , R ¹⁵ , R ¹⁶ , R ^1a , R ^1b are each independently selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, Substituted or unsubstituted C ₂ -C ₁₀ alkynyl, substituted or unsubstituted C ₃ -C ₁₀ alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted Substituted C ₃ -C ₁₀ alicyclic hydrocarbon group, substituted or unsubstituted C ₂ -C ₁₀ heterocyclic group, and, when substituted, the substituent is halogen, wherein R ¹⁴ and R ¹⁵ may bond combined to form a ring structure;

R ¹⁸选自经取代或未经取代的C ₁-C ₁₀次烷基、经取代或未经取代的C ₂-C ₁₀次烯基、经取代或未经取代的C ₃-C ₁₀次连烯基、经取代或未经取代的C ₆-C ₁₀次芳基、经取代或未经取代C ₃-C ₁₀次脂环烃基、经取代或未经取代的C ₂-C ₁₀次杂环基，并且，当经取代时，取代基为卤素； R ¹⁸ is selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₃ -C ₁₀ linked Alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic, substituted or unsubstituted C ₂ -C ₁₀ heterocycle and, when substituted, the substituent is halogen;

R ¹²选自经取代或未经取代的C ₁-C ₁₀次烷基、经取代或未经取代的C ₂-C ₁₀次烯基、经取代或未经取代的C ₃-C ₁₀次连烯基、经取代或未经取代的C ₆-C ₁₀次芳基、经取代或未经取代C ₃-C ₁₀次脂环烃基、经取代或未经取代的C ₂-C ₁₀次杂环基，并且，当经取代时，取代基为卤素； R ¹² is selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₃ -C ₁₀ linked Alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic, substituted or unsubstituted C ₂ -C ₁₀ heterocycle and, when substituted, the substituent is halogen;

R ¹³选自共价单键、经取代或未经取代的C ₁-C ₁₀亚烷基、经取代或未经取代的C ₂-C ₁₀亚烯基、经取代或未经取代的C ₂-C ₁₀亚炔基、经取代或未经取代的C ₃-C ₁₀亚连烯基、经取代或未经取代的C ₆-C ₁₀亚芳基、经取代或未经取代的C ₃-C ₁₀亚脂环烃基、经取代或未经取代的C ₂-C ₁₀亚杂环基、经取代或未经取代的含杂原子的官能团，并且，当经取代时，取代基为卤素； R ¹³ is selected from covalent single bond, substituted or unsubstituted C ₁ -C ₁₀ alkylene, substituted or unsubstituted C ₂ -C ₁₀ alkenylene, substituted or unsubstituted C ₂ -C ₁₀ alkynylene, substituted or unsubstituted C ₃ -C ₁₀ alkenylene, substituted or unsubstituted C ₆ -C ₁₀ arylene, substituted or unsubstituted C ₃ - C ₁₀ alicyclic alkylene, substituted or unsubstituted C ₂ -C ₁₀ heterocyclylene, substituted or unsubstituted heteroatom-containing functional groups, and, when substituted, the substituent is halogen;

所述杂原子包括B、N、O、Si、P、S中的至少一种。The heteroatom includes at least one of B, N, O, Si, P, and S.

在一些实施例中，所述化合物A包括式(I-1)至式(I-20)表示的化合物中的至少一种；In some embodiments, the compound A includes at least one of the compounds represented by formula (I-1) to formula (I-20);

在一些实施例中，基于所述电解液的总质量，所述化合物A的质量百分含量为0.01％-10％。In some embodiments, based on the total mass of the electrolyte, the mass percentage of the compound A is 0.01%-10%.

在一些实施例中，所述电解液还包括含硫氧双建的化合物，所述含硫氧双建的化合物包括式(II-A)和式(II-B)表示的化合物中的至少一种；In some embodiments, the electrolyte further includes a sulfur-oxygen bisulfite compound, and the sulfur-oxygen bisulfite compound includes at least one of the compounds represented by formula (II-A) and formula (II-B) kind;

在式(II-A)和式(II-B)中，In formula (II-A) and formula (II-B),

R ²¹、R ²²、R ²³和R ²⁴各自独立地选自经取代或未经取代的C ₁-C ₅烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₂-C ₆杂环基中的任意一种，并且，当经取代时，取代基包括卤素和含杂原子的官能团中的至少一种，其中，R ²¹和R ²²之间可以键合而形成环结构，R ²³和R ²⁴之间可以键合而形成环结构；所述杂原子包括B、N、O、Si、P、S中的至少一种。 R ²¹ , R ²² , R ²³ and R ²⁴ are each independently selected from substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted Substituted C ₂ -C ₁₀ alkynyl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic hydrocarbon, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C Any one of ₂ -C ₆ heterocyclic groups, and, when substituted, the substituent includes at least one of halogen and heteroatom-containing functional groups, wherein R ²¹ and R ²² can be bonded to form Ring structure, R ²³ and R ²⁴ can be bonded to form a ring structure; the heteroatom includes at least one of B, N, O, Si, P, and S.

在一些实施例中，所述含硫氧双建的化合物包括式(II-1)至式(II-15)表示的化合物中的至少一种；In some embodiments, the sulfur-oxygen-containing compound includes at least one of the compounds represented by formula (II-1) to formula (II-15);

在一些实施例中，基于所述电解液的总质量，所述含硫氧双建的化合物的质量百分含量为0.01％-10％。In some embodiments, based on the total mass of the electrolyte, the mass percentage of the compound containing sulfur and oxygen is 0.01%-10%.

在一些实施例中，所述电解液还包括硼酸锂类化合物，所述硼酸锂类化合物包括四氟硼酸锂、二草酸硼酸锂、二氟草酸硼酸锂中的至少一种；In some embodiments, the electrolyte further includes a lithium borate compound, and the lithium borate compound includes at least one of lithium tetrafluoroborate, lithium dioxalate borate, and lithium difluorooxalate borate;

基于所述电解液的总质量，所述硼酸锂类化合物的质量百分含量为0.01％-1％。Based on the total mass of the electrolyte, the mass percentage content of the lithium borate compound is 0.01%-1%.

在一些实施例中，所述电解液还包括磷酸锂类化合物，所述磷酸锂类化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂中的至少一种；In some embodiments, the electrolyte further includes a lithium phosphate compound, and the lithium phosphate compound includes at least one of lithium difluorophosphate, lithium difluorobisoxalate, and lithium tetrafluorooxalate;

基于所述电解液的总质量，所述磷酸锂类化合物的质量百分含量为0.01％-1％。Based on the total mass of the electrolyte, the mass percentage content of the lithium phosphate compound is 0.01%-1%.

在一些实施例中，本申请还提供了一种电化学装置，包括正极片、负极片、隔离膜以及上述电解液。In some embodiments, the present application also provides an electrochemical device, including a positive electrode sheet, a negative electrode sheet, a separator, and the above electrolyte.

在一些实施例中，所述正极片的压实密度小于或等于3.65g/cm ³。 In some embodiments, the compacted density of the positive electrode sheet is less than or equal to 3.65 g/cm ³ .

在一些实施例中，所述正极片包括正极集流体以及正极活性物质层，所述正极活性物质层包括正极活性物质；In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer includes a positive electrode active material;

所述正极活性物质包括第一颗粒和第二颗粒，所述第一颗粒与第二颗粒的粒径不同。The positive electrode active material includes first particles and second particles, and the first particles and the second particles have different particle sizes.

在一些实施例中，所述正极活性物质满足条件(a)-(d)中的至少一种：In some embodiments, the positive active material satisfies at least one of conditions (a)-(d):

(a)所述第一颗粒的平均粒径为0.1μm-1.5μm；(a) the average particle size of the first particles is 0.1 μm-1.5 μm;

(b)所述第二次颗粒的BET比表面积为0.14m ²/g-0.95m ²/g； (b) the BET specific surface area of the second particles is 0.14m ² /g-0.95m ² /g;

(c)所述正极活性物质的Dv50为5.5μm-14.5μm；(c) Dv50 of the positive electrode active material is 5.5 μm-14.5 μm;

(d)所述正极活性物质的Dv10小于或等于18μm。(d) Dv10 of the positive electrode active material is less than or equal to 18 μm.

在一些实施例中，本申请还提供了一种电子装置，包括上述电化学装置。In some embodiments, the present application also provides an electronic device including the above electrochemical device.

具体实施方式detailed description

将理解的是，所公开的实施例仅仅是本申请的示例，本申请可以以各种形式实施，因此，本文公开的具体细节不应被解释为限制，而是仅作为权利要求的基础且作为表示性的基础用于教导本领域普通技术人员以各种方式实施本申请。It is to be understood that the disclosed embodiments are merely exemplary of the application, which may be embodied in various forms, and therefore that specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as A representative basis is provided for teaching one of ordinary skill in the art to variously implement the application.

在本申请的说明中，除非另有明确的规定和限定，术语“第一”、“第二”、“第三”、“第四”、“第五”、“第六”“式(I-A)”、“式(I-B)”、“式(I-C)”、“式(I-D)”、“式(I-E)”、“式(I-F)”、“式(II-A)”、“式(II-B)”、“式(III)”等仅用于说明的目的，而不能理解为指示或暗示相对重要性以及相互存在关系。In the description of this application, unless otherwise expressly specified and defined, the terms "first", "second", "third", "fourth", "fifth", "sixth", "formula (IA)" )", "Formula (IB)", "Formula (IC)", "Formula (ID)", "Formula (IE)", "Formula (IF)", "Formula (II-A)", "Formula ( II-B)", "Formula (III)", etc. are only for the purpose of illustration, and should not be construed as indicating or implying relative importance and mutual existence relationship.

在本申请的说明中，除非另有说明，所有化合物的官能团可以是经取代的或未经取代的。In the description of this application, unless otherwise stated, the functional groups of all compounds may be substituted or unsubstituted.

在本申请的说明中，术语“杂原子”表示除C、H以外的原子。在一些实施例中，杂原子包括B、N、O、Si、P、S中的至少一种。In the description of this application, the term "heteroatom" refers to atoms other than C, H. In some embodiments, the heteroatoms include at least one of B, N, O, Si, P, S.

在本申请的说明中，术语“杂环基”是指包含至少一个杂原子的环基。在一些实施例中，所述杂环基包含脂杂环基和芳杂环基中的至少一种。在一些实施例中，杂环基为一价基团。在一些实施例中，亚杂环基为二价基团。在一些实施例中，次杂环基为三价基团。In the specification of this application, the term "heterocyclyl" refers to a cyclic group containing at least one heteroatom. In some embodiments, the heterocyclyl group comprises at least one of an alicyclic heterocyclyl group and an aromatic heterocyclyl group. In some embodiments, the heterocyclyl group is a monovalent group. In some embodiments, the heterocyclylene group is a divalent group. In some embodiments, a sub-heterocyclyl group is a trivalent group.

在本申请的说明中，术语“含杂原子的官能团”是指包含至少一个杂原子的官能团。In the description of the present application, the term "heteroatom-containing functional group" refers to a functional group containing at least one heteroatom.

在本申请的说明中，术语“亚烷基”是指二价烷基，术语“亚烯基”是指二价烯基，术语“亚炔基”是指二价炔基，术语“亚芳基”是指二价芳基。In the specification of this application, the term "alkylene" refers to a divalent alkyl group, the term "alkenylene" refers to a divalent alkenyl group, the term "alkynylene" refers to a divalent alkynyl group, the term "arylene" "Radical" refers to a divalent aryl group.

在本申请的说明中，术语“次烷基”意指直链或具支链的三价饱和烃基。代表性的次烷基包括但不限于次甲基(-CH-)、乙烷-1,1,2-三基(-CHCH ₂-)、丙烷-1,2,2-三基、丙烷-1,1,3-三基、丁烷-1,1,4-三基、戊烷-1,1,5-三基等等。术语“次烯基”意指直链或具支链的三价烯基。当指定具有具体碳数的次烯基时，预期涵盖具有该碳数的所有几何异构体。代表性的次烯基包括但不限于次乙烯基

丙烯-1,1,3-三基

丙烯-1,2,2-三基、丙烯-1,3,3-三基、丁烯-1,1,4-三基、戊烯-1,1,5-三基等等。术语“次芳基”是指三价芳基。 In the description of the present application, the term "alkylene" means a straight or branched trivalent saturated hydrocarbon group. Representative alkylene groups include, but are not limited to, methine (-CH-), ethane-1,1,2-triyl ( _-CHCH2- ), propane-1,2,2-triyl, propane- 1,1,3-triyl, butane-1,1,4-triyl, pentane-1,1,5-triyl and the like. The term "alkenyl" means a linear or branched trivalent alkenyl group. When specifying an alkenyl group having a specific number of carbons, it is intended to encompass all geometric isomers having that number of carbons. Representative alkenylene groups include, but are not limited to, vinylene groups

Propylene-1,1,3-triyl

Propene-1,2,2-triyl, propene-1,3,3-triyl, butene-1,1,4-triyl, pentene-1,1,5-triyl and the like. The term "subaryl" refers to a trivalent aryl group.

在本申请的说明中，术语“连烯基”表示两个烯基共用同一个碳的基团。在一些实施例中，连烯基为一价基团，化合结构式为-CH＝C＝CH ₂。在一些实施例中，亚连烯基为二价基团，化学结构式为-CH＝C＝CH-。在一些实施例中，次连烯基为三价基团，化学结构式为

In the specification of this application, the term "alkenyl" refers to a group in which two alkenyl groups share the same carbon. In some embodiments, the alkenyl group is a monovalent group, and the compound structural formula is -CH=C=CH ₂ . In some embodiments, the alkenylene group is a divalent group with the chemical structural formula -CH=C=CH-. In some embodiments, the alkenyl group is a trivalent group, and the chemical structural formula is

在本申请的说明中，术语“脂环烃基”表示具有脂肪族性质的环烃，分子中含有闭合的碳环。在一些实施例中，脂环烃基为一价基团。在一些实施例中，亚脂环烃基为二价基团。在一些实施例中，次脂环烃基为三价基团。In the description of the present application, the term "alicyclic hydrocarbon group" refers to a cyclic hydrocarbon having aliphatic properties and containing a closed carbocyclic ring in the molecule. In some embodiments, the alicyclic hydrocarbon group is a monovalent group. In some embodiments, the alicyclic hydrocarbon group is a divalent group. In some embodiments, the subalicyclic hydrocarbon group is a trivalent group.

(电解液)(electrolyte)

[第一添加剂][First Additive]

在一些实施例中，电解液包含第一添加剂，第一添加剂包含具有羧酸酯基团和硼酸酯基团的化合物A，化合物A包含式(I-A)和式(I-B)表示的化合物中的至少一种；In some embodiments, the electrolyte includes a first additive, the first additive includes a compound A having a carboxylate group and a borate group, and the compound A includes the compounds represented by formula (IA) and formula (IB) at least one;

在式(I-A)和式(I-B)中，In formula (I-A) and formula (I-B),

R ¹³选自供价单键、经取代或未经取代的C ₁-C ₁₀亚烷基、经取代或未经取代的 C ₂-C ₁₀亚烯基、经取代或未经取代的C ₂-C ₁₀亚炔基、经取代或未经取代的C ₃-C ₁₀连烯基、经取代或未经取代的C ₆-C ₁₀亚芳基、经取代或未经取代的C ₃-C ₁₀亚脂环烃基、经取代或未经取代的C ₂-C ₁₀亚杂环基、经取代或未经取代的含杂原子的官能团，并且，当经取代时，取代基为卤素； R ¹³ is selected from donating single bond, substituted or unsubstituted C ₁ -C ₁₀ alkylene, substituted or unsubstituted C ₂ -C ₁₀ alkenylene, substituted or unsubstituted C ₂ -C ₁₀ alkynylene, substituted or unsubstituted C ₃ -C ₁₀ alkenyl, substituted or unsubstituted C ₆ -C ₁₀ arylene, substituted or unsubstituted C ₃ -C ₁₀ alicyclic alkylene, substituted or unsubstituted C2 _- _C10 heterocyclylene, substituted or unsubstituted heteroatom-containing functional groups, and, when substituted, the substituent is halogen;

表示与相邻原子的结合位点；

represents the binding site with adjacent atoms;

n选自1-6的整数。n is selected from an integer of 1-6.

提高电化学装置能量密度的方式可以采用提高电化学装置的电压或增加电化学装置中活性物质的容量的方式。然而，这些方式均容易加速电化学装置中电解液的分解并导致产气，电芯膨胀，以及电化学装置的循环寿命变短。The energy density of the electrochemical device can be increased by increasing the voltage of the electrochemical device or increasing the capacity of the active material in the electrochemical device. However, these methods all easily accelerate the decomposition of the electrolyte in the electrochemical device and cause gas generation, cell expansion, and shortening of the cycle life of the electrochemical device.

本申请在电解液中加入上述化合物A，能够显著改善电化学装置的循环性能和高温存储性能，从而使电化学装置能够在具有较高能量密度的同时保持较好的循环性能和高温存储性能。In the present application, adding the above-mentioned compound A to the electrolyte can significantly improve the cycle performance and high temperature storage performance of the electrochemical device, so that the electrochemical device can maintain good cycle performance and high temperature storage performance while having a higher energy density.

式(I-A)和式(I-B)表示的化合物能够在电化学装置的正极片的表面形成性能优良的保护膜，还能够在减小膜阻抗的同时提高膜的抗氧化性，从而能够减少膜的二次氧化分解，有助于抑制电解液的持续分解，因此，式(I-A)和式(I-B)表示的化合物可以有效抑制电化学装置在循环过程中阻抗的增加，改善电化学装置的循环性能和高温存储性能。The compounds represented by the formula (IA) and the formula (IB) can form a protective film with excellent performance on the surface of the positive electrode sheet of an electrochemical device, and can also reduce the film resistance while improving the oxidation resistance of the film, thereby reducing the film's oxidation resistance. The secondary oxidative decomposition helps to inhibit the continuous decomposition of the electrolyte. Therefore, the compounds represented by formula (IA) and formula (IB) can effectively inhibit the increase of the impedance of the electrochemical device during the cycle process and improve the cycle performance of the electrochemical device. and high temperature storage performance.

在一些实施例中，所述化合物A包含式(I-1)至式(I-20)表示的化合物中的至少一种；In some embodiments, the compound A comprises at least one of the compounds represented by formula (I-1) to formula (I-20);

在一些实施例中，基于所述电解液的总质量，所述化合物A的质量百分含量为0.01％-10％。当所述化合物A的质量百分含量位于上述范围内时，能够进一步改善电化学装置的循环性能和高温存储性能。In some embodiments, based on the total mass of the electrolyte, the mass percentage of the compound A is 0.01%-10%. When the mass percentage content of the compound A is within the above range, the cycle performance and high temperature storage performance of the electrochemical device can be further improved.

[第二添加剂][Second additive]

在一些实施例中，电解液还包含第二添加剂，所述第二添加剂包含含硫氧双建的化合物，所述含硫氧双建的化合物包括式(II-A)和式(II-B)表示的化合物中的至少一种；In some embodiments, the electrolyte further includes a second additive, the second additive includes a sulfur-oxygen bisulfite compound, and the sulfur-oxygen bisulfite compound includes formula (II-A) and formula (II-B) ) at least one of the compounds represented;

在式(II-A)和式(II-B)中，In formula (II-A) and formula (II-B),

R ²¹、R ²²、R ²³和R ²⁴各自独立地选自经取代或未经取代的C ₁-C ₅烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₂-C ₆杂环基中的任意一种，并且，当经取代时，取代基包括卤素和含杂原子的官能团中的至少一种，其中，R ²¹和R ²²之间可以键合而形成环结构，R ²³和R ²⁴之间可以键合而形成环结构。 R ²¹ , R ²² , R ²³ and R ²⁴ are each independently selected from substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted Substituted C ₂ -C ₁₀ alkynyl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic hydrocarbon, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C Any one of ₂ -C ₆ heterocyclic groups, and, when substituted, the substituent includes at least one of halogen and heteroatom-containing functional groups, wherein R ²¹ and R ²² can be bonded to form Ring structure, R ²³ and R ²⁴ may be bonded to form a ring structure.

当在电解液中同时加入第一添加剂和第二添加剂时，能够进一步改善电化学装置的循环性能和高温存储性能。可能的原因是，一方面，第二添加剂具有较强的抗氧化能力，在正极材料中不易被氧化，另一方面，在阳极析锂的情况下，第二添加剂能够在金属锂表面还原，形成一层保护膜，抑制金属锂与电解液的分解产热，进一步增强对活性材料的保护，从而进一步改善电化学装置的循环性能和高温存储性能。When the first additive and the second additive are simultaneously added to the electrolyte, the cycle performance and high temperature storage performance of the electrochemical device can be further improved. The possible reason is that, on the one hand, the second additive has strong anti-oxidation ability and is not easy to be oxidized in the positive electrode material; A protective film suppresses the decomposition of lithium metal and electrolyte to generate heat, further enhances the protection of active materials, and further improves the cycle performance and high-temperature storage performance of electrochemical devices.

在一些实施例中，所述含硫氧双建的化合物包含式(II-1)至式(II-15)表示的化合物中的至少一种；In some embodiments, the sulfur-oxygen-containing compound comprises at least one of the compounds represented by formula (II-1) to formula (II-15);

在一些实施例中，基于所述电解液的总质量，所述含硫氧双建的化合物的质量百分含量为0.01％-10％。当含硫氧双建的化合物的质量百分含量位于上述范围内时，能够进一步改善电化学装置的循环性能和高温存储性能。在一些实施例中，基于所述电解液的总质量，所述含硫氧双建的化合物的质量百分含量为0.1％-8％。In some embodiments, based on the total mass of the electrolyte, the mass percentage of the compound containing sulfur and oxygen is 0.01%-10%. When the mass percentage content of the compound containing sulfur and oxygen is within the above range, the cycle performance and high temperature storage performance of the electrochemical device can be further improved. In some embodiments, based on the total mass of the electrolyte, the mass percentage of the compound containing sulfur and oxygen is 0.1%-8%.

[第三添加剂][Third additive]

在一些实施例中，电解液还包含第三添加剂，第三添加剂包含硼酸锂类化合物，所述硼酸锂类化合物包括四氟硼酸锂(LiBF ₄)、二草酸硼酸锂(LiBOB)、二氟草酸硼酸锂(LiDFOB)中的至少一种。 In some embodiments, the electrolyte further includes a third additive, and the third additive includes a lithium borate compound, and the lithium borate compound includes lithium tetrafluoroborate (LiBF ₄ ), lithium bisoxalate borate (LiBOB), difluorooxalic acid At least one of lithium borate (LiDFOB).

当在电解液中同时加入第一添加剂和第三添加剂时，能够进一步改善电化学装置的高温存储性能。可能的原因是，第三添加剂具有较高的热稳定性，当添加于电解液中时，能够在负极片的表面形成含氟的保护膜，减少FEC与负极片的反应，抑制气体产生，从而进一步改善电化学装置的高温存储性能。When the first additive and the third additive are simultaneously added to the electrolyte, the high-temperature storage performance of the electrochemical device can be further improved. The possible reason is that the third additive has high thermal stability. When added to the electrolyte, it can form a fluorine-containing protective film on the surface of the negative electrode sheet, reduce the reaction between the FEC and the negative electrode sheet, and inhibit the generation of gas. Further improve the high temperature storage performance of electrochemical devices.

在一些实施例中，基于所述电解液的总质量，所述硼酸锂类化合物的质量百分含量为0.01％-1％。In some embodiments, the mass percentage content of the lithium borate compound is 0.01%-1% based on the total mass of the electrolyte.

[第四添加剂][Fourth Additive]

在一些实施例中，电解液还包含第四添加剂，第四添加剂包含磷酸锂类化合物，所述磷酸锂类化合物包括二氟磷酸锂(LiPO ₂F ₂)、二氟双草酸磷酸锂(LiDFOP)、四氟草酸磷酸锂(LiTFOP)中的至少一种。 In some embodiments, the electrolyte further includes a fourth additive, and the fourth additive includes a lithium phosphate compound, and the lithium phosphate compound includes lithium difluorophosphate (LiPO ₂ F ₂ ), lithium difluorobisoxalate phosphate (LiDFOP) , at least one of lithium tetrafluorooxalate phosphate (LiTFOP).

当在电解液中同时加入第一添加剂和第四添加剂时，能够进一步改善电化学装置的循环性能和高温存储性能。可能的原因是，第四添加剂能够在正极片的表面成膜，减少电解液与正极片的接触，抑制气体产生，从而进一步改善电化学装置的循环性能和高温存储性能。When the first additive and the fourth additive are simultaneously added to the electrolyte, the cycle performance and high temperature storage performance of the electrochemical device can be further improved. The possible reason is that the fourth additive can form a film on the surface of the positive electrode sheet, reduce the contact between the electrolyte and the positive electrode sheet, and inhibit the generation of gas, thereby further improving the cycle performance and high-temperature storage performance of the electrochemical device.

在一些实施例中，基于所述电解液的总质量，所述磷酸锂类化合物的质量百分含量为0.01％-1％。In some embodiments, the mass percentage content of the lithium phosphate compound is 0.01%-1% based on the total mass of the electrolyte.

[第五添加剂][Fifth additive]

在一些实施例中，电解液还包含第五添加剂，第五添加剂包含环状碳酸酯类化合物。In some embodiments, the electrolyte further includes a fifth additive, and the fifth additive includes a cyclic carbonate compound.

在一些实施例中，环状碳酸酯类化合物包含式(III)表示的化合物；In some embodiments, the cyclic carbonate compound comprises a compound represented by formula (III);

在式(III)中，In formula (III),

R ³选自经取代或未经取代的C ₁-C ₆亚烷基、经取代或未经取代的C ₂-C ₆亚烯基中的任意一种，并且，当经取代时，取代基包含卤素、C ₁-C ₆烷基、C ₂-C ₆烯基中的至少一种。 R ³ is selected from any one of substituted or unsubstituted C ₁ -C ₆ alkylene, substituted or unsubstituted C ₂ -C ₆ alkenylene, and, when substituted, the substituent Contains at least one of halogen, C ₁ -C ₆ alkyl, and C ₂ -C ₆ alkenyl.

式(III)表示环状碳酸酯类化合物能够提高形成于电化学装置的电极片表面的SEI膜的柔性，从而有助于增强对于电极活性物质的保护作用，降低电极活性物质与电解液接触的几率，抑制电化学装置在循环过程中因副产物累积产生而导致的阻抗的增加。Formula (III) represents that the cyclic carbonate compound can improve the flexibility of the SEI film formed on the surface of the electrode sheet of the electrochemical device, thereby helping to enhance the protection of the electrode active material and reduce the contact between the electrode active material and the electrolyte. It is possible to suppress the increase in impedance of the electrochemical device due to the accumulation of by-products during cycling.

在一些实施例中，式(III)表示的化合物包含式(III-1)至式(III-1)表示的化合物中的至少一种；In some embodiments, the compound represented by formula (III) comprises at least one of compounds represented by formula (III-1) to formula (III-1);

在一些实施例中，基于所述电解液的总质量，式(III)表示的化合物的质量百分含量为0.01％～30％。在一些实施例中，基于所述电解液的总质量，式(III)表示的化合物的质量百分含量为0.1％～10％。In some embodiments, based on the total mass of the electrolyte, the mass percentage content of the compound represented by formula (III) is 0.01% to 30%. In some embodiments, based on the total mass of the electrolyte, the mass percentage content of the compound represented by formula (III) is 0.1% to 10%.

[第六添加剂][Sixth additive]

在一些实施例中，电解液还包含第六添加剂，第六添加剂包含盐类化合物，所述盐类化合物的阴离子选自BF ₄ ^-、POF ₂ ^-、FSI ^-、TFSI ^-、二氟草酸硼酸根(DFOB ^-)、二氟双草酸磷酸根(DFOP ^-)、双草酸硼酸根(BOB ^-)中的任意一种，所述盐类化合物的阳离子选自钠离子、钾离子中的任意一种。 In some embodiments, the electrolyte further includes a sixth additive, and the sixth additive includes a salt compound, and the anion of the salt compound is selected from BF ₄ ⁻ , POF ₂ ⁻ , FSI ⁻ , TFSI ⁻ , difluorooxalate borate Any one of (DFOB ⁻ ), difluorobisoxalate phosphate (DFOP ⁻ ), and bisoxalate borate (BOB ⁻ ), and the cation of the salt compound is selected from any one of sodium ion and potassium ion.

在一些实施例中，所述盐类化合物可以单独使用或以混合物使用。In some embodiments, the salt compounds can be used alone or in a mixture.

[有机溶剂][Organic solvents]

在一些实施例中，电解液还包含有机溶剂。有机溶剂是本领域技术公知的适用于电化学装置的有机溶剂，例如通常使用非水有机溶剂。In some embodiments, the electrolyte further includes an organic solvent. The organic solvent is an organic solvent known to those skilled in the art and suitable for electrochemical devices, for example, a non-aqueous organic solvent is generally used.

在一些实施例中，非水有机溶剂为碳酸酯类、羧酸酯类、醚类、砜类或其他非质子溶剂。在一些实施例中，碳酸酯类非水有机溶剂包含碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯中的至少一种。在一些实施例中，羧酸酯类非水有机溶剂包含乙酸乙酯、乙酸正丙酯、乙酸正丁酯、丙酸乙酯、γ-丁内酯、乙酸2,2-二氟乙酯、戊内酯、丁内酯中的至少一种。在一些实施例中，醚类非水有机溶剂包含乙二醇二甲醚、二乙二醇二甲醚、四乙二醇二甲醚、二丁醚、四氢呋喃、2-甲基四氢呋喃中的至少一种。在一些实施例中，砜类非水有机溶剂包含乙基乙烯基砜、甲基异丙基砜、异丙基仲丁基砜、环丁砜中的至少一种。In some embodiments, the non-aqueous organic solvent is a carbonate, carboxylate, ether, sulfone, or other aprotic solvent. In some embodiments, the carbonate-based non-aqueous organic solvent comprises dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, propyl methyl carbonate, ethyl propyl carbonate, dipropyl carbonate, ethylene carbonate, propylene carbonate At least one of ester and butylene carbonate. In some embodiments, the carboxylate non-aqueous organic solvent comprises ethyl acetate, n-propyl acetate, n-butyl acetate, ethyl propionate, γ-butyrolactone, 2,2-difluoroethyl acetate, At least one of valerolactone and butyrolactone. In some embodiments, the ether-based non-aqueous organic solvent comprises at least one of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dibutyl ether, tetrahydrofuran, and 2-methyltetrahydrofuran A sort of. In some embodiments, the sulfone-based non-aqueous organic solvent comprises at least one of ethyl vinyl sulfone, methyl isopropyl sulfone, isopropyl sec-butyl sulfone, and sulfolane.

非水有机溶剂可以单独使用或以混合物使用，当以混合物使用时，可以根据期望的电化学装置性能控制混合物的比例。The non-aqueous organic solvent can be used alone or in a mixture, and when used in a mixture, the ratio of the mixture can be controlled according to the desired electrochemical device performance.

[电解质盐][electrolyte salt]

在一些实施例中，电解液还包含电解质盐。电解质盐是本领域技术公知的适用于电化学装置的电解质盐，针对不同的电化学装置，可以选用合适的电解质盐。例如对于锂离子电池，电解质盐通常使用锂盐。In some embodiments, the electrolyte further includes an electrolyte salt. The electrolyte salt is a known electrolyte salt suitable for electrochemical devices in the art, and suitable electrolyte salts can be selected for different electrochemical devices. For example, for lithium ion batteries, lithium salts are generally used as electrolyte salts.

在一些实施例中，锂盐包含有机锂盐或无机锂盐中的至少一种。In some embodiments, the lithium salt comprises at least one of an organic lithium salt or an inorganic lithium salt.

在一些实施例中，锂盐包含六氟磷酸锂(LiPF ₆)。 In some embodiments, the lithium salt comprises lithium hexafluorophosphate (LiPF ₆ ).

在一些实施例中，基于所述电解液的总体积，所述锂盐中锂的摩尔浓度为0.5-3mol/L。在一些实施例中，基于所述电解液的总体积，所述锂盐中锂的摩尔浓度为0.5-2mol/L。在一些实施例中，基于所述电解液的总体积，所述锂盐中锂的摩尔浓度为0.8-1.5mol/L。In some embodiments, the molar concentration of lithium in the lithium salt is 0.5-3 mol/L based on the total volume of the electrolyte. In some embodiments, the molar concentration of lithium in the lithium salt is 0.5-2 mol/L based on the total volume of the electrolyte. In some embodiments, the molar concentration of lithium in the lithium salt is 0.8-1.5 mol/L based on the total volume of the electrolyte.

(电化学装置)(electrochemical device)

本申请的电化学装置例如为一次电池、二次电池、燃料电池、太阳能电池或电容器。二次电池例如为锂二次电池，锂二次电池包含但不限于括锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。The electrochemical device of the present application is, for example, a primary battery, a secondary battery, a fuel cell, a solar cell, or a capacitor. The secondary battery is, for example, a lithium secondary battery, and the lithium secondary battery includes, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery.

在一些实施例中，电化学装置包含正极片、负极片、隔离膜以及本申请前述的电解液。In some embodiments, the electrochemical device includes a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte as previously described herein.

[正极片][Positive plate]

正极片是本领域技术公知的可被用于电化学装置的正极片。在一些实施例中，正极片包含正极集流体以及正极活性物质层。正极活性物质层设置于正极集流体的表面上。正极活性物质层包含正极活性物质。The positive electrode sheet is known in the art as a positive electrode sheet that can be used in electrochemical devices. In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is provided on the surface of the positive electrode current collector. The positive electrode active material layer contains a positive electrode active material.

在一些实施例中，正极集流体为金属，金属例如但不限于铝箔。In some embodiments, the positive electrode current collector is a metal, such as, but not limited to, aluminum foil.

正极活性物质可选用本领域技术公知的各种可被用作电化学装置的正极活性物质的能够可逆地嵌入、脱嵌活性离子的传统公知的物质。As the positive electrode active material, various conventionally known materials that can reversibly intercalate and deintercalate active ions and can be used as a positive electrode active material of an electrochemical device, which are known in the art, can be selected.

在一些实施例中，正极活性物质包含锂与钴、锰、镍的金属或其组合的复合氧化物中的至少一种。In some embodiments, the positive active material includes at least one composite oxide of lithium and a metal of cobalt, manganese, nickel, or a combination thereof.

在一些实施例中，正极活性物质包含LiCoO ₂、LiNiO ₂、LiMnO ₂、LiMn ₂O ₄、Li(Ni _aCo _bMn _c)O ₂(0<a<1，0<b<1，0<c<1，a+b+c＝1)、LiMn ₂O ₄LiNi _1-yCo _yO ₂、LiCo _l-yMn _yO ₂、LiNi _l-yMn _yO ₂(0<y<1)、Li(Ni _aMn _bCo _c)04(0<a<2，0<b<2，0<c<2，a+b+c＝2)、LiMn _2-zNi _zO ₄、LiMn _2-zCo _zO ₄(0<z<2)、Li(Ni _aCo _bAl _c)O ₂(0<a<1，0<b<1，0<c<1，a+b+c＝1)、LiCoPO ₄、LiFePO ₄中的至少一种。 In some embodiments, the positive active material comprises LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li(Ni _a Co _b Mn _c )O ₂ (0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiMn ₂ O ₄ LiNi _1-y Co _y O ₂ , LiCo _ly Mn _y O ₂ , LiNi _ly Mn _y O ₂ (0<y<1), Li(Ni _a Mn _b Co _c )04 (0<a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn _2-z Ni _z O ₄ , LiMn _2-z Co _z O ₄ (0<z<2), Li(Ni _a Co _b Al _c )O ₂ (0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiCoPO _4. At least one of LiFePO ₄ .

在一些实施例中，正极活性物质包含硫化物、硒化物、卤化物中的至少一种。In some embodiments, the positive active material includes at least one of sulfide, selenide, and halide.

在一些实施例中，正极活性物质包括第一颗粒和第二颗粒，第一颗粒与第二颗粒的粒径不同。其中，一次颗粒表示未团聚的颗粒，多个一次颗粒经团聚形成二次颗粒。In some embodiments, the positive active material includes first particles and second particles, and the first particles and the second particles have different particle sizes. Among them, the primary particles refer to unagglomerated particles, and a plurality of primary particles are aggregated to form secondary particles.

在一些实施例中，第一颗粒的平均粒径为0.1μm-1.5μm。In some embodiments, the average particle size of the first particles is 0.1 μm-1.5 μm.

在一些实施例中，第二次颗粒的BET比表面积为0.14m ²/g-0.95m ²/g。 In some embodiments, the BET specific surface area of the secondary particles ranges from 0.14 m ² /g to 0.95 m ² /g.

在一些实施例中，正极活性物质的Dv50为5.5μm～14.5μm。其中，Dv50表示颗粒累积分布为50％的粒径。In some embodiments, the Dv50 of the positive active material is 5.5 μm to 14.5 μm. Here, Dv50 represents the particle size at which the cumulative distribution of particles is 50%.

在一些实施例中，正极活性物质的Dv10小于或等于18μm。其中，Dv10表示颗粒累积分布为10％的粒径。In some embodiments, the Dv10 of the positive active material is less than or equal to 18 μm. Among them, Dv10 represents the particle size at which the cumulative distribution of particles is 10%.

在一些实施例中，正极活性物质具有包覆层，包覆层包覆于正极活性物质的表面。在一些实施例中，正极活性物质与具有包覆层的正极活性物质混合。在一些实施例中，包覆层中的包覆元素化合物包含包覆元素的氧化物、包覆元素的氢氧化物、包覆元素的羟基氧化物、包覆元素的碳酸氧盐(oxycarbonate)、包覆元素的碱式碳酸盐中的至少一种。在一些实施例中，包覆层中的包覆元素化合物为非晶形态或结晶形态。在一些实施例中，包覆层中的包覆元素包含Mg、Al、Co、K、Na、Ca、Si、Ti、V、Sn、Ge、Ga、B、As、Zr或它们的混合物。通过在包覆元素化合物中使用所述包覆元素，可以以对正极活性物质的性质没有不利影响的任何方法形成包覆层。形成包覆层的方法可以是本领域公知的任何方法，包括但不限于喷涂、浸渍等。In some embodiments, the positive electrode active material has a coating layer, and the coating layer covers the surface of the positive electrode active material. In some embodiments, the positive active material is mixed with the positive active material having the coating layer. In some embodiments, the cladding element compound in the cladding layer comprises an oxide of a cladding element, a hydroxide of the cladding element, an oxyhydroxide of the cladding element, an oxycarbonate of the cladding element, At least one of the hydroxycarbonates of the coating element. In some embodiments, the cladding element compound in the cladding layer is in an amorphous or crystalline form. In some embodiments, the cladding elements in the cladding layer comprise Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. By using the coating element in the coating element compound, the coating layer can be formed in any method that does not adversely affect the properties of the positive electrode active material. The method of forming the cladding layer may be any method known in the art, including but not limited to spraying, dipping, and the like.

在一些实施例中，正极活性物质层还包含粘结剂和导电材料。粘结剂是本领域公知的可被用作正极活性物质层的粘结剂。在一些实施例中，粘结剂包含聚乙烯醇、羧甲基纤维素、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙中的至少一种。粘结剂用于改善正极活性物质颗粒彼此间以及正极活性物质颗粒与集流体之间的粘结性能。导电材料是本领域公知的可被用作正极活性物质层的导电材料。在一些实施例中，导电材料包含天然石墨、人造石墨、炭黑、乙炔黑、科琴黑、碳纤维、金属粉、金属纤维中的至少一种。在一些实施例中，金属粉包含铜、镍、铝、银的金属粉中的至少一种。在一些实施例中，金属纤维包含铜、镍、铝、银的金属纤维中的至少一种。导电材料用于为电极提供导电性。In some embodiments, the positive active material layer further includes a binder and a conductive material. The binder is known in the art and can be used as a binder for the positive electrode active material layer. In some embodiments, the binder comprises polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-containing Oxygen-based polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic (esterified) styrene-butadiene rubber, epoxy resin, nylon at least one. The binder is used to improve the bonding performance between the positive electrode active material particles and between the positive electrode active material particles and the current collector. The conductive material is a conductive material known in the art that can be used as the positive electrode active material layer. In some embodiments, the conductive material includes at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, and metal fiber. In some embodiments, the metal powder includes at least one of copper, nickel, aluminum, silver metal powders. In some embodiments, the metal fibers comprise at least one of copper, nickel, aluminum, silver metal fibers. Conductive materials are used to provide electrical conductivity to the electrodes.

在一些实施例中，正极片的结构为本领域技术公知的可被用于电化学装置的正极片的结构。In some embodiments, the structure of the positive electrode sheet is known in the art as the structure of the positive electrode sheet that can be used in an electrochemical device.

在一些实施例中，正极片的制备方法是本领域技术公知的可被用于电化学装置的正极片的制备方法。在一些实施例中，在正极浆料的制备中，通常加入溶剂，正极活性物质加入粘结剂并根据需要加入导电材料和增稠剂后溶解或分散于溶剂中制成正极浆料。溶剂在干燥过程中挥发去除。溶剂是本领域公知的可被用作正极活性物质层的溶剂，溶剂例如但不限于N-甲基吡咯烷酮(NMP)。In some embodiments, the preparation method of the positive electrode sheet is known in the art and can be used for the preparation of the positive electrode sheet of the electrochemical device. In some embodiments, in the preparation of the positive electrode slurry, a solvent is usually added, the positive electrode active material is added with a binder, and a conductive material and a thickener are added as required, and then dissolved or dispersed in the solvent to prepare the positive electrode slurry. The solvent is evaporated and removed during the drying process. The solvent is known in the art and can be used as the positive electrode active material layer, such as but not limited to N-methylpyrrolidone (NMP).

本申请对正极片的压实密度没有特别的限制，可以根据实际需要进行调整。在一些实施例中，正极片的压实密度小于或等于3.65g/cm ³。 The compaction density of the positive electrode sheet is not particularly limited in the present application, and can be adjusted according to actual needs. In some embodiments, the compacted density of the positive electrode sheet is less than or equal to 3.65 g/cm ³ .

[负极片][Negative plate]

负极片是本领域技术公知的可被用于电化学装置的负极片。在一些实施例中，负极片包含负极集流体以及负极活性物质层。负极活性物质层设置于负极集流体的表面上。负极活性物质层包含负极活性物质。The negative electrode sheet is a negative electrode sheet known in the art that can be used in an electrochemical device. In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is provided on the surface of the negative electrode current collector. The negative electrode active material layer contains a negative electrode active material.

在一些实施例中，负极集流体金属，例如但不限于铜箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜、包覆有导电金属的聚合物基板或它们的组合。In some embodiments, the negative current collector metal, such as, but not limited to, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, conductive metal clad polymer substrate, or combinations thereof.

负极活性物质可选用本领域技术公知的各种可被用作电化学装置的负极活性物质的能够可逆地嵌入、脱嵌活性离子的传统公知的物质或能够可逆地掺杂、脱掺杂活性离子的传统公知的物质。The negative electrode active material can be selected from various conventionally known materials known in the art that can be used as negative electrode active materials of electrochemical devices, which can reversibly intercalate and deintercalate active ions, or can reversibly dope and dedope active ions. traditionally known substances.

在一些实施例中，负极活性物质包含锂金属、锂金属合金、碳材料中的至少一种。在一些实施例中，锂金属合金包含锂与选自Na、K、Rb、Cs、Fr、Be、Mg、Ca、Sr、Si、Sb、Pb、In、Zn、Ba、Ra、Ge、Al、Sn的金属的合金。碳材料可选用本领域技术公知的各种可被用作电化学装置的碳基负极活性物质的碳材料。在一些实施例中，碳材料包含结晶碳、非晶碳中的至少一种。在一些实施例中，结晶碳为天然石墨或人造石墨。在一些实施例中，结晶碳的形状为无定形、板形、小片形、球形或纤维形。在一些实施例中，结晶碳为低结晶碳或高结晶碳。在一些实施例中，低结晶碳包含软碳、硬碳中的至少一种。在一些实施例中，高结晶碳包含天然石墨、结晶石墨、热解碳、中间相沥青基碳纤维、中间相碳微珠、中间相沥青、高温锻烧炭中的至少一种。在一些实施例中，高温锻烧炭为石油或衍生自煤焦油沥青的焦炭。在一些实施例中，非晶碳包含软碳、硬碳、中间相沥青碳化产物、烧制焦炭中的至少一种。在一些实施例中，负极活性物质包含过渡金属氧化物。在一些实施例中，过渡金属氧化物包含氧化钒、氧化锂钒中的至少一种。在一些实施例中，负极活性物质包含Si、SiOx(0<x<2)、Si/C复合物、Si-Q合金、Sn、SnO _z、Sn-C复合物、Sn-R合金中的至少一种，其中，Q选自碱金属、碱土金属、第13族至第16族元素、过渡元素、稀土元素中的至少一种且Q不为Si，R选自碱金属、碱土金属、第13族至第16族元素、过渡元素、稀土元素中的至少一种且R不为Sn。在一些实施例中，Q和R包含Mg、Ca、Sr、Ba、Ra、Sc、Y、Ti、Zr、Hf、Rf、V、Nb、Ta、Db、Cr、Mo、W、Sg、Tc、Re、Bh、Fe、Pb、Ru、Os、Hs、Rh、Ir、Pd、Pt、Cu、Ag、Au、Zn、Cd、B、Al、 Ga、Sn、In、Tl、Ge、P、As、Sb、Bi、S、Se、Te、Po中的至少一种。在一些实施例中，SiOx(0<x<2)为多孔性负极活性物质。在一些实施例中，SiOx粒子的平均粒径(D ₅₀)为1-20μm。在一些实施例中，在表面进行测定时，SiOx粒子中气孔的平均直径为30-500nm。在一些实施例中，SiOx粒子的比表面积为5-50m ²/g。在一些实施例中，负极活性物质包含SiOx(0<x<2)以及选自Li ₂SiO ₃、Li ₄SiO ₄中的至少一种。在一些实施例中，在Si/C复合物中，碳(C)不是以块状凝聚并分散在Si粒子的内部，而是以原子状态均匀地分散在Si粒子内。在一些实施例中，在Si/C复合物中，C与Si的摩尔比满足：0<C/Si<18。在一些实施例中，基于Si/C复合物的总重量，C的重量百分含量为1wt％-50wt％。在一些实施例中，Si/C复合物粒子的平均粒径为10-100μm。 In some embodiments, the negative active material includes at least one of lithium metal, lithium metal alloy, and carbon material. In some embodiments, the lithium metal alloy comprises lithium and is selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, Alloy of Sn metal. As the carbon material, various carbon materials known in the art that can be used as a carbon-based negative electrode active material of an electrochemical device can be selected. In some embodiments, the carbon material includes at least one of crystalline carbon, amorphous carbon. In some embodiments, the crystalline carbon is natural graphite or artificial graphite. In some embodiments, the crystalline carbon is amorphous, plate, platelet, spherical, or fibrous in shape. In some embodiments, the crystalline carbon is low crystalline carbon or high crystalline carbon. In some embodiments, the low crystalline carbon comprises at least one of soft carbon, hard carbon. In some embodiments, the highly crystalline carbon comprises at least one of natural graphite, crystalline graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesophase carbon microbeads, mesophase pitch, and high temperature calcined carbon. In some embodiments, the high temperature calcined char is petroleum or coke derived from coal tar pitch. In some embodiments, the amorphous carbon comprises at least one of soft carbon, hard carbon, mesophase pitch carbonization product, fired coke. In some embodiments, the negative active material includes a transition metal oxide. In some embodiments, the transition metal oxide comprises at least one of vanadium oxide, lithium vanadium oxide. In some embodiments, the negative active material comprises at least one of Si, SiOx (0<x<2), Si/C composite, Si-Q alloy, Sn, SnO _z , Sn-C composite, Sn-R alloy One, wherein Q is selected from at least one of alkali metals, alkaline earth metals, elements from Groups 13 to 16, transition elements, and rare earth elements, and Q is not Si, and R is selected from alkali metals, alkaline earth metals, 13 At least one of Group to Group 16 elements, transition elements, rare earth elements, and R is not Sn. In some embodiments, Q and R comprise Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, At least one of Sb, Bi, S, Se, Te, and Po. In some embodiments, SiOx (0<x<2) is a porous negative active material. In some embodiments, the SiOx particles have an average particle size (D ₅₀ ) of 1-20 μm. In some embodiments, the pores in the SiOx particles have an average diameter of 30-500 nm when measured on the surface. In some embodiments, the specific surface area of the SiOx particles is 5-50 m ² /g. In some embodiments, the negative electrode active material includes SiOx (0<x<2) and at least one selected from Li ₂ SiO ₃ and Li ₄ SiO ₄ . In some embodiments, in the Si/C composite, the carbon (C) is not aggregated and dispersed in the inside of the Si particles in a bulk, but uniformly dispersed in the Si particles in an atomic state. In some embodiments, in the Si/C composite, the molar ratio of C to Si satisfies: 0<C/Si<18. In some embodiments, the weight percentage of C is 1 wt % to 50 wt % based on the total weight of the Si/C composite. In some embodiments, the Si/C composite particles have an average particle size of 10-100 μm.

在一些实施例中，负极活性物质层还包含粘合剂。粘合剂是本领域公知的可被用作负极活性物质层的粘合剂。在一些实施例中，粘合剂为任何粘合剂聚合物，例如但不限于二氟乙烯一六氟丙烯共聚物(PVDF-co-HFP)，聚偏二氟乙烯、聚丙烯睛、聚甲基丙烯酸甲醋、聚乙烯醇、羧甲基纤维素、羟丙基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙。粘合剂用于改善负极活性物质颗粒之间以及负极活性物质颗粒与负极集流体之间的粘结性能。In some embodiments, the negative active material layer further includes a binder. The binder is known in the art and can be used as the negative electrode active material layer. In some embodiments, the binder is any binder polymer such as, but not limited to, vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate Methyl acrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane , PTFE, polyethylene, polypropylene, styrene-butadiene rubber, acrylic (esterified) styrene-butadiene rubber, epoxy resin, nylon. The binder is used to improve the bonding properties between the negative electrode active material particles and between the negative electrode active material particles and the negative electrode current collector.

在一些实施例中，负极活性物质层还包含导电材料。导电材料是本领域公知的可被用作负极活性物质层的导电材料。在一些实施例中，导电材料为任何不引起化学变化的导电材料，例如但不限碳基材料、金属基材料、导电聚合物，其中，碳基材料例如但不限于天然石墨、人造石墨、炭黑、乙炔黑、科琴黑、碳纤维，金属基材料例如但不限于铜、镍、铝、银等的金属粉或金属纤维，导电聚合物例如但不限于聚亚苯基衍生物。导电材料用于改善负极片的导电率。In some embodiments, the anode active material layer further includes a conductive material. The conductive material is a conductive material known in the art that can be used as the negative electrode active material layer. In some embodiments, the conductive material is any conductive material that does not cause chemical changes, such as but not limited to carbon-based materials, metal-based materials, conductive polymers, wherein carbon-based materials such as but not limited to natural graphite, artificial graphite, carbon Black, acetylene black, Ketjen black, carbon fibers, metal powders or metal fibers of metal-based materials such as but not limited to copper, nickel, aluminum, silver, etc., conductive polymers such as but not limited to polyphenylene derivatives. The conductive material is used to improve the conductivity of the negative electrode sheet.

在一些实施例中，负极片的结构为本领域技术公知的可被用于电化学装置的负极片的结构。In some embodiments, the structure of the negative electrode sheet is known in the art as the structure of the negative electrode sheet that can be used in an electrochemical device.

在一些实施例中，负极片的制备方法是本领域技术公知的可被用于电化学装置的负极片的制备方法。在一些实施例中，在负极浆料的制备中，通常加入溶剂，负极活性物质加入粘合剂并根据需要加入导电材料和增稠剂后溶解或分散于溶剂中制成负极浆料。溶剂在干燥过程中挥发去除。溶剂是本领域公知的可被用作负极活性物质层的溶剂，溶剂例如但不限于水。增稠剂是本领域公知的可被用作负极活性物质层的增稠剂，增稠剂例如但不限于羧甲基纤维素钠。In some embodiments, the preparation method of the negative electrode sheet is known in the art for the preparation method of the negative electrode sheet that can be used in an electrochemical device. In some embodiments, in the preparation of the negative electrode slurry, a solvent is usually added, the negative electrode active material is added with a binder, and a conductive material and a thickener are added as required, and then dissolved or dispersed in the solvent to prepare the negative electrode slurry. The solvent is evaporated and removed during the drying process. The solvent is known in the art and can be used as the negative electrode active material layer, and the solvent is, for example, but not limited to, water. Thickeners are known in the art and can be used as thickeners for the negative active material layer, such as, but not limited to, sodium carboxymethylcellulose.

本申请对负极片的压实密度没有特别的限制，可以根据实际需要进行调整。The compaction density of the negative electrode sheet is not particularly limited in the present application, and can be adjusted according to actual needs.

[隔离膜][Isolation film]

隔离膜是本领域技术公知的可被用于电化学装置的隔离膜，例如但不限于聚烯烃类微多孔膜。在一些实施例中，隔离膜选自聚乙烯(PE)、乙烯-丙烯共聚物、聚丙烯(PP)、乙烯-丁烯共聚物、乙烯-己烯共聚、乙烯-甲基丙烯酸甲酯共聚物中的至少一种。The separator is a separator known in the art that can be used in electrochemical devices, such as, but not limited to, a polyolefin-based microporous membrane. In some embodiments, the release film is selected from polyethylene (PE), ethylene-propylene copolymer, polypropylene (PP), ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-methyl methacrylate copolymer at least one of them.

在一些实施例中，隔离膜为单层隔离膜或多层隔离膜。In some embodiments, the separator is a single-layer separator or a multi-layer separator.

在一些实施例中，聚烯烃类微多孔膜上涂覆有涂层。在一些实施例中，涂层包含有机涂层和无机涂层，其中，有机涂层选自聚偏氟乙烯、偏氟乙烯-六氟丙烯共聚物、聚丙烯腈、聚酰亚胺、丙烯腈-丁二烯共聚物、丙烯腈-苯乙烯-丁二烯共聚物、聚甲基丙烯酸甲酯、聚丙烯酸甲酯、聚丙烯酸乙酯、丙烯酸-苯乙烯共聚物、聚二甲基硅氧烷、聚丙烯酸钠、羧甲基纤维素钠中的至少一种，无机涂层选自SiO ₂、Al ₂O ₃、CaO、TiO ₂、ZnO ₂、MgO、ZrO ₂以及SnO ₂中至少一种。 In some embodiments, the polyolefin-based microporous membrane is coated with a coating. In some embodiments, the coating comprises an organic coating and an inorganic coating, wherein the organic coating is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile -Butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethyl methacrylate, polymethyl acrylate, polyethyl acrylate, acrylic-styrene copolymer, polydimethylsiloxane , at least one of sodium polyacrylate and sodium carboxymethyl cellulose, and the inorganic coating is selected from at least one of SiO ₂ , Al ₂ O ₃ , CaO, TiO ₂ , ZnO ₂ , MgO, ZrO ₂ and SnO ₂ .

本申请对隔离膜的形态和厚度没有特别的限制。本申请对隔离膜的孔隙率没有特别的限制，可以根据实际需要进行调整。隔离膜的制备方法是本领域技术公知的可被用于电化学装置的隔离膜的制备方法。The present application has no particular restrictions on the shape and thickness of the separator. The porosity of the separator is not particularly limited in the present application, and can be adjusted according to actual needs. The preparation method of the separator is known in the art and can be used for the preparation of the separator of the electrochemical device.

[外包装壳体][Outer packaging shell]

在一些实施例中，电化学装置还包含外包装壳体。外包装壳体是本领域技术公知的可被用于电化学装置并且对于所使用的电解液稳定的外包装壳体，例如但不限于金属类外包装壳体。In some embodiments, the electrochemical device further includes an overpack housing. The overwrap case is an overwrap case known in the art that can be used in an electrochemical device and is stable to the electrolyte used, such as, but not limited to, a metal-type overwrap case.

(电子装置)(electronic device)

本申请的电子装置是任何电子装置，例如但不限于笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池、锂离子电容器。注意的是，本申请的电化学装置除了适用于上述例举的电子装置外，还适用于储能电站、海运运载工具、空运运载工具。空运运载装置包含在大气层内的空运运载装置和大气层外的空运运载装置。The electronic device of this application is any electronic device, such as but not limited to notebook computers, pen-type computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, video recorders , LCD TV, Portable Cleaner, Portable CD Player, Mini CD, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Power-assisted Bicycle, Bicycle, Lighting Appliances, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, lithium-ion capacitors. It should be noted that the electrochemical device of the present application is not only applicable to the electronic devices exemplified above, but also applicable to energy storage power stations, marine vehicles, and air vehicles. Airborne vehicles include airborne vehicles within the atmosphere and airborne vehicles outside the atmosphere.

在一些实施例中，电子装置包含本申请前述的电化学装置。In some embodiments, the electronic device comprises an electrochemical device as previously described herein.

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

在下述实施例、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，均可商购获得或合成获得。In the following examples and comparative examples, the used reagents, materials and instruments can be obtained commercially or synthetically unless otherwise specified.

电解液中具体所用到的试剂如下：The specific reagents used in the electrolyte are as follows:

添加剂：additive:

乙酸甲酯、甲基硼酸频哪醇酯；Methyl acetate, pinacol methyl borate;

第一添加剂：First additive:

第二添加剂：Second additive:

第三添加剂：Third additive:

四氟硼酸锂(LiBF ₄)、二氟草酸硼酸锂(LiDFOB)； Lithium tetrafluoroborate (LiBF ₄ ), lithium difluorooxalate borate (LiDFOB);

第四添加剂：Fourth additive:

二氟磷酸锂(LiPO ₂F ₂)、四氟草酸磷酸锂(LiTFOP)； Lithium difluorophosphate (LiPO ₂ F ₂ ), lithium tetrafluorooxalate phosphate (LiTFOP);

有机溶剂：Organic solvents:

碳酸乙烯酯(简写为EC)；Ethylene carbonate (abbreviated as EC);

碳酸丙烯酯(简写为PC)；Propylene carbonate (abbreviated as PC);

碳酸二乙酯(简写为DEC)；Diethyl carbonate (abbreviated as DEC);

锂盐：Lithium salt:

六氟磷酸锂(LiPF ₆)。 Lithium hexafluorophosphate (LiPF ₆ ).

实施例1-56和对比例1-9的锂离子电池均按照下述方法制备The lithium ion batteries of Examples 1-56 and Comparative Examples 1-9 were prepared according to the following methods

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

在含水量<10ppm的氩气气氛手套箱中，将有机溶剂EC、PC和DEC按照3:3:4的质量比混合均匀，再加入充分干燥的锂盐LiPF ₆溶解于上述有机溶剂中，最后加入一定质量的添加剂，充分混合后得到锂盐浓度为1mol/L的电解液。 In an argon atmosphere glove box with water content <10ppm, organic solvents EC, PC and DEC were mixed uniformly in a mass ratio of 3:3:4, and then fully dried lithium salt LiPF ₆ was added to dissolve in the above organic solvent, and finally A certain mass of additives is added and fully mixed to obtain an electrolyte with a lithium salt concentration of 1 mol/L.

(2)正极片的制备(2) Preparation of positive electrode sheet

将正极活性物质NCM811(分子式LiNi _0.8Mn _0.1Co _0.1O ₂)、导电剂乙炔黑、粘结剂聚偏二氟乙烯(简写为PVDF)按重量比96:2:2在适量的N-甲基吡咯烷酮(简写为NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此正极浆料涂覆于正极集流体Al箔上，烘干、冷压，得到正极片，得到的正极片的压实密度为3.50g/cm ³。 The positive active material NCM811 (molecular formula LiNi _0.8 Mn _0.1 Co _0.1 O ₂ ), the conductive agent acetylene black, and the binder polyvinylidene fluoride (abbreviated as PVDF) are mixed in an appropriate amount of N-methyl fluoride in a weight ratio of 96:2:2. Pyrrolidone (abbreviated as NMP) solvent is fully stirred and mixed to form a uniform positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector Al foil, dried and cold pressed to obtain a positive electrode sheet, the obtained positive electrode sheet The compacted density was 3.50 g/cm ³ .

(3)隔离膜的制备(3) Preparation of separator

以单层聚乙烯(PE)多孔聚合物薄膜作为隔离膜，其厚度为5微米，孔隙率为39％，无机涂层为Al ₂O ₃，有机颗粒为聚偏二氟乙烯。 A single-layer polyethylene (PE) porous polymer film was used as the separator, its thickness was 5 microns, the porosity was 39%, the inorganic coating was Al ₂ O ₃ , and the organic particles were polyvinylidene fluoride.

(4)负极片的制备(4) Preparation of negative electrode sheet

将负极活性物质石墨、粘结剂丁苯橡胶(简写为SBR)、增稠剂羧甲基纤维素钠(简写为CMC)按照重量比97.4:1.4:1.2在适量的去离子水溶剂中充分搅拌混合，使其形成均匀的负极浆料；将此负极浆料涂覆于负极集流体Cu箔上，烘干、冷压，得到负极片，得到的负极片的压实密度为1.80g/cm ³。 The negative electrode active material graphite, binder styrene-butadiene rubber (abbreviated as SBR), and thickener sodium carboxymethyl cellulose (abbreviated as CMC) are fully stirred in an appropriate amount of deionized water solvent according to the weight ratio of 97.4:1.4:1.2 Mixing to form a uniform negative electrode slurry; coating the negative electrode slurry on the negative electrode current collector Cu foil, drying and cold pressing to obtain a negative electrode sheet, and the compaction density of the obtained negative electrode sheet is 1.80g/cm ³ .

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

将制得的正极片、隔离膜、负极片按次序层叠，使隔离膜处于正极片和负极片之间起到隔离的作用，然后卷绕得到裸电池；将裸电池置于外包装箔中，留下注液口，从注液口灌注上述制备的电解液，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备。The prepared positive electrode sheets, separators, and negative electrode sheets are stacked in sequence, so that the separators are placed between the positive electrode sheets and the negative electrode sheets to act as isolation, and then rolled to obtain a bare cell; the bare cell is placed in an outer packaging foil, The liquid injection port is left, the electrolyte prepared above is poured from the liquid injection port, and the preparation of the lithium ion battery is completed after the processes of vacuum packaging, standing, forming, shaping and the like.

实施例1-56和对比例1-9中，所用到的添加剂的种类及含量如表1、表2所示，其中，各添加剂的含量为基于电解液的总质量计算得到的重量百分数。In Examples 1-56 and Comparative Examples 1-9, the types and contents of the additives used are shown in Table 1 and Table 2, wherein the content of each additive is the weight percentage calculated based on the total mass of the electrolyte.

表1对比例1-5以及实施例1-21中加入的添加剂种类及含量The types and contents of additives added in Table 1 Comparative Examples 1-5 and Examples 1-21

接下来说明锂离子电池的性能测试过程以及测试结果。Next, the performance test process and test results of the lithium-ion battery are described.

(1)循环性能测试(1) Cycle performance test

在25℃条件下，将锂离子电池以1C恒流充电至4.25V，再在4.25V条件下恒压充电至0.05C，然后以4C的恒电流放电至2.8V，记录放电容量为D ₀；按照上述条件使锂离子电池进行多次“1C充电-4C放电”的循环流程，循环进行800圈，记录第800次循环的放电容量为D。 Under the condition of 25°C, the lithium-ion battery was charged to 4.25V with a constant current of 1C, then charged to a constant voltage of 0.05C under the condition of 4.25V, and then discharged to 2.8V with a constant current of 4C, and the discharge capacity was recorded as D ₀ ; According to the above conditions, the lithium-ion battery is subjected to multiple cycles of "1C charge-4C discharge", and the cycle is carried out for 800 cycles, and the discharge capacity of the 800th cycle is recorded as D.

常温循环后的容量保持率按照下式进行计算：The capacity retention rate after normal temperature cycle is calculated according to the following formula:

25℃循环800圈后的容量保持率(％)＝D/D ₀×100％。 Capacity retention rate (%) after 800 cycles at 25°C = D/D ₀ ×100%.

(2)高温存储性能测试(2) High temperature storage performance test

在25℃下，将锂离子电池以0.5C恒流充电至4.25V，然后恒压充电至电流为0.05C，测试此时锂离子电池的厚度并记为d ₀；之后将锂离子电池放入85℃烘箱中，6h后取出，测试此时锂离子电池的厚度并记为d。 At 25°C, charge the lithium-ion battery with a constant current of 0.5C to 4.25V, and then charge it with a constant voltage until the current is 0.05C. Test the thickness of the lithium-ion battery at this time and record it as d ₀ ; then put the lithium-ion battery into the 85 ℃ oven, take out after 6 hours, test the thickness of the lithium-ion battery at this time and record it as d.

高温存储6h后的厚度膨胀率按照下式进行计算：The thickness expansion rate after high temperature storage for 6h is calculated according to the following formula:

85℃存储6h后的厚度膨胀率(％)＝(d-d ₀)/d ₀×100％。 Thickness expansion ratio (%)=(dd ₀ )/d ₀ ×100% after storage at 85°C for 6 hours.

(期间，若锂离子电池的厚度膨胀率超过50％，则暂停并结束测试。)(During this period, if the thickness expansion rate of the lithium-ion battery exceeds 50%, the test will be suspended and ended.)

表3对比例1-9以及实施例1-56的性能测试结果The performance test results of Table 3 Comparative Examples 1-9 and Examples 1-56

注：无效表示电池无法循环800圈Note: Invalid means that the battery cannot be cycled for 800 cycles

由表3的相关数据分析可知，锂离子电池中加入式(I-A)或式(I-B)表示的化合物时能够具有较好的循环性能和高温存储性能。由表1和表3的数据可以看到，当仅加入含羧酸酯官能团的化合物，或者仅加入含硼酸酯官能团的化合物，或者同时加入含羧酸酯官能团的化合物和含硼酸酯官能团的化合物时，其改善效果均不如直接加入式(I-A)或式(I-B)表示的化合物，这是由于，在式(I-A)和式(I-B)表示的化合物中，硼酸酯官能团能够在正极表面形成保护膜，同时，由于化合物中还含有羧酸酯官能团，因此，羧酸酯官能团随着硼酸酯官能团在正极表面形成保护膜而能够同步附着在正极表面的保护膜上，从而能够较好地减小膜阻抗，同时，保护膜中的硼酸酯官能团能够提高膜的抗氧化性，减少膜的二次氧化分解。式(I-A)或式(I-B)表示的化合物中的羧酸酯官能团和硼酸酯官能团之间发生了上述相互协同作用，该协同作用能够较好地抑制电化学装置在循环过程中阻抗的增加，改善电化学装置的循环性能和高温存储性能。It can be seen from the relevant data analysis in Table 3 that the lithium ion battery can have better cycle performance and high temperature storage performance when the compound represented by formula (I-A) or formula (I-B) is added. It can be seen from the data in Table 1 and Table 3 that when only the compound containing carboxylate functional group is added, or only the compound containing boron ester functional group is added, or the compound containing carboxylate functional group and the functional group containing boronate are added simultaneously When the compound represented by the formula (IA) or the formula (IB) is directly added, the improvement effect is not as good as that of the compound represented by the formula (IA) or the formula (IB). A protective film is formed on the surface, and at the same time, since the compound also contains a carboxylate functional group, the carboxylate functional group can simultaneously attach to the protective film on the positive electrode surface along with the boronate functional group to form a protective film on the surface of the positive electrode. It can effectively reduce the film resistance, and at the same time, the borate functional group in the protective film can improve the oxidation resistance of the film and reduce the secondary oxidative decomposition of the film. The above-mentioned mutual synergistic effect occurs between the carboxylate functional group and the boronate ester functional group in the compound represented by the formula (IA) or the formula (IB), and the synergistic effect can better suppress the increase of the impedance of the electrochemical device during the cycle process. , to improve the cycle performance and high temperature storage performance of electrochemical devices.

根据实施例1-11的相关数据分析可知，当式(I-A)或式(I-B)表示的化合物的质量百分含量为0.3％-3％时，对于锂离子电池的循环性能和高温存储性能的改善效果更佳。According to the relevant data analysis of Examples 1-11, when the mass percentage of the compound represented by formula (IA) or formula (IB) is 0.3%-3%, the cycle performance and high-temperature storage performance of lithium ion batteries are affected. The improvement effect is better.

根据对比例5和实施例1-21的相关数据分析可知，在加入了式(I-A)或式(I-B)表示的化合物的电解液中进一步加入本申请所述的含硫氧双建的化合物时，能够进一步地同时改善锂离子电池的循环性能和高温存储性能，可能的原因是，一方面，含硫氧双建的化合物具有较强的抗氧化能力，在正极材料中不易被氧化，另一方面，在阳极析锂的情况下，含硫氧双建的化合物能够在金属锂表面还原，形成一层保护膜，抑制金属锂与电解液的分解产热，进一步增强对活性材料的保护，从而进一步改善电化学装置的循环性能和高温存储性能。According to the analysis of the relevant data of Comparative Example 5 and Examples 1-21, it can be seen that when the compound of the present application is further added with the sulfur-oxygen doublet compound to the electrolyte solution to which the compound represented by the formula (IA) or the formula (IB) is added , which can further improve the cycle performance and high-temperature storage performance of lithium-ion batteries at the same time. The possible reason is that, on the one hand, the compound containing sulfur and oxygen has strong anti-oxidation ability, and it is not easy to be oxidized in the positive electrode material. On the other hand, in the case of lithium deposition at the anode, the compound containing sulfur and oxygen can be reduced on the surface of metal lithium to form a protective film, which can inhibit the decomposition and heat generation of metal lithium and electrolyte, and further enhance the protection of active materials. Further improve the cycle performance and high temperature storage performance of electrochemical devices.

根据对比例6、7和实施例1-11、22-35的相关数据分析可知，在加入了式(I-A)或式(I-B)表示的化合物的电解液中进一步加入本申请所述的硼酸锂类化合物时，能够进一步地显著改善锂离子电池的高温存储性能，这是由于，第三添加剂具有较高的热稳定性，当添加于电解液中时，能够在负极片的表面形成含氟的保护膜，减少FEC与负极片的反应，抑制气体产生。根据实施例22-35的相关数据分析可知，当本申请所述的硼酸锂类化合物的质量百分含量为0.3％-1％，对于锂离子电池的循环性能和高温存储性能的改善效果更佳。根据对比例6和实施例1-36的相关数据分析可知，在加入了式(I-A)或式(I-B)表示的化合的电解液中进一步加入本申请所述的含硫氧双建的化合物以及本申请所述的硼酸锂类化合物时，能够进一步地同时改善锂离子电池的循环性能和高温存储性能，说明式(I-A)或式(I-B)表示的化合物和本申请所述的含硫氧双建的化合物以及本申请所述的硼酸锂类化合物在负极表面形成保护膜的同时还能够同时在负极析锂的锂金属表面形成保护膜，增强对负极保护的同时，再与正极的成膜保护协同，可进一步抑制电解液的分解，实现对锂离子电池更好的改善效果。According to the relevant data analysis of Comparative Examples 6, 7 and Examples 1-11, 22-35, it can be known that the lithium borate described in this application is further added to the electrolyte solution to which the compound represented by formula (IA) or formula (IB) is added. When added to the electrolyte, the high-temperature storage performance of the lithium-ion battery can be further significantly improved. This is because the third additive has high thermal stability. When added to the electrolyte, it can form fluorine-containing compounds on the surface of the negative electrode sheet. The protective film reduces the reaction between FEC and the negative electrode sheet and inhibits the generation of gas. According to the relevant data analysis of Examples 22-35, it can be seen that when the mass percentage content of the lithium borate compound described in this application is 0.3%-1%, the improvement effect on the cycle performance and high-temperature storage performance of the lithium ion battery is better. . According to the analysis of the relevant data of Comparative Example 6 and Examples 1-36, it can be known that the compound containing sulfur and oxygen described in the present application and When the lithium borate compound described in this application is used, the cycle performance and high temperature storage performance of lithium ion batteries can be further improved simultaneously. The built compound and the lithium borate compound described in this application can form a protective film on the surface of the negative electrode and simultaneously form a protective film on the lithium metal surface of the negative electrode, which enhances the protection of the negative electrode. Synergistically, the decomposition of the electrolyte can be further inhibited, and a better improvement effect on lithium-ion batteries can be achieved.

根据对比例8、9和实施例1-11、37-48的相关数据分析可知，在加入了式(I-A)或式(I-B)表示的化合物的电解液中进一步加入本申请所述的磷酸锂类化合物时，能够进一步地同时改善锂离子电池的循环性能和高温存储性能，这是由于，第四添加剂能够在正极片的表面成膜，减少电解液与正极片的接触，抑制气体产生。根据对比例8、9和和实施例1-56的相关数据分析可知，在加入了式(I-A)或式(I-B)表示的化合物的电解液中进一步加入本申请所述的含硫氧双建的化合物以及本申请所述的磷酸锂类化合物时，能够进一步改善锂离子电池的循环性能和高温存储性能；在加入了式(I-A)或式(I-B)表示的化合物的电解液中进一步加入本申请所述的含硫氧双建的化合物以及本申请所述的硼酸锂类化合物、本申请所述的磷酸锂类化合物时，能够进一步改善锂离子电池的循环性能并显著改善锂离子电池的高温存储性能。说明，本申请所述的几种添加剂组合之间能够相互协作以实现对锂离子电池更好的改善效果。According to the analysis of relevant data of Comparative Examples 8 and 9 and Examples 1-11 and 37-48, it can be seen that the lithium phosphate described in this application is further added to the electrolyte solution to which the compound represented by formula (IA) or formula (IB) is added. When such compounds are used, the cycle performance and high-temperature storage performance of the lithium-ion battery can be further improved at the same time. This is because the fourth additive can form a film on the surface of the positive electrode sheet, reduce the contact between the electrolyte and the positive electrode sheet, and inhibit gas generation. According to the analysis of the relevant data of Comparative Examples 8, 9 and Examples 1-56, it can be known that the sulfur-containing oxygen bicarbonate described in this application is further added to the electrolyte to which the compound represented by formula (IA) or formula (IB) is added. When the compound and the lithium phosphate compound described in this application are used, the cycle performance and high temperature storage performance of the lithium ion battery can be further improved. When the sulfur-oxygen compound described in the application, the lithium borate compound described in this application, and the lithium phosphate compound described in this application can further improve the cycle performance of lithium ion batteries and significantly improve the high temperature of lithium ion batteries storage performance. It is indicated that several additive combinations described in this application can cooperate with each other to achieve better improvement effect on lithium ion batteries.

上面详细的说明描述多个示范性实施例，但本文不意欲限制到明确公开的组合。因此，除非另有说明，本文所公开的各种特征可以组合在一起而形成出于简明目的而未示出的多个另外组合。The foregoing detailed description describes various exemplary embodiments, but is not intended to be limited to the explicitly disclosed combinations. Thus, unless stated otherwise, various features disclosed herein may be combined together to form various additional combinations not shown for brevity.

Claims

一种电解液，其中，所述电解液包括化合物A，所述化合物A包括式(I-A)和式(I-B)表示的化合物中的至少一种；An electrolyte solution, wherein the electrolyte solution includes a compound A, and the compound A includes at least one of the compounds represented by formula (I-A) and formula (I-B);

在式(I-A)和式(I-B)中，In formula (I-A) and formula (I-B),

n选自1-6的整数；n is selected from an integer of 1-6;

R ¹选自式(I-C)、式(I-D)、式(I-E)、式(I-F)表示的结构式中的任意一种， R ¹ is selected from any one of the structural formulas represented by formula (IC), formula (ID), formula (IE) and formula (IF),

表示与相邻原子的结合位点；
represents the binding site with adjacent atoms;

R ¹¹选自氢、经取代或未经取代的C ₁-C ₁₀烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀连烯基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₂-C ₁₀杂环基、经取代或未经取代的含杂原子的官能团，并且，当经取代时，取代基为卤素； R ¹¹ is selected from hydrogen, substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₂ -C ₁₀ alkynyl , substituted or unsubstituted C ₃ -C ₁₀ alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic hydrocarbon group, substituted or unsubstituted C2 _- _C10 heterocyclyl, substituted or unsubstituted heteroatom-containing functional groups, and, when substituted, the substituent is halogen;

R ¹⁷、R ¹⁹、R ^1c各自独立地选自经取代或未经取代的C ₁-C ₁₀亚烷基、经取代或未经取代的C ₂-C ₁₀亚烯基、经取代或未经取代的C ₂-C ₁₀亚炔基、经取代或未经取代的C ₃-C ₁₀亚连烯基、经取代或未经取代的C ₆-C ₁₀亚芳基、经取代或未经取代的C ₃-C ₁₀亚脂环烃基、经取代或未经取代的C ₂-C ₁₀亚杂环基，并且，当经取代时，取代基为卤素； R ¹⁷ , R ¹⁹ , R ^1c are each independently selected from substituted or unsubstituted C ₁ -C ₁₀ alkylene, substituted or unsubstituted C ₂ -C ₁₀ alkenylene, substituted or unsubstituted Substituted C ₂ -C ₁₀ alkynylene, substituted or unsubstituted C ₃ -C ₁₀ alkenylene, substituted or unsubstituted C ₆ -C ₁₀ arylene, substituted or unsubstituted C ₃ -C ₁₀ alicyclic alkylene, substituted or unsubstituted C ₂ -C ₁₀ heterocyclylene, and, when substituted, the substituent is halogen;

R ¹⁴、R ¹⁵、R ¹⁶、R ^1a、R ^1b各自独立地选自经取代或未经取代的C ₁-C ₁₀烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀连烯基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₂-C ₁₀杂环基，并且，当经取代时，取代基为卤素，其中，R ¹⁴和R ¹⁵之间可以键合而形成环结构； R ¹⁴ , R ¹⁵ , R ¹⁶ , R ^1a , R ^1b are each independently selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, Substituted or unsubstituted C ₂ -C ₁₀ alkynyl, substituted or unsubstituted C ₃ -C ₁₀ alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted Substituted C ₃ -C ₁₀ alicyclic hydrocarbon group, substituted or unsubstituted C ₂ -C ₁₀ heterocyclic group, and, when substituted, the substituent is halogen, wherein R ¹⁴ and R ¹⁵ may bond combined to form a ring structure;

R ¹⁸选自经取代或未经取代的C ₁-C ₁₀次烷基、经取代或未经取代的C ₂-C ₁₀次烯基、经取代或未经取代的C ₃-C ₁₀次连烯基、经取代或未经取代的C ₆-C ₁₀次芳基、经取代或未经取代C ₃-C ₁₀次脂环烃基、经取代或未经取代的C ₂-C ₁₀次杂环基，并且，当经取代时，取代基为卤素； R ¹⁸ is selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₃ -C ₁₀ linked Alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic, substituted or unsubstituted C ₂ -C ₁₀ heterocycle and, when substituted, the substituent is halogen;

R ¹²选自经取代或未经取代的C ₁-C ₁₀次烷基、经取代或未经取代的C ₂-C ₁₀次烯基、经取代或未经取代的C ₃-C ₁₀次连烯基、经取代或未经取代的C ₆-C ₁₀次芳基、经取代或未经取代C ₃-C ₁₀次脂环烃基、经取代或未经取代的C ₂-C ₁₀次杂环基，并且，当经取代时，取代基为卤素； R ¹² is selected from substituted or unsubstituted C ₁ -C ₁₀ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted C ₃ -C ₁₀ linked Alkenyl, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic, substituted or unsubstituted C ₂ -C ₁₀ heterocycle and, when substituted, the substituent is halogen;

R ¹³选自共价单键、经取代或未经取代的C ₁-C ₁₀亚烷基、经取代或未经取代的C ₂-C ₁₀亚烯基、经取代或未经取代的C ₂-C ₁₀亚炔基、经取代或未经取代的C ₃-C ₁₀亚连烯基、经取代或未经取代的C ₆-C ₁₀亚芳基、经取代或未经取代的C ₃-C ₁₀亚脂环烃基、经取代或未经取代的C ₂-C ₁₀亚杂环基、经取代或未经取代的含杂原子的官能团，并且，当经取代时，取代基为卤素； R ¹³ is selected from covalent single bond, substituted or unsubstituted C ₁ -C ₁₀ alkylene, substituted or unsubstituted C ₂ -C ₁₀ alkenylene, substituted or unsubstituted C ₂ -C ₁₀ alkynylene, substituted or unsubstituted C ₃ -C ₁₀ alkenylene, substituted or unsubstituted C ₆ -C ₁₀ arylene, substituted or unsubstituted C ₃ - C ₁₀ alicyclic alkylene, substituted or unsubstituted C ₂ -C ₁₀ heterocyclylene, substituted or unsubstituted heteroatom-containing functional groups, and, when substituted, the substituent is halogen;

所述杂原子包括B、N、O、Si、P、S中的至少一种。The heteroatom includes at least one of B, N, O, Si, P, and S.
根据权利要求1所述的电解液，其中，The electrolyte according to claim 1, wherein,

所述化合物A包括式(I-1)至式(I-20)表示的化合物中的至少一种；The compound A includes at least one of the compounds represented by formula (I-1) to formula (I-20);
根据权利要求1所述的电解液，其中，The electrolyte according to claim 1, wherein,

基于所述电解液的总质量，所述化合物A的质量百分含量为0.01％-10％。Based on the total mass of the electrolyte, the mass percentage content of the compound A is 0.01%-10%.
根据权利要求1所述的电解液，其中，还包括含硫氧双建的化合物，所述含硫氧双建的化合物包括式(II-A)和式(II-B)表示的化合物中的至少一种；The electrolyte solution according to claim 1, further comprising a sulfur-oxygen bisulfite-containing compound, the sulfur-oxygen bisulfite-containing compound comprising the compounds represented by formula (II-A) and formula (II-B) at least one;

在式(II-A)和式(II-B)中，In formula (II-A) and formula (II-B),

R ²¹、R ²²、R ²³和R ²⁴各自独立地选自经取代或未经取代的C ₁-C ₅烷基、经取代或未经取代的C ₂-C ₁₀烯基、经取代或未经取代的C ₂-C ₁₀炔基、经取代或未经取代的C ₃-C ₁₀脂环烃基、经取代或未经取代的C ₆-C ₁₀芳基、经取代或未经取代的C ₂-C ₆杂环基中的任意一种，并且，当经取代时，取代基包括卤素和含杂原子的官能团中的至少一种，其中，R ²¹和R ²²之间可以键合而形成环结构，R ²³和R ²⁴之间可以键合而形成环结构； R ²¹ , R ²² , R ²³ and R ²⁴ are each independently selected from substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₁₀ alkenyl, substituted or unsubstituted Substituted C ₂ -C ₁₀ alkynyl, substituted or unsubstituted C ₃ -C ₁₀ alicyclic hydrocarbon, substituted or unsubstituted C ₆ -C ₁₀ aryl, substituted or unsubstituted C Any one of ₂ -C ₆ heterocyclic groups, and, when substituted, the substituent includes at least one of halogen and heteroatom-containing functional groups, wherein R ²¹ and R ²² can be bonded to form Ring structure, R ²³ and R ²⁴ can be bonded to form a ring structure;

所述杂原子包括B、N、O、Si、P、S中的至少一种。The heteroatom includes at least one of B, N, O, Si, P, and S.
根据权利要求4所述的电解液，其中，所述含硫氧双建的化合物包括式(II-1)至式(II-15)表示的化合物中的至少一种；The electrolyte according to claim 4, wherein the compound containing sulfur and oxygen bisulfite comprises at least one of the compounds represented by formula (II-1) to formula (II-15);
根据权利要求4所述的电解液，其中，基于所述电解液的总质量，所述含硫氧双建的化合物的质量百分含量为0.01％-10％。The electrolyte solution according to claim 4, wherein, based on the total mass of the electrolyte solution, the mass percentage of the compound containing sulfur and oxygen is 0.01%-10%.
根据权利要求1所述的电解液，其中，还包括硼酸锂类化合物，所述硼酸锂类化合物包括四氟硼酸锂、二草酸硼酸锂、二氟草酸硼酸锂中的至少一种；The electrolyte according to claim 1, further comprising a lithium borate compound, the lithium borate compound comprising at least one of lithium tetrafluoroborate, lithium dioxalate borate, and lithium difluorooxalate borate;

基于所述电解液的总质量，所述硼酸锂类化合物的质量百分含量为0.01％-1％。Based on the total mass of the electrolyte, the mass percentage content of the lithium borate compound is 0.01%-1%.
根据权利要求1所述的电解液，其中，还包括磷酸锂类化合物，所述磷酸锂类化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂中的至少一种；The electrolyte according to claim 1, further comprising a lithium phosphate compound, the lithium phosphate compound comprising at least one of lithium difluorophosphate, lithium difluorobisoxalate, and lithium tetrafluorooxalate;

基于所述电解液的总质量，所述磷酸锂类化合物的质量百分含量为0.01％-1％。Based on the total mass of the electrolyte, the mass percentage content of the lithium phosphate compound is 0.01%-1%.
一种电化学装置，包括正极片、负极片、隔离膜以及根据权利要求1-8中任一项所述的电解液。An electrochemical device, comprising a positive electrode sheet, a negative electrode sheet, a separator, and the electrolyte according to any one of claims 1-8.
一种电子装置，包括根据权利要求9所述的电化学装置。An electronic device comprising the electrochemical device of claim 9 .