Secondary battery and power consumption device

Abstract

This application provides a secondary battery. The negative electrode active material contains a graphite material, the non-aqueous electrolyte contains a chain carboxylic acid ester, and the OI value of the negative electrode tab, the resistance value R of the negative electrode tab, and the mass ratio W0 of the first solvent in the solvent satisfy 0.08 / mΩ ≤ W0×100 / (R×OI) ≤ 5 / mΩ. Here, the OI value refers to the ratio of the diffraction peak intensity on the 004 crystal plane of the graphite material to the diffraction peak intensity on the 110 crystal plane, and the unit of R is mΩ.

Description

Technical Field

[0001] This application relates to the technical field of secondary batteries, and more particularly to secondary batteries and power consumption devices.

Background Art

[0002] The descriptions herein only provide the background art related to this application and do not necessarily constitute the prior art.

[0003] With the development of secondary battery technology, secondary batteries are widely used in energy storage power systems such as hydraulic, thermal, wind, and solar power plants, and are also used in various fields such as power sources for electronic devices, power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. With the development of science and technology and society, the overall requirements for the rapid charging performance, cycle performance, safety performance, etc. of secondary batteries are further increasing.

[0004] Therefore, it is necessary to develop new technologies for secondary batteries that can balance rapid charging performance, cycle performance, and safety performance.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of the above problems, this application provides a secondary battery including a negative electrode tab and a non-aqueous electrolyte that are appropriately combined, and having an excellent overall function in terms of rapid charging performance, cycle performance, and safety performance, as well as a power consumption device.

Means for Solving the Problems

[0006] According to a first aspect, this application provides a secondary battery including a positive electrode tab, a negative electrode tab, and a non-aqueous electrolyte. The negative electrode tab includes a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material includes a graphite material. The non-aqueous electrolyte includes a solvent, the solvent includes a first solvent, and the first solvent is a chain carboxylic acid ester. The OI value of the negative electrode tab, the resistance value R of the negative electrode tab, and the mass ratio W0 of the first solvent in the solvent satisfy the relationship: 0.08 / mΩ ≤ W0×100 / (R×OI) ≤ 5 / mΩ. However, the OI value of the negative electrode tab refers to the ratio of the diffraction peak intensity on the 004 crystal plane of the graphite material to the diffraction peak intensity on the 110 crystal plane, and the unit of R is mΩ.

[0007] The OI value of the negative electrode tab reflects the degree of anisotropy in the arrangement direction of crystal grains in the negative electrode active material layer. By coordinately controlling the OI value of the negative electrode tab, the resistance value R of the negative electrode tab, and the mass ratio W0 of the solvent in the chain carboxylic acid ester solvent, it is possible to achieve both rapid charging performance, cycle performance, and safety performance of the secondary battery. When the OI value, R, and W0 satisfy the above relationship, the chain carboxylic acid ester in the non-aqueous electrolyte has the characteristics of low viscosity and conductivity, can significantly improve the conductivity of the battery, and can also improve the low-temperature performance and cycle stability of the battery. In addition, the negative electrode tab has an appropriate degree of orientation and has appropriate direction selectivity in the process of intercalating active ions (for example, lithium ions). Thereby, the intercalation expansion of active ions (for example, lithium intercalation expansion) can be dispersed in different directions, reducing the cycle expansion of the tab and the cell, and effectively alleviating the problem of deterioration of the expansion of the tab itself due to poor interfacial stability between the chain carboxylic acid ester and the negative electrode. As a result, the safety of the battery can be improved, the concentration polarization of active ions during the transportation process of the negative electrode tab can be reduced, and the rapid charging ability of the battery can be significantly improved together with the resistance value R of the negative electrode tab. Therefore, by coordinately controlling the OI value, R, and W0, the secondary battery can have excellent comprehensive functions in terms of rapid charging performance, cycle performance, and safety performance, and can achieve both a short rapid charging time, low cycle expansion, and a high cycle capacity retention rate.

[0008] In some embodiments, 6 ≤ OI ≤ 25, optionally, 6 ≤ OI ≤ 18, and more optionally, 12 ≤ OI ≤ 18.

[0009] By adjusting the QI value within a relatively appropriate range, it is further advantageous to reduce the direction selectivity in the occlusion process of active ions, and to better disperse the occlusion expansion of active ions in different directions. In addition, the transport performance of active ions in the negative electrode tab can also be improved better.

[0010] In some embodiments, 1 mΩ ≤ R ≤ 50 mΩ, optionally, 5 mΩ ≤ R ≤ 30 mΩ, and further optionally, 10 mΩ ≤ R ≤ 20 mΩ.

[0011] By controlling the resistance value R of the negative electrode tab within a certain range, W0×100 / (R×OI) can be controlled within a more appropriate range. Therefore, it is further advantageous to achieve a better comprehensive effect in terms of short rapid charging time, low cycle expansion, and high cycle capacity retention rate, and to improve the transport performance and electron transfer performance of active ions in the negative electrode tab.

[0012] In some embodiments, 10% ≤ W0 ≤ 80%, optionally, 20% ≤ W0 ≤ 80%, further optionally, 30% ≤ W0 ≤ 70%, and still further optionally, 50% ≤ W0 ≤ 70%. Also, optionally, 10% ≤ W0 ≤ 60%, and further optionally, 20% ≤ W0 ≤ 60%.

[0013] By controlling the content W0 of the first solvent in the solvent within a certain range, it is further advantageous to improve the conductivity of the battery while achieving both rapid charging performance, cycle performance, and safety performance of the secondary battery, and to further improve the low-temperature performance and cycle stability of the secondary battery.

[0014] In some embodiments, 0.67 ≤ W0×100 / OI ≤ 10, optionally, 1 ≤ W0×100 / OI ≤ 10, further optionally, 1 ≤ W0×100 / OI ≤ 5, and still further optionally, 3 ≤ W0×100 / OI ≤ 5. Alternatively, selectively, 0.67 ≦ W0 × 100 / OI ≦ 4, and more selectively, 1 ≦ W0 × 100 / OI ≦ 4.

[0015] After controlling such that W0 × 100 / (R × OI) satisfies the above relationship, by further adjusting and controlling the combination situation of the chain carboxylic acid ester in the non-aqueous electrolyte and the crystal grain alignment direction in the negative electrode active material layer by W0 × 100 / OI, it is easier to realize an improvement in the overall performance including rapid charging performance, cycle performance, and safety performance.

[0016] In some embodiments, 0.1 / mΩ ≦ W0 × 100 / (R × OI) ≦ 5 / mΩ, and selectively, 0.1 / mΩ ≦ W0 × 100 / (R × OI) ≦ 2 / mΩ.

[0017] By further controlling W0 × 100 / (R × OI) within the above range, it is more advantageous for overall and comprehensive improvement of rapid charging performance, cycle performance, and safety performance.

[0018] In some embodiments, the secondary battery satisfies a combination of features of 6 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 20% ≦ W0 ≦ 80%, selectively, 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 10% ≦ W0 ≦ 60%, and more selectively, 20% ≦ W0 ≦ 60%. Alternatively, selectively, 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 50% ≦ W0 ≦ 70%.

[0019] By finely and coordinately controlling such that the OI value of the negative electrode tab is 12 to 18, the resistance value R of the negative electrode tab is 10 mΩ to 20 mΩ, and the mass ratio W0 in the solvent of the chain carboxylic acid ester solvent is 20% to 80% (more selectively 10% to 60%), it is possible to better realize the compatibility of rapid charging performance, cycle performance, and safety performance. As a result, it is more advantageous for the secondary battery to simultaneously have excellent rapid charging ability, low cycle expansion, and high cycle capacity retention rate.

[0020] By controlling the values of different parameters, it may be more advantageous in one or several aspects. For example, when 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 20% ≦ W0 ≦ 60%, it can further have significantly excellent low cycle expansion and cycle performance on the basis of excellent comprehensive performance. Also, for example, when 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 50% ≦ W0 ≦ 70%, it can further have significant advantages in short rapid charging time and low cycle expansion on the basis of excellent comprehensive performance.

[0021] In some embodiments, the first solvent contains a compound whose structure is shown in formula (1).

[0022] JPEG2025519071000002.jpg30129 However, R1 and R2 are each independently a C 1-3 alkyl group or a C 1-3 halogenated alkyl group, Optionally, R1 and R2 are each independently a C 1-3 alkyl group or a C 1-3 fluorinated alkyl group. Further optionally, R1 and R2 are each independently one of a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group, Also, further optionally, R1 and R2 are each independently one of a methyl group, an ethyl group, a fluoromethyl group, and a fluoroethyl group. Also, further optionally, the first solvent contains one or more of the compounds such as methyl acetate, ethyl acetate, methyl difluoroacetate, and ethyl difluoroacetate.

[0023] A first solvent with a small molecular size may be selected. In this case, the viscosity of the first solvent is low, and it is advantageous for the secondary battery to obtain better rapid charging performance.

[0024] In some embodiments, the non-aqueous electrolyte further contains a first additive, and the first additive is a diisocyanate.

[0025] In some embodiments, the first additive includes a compound whose structure is represented by formula (2).

[0026] JPEG2025519071000003.jpg30129 However, R3 is an unsubstituted or Ra-substituted C 1-18 hydrocarbylene group, and Ra includes one or more of substituents such as a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC(=O)R 11 , R 12 OC(=O)-, C 1-10 alkyl group, C 2-10 alkenyl group, C 2-10 alkynyl and C 2-10 oxaalkyl group, and R 11 and R 12 are each independently an alkyl group or a halogenated alkyl group. Optionally, R3 is a C 2-10 alkylene group, C 2-10 heteroalkylene group, C 6-18 arylene group, C 2-18 heteroarylene group, C 3-18 alicyclic or C 3-18 heteroalicyclic, and any one of the above-mentioned groups is unsubstituted or Ra-substituted. Also, optionally, R3 is an unsubstituted or Ra-substituted C 2-10 alkylene group, an unsubstituted or Ra-substituted C 3-18 divalent cycloalkyl or an unsubstituted or Ra-substituted C 6-18 arylene group, and further optionally, R3 is a C 2-10 alkylene group, C 6-18 divalent cycloalkyl or C 6-18 arylene group, and furthermore optionally, R3 is a C 4-10 alkylene group, C 6-14 divalent cycloalkyl or C 6-14It is an arylene group. Further selectively, R3 is C 4-10 an alkylene group, C 6-10 a divalent cycloalkyl or C 6-10 an arylene group. Further selectively, R3 is C 4-8 a hexylene group, C containing a hexyl ring 6-10 a divalent cycloalkyl or C containing a benzene ring 6-10 an arylene group. Also selectively, the first additive contains one or more of the compounds hexamethylene diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, and 2,4-diisocyanate-1-toluene.

[0027] In some embodiments, the mass ratio of the first additive in the non-aqueous electrolyte is 0 to 11%, Selectively, the mass ratio of the first additive in the non-aqueous electrolyte is 0.005% to 11%, More selectively, the mass ratio of the first additive in the non-aqueous electrolyte is 0.005% to 10%. Also more selectively, the mass ratio of the first additive in the non-aqueous electrolyte is 0.01% to 10%, Also more selectively, the mass ratio of the first additive in the non-aqueous electrolyte is 0.1% to 5%, Also more selectively, the mass ratio of the first additive in the non-aqueous electrolyte is 1% to 5%.

[0028] Introducing a chain carboxylic acid ester (first solvent) is advantageous for improving the rapid charging ability of the battery. However, due to the compatibility factors between the carboxylic acid ester and the negative electrode tab, if the consistency among its usage amount W0, the OI value of the negative electrode tab, and the resistance value R is not good, it may exacerbate the swelling problem existing in the negative electrode tab itself, may also affect the problem of gas generation existing at the interface, and may further cause capacity fade of the cell and deterioration of the cycle performance of the battery. By introducing a first additive into the non-aqueous electrolyte, a solid electrolyte interface (SEI) layer having a protective effect can be formed on the surface of the negative electrode tab. The protective layer can cooperate with the occlusion of active ions into the negative electrode active material layer of the negative electrode tab, and can uniformly transmit the occlusion expansion effect caused by the active ions of the negative electrode tab in all directions. Thereby, the cycle expansion rate of the negative electrode tab is reduced. In addition, the first additive can also significantly improve the stability of the interface between the electrolyte and the negative electrode tab, can reduce the consumption of the electrolyte and the destruction of the negative electrode structure during the cycle process of the secondary battery, and can significantly improve the cycle performance of the secondary battery.

[0029] In some embodiments, the non-aqueous electrolyte further includes a second additive, and the second additive includes one or more of lithium monofluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate, the compound represented by formula (3), and fluorosulfonate.

[0030] JPEG2025519071000004.jpg37129 In formula (3), a, b, and c are each independently a positive integer, m is an integer selected from 1-3, n is an integer selected from 0-4, q is 0 or 1, and M a+ is a metal ion having an a-valent positive charge, any one Y is independently a boron atom or a phosphorus atom, and X is a halogen atom. Also, any one R is independently a substituted or unsubstituted C 1-10 alkylene group, a substituted or unsubstituted C 1-10 halogenated alkylene group, a substituted or unsubstituted C 6-20An arylene group, and a substituted or unsubstituted C 6-20 is one of a halogenated arylene group, Optionally, any one of R is independently a C substituted or unsubstituted with Rc 1-10 alkylene group, a C substituted or unsubstituted with Rc 1-10 halogenated alkylene group, a C substituted or unsubstituted with Rc 6-20 arylene group, and a C substituted or unsubstituted with Rc 6-20 is one of a halogenated arylene group. Also, the substituent in the C 1-10 alkylene group substituted with Rc, the substituent in the C 1-10 halogenated alkylene group substituted with Rc, the substituent in the C 6-20 arylene group substituted with Rc and the Rc substituent in the C 6-20 halogenated arylene group may each independently contain one or more of a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC=(O)R 41 , -C=(O)OR 42 , C 1-10 alkyl group, C 2-10 alkenyl group, C 2-10 alkynyl and C 2-10 may contain one or more of the substituents of an alkoxy group. However, R 41 and R 42 are each independently a C 1-6 alkyl group, Optionally, in the non-aqueous electrolyte, M a+ in contains one or more of Li, Na, K, Rb, Cs, Mg, Ca, Ba, Al, Fe, Cu and Ni, Optionally, a, b and c are each independently selected from 1, 2 or 3.

[0031] In some embodiments, the second additive includes one or more of lithium difluorophosphate, lithium monofluorophosphate, lithium tetrafluoroborate, lithium fluorosulfonate and sodium fluorosulfonate.

[0032] In some embodiments, the mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 11%, Optionally, the mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 11%, Furthermore, the mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 10%. Also, optionally, the mass ratio of the second additive in the non-aqueous electrolyte is 0.05% to 5%.

[0033] By introducing a second additive into the non-aqueous electrolyte, an SEI film with a high content of inorganic substances can be formed on the negative electrode. Thereby, the rapid charging performance of the secondary battery can be improved, and the cycle performance of the secondary battery can also be further improved.

[0034] In some embodiments, the volume average particle size D of the negative electrode active material v 50 ≥ 6 μm. However, D v 50 represents the particle size corresponding when the cumulative volume distribution percentage of the substance or material reaches 50%, Optionally, the volume average particle size D of the negative electrode active material v 50 is 6 μm to 20 μm, Furthermore optionally, the volume average particle size D of the negative electrode active material v 50 is 15 μm to 20 μm.

[0035] By controlling the particle size of the negative electrode active material to have a relatively large particle size, the contact area between the negative electrode material and the electrolyte can be reduced. Thereby, the probability of side reactions with the solvent on the negative electrode surface can be reduced, which is more advantageous for reducing the tab expansion rate, and the cycle performance of the cell can be improved better.

[0036] In some embodiments, the BET specific surface area of the negative electrode active material is 0.5 m 2 / g to 2.0 m 2 / g, Optionally, the BET specific surface area of the negative electrode active material is 0.8 m 2 / g to 1.5 m2 It is / g.

[0037] By controlling the particle size of the negative electrode active material to have a certain specific surface area, the surface area of the negative electrode material can be reduced. Thereby, the contact area between the negative electrode material and the electrolyte is reduced, the occurrence of side reactions of the solvent on the negative electrode surface is reduced, and the cycle performance of the cell is improved better.

[0038] In some embodiments, the graphite material includes one or more of artificial graphite and natural graphite. Optionally, the graphite material includes artificial graphite.

[0039] In some embodiments, the weight percentage of the graphite material in the negative electrode active material ≥ 50%. Optionally, the weight percentage of the graphite material in the negative electrode active material ≥ 80%. Further optionally, the weight percentage of the graphite material in the negative electrode active material is 100%.

[0040] In some embodiments, the secondary battery is a lithium-ion secondary battery.

[0041] According to a second aspect, the present application provides a power consumption device including the secondary battery described in the first aspect of the present application.

[0042] Details of one or more embodiments of the present application are provided in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the specification, drawings, and claims.

Brief Description of the Drawings

[0043] To better describe or explain the embodiments or examples of these applications disclosed herein, one or more drawings can be referred to. Additional details or examples for describing the drawings should not be considered as limiting any one of the disclosed applications, the currently described embodiments or examples, and the currently understood optimal aspects of these applications. And in all the drawings, similar members are denoted by similar reference numerals.

[0044]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0045] Hereinafter, some embodiments of the secondary battery and the power consumption device disclosed in the present application will be described in detail with appropriate reference to the drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of matters that are already well-known or a repeated description of substantially the same structure may be omitted. This is to avoid making the following description unnecessarily long and to facilitate the understanding of those skilled in the art. Note that the drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand the present application and are not intended to limit the theme described in the claims.

[0046] The "range" of numerical values disclosed in this application is limited in the form of a lower limit and an upper limit. When a given range is limited by selecting one lower limit and one upper limit, the selected lower limit and upper limit define the boundaries of the specific range. The range thus limited may or may not include the end values, either end value may be independently included or not included, and they may be combined in any way. That is, one range may be formed by combining any lower limit with any upper limit. For example, when ranges such as 60-120 and 80-110 are listed for a specific parameter, it should be understood that ranges of 60-110 and 80-120 are also contemplated. In addition, when the minimum range values 1 and 2 are listed, and the maximum range values 3, 4, and 5 are further listed, ranges of 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5 are all possible. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviated expression of any combination of real numbers between a and b, and both a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this application, and "0-5" is just an abbreviated expression of the combination of these numerical values. Also, when expressing a certain parameter as an integer greater than or equal to 2, it is equivalent to disclosing that the parameter is an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when expressing a certain parameter as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0047] Unless otherwise specified, new technical solutions can be formed by combining all the embodiments and alternative embodiments of this application with each other.

[0048] Unless otherwise specified, all steps of the present application may be performed in order, may be performed randomly, and are preferably performed in order. For example, the fact that the method includes steps (a) and (b) means that the method may include steps (a) and (b) performed in order, or may include steps (b) and (a) performed in order. For example, the fact that the method may further include step (c) means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), may include steps (a), (c), and (b), may include steps (c), (a), and (b), etc.

[0049] Unless otherwise specified, the terms "having", "including", "containing", and "comprising" referred to in the present application may each independently represent an open end or a closed end. For example, the "including" and "comprising" can mean that they may further include or comprise other elements or sequence features not listed, or may include or comprise only the listed elements or sequence features. Elements are, for example, materials or components, structures, elements, devices, etc. A non-limiting listing of sequence features is, for example, operations, conditions under which the operations occur, timings, states, etc.

[0050] Unless otherwise specified, in the present application, the term "or" is inclusive. For example, the phrase "A or B" represents "A, B, or both A and B". Further, any one of the conditions that A is true (or exists), and B is false (or does not exist), A is false (or does not exist) but B is true (or exists), or both A and B are true (or exist) satisfies the condition of "A or B".

[0051] In the present application, unless otherwise explained, A (for example, B) means that B is a non-limiting example of A, and as can be understood, A is not limited to B.

[0052] In this application, unless otherwise stated, features or solutions corresponding to "and / or" include any one of two or more listed related items, and also include any or all combinations of the listed related items. The above-mentioned any and all combinations include combinations of any two listed related items, any more listed related items, or combinations of all listed related items. For example, "A and / or B" represents a set composed of A, B, and "the combination of A and B". Here, "including A and / or B" may represent "including A, including B, and including A and B", or may further represent "including A, including B, or including A and B", which can be appropriately understood according to the context of the located text.

[0053] In this application, when referring to "a plurality", "a plurality of types", etc., unless otherwise limited, it means that the number is 2 or more. For example, "one or more" means one or two or more. As can be understood, when referring to "any plurality of" items, it means any appropriate combination of a plurality of items, that is, a combination of "any plurality of" items carried out in a manner that is non-contradictory and capable of implementing this application.

[0054] In this application, expressions such as "its combination", "any combination thereof", "any combination manner thereof", etc. include all appropriate combination manners of any two or more of the listed items.

[0055] In this application, "appropriate" in expressions such as "appropriate combination manner", "appropriate manner", "any appropriate manner", etc. is in line with the ability to implement the technical solution of this application.

[0056] In this application, "preferred" and "better" are merely for describing embodiments or examples with better effects. It should be understood that they do not constitute a limitation on the protection scope of this application. If multiple "preferred" appear in one technical solution, and there is no special explanation and no contradiction or mutual restriction relationship, each "preferred" is independent.

[0057] In this application, "selectively", "selective", and "selectable" may or may not exist, that is, they refer to any one selected from the parallel options of "present" or "absent". When multiple "selectable" appear in one technical solution, without special explanation and without contradiction or mutual restriction relationship, each "selectable" item is independent.

[0058] In this application, terms such as "further", "even further", and "special" are used to describe the purpose or represent the difference in content, but should not be understood as a limitation to the protection scope of this application.

[0059] In this application, in "the first aspect", "the second aspect", etc., the terms "first", "second", etc. are only for the purpose of describing the purpose, and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the indicated technical features. And "first", "second", etc. only play a role in listing the purpose of description non-exclusively, and should be understood that they do not constitute a closed limitation to the number.

[0060] In this application, regarding the unit of the data range, when the unit is attached only after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, 3~5h or 3-5h both indicate that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0061] In the description of the embodiments of this application, the weight of the related components mentioned can not only refer to the content of each component, but also represent the proportional relationship of the weights between the components. Therefore, if the content of the related components in the description of the embodiments of this application is enlarged or reduced according to the proportion, they are all within the scope disclosed in the description of the embodiments of this application. Furthermore, the weight described in the description of the embodiments of this application may be a mass unit well-known in the chemical industry field such as μg, mg, g, kg, etc.

[0062] With the development of science and technology and society, higher comprehensive requirements are imposed on the rapid charging performance, cycle performance, safety performance, etc. of secondary batteries. The electrolyte has an important impact on the realization of the above comprehensive performance of secondary batteries. Compared with other types of ester solvents, chain carboxylic acid esters have a lower freezing point and a smaller viscosity, can significantly improve the conductivity of the battery, and can improve the low-temperature performance and cycle stability of the battery. However, the stability of the interface between the chain carboxylic acid ester and the negative electrode is poor, which not only worsens the swelling problem existing in the tab itself, but also affects the gas generation problem existing at the interface, accelerates the capacity fade of the cell, and deteriorates the cycle performance of the battery. In addition, after such an electrolyte undergoes long-term cycle use, especially at high temperature and high pressure, the swelling problem of the tab deteriorates, which has a serious impact on the service life of the cell and ultimately leads to safety problems.

[0063] Regarding the above generally existing technical problems, according to the first aspect, the present application provides a secondary battery including a positive electrode tab, a negative electrode tab, and a non-aqueous electrolyte. The negative electrode tab includes a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, the negative electrode active material includes a graphite material, the non-aqueous electrolyte includes a solvent, the solvent includes a first solvent, and the first solvent is a chain carboxylic acid ester. The OI value of the negative electrode tab, the resistance value R of the negative electrode tab, and the mass ratio W0 of the first solvent in the solvent satisfy the relationship of 0.08 / mΩ ≦ W0×100 / (R×OI) ≦ 5 / mΩ. However, the OI value of the negative electrode tab refers to the ratio of the diffraction peak intensity on the 004 crystal plane of the graphite material to the diffraction peak intensity on the 110 crystal plane, and the unit of R is mΩ.

[0064] In this application, unless otherwise specified, the electrode tab may be a positive electrode tab or a negative electrode tab. The "active material" in the electrode tab refers to a material having the ability to reversibly occlude and release active ions. Unless otherwise specified, the "negative electrode active material" refers to a material used for the negative electrode tab and having the ability to reversibly occlude and release active ions. The "positive electrode active material" refers to a material used for the positive electrode tab and having the ability to reversibly occlude and release active ions. When the secondary battery is charged, active ions are released from the positive electrode and occluded in the negative electrode through the electrolyte. On the other hand, when the secondary battery is discharged, active ions are released from the negative electrode and occluded in the positive electrode. The active ions are not particularly limited and may be lithium ions, in which case it corresponds to a lithium ion secondary battery.

[0065] In this application, "active material" and "active material" have the same meaning and may be used synonymously. "Positive electrode active material" and "positive electrode active material" have the same meaning and may be used synonymously. "Negative electrode active material" and "negative electrode active material" have the same meaning and may be used synonymously.

[0066] In this application, unless otherwise specified, the "active material layer" includes the positive electrode active material layer of the positive electrode tab and the negative electrode active material layer of the negative electrode tab, and may refer to the positive electrode active material layer or the negative electrode active material layer depending on the detailed situation. As can be understood, the positive electrode active material layer contains the positive electrode active material, and the negative electrode active material layer contains the negative electrode active material.

[0067] In the present application, the OI value of the negative electrode tab has the meaning well-known in the art. The OI value of the negative electrode tab refers to the ratio of the diffraction peak intensity of the 004 crystal plane of the graphite material in the negative electrode active material layer to the diffraction peak intensity of the 110 crystal plane, and can be used to characterize the orientation of the negative electrode active material layer, and can reflect the degree of anisotropy of the crystal grain arrangement in the negative electrode active material layer. The layer structure corresponding to the 004 crystal plane is parallel to the graphite of the electrode tab, and the layer structure corresponding to the 110 crystal plane is perpendicular to the graphite of the electrode tab. The smaller the OI value, the more advantageous it is for the diffusion of active ions (for example, lithium ions), and the more advantageous it is to reduce the expansion of the tab itself. The intensity of the diffraction peak in the 004 crystal plane and the diffraction peak in the 110 crystal plane can be tested by an X-ray powder diffractometer (a non-limiting example is X´pert PRO), and an X-ray diffraction spectrum can be obtained according to the general rules of X-ray diffraction analysis method and the lattice constant measurement method of graphite JIS K 0131-1996, JB / T4220-2011. And, OI = I 004 / I 110 According to this, the ratio of the intensity of the diffraction peak in the 004 crystal plane and the diffraction peak in the 110 crystal plane of the negative electrode active material layer is obtained. However, I 004 is the intensity of the diffraction peak in the 004 crystal plane, and I 110 is the intensity of the diffraction peak in the 110 crystal plane.

[0068] In some embodiments, the OI value of the negative electrode tab may be adjusted by at least one parameter such as the OI value of the graphite particles, the particle size of the graphite particles (for example, D v 50), the porosity of the negative electrode tab, the press density of the negative electrode tab, the components, types and contents of the negative electrode tab, etc., but not limited thereto. This can be realized by those skilled in the art.

[0069] In the present application, the resistance value R of the negative electrode tab has the meaning well-known in the art. Without other explanations, R in the present application may be obtained by testing with a resistance meter. For example, the test may be carried out with a BER1300 multifunctional tab resistance meter. Further, the negative electrode tab is cut into a sample to be measured having a certain size (a small circular sheet with a diameter of 40 mm), the sample to be measured is placed between two probes of a resistance meter (for example, a BER1300 multifunctional tab resistance meter), the test value of the resistance value is recorded, a plurality of (for example, at least five) samples to be measured are taken, and the average value of the plurality of samples to be measured is calculated and used as the test result of the resistance value R of the negative electrode tab. The test may also be carried out by adopting such a method.

[0070] In the present application, the "chain carboxylic acid ester" has the meaning well-known in the art. The chain carboxylic acid ester refers to a carboxylic acid ester organic compound having an ester group (-C(=O)-O-) structure and not containing a ring structure in the carboxylic acid ester. In the present application, the chain carboxylic acid ester serves as a solvent and is denoted as the first solvent. As can be understood, both of the substances bonded to both sides of -C(=O)-O- are chain structures, not cyclic structures, and -C(=O)-O- itself is not involved in ring formation. As can be understood, the chain carboxylic acid ester is a liquid in the cell.

[0071] By coordinately controlling the OI value of the negative electrode tab and the mass ratio W0 of the chain carboxylic acid ester solvent in the solvent, it is possible to achieve both rapid charging performance, cycle performance, and safety performance of the secondary battery. When the OI value and W0 satisfy 0.08 / mΩ ≦ W0×100 / (R×OI) ≦ 5 / mΩ having the above relationship, the chain carboxylic acid ester in the non-aqueous electrolyte has characteristics of low viscosity and conductivity. Therefore, the conductivity of the battery can be significantly improved, and the low-temperature performance and cycle stability of the battery can also be improved. In addition, the negative electrode tab has an appropriate degree of orientation, has appropriate direction selectivity in the process of occluding active ions (for example, lithium ions), and can disperse the occlusion expansion of active ions (for example, lithium occlusion expansion) in different directions. As a result, the cycle expansion of the tab and the cell is reduced, the problem of deterioration of the expansion of the tab itself due to poor interfacial stability between the chain carboxylic acid ester and the negative electrode is effectively alleviated, the safety of the battery is improved, the concentration polarization of active ions in the transportation process of the negative electrode tab can also be reduced, and the rapid charging ability of the battery is greatly improved together with the resistance value R of the negative electrode tab. Therefore, by coordinately controlling the OI value, R, and W0, the secondary battery can have excellent comprehensive functions in terms of rapid charging performance, cycle performance, and safety performance, and can achieve both a short rapid charging time, low cycle expansion, and a high cycle capacity retention rate.

[0072] In the present application, when the value of W0×100 / (R×OI) is large, it is advantageous for the rapid charging ability of the battery. However, if the value is too large, it is likely to cause excessive expansion of the tab itself, and significantly deteriorate the cycle and safety performance of the cell. If W0×100 / (R×OI) is too high, there is a possibility of causing the release of the tab, resulting in the inability of the cell to operate.

[0073] In some embodiments, 6 ≦ OI ≦ 25, optionally 6 ≦ OI ≦ 18, and further optionally 12 ≦ OI ≦ 18. The OI value of the negative electrode tab may be any one of the numerical values such as 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or may be selected from an interval composed of any two numerical values. The OI value of the negative electrode tab may be selected from any one of the ranges such as 6 - 15, 12 - 25, 6 - 18, 14 - 16, etc.

[0074] By adjusting the QI value within a relatively appropriate range, it is further advantageous to reduce the direction selectivity in the process of intercalation of active ions, and to better disperse the intercalation expansion of active ions in different directions. In addition, the transport performance of active ions of the negative electrode tab can also be better improved.

[0075] In some embodiments, 1 mΩ ≦ R ≦ 50 mΩ, optionally 5 mΩ ≦ R ≦ 30 mΩ, and further optionally 10 mΩ ≦ R ≦ 20 mΩ. The resistance value R of the negative electrode tab may be any one of the numerical values such as 1 mΩ, 2 mΩ, 3 mΩ, 4 mΩ, 5 mΩ, 6 mΩ, 8 mΩ, 10 mΩ, 12 mΩ, 15 mΩ, 16 mΩ, 18 mΩ, 20 mΩ, 25 mΩ, 30 mΩ, 35 mΩ, 40 mΩ, 45 mΩ, 50 mΩ, or may be selected from an interval composed of any two numerical values. The resistance value R of the negative electrode tab may be selected from any one of the ranges such as 12 mΩ - 18 mΩ, 14 mΩ - 16 mΩ, 5 mΩ - 20 mΩ, 5 mΩ - 18 mΩ, 10 mΩ - 18 mΩ, etc.

[0076] In some embodiments, the resistance value R of the negative electrode tab may be adjusted in ways such as the press density of the negative electrode tab, the porosity of the negative electrode tab, the components, types and contents of the negative electrode tab, etc., but not limited thereto. For example, by adjusting the type and / or content of the conductive agent in the negative electrode tab, the resistance value R of the negative electrode tab can be adjusted.

[0077] By controlling the resistance value R of the negative electrode tab within a certain range, it is possible to control W0×100 / (R×OI) within a more appropriate range. Therefore, it is more advantageous to achieve a better overall effect in terms of short rapid charging time, low cycle expansion, and high cycle capacity retention rate, and further improve the transport performance of active ions and the electron transfer performance of the negative electrode tab.

[0078] In the present application, the mass ratio of the first solvent in the solvent is denoted as W0.

[0079] In some embodiments, 10%≦W0≦80%. W0 may be any one of the percentages such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc., or may be selected from the intervals composed of any two of the above-mentioned percentages. For example, 20%≦W0≦80%, 30%≦W0≦70%, 50%≦W0≦70%, 10%≦W0≦60%, 20%≦W0≦60%, etc. may also be possible.

[0080] By controlling the content W0 of the chain carboxylic acid ester (the first solvent) in the solvent within a certain range, it is more advantageous to improve the conductivity of the battery while achieving both rapid charging performance, cycle performance, and safety performance of the secondary battery, and further advantageous to improve the low-temperature performance and cycle stability of the secondary battery.

[0081] In some embodiments, 0.67≦W0×100 / OI≦10. W0×100 / OI may further be any one of the numerical values such as 0.67, 0.8, 1, 1.2, 1.3, 1.33, 1.33±0.01, 1.4, 1.5, 2, 2.5, 2.67, 2.67±0.01, 3, 4, 4.5, 4.67, 4.67±0.01, 5, 5.33, 5.33±0.01, 6, 7, 8, 9, 10, etc., or may be selected from the intervals composed of any two numerical values.

[0082] In some embodiments, 1 ≦ W0×100 / OI ≦ 10, optionally, 1 ≦ W0×100 / OI ≦ 5, and more optionally, 3 ≦ W0×100 / OI ≦ 5.

[0083] In some embodiments, 0.67 ≦ W0×100 / OI ≦ 4, optionally, 1 ≦ W0×100 / OI ≦ 4.

[0084] After controlling so that W0×100 / (R×OI) satisfies the above relationship, by further adjusting and controlling the combination situation of the chain carboxylic acid ester in the non-aqueous electrolyte and the arrangement direction of the crystal grains in the negative electrode active material layer according to W0×100 / OI, it is easier to realize the improvement of the comprehensive performance including rapid charging performance, cycle performance, and safety performance.

[0085] In the present application, the secondary battery has the characteristic that 0.08 / mΩ ≦ W0×100 / (R×OI) ≦ 5 / mΩ. Regarding the secondary battery according to the present application, W0×100 / (R×OI) may further be any one numerical value among 0.1 / mΩ, 0.13 / mΩ, 0.15 / mΩ, 0.2mΩ, 0.3 / mΩ, 0.4 / mΩ, 0.5 / mΩ, 0.6 / mΩ,.8 / mΩ, 1 / mΩ, 1.2 / mΩ, 1.4 / mΩ, 1.5 / mΩ, 1.6 / mΩ, 1.8 / mΩ, 2 / mΩ, 2.2 / mΩ, 2.4 / mΩ, 2.5 / mΩ, 2.6 / mΩ, 2.8 / mΩ, 3 / mΩ, 3.5 / mΩ, 3.6 / mΩ, 3.8 / mΩ, 4 / mΩ, 4.5 / mΩ, 4.8 / mΩ, 5 / mΩ, etc., or may be selected from an interval composed of any two numerical values.

[0086] In some embodiments, 0.1 / mΩ ≦ W0×100 / (R×OI) ≦ 5 / mΩ.

[0087] In some embodiments, 0.1 / mΩ ≦ W0×100 / (R×OI) ≦ 2 / mΩ.

[0088] After coordinately controlling the orientation degree of the negative electrode tab and the content of the first solvent (chain carboxylic acid ester) in the solvent, and further coordinately controlling the resistance value R of the negative electrode tab, it is possible to control W0×100 / (R×OI) within an appropriate range. Thereby, it is possible to better balance the comprehensive performance of the rapid charging performance, cycle performance, and safety performance of the secondary battery.

[0089] In some embodiments, the secondary battery satisfies the characteristic combination of 6≦OI≦18, 10mΩ≦R≦20mΩ, and 20%≦W0≦80%. In some of these embodiments, 12≦OI≦18, 10mΩ≦R≦20mΩ, and 10%≦W0≦60%.

[0090] By finely and coordinately controlling such that the OI value of the negative electrode tab is 12 - 18, the resistance value R of the negative electrode tab is 10mΩ - 20mΩ, and the mass ratio W0 of the chain carboxylic acid ester solvent in the solvent is 20% - 80% (more selectively 10% - 60%), it is possible to better achieve the balance of rapid charging performance, cycle performance, and safety performance. As a result, it is more advantageous for the secondary battery to simultaneously have relatively excellent rapid charging ability, low cycle expansion, and high cycle capacity retention rate.

[0091] In some embodiments, 12≦OI≦18, 10mΩ≦R≦20mΩ, and 20%≦W0≦60%.

[0092] In some embodiments, 12≦OI≦18, 10mΩ≦R≦20mΩ, and 50%≦W0≦70%.

[0093] By controlling the values of different parameters, further advantages can be achieved in certain aspects. For example, when 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 20% ≦ W0 ≦ 60%, it can have relatively excellent overall performance and further have significantly excellent low cycle expansion and cycle performance. Also, for example, when 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 50% ≦ W0 ≦ 70%, it can have relatively excellent overall performance and further have significant advantages in short rapid charging time and low cycle expansion.

[0094] In some embodiments, the first solvent contains a compound whose structure is represented by formula (1).

[0095] JPEG2025519071000005.jpg30129 R1 and R2 are each independently an alkyl group or a halogenated alkyl group. As can be seen from this, R1 and R2 do not form a ring, and the compound having the structure shown in formula (1) is a chain carboxylic acid ester.

[0096] Optionally, R1 and R2 are each independently C 1-3 alkyl group or C 1-3 halogenated alkyl group.

[0097] Optionally, R1 and R2 are each independently C 1-3 alkyl group or C 1-3 fluorinated alkyl group.

[0098] However, the C 1-3 alkyl group may be a methyl group (Me, which may also be represented as -CH3), an ethyl group (Et, which may also be represented as -CH2CH3), or a propyl group. The propyl group may be n-propyl (1-propyl group, n-Pr, n-propyl group, which may also be represented as -CH2CH2CH3) or isopropyl group (2-propyl group, i-Pr, i-propyl group, which may also be represented as -CH(CH3)2). Further, C 1-3The alkyl group may be a methyl group, an ethyl group, or an n-propyl group. Additionally, C 1-3 The alkyl group may be a methyl group or an ethyl group.

[0099] However, C 1-3 The carbon atom in the alkyl halide group may be 1, 2, or 3. That is, it may be a C1 alkyl halide group, a C2 alkyl halide group, or a C3 alkyl halide group. C 1-3 The halogen atom in the alkyl halide group may be fluorine. C 1-3 The number of halogen atoms in the alkyl halide group may be one or more. C 1-3 When the number of halogen atoms in the alkyl halide group is more than one, two alkyl group hydrogen atoms or all alkyl group hydrogen atoms may be substituted.

[0100] However, C 1-3 The carbon atom in the fluorinated alkyl group may be 1, 2, or 3. That is, it may be a C1 fluorinated alkyl group, a C2 fluorinated alkyl group, or a C3 fluorinated alkyl group. C 1-3 The number of fluorine atoms in the fluorinated alkyl group may be one or more. C 1-3 When the number of fluorine atoms in the fluorinated alkyl group is more than one, it may be two fluorine substitutions to full fluorine substitutions.

[0101] In some embodiments, R1 and R2 may each independently be one of a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group. Alternatively, R1 and R2 may each independently be one of a methyl group, an ethyl group, a fluoromethyl group, and a fluoroethyl group. The number of fluorine atoms in the fluoromethyl group may independently be 1, 2, or 3. The number of fluorine atoms in the fluoroethyl group may independently be 1, 2, 3, 4, 5, or 6, and may further independently be 1, 2, or 3. The number of fluorine atoms in the fluoropropyl group may independently be 1, 2, 3, 4, 5, 6, 7, 8, or 9, and may further independently be 1, 2, or 3.

[0102] A first solvent with a small molecular size can be selected. In this case, the viscosity of the first solvent is low, which is advantageous for the secondary battery to obtain better rapid charging performance.

[0103] In some embodiments, the first solvent includes one or more of the compounds CH3CH2-OC(=O)-CH3 (i.e., ethyl acetate), CH3-OC(=O)-CH3 (i.e., methyl acetate), CH3CH2-OC(=O)-CH2CH3 (i.e., ethyl propionate), CH3-OC(=O)-CH2CH3 (i.e., methyl propionate), CH3CH2-OC(=O)-CH2F, CH3CH2-OC(=O)-CHF2, CH3CH2-OC(=O)-CF3, CH3-OC(=O)-CH2F, CH3-OC(=O)-CHF2, CH3-OC(=O)-CF3, CF3-OC(=O)-CH 3、 and CHF2-OC(=O)-CH3, and may be selected from one or more of these compounds. That is, the first solvent JPEG2025519071000006.jpg137157 includes one or more of the compounds, and may be selected from one or more of these compounds.

[0104] In some embodiments, the first solvent includes one or more of the compounds methyl acetate, ethyl acetate, methyl difluoroacetate, and ethyl difluoroacetate. In some of these embodiments, the first solvent is selected from one or more of the compounds methyl acetate, ethyl acetate, methyl difluoroacetate, and ethyl difluoroacetate.

[0105] In some embodiments, the non-aqueous electrolyte further includes a first additive, and the first additive is a diisocyanate.

[0106] In the present application, diisocyanate refers to a compound containing two isocyanate groups (-NCO).

[0107] Introducing a chain carboxylic acid ester (the first solvent) is advantageous for improving the rapid charging ability of the battery. However, due to the compatibility factors between the carboxylic acid ester and the negative electrode tab, if the compatibility between its usage amount W0, the OI value of the negative electrode tab, and the resistance value R is not good, it may exacerbate the swelling problem existing in the negative electrode tab itself, may also affect the problem of gas generation existing at the interface, and may also lead to capacity fade of the cell and deterioration of the cycle performance of the battery. By introducing a diisocyanate (denoted as the first additive), which is an additive, into the non-aqueous electrolyte, a solid electrolyte interface (SEI) layer having a protective effect can be formed on the surface of the negative electrode tab. The protective layer can cooperate to allow active ions to be occluded in the negative electrode active material layer of the negative electrode tab, and can uniformly transmit the occlusion expansion effect caused by the active ions of the negative electrode tab in all directions. Thereby, the cycle expansion rate of the negative electrode tab can be reduced. In addition, the first additive can also significantly improve the stability of the electrolyte and the negative electrode tab interface, can reduce the consumption of the electrolyte and the destruction of the negative electrode structure during the cycle process of the secondary battery, and can significantly improve the cycle performance of the secondary battery.

[0108] In some embodiments, the first additive includes a compound whose structure is shown in formula (2).

[0109] JPEG2025519071000007.jpg30129 However, R3 is an unsubstituted or Ra-substituted C 1-18 hydrocarbylene group, and Ra is a halogen atom (which may be one or more of fluorine, chlorine, bromine, and iodine, and may further be fluorine), -CN, -NCO, -OH, -COOH, -SOOH, -OC(=O)R 11 , R 12 OC(=O)-, C 1-10 alkyl group, C 2-10 alkenyl group, C 2-10 alkynyl and C 2-10 oxaalkyl group, and may contain one or more of these substituents, and may be selected from one or more of these substituents. R 11 and R 12 are each independently an alkyl group or a halogenated alkyl group. Unless otherwise specified, in the case of "Ra substitution", the number of Ra may be one or more.

[0110] In the substituent Ra, R 11 and R 12 are each independently an alkyl group or a halogenated alkyl group. Optionally, R 11 and R 12 are each independently a C 1-3 alkyl group or a C 1-3 halogenated alkyl group. Further optionally, R 11 and R 12 are each independently a C 1-3 alkyl group or a C 1-3 fluorinated alkyl group.

[0111] In some embodiments, R 11 and R 12 are each independently one of a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group, and optionally, R 11 and R 12is independently one of a methyl group, an ethyl group, a fluoromethyl group, and a fluoroethyl group. The number of fluorine atoms in the fluoromethyl group may be independently 1, 2, or 3. The number of fluorine atoms in the fluoroethyl group may be independently 1, 2, 3, 4, 5, or 6, and may further be independently 1, 2, or 3. The number of fluorine atoms in the fluoropropyl group may be independently 1, 2, 3, 4, 5, 6, 7, 8, or 9, and may further be independently 1, 2, or 3.

[0112] In some embodiments, in "R3 is an unsubstituted or Ra-substituted C 1-18 hydrocarbylene group", the number of carbon atoms in the "C 1-18 hydrocarbylene group" is 1 to 16, and further, the number of carbon atoms in the "C 1-18 hydrocarbylene group" may further be any one of the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16, or may be selected from an interval composed of any two numerical values. However, the interval composed of any two numerical values is, for example, 1 to 16, 2 to 16, 4 to 16, 6 to 16, 1 to 14, 2 to 14, 4 to 14, 6 to 14, 1 to 10, 2 to 10, 4 to 10, 6 to 10, etc.

[0113] In some embodiments, in "R3 is an unsubstituted or Ra-substituted C 1-18 hydrocarbylene group", the number of carbon atoms in R3 is 1 to 16, and further, the number of carbon atoms in R3 may further be any one of the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and 16, or may be selected from an interval composed of any two numerical values. The interval composed of any two numerical values is, for example, 1 to 16, 2 to 16, 4 to 16, 6 to 16, 1 to 14, 2 to 14, 4 to 14, 6 to 14, 1 to 10, 2 to 10, 4 to 10, 6 to 10, etc.

[0114] In some embodiments, R3 is an unsubstituted or Ra-substituted C 2-10an alkylene group, an unsubstituted or Ra-substituted C 3-18 divalent cycloalkyl, or an unsubstituted or Ra-substituted C 6-18 arylene group. Optionally, R3 is a C 2-10 alkylene group, C 6-18 divalent cycloalkyl or C 6-18 arylene group, and further optionally, R3 is a C 4-10 alkylene group, C 6-14 divalent cycloalkyl or C 6-14 arylene group, and also further optionally, R3 is a C 4-10 alkylene group, C 6-10 divalent cycloalkyl or C 6-10 arylene group. Also further optionally, R3 is a C 4-8 hexylene group, a C containing a hexyl ring 6-10 divalent cycloalkyl or a C containing a benzene ring 6-10 arylene group.

[0115] In some embodiments, Ra is a halogen atom (one or more of fluorine, chlorine, bromine, and iodine, and further may be fluorine), -CN, -NCO, -OH, -COOH, -SOOH, -OC(=O)R 11 , R 12 OC(=O)-, C 1-10 alkyl group, C 2-10 alkenyl group, C 2-10 alkynyl and C 2-10 selected from one or more of the substituents of an oxaalkyl group. In some of those examples, Ra is a halogen atom (one or more of fluorine, chlorine, bromine, and iodine, and further may be fluorine), -CN, -NCO, -OH, -COOH, -SOOH, -OC(=O)R 11 , R 12 OC(=O)- and C 2-10 selected from one or more of the substituents of an oxaalkyl group.

[0116] In some embodiments, Ra is a halogen atom, which may be one or more of fluorine, chlorine, bromine, and iodine, and may further be fluorine.

[0117] In R3, the number of Ra may be 0, one, or more. When the number of Ra is 0, it corresponds to the case of "unsubstituted". When the number of Ra is one or more, it corresponds to the case of "Ra-substituted".

[0118] In some embodiments, in R3, the number of Ra may be 0. In this case, the number of carbon atoms in R3 may be as defined above. For example, R3 may be an unsubstituted C 1-18 hydrocarbylene group, an unsubstituted C 1-16 hydrocarbylene group, an unsubstituted C 2-14 hydrocarbylene group, etc.

[0119] In some embodiments, in R3, the number of Ra may be one or more.

[0120] In some examples, Ra is a C 1-10 alkyl group, and may further be a C 1-3 alkyl group, and may further be a methyl group or an ethyl group. In some examples, Ra is a methyl group.

[0121] In some embodiments, R3 is a C 2-10 alkylene group, a C 2-10 heteroalkylene group, a C 6-18 arylene group, a C 2-18 heteroarylene group, a C 3-18 alicyclic or a C 3-18 heteroalicyclic, and any one of the above-mentioned groups may be unsubstituted or Ra-substituted. Unless otherwise stated, in the case of "Ra-substituted", the number of Ra may be one or more. Among them, the C 6-18 arylene group may be a C 6-14 arylene group, and may further be a C 6-14 arylene group.

[0122] In the present application, unless otherwise specifically indicated, "unsubstituted" is meant when "substitution" is not specified.

[0123] In the present application, the term "hydrocarbon" compound refers to a compound composed of carbon atoms and hydrogen atoms. The hydrocarbon compound may have a saturated structure (i.e., saturated hydrocarbon), an unsaturated structure (i.e., unsaturated hydrocarbon), may contain a ring structure (i.e., cyclic hydrocarbon), may not contain a ring structure (i.e., chain hydrocarbon), may have aromaticity (i.e., arene or aromatic hydrocarbon), or may not have aromaticity (i.e., aliphatic hydrocarbon). A hydrocarbon with a saturated structure, i.e., a saturated hydrocarbon, may be an alkane or a cycloalkane. An alkane does not contain a ring structure and may have a straight-chain structure or may contain branches. A cycloalkane contains a ring structure, and the number of ring structures may be one or more, for example, 1, 2, or 3. A cycloalkane is a saturated hydrocarbon containing a ring structure and is a non-aromatic hydrocarbon. A hydrocarbon with aromaticity, i.e., an arene, contains an aromatic ring structure. An unsaturated hydrocarbon may contain a carbon-carbon double bond, a carbon-carbon triple bond, etc. An unsaturated hydrocarbon may contain a ring structure or may not contain a ring structure. Unless otherwise explained, "olefin" refers to a chain hydrocarbon containing one or more carbon-carbon double bonds, "cycloolefin" refers to a cyclic hydrocarbon containing one or more carbon-carbon double bonds, "alkyne" refers to a chain hydrocarbon containing one or more carbon-carbon triple bonds, and "cycloalkyne" refers to a cyclic hydrocarbon containing one or more carbon-carbon triple bonds. " Alicyclic hydrocarbon" refers to a non-aromatic hydrocarbon containing a ring structure, which may be saturated or unsaturated, and the carbon atoms constituting the unsaturated bond may or may not be ring-forming atoms. For example, alicyclic hydrocarbons may include, but are not limited to, cycloalkanes, cycloolefins, cycloalkynes, etc.

[0124] In the present application, the term "hydrocarbon group" refers to a monovalent residue obtained by removing one hydrogen atom from a hydrocarbon compound containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. A phrase containing the term, for example, " 10 hydrocarbon group" refers to a hydrocarbon group containing 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 hydrocarbon group, a C2 hydrocarbon group, a C3 hydrocarbon group, a C4 hydrocarbon group, a C5 hydrocarbon group, a C6 hydrocarbon group, a C7 hydrocarbon group, a C8 hydrocarbon group, a C9 hydrocarbon group or a C 10 hydrocarbon group may be used.

[0125] In the present application, the term "hydrocarbylene group" refers to a divalent hydrocarbon group having two monovalent group centers, which is derived by removing two hydrogen atoms from a hydrocarbon compound (or derived by further losing one hydrogen atom from a hydrocarbon group), and may have a saturated branched structure or a saturated straight-chain structure. For example, " 10 hydrocarbylene group" means that the hydrocarbon group moiety contains 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 hydrocarbylene group, a C2 hydrocarbylene group, a C3 hydrocarbylene group, a C4 hydrocarbylene group, a C5 hydrocarbylene group, a C6 hydrocarbylene group, a C7 hydrocarbylene group, a C8 hydrocarbylene group, a C9 hydrocarbylene group or a C 10 hydrocarbylene group may be used.

[0126] In the present application, the term "alkyl group" refers to a monovalent residue obtained by removing one hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. A phrase containing the term, for example, " 10 alkyl group" refers to an alkyl group containing 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 alkyl group, a C2 alkyl group, a C3 alkyl group, a C4 alkyl group, a C5 alkyl group, a C6 alkyl group, a C7 alkyl group, a C8 alkyl group, a C9 alkyl group or a C 10It may be an alkyl group. Suitable examples include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3) and octyl (-(CH2)7CH3).

[0127] In the present application, the term "alkylene group" refers to a divalent hydrocarbon group having two monovalent group centers, which is derived by removing two hydrogen atoms from an alkane (or further losing one hydrogen atom from an alkyl group), and may have a saturated branched structure or a saturated straight-chain structure. For example, "C1-C 10The term "alkylene group" means that the alkyl group moiety contains 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 alkylene group (i.e., methylene group), a C2 alkylene group (i.e., ethylene group), a C3 alkylene group (i.e., propylene group), a C4 alkylene group (i.e., butylene group), a C5 alkylene group (i.e., pentylene group), a C6 alkylene group (i.e., hexylene group), a C7 alkylene group (i.e., heptylene group), a C8 alkylene group (i.e., octylene group), a C9 alkylene group (i.e., nonylene group) or a C 10 alkylene group (i.e., decylene group) may be used. Suitable examples include, but are not limited to, methylene group (-CH2-), 1,1-ethyl group (-CH(CH3)-), 1,2-ethyl group (-CH2CH2-), 1,1-propyl group (-CH(CH2CH3)-), 1,2-propyl group (-CH2CH(CH3)-), 1,3-propyl group (-CH2CH2CH2-) and 1,4-butyl group (-CH2CH2CH2CH2-).

[0128] In the present application, the term "alkenyl group" refers to a monovalent residue obtained by removing one hydrogen atom from a polyolefin compound having a chain structure, and the hydrogen atom may be at a carbon-carbon double bond or at an alkyl group substituent of the carbon-carbon double bond. Phrases containing the term, for example, "C2~ 10 alkenyl group" refers to an alkenyl group containing 2 to 10 carbon atoms, and in each occurrence, independently of one another, a C2 alkenyl group, a C3 alkenyl group, a C4 alkenyl group, a C5 alkenyl group, a C6 alkenyl group, a C7 alkenyl group, a C8 alkenyl group, a C9 alkenyl group or a C 10 alkenyl group may be used. Suitable examples include, but are not limited to, vinyl ester (CH2=CH-), allyl group (CH2=CH-CH 2- -), CH3-CH=CH-, etc.

[0129] In the present application, the term "alkynyl group" refers to a monovalent residue obtained by removing one hydrogen atom from an alkyne compound having a chain structure, and the hydrogen atom may be at a carbon-carbon triple bond or at an alkyl group substituent of the carbon-carbon triple bond. Phrases containing the term, for example, "C2~10 "Alkynyl" refers to an alkynyl group containing 2 to 10 carbon atoms, and in each occurrence, independently of each other, C2 alkynyl, C3 alkynyl, C4 alkynyl, C5 alkynyl, C6 alkynyl, C7 alkynyl, C8 alkynyl, C9 alkynyl or C 10 alkynyl may be used. Suitable examples include ethynyl group (CH ≡ C-), propargyl group (CH ≡ C-CH2-), CH3-C ≡ C- and the like may be included, but are not limited thereto.

[0130] In the present application, the term "heteroalkyl group" means that at least one carbon atom in the alkyl group is substituted by a heteroatom, and the heteroatom is an atom other than a hydrocarbon atom, and may be an N atom, an O atom, an S atom, a P atom, etc., but is not limited thereto. Hereinafter, O, N, and S will be described as examples. For example, when the carbon atom bonded to the adjacent group in the alkyl group is substituted by the heteroatoms O, N, S, the resulting heteroalkyl groups are an alkoxy group (e.g., -OCH3, etc.), an amino group (e.g., -NHCH3, -N(CH3)2, etc.) or a thioalkyl group (e.g., -SCH3), respectively. When the carbon atom not directly bonded to the adjacent group in the alkyl group is substituted by the heteroatoms O, N, S, the resulting heteroalkyl groups are an alkoxyalkyl group (e.g., -CH2CH2-O-CH3, etc.), an alkylaminoalkyl group (e.g., -CH2NHCH3, -CH2N(CH3)2, etc.) or an alkylthioalkyl group (e.g., -CH2-S-CH3), respectively. When the terminal carbon atom of the alkyl group is substituted by a heteroatom, the resulting heteroalkyl group may be a hydroxyalkyl group (e.g., -CH2CH2-OH), an aminoalkyl group (e.g., -CH2NH2) or a mercaptoamino group (e.g., -CH2CH2-SH). A phrase containing the term "heteroalkyl group", for example, "C1- 10The term "heteroalkyl group" refers to a heteroalkyl group containing 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 heteroalkyl group, a C2 heteroalkyl group, a C3 heteroalkyl group, a C4 heteroalkyl group, a C5 heteroalkyl group, a C6 heteroalkyl group, a C7 heteroalkyl group, a C8 heteroalkyl group, a C9 heteroalkyl group or C 10 may be a heteroalkyl group.

[0131] In the present application, the term "alkoxy group" refers to a monovalent group formed by bonding an alkyl group to -O-. Phrases containing this term, for example, "C1- 10 The term "oxaalkyl group" refers to an alkoxy group containing 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 alkoxy group, a C2 alkoxy group, a C3 alkoxy group, a C4 alkoxy group, a C5 alkoxy group, a C6 alkoxy group, a C7 alkoxy group, a C8 alkoxy group, a C9 alkoxy group or C 10 may be an alkoxy group. Suitable examples may include, but are not limited to, a methoxy group (CH3O-), an ethoxy group (CH3CH2O-), etc.

[0132] In the present application, the term "oxaalkyl group" means that at least one carbon atom in the alkyl group is replaced by an oxygen atom, and the oxygen atom may or may not be at the bonding site of the alkyl group. The number of oxygen atoms may be one or more. Taking the hybrid of one oxygen atom as an example, for example, an alkoxy group, an alkoxy group alkyl group, etc. Phrases containing this term, for example, "C1- 10 The term "oxaalkyl group" refers to an oxaalkyl group containing 1 to 10 carbon atoms, and in each occurrence, independently of one another, a C1 oxaalkyl group, a C2 oxaalkyl group, a C3 oxaalkyl group, a C4 oxaalkyl group, a C5 oxaalkyl group, a C6 oxaalkyl group, a C7 oxaalkyl group, a C8 oxaalkyl group, a C9 oxaalkyl group or C 10 may be an oxaalkyl group.

[0133] In the present application, the term "heteroalkylene group" is also referred to as a "divalent heteroalkyl group", and refers to a divalent heterohydrocarbon group having two monovalent group centers derived by further losing one hydrogen atom from a heteroalkyl group (the hydrogen atom may be on a carbon atom or a hetero atom), or refers to the substitution of at least one carbon atom in an alkylene group by a hetero atom (any one hetero atom may or may not be at the bonding site of the alkylene group), and the hetero atom may be, but is not limited to, an N atom, an O atom, an S atom, a P atom, etc. A phrase containing the term, for example, "C1- 10 heteroalkylene group" refers to a heteroalkylene group containing 1 to 10 carbon atoms, and in each occurrence, independently of each other, a C1 heteroalkylene group, a C2 heteroalkylene group, a C3 heteroalkylene group, a C4 heteroalkylene group, a C5 heteroalkylene group, a C6 heteroalkylene group, a C7 heteroalkylene group, a C8 heteroalkylene group, a C9 heteroalkylene group or a C 10 heteroalkylene group may be used.

[0134] In the present application, the term "cycloalkyl" refers to a monovalent residue obtained by removing one hydrogen atom on a saturated cycloalkane on or off the ring, and may directly form a monovalent bonding site on the ring or form a monovalent bonding site at the substituent position of an alkyl group on the ring. A phrase containing the term, for example, "C 3-10 cycloalkyl" refers to a cycloalkyl containing 3 to 10 carbon atoms, and in each occurrence, independently of each other, a C3 cycloalkyl, a C4 cycloalkyl, a C5 cycloalkyl, a C6 cycloalkyl, a C7 cycloalkyl, a C8 cycloalkyl, a C9 cycloalkyl or a C 10 cycloalkyl may be used. The number of ring structures in the cycloalkyl may be one or more, for example, 1, 2 or 3. The number of ring-forming atoms in any one ring structure in the cycloalkyl may be 3 to 8, for example, 3, 4, 5, 6, 7 or 8, for example, JPEG2025519071000008.jpg14152 It is a heptacyclic or octacyclic ring. The situation of directly forming a monovalent bonding site on the ring is JPEG2025519071000009.jpg25165 and may include, but is not limited to, a cycloheptyl group. The situation of forming a monovalent bonding site from the substituent position of the alkyl group on the ring is JPEG2025519071000010.jpg17124 may include, but is not limited to,

[0135] In the present application, unless otherwise explained, the JPEG2025519071000011.jpg1421 at the end in the structural formula represents the bonding site of a covalent bond.

[0136] In the present application, the term "alicyclic" is also called "divalent alicyclic group" and refers to a divalent residue derived by the loss of two hydrogen atoms on the ring or in the non-ring from an alicyclic hydrocarbon. Either of the lost hydrogen atoms may be on the ring or not. That is, a monovalent bonding site may be directly formed on the ring, or a monovalent bonding site may be formed at the substituent position of the hydrocarbon group on the ring. Alicyclic may include, but is not limited to, divalent cycloalkyl, divalent cycloalkenyl group, divalent cycloalkynyl group, etc. A phrase containing the term, for example, "C 3-10 alicyclic" refers to an alicyclic containing 3 to 10 carbon atoms, and in each occurrence, independently of each other, it may be a C3 alicyclic, C4 alicyclic, C5 alicyclic, C6 alicyclic, C7 alicyclic, C8 alicyclic, C9 alicyclic or C 10 alicyclic.

[0137] In the present application, the term "divalent cycloalkyl" is also referred to as "cycloalkylene group", and refers to a divalent saturated hydrocarbon group having two monovalent group centers, which is derived by removing two hydrogen atoms from cycloalkane (or further losing one hydrogen atom from cycloalkyl). The position of any one of the monovalent group centers may independently be on the ring or not on the ring. A phrase containing the term, for example, "C3- 10 divalent cycloalkyl" refers to a divalent cycloalkyl containing 3 to 10 carbon atoms, and in each occurrence, independently of each other, C3 divalent cycloalkyl, C4 divalent cycloalkyl, C5 divalent cycloalkyl, C6 divalent cycloalkyl, C7 divalent cycloalkyl, C8 divalent cycloalkyl, C9 divalent cycloalkyl or C 10 divalent cycloalkyl may be used. The number of carbon atoms in the "divalent cycloalkyl" may be 3 to 10, may be 3, 4, 5, 6, 7, 8, 9 or 10, for example, may be 6 to 10. The number of ring structures in the divalent cycloalkyl may be one or more, for example, 1, 2 or 3. The number of ring-forming atoms of any one of the ring structures in the "divalent cycloalkyl" may be 3 to 8, may be 3, 4, 5, 6, 7 or 8. As a non-limiting example, "C 6-10 divalent cycloalkyl" refers to a divalent cycloalkyl containing 6 to 10 carbon atoms. However, the number of ring-forming atoms of one ring structure is not particularly limited. "C 6-10 divalent cycloalkyl containing a hexyl ring" refers to a divalent cycloalkyl containing a hexyl ring and containing 6 to 10 carbon atoms, for example, a divalent cyclohexyl group JPEG2025519071000012.jpg44144 and the like.

[0138] In the present application, the term "divalent cycloalkenyl group" is also referred to as "cycloalkenylene group", and refers to a divalent unsaturated hydrocarbon group having two monovalent group centers, which is derived by removing two hydrogen atoms from a cycloolefin. The position of either one of the monovalent group centers may independently be on the ring or not on the ring. A phrase containing the term, for example, "C 3-10 divalent cycloalkenyl group" refers to a divalent cycloalkenyl group containing 3 to 10 carbon atoms, and in each occurrence, independently of one another, a C3 divalent cycloalkenyl group, a C4 divalent cycloalkenyl group, a C5 divalent cycloalkenyl group, a C6 divalent cycloalkenyl group, a C7 divalent cycloalkenyl group, a C8 divalent cycloalkenyl group, a C9 divalent cycloalkenyl group or a C 10 divalent cycloalkenyl group may be used.

[0139] In the present application, the term "heteroalicyclic" is also referred to as "divalent heterocyclyl group", and refers to the substitution of at least one carbon atom of a hydrocarbon group moiety in an alicyclic by a heteroatom, and the heteroatom may be at a bonding site of the alicyclic or not at the bonding site, and the heteroatom may be on the ring or not on the ring. The heteroatom may be, but is not limited to, an N atom, an O atom, an S atom, a P atom, etc. The heteroatom may be at a bonding site (i.e., a terminal) of the alicyclic or not at the bonding site. A phrase containing the term, for example, "C3- 10 heteroalicyclic" refers to a heteroalicyclic containing 3 to 10 carbon atoms, and in each occurrence, independently of one another, a C3 heteroalicyclic, a C4 heteroalicyclic, a C5 heteroalicyclic, a C6 heteroalicyclic, a C7 heteroalicyclic, a C8 heteroalicyclic, a C9 heteroalicyclic or a C 10 heteroalicyclic may be used.

[0140] In the present application, the term "arylene group" refers to a divalent residue having two monovalent group centers obtained by removing two hydrogen atoms from an aromatic hydrocarbon (either of the two lost hydrogen atoms may independently be on or not on the aromatic ring). The arylene group may be a monocyclic arylene group, a condensed-ring arylene group, or a polycyclic arylene group, and for polycyclic ring types, at least one is an aromatic ring system. For example, "C6- 14 arylene group" refers to an arylene group containing 6 to 14 carbon atoms, and in each occurrence, independently of each other, it may be a C6 arylene group, a C7 arylene group, a C8 arylene group, a C9 arylene group, a C 10 arylene group, a C 11 arylene group, a C 12 arylene group, a C 13 arylene group or a C 14 arylene group. Suitable examples include phenyl, biphenyl, methyldiphenyl, naphthyl, anthranyl, phenanthrenyl, perylene, triphenylene, or any one of the above hydrocarbon group substitution forms, for example, those derived from arylene groups of aromatic rings such as toluene, xylene, tetramethylbenzene, ethylbenzene, dimethyldiphenyl, etc., but are not limited thereto.

[0141] In the present application, the term "heteroarylene group" is also referred to as "divalent heteroaryl", and refers to the substitution of at least one carbon atom in the arylene group with a heteroatom. Any one heteroatom may be at the bonding site of the arylene group or not at the bonding site, and any one heteroatom may be on or not on the aromatic ring. The heteroatom may be, but is not limited to, an N atom, an O atom, an S atom, a P atom, etc. Phrases containing the term, for example, "C2- 10 heteroarylene group" refers to a heteroarylene group containing 2 to 10 carbon atoms, and in each occurrence, independently of each other, it may be a C2 heteroarylene group, a C3 heteroarylene group, a C4 heteroarylene group, a C5 heteroarylene group, a C6 heteroarylene group, a C7 heteroarylene group, a C8 heteroarylene group, a C9 heteroarylene group or a C10 It may be a heteroarylene group.

[0142] In some embodiments, R3 is C 1-8 an alkylene group, C 6-14 an arylene group, -(Z1) p1 -C A -(Z2) p2 -, and -(Z1) q1 -C A1 -(Z3) q3 -C A2 -(Z2) q2 -, or one or more hydrogen atoms in any one of the above-mentioned divalent groups are replaced by a substituent R a . However, Z1, Z2, and Z3 are each independently a single covalent bond or a C 1-3 alkylene group, C A is a C 4-14 divalent alicyclic group, C A1 and C A2 are each independently a C 5-12 divalent alicyclic group, and p1, p2, q1, q2, and q3 are each independently 0 or 1.

[0143] In some embodiments, Z1, Z2, and Z3 are each independently a single covalent bond or a methylene group.

[0144] In some embodiments, C A is a divalent cyclobutyl group, a divalent cyclopentyl group, a divalent cyclohexyl group, or JPEG2025519071000013.jpg13129 .

[0145] In some embodiments, C A1 and C A2 are each independently a C 5-12 divalent alicyclic group, optionally, C A1 and C A2 are each independently a C 4-6 divalent alicyclic group, and further optionally, C A1and C A2 is each independently a divalent cyclopentyl group or a divalent cyclohexyl group. Further optionally, C A1 and C A2 are each independently a divalent cyclopentyl group.

[0146] In some embodiments, R3 is a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a phenylene group, -CH2-Ph-CH2-, a naphthylene group, an anthrylene group, -Ph-CH2-Ph-, -Ph-Ph-, a divalent cyclobutyl group, a divalent cyclopentyl group, a divalent cyclohexyl group, JPEG2025519071000014.jpg18152, or a divalent group formed by substituting one or more hydrogen atoms in any one of the above-mentioned divalent groups with a substituent R a . However, Ph is a phenyl ring.

[0147] In the present application, JPEG2025519071000015.jpg30162 refers to two monovalent moieties formed by withdrawing two single bonds from any position on the ring. These two monovalent moieties may be in the same ring, in different rings, on different ring-forming atoms, or on the same ring-forming atom, but preferably, the two single bonds may be withdrawn from different ring-forming atoms.

[0148] In some embodiments, any one of R a is independently a halogen atom or a C 1-3 alkyl group, and further optionally, any one of R a is independently a fluorine atom, a methyl group or an ethyl group. Further optionally, any one of R a is independently a fluorine atom or a methyl group.

[0149] In some embodiments, the first additive is JPEG2025519071000016.jpg230170 JPEG2025519071000017.jpg234170 JPEG2025519071000018.jpg213170 JPEG2025519071000019.jpg234170 JPEG2025519071000020.jpg221170 comprises one or more of compounds such as

[0150] In some embodiments, the first additive includes one or more of the following compounds: 1,4-phenylene diisocyanate, 1,3-phenylene diisocyanate, m-xylene diisocyanate, 2,3,5,6-tetrafluorobenzene diisocyanate, 1,3-diisocyanate-2-toluene, 2,4-diisocyanate-1-toluene, 2,5-diisocyanato-1,3-xylene, 1,4-diisocyanato-2,5-xylene, 1,4-diisocyanato-2,3-xylene, 1,4-diisocyanato-2,3,5,6-tetramethylbenzene, 2,3-diisocyanate-1-ethylbenzene, 1,5-diisocyanatonaphthalene, 9,10-diisocyanatoanthracene, diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, cyclohexane-1,4-diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,2-bis(isocyanatomethyl)cyclohexane, cyclopentane-1,3-diisocyanate, 1,2-cyclobutane dimethyldiisocyanate, 9,10-diisocyanate tetradecahydroanthracenyl, 1,3,3-trimethylcyclohexane-1,5-diisocyanate, 1,1,3-trimethylcyclohexane-2,5-diisocyanate, 2,3,5,6-tetramethylcyclohexane-1,4-diisocyanate, 1-isocyanato-4-(isocyanatomethyl)-1-methylcyclohexane, isophorone diisocyanate, 4,4-diisocyanate dicyclohexylmethane, methylene diisocyanate, 1,4-diisocyanate butyl, 1,4-diisocyanatopentane, and hexamethylene diisocyanate. Further, the first additive may be selected from one or more of the diisocyanates listed above.

[0151] In some embodiments, the first additive includes one or more of the compounds hexamethylene diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, and 2,4-diisocyanate-1-toluene. In some of these embodiments, the first additive is selected from one or more of the compounds hexamethylene diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, and 2,4-diisocyanate-1-toluene.

[0152] In some embodiments, the mass ratio (which may be denoted as W1) of the first additive in the non-aqueous electrolyte is 0 to 11%. When W1 is 0, that is, the first additive is not added to the non-aqueous electrolyte. The mass ratio W1 of the first additive in the non-aqueous electrolyte may be any one percentage among 0, 0.005%, 0.01%, 0.015%, 0.02%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 11%, etc., or may be selected from the intervals composed of any two of the percentages described above. For example, it may be 0.005% - 11%, 0.005% - 10%, 0.1% - 5%, 1% - 5%, 0 - 1%, 0.1% - 1%, 0.01% - 10%, 1% - 10%, etc.

[0153] In some embodiments, the non-aqueous electrolyte further includes a second additive. The second additive includes one or more of lithium monofluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate, the compound shown in formula (3), and fluorosulfonate.

[0154] JPEG2025519071000021.jpg37129 In formula (3), a, b, and c are each independently positive integers, m is an integer selected from 1 - 3, n is an integer selected from 0 - 4, q is 0 or 1, and M a+is a metal ion having an a-valent positive charge. Any one of Y is independently a boron atom or a phosphorus atom, and X is a halogen atom. Any one of R is independently a substituted or unsubstituted C 1-10 alkylene group, a substituted or unsubstituted C 1-10 halogenated alkylene group, a substituted or unsubstituted C 6-20 arylene group, and a substituted or unsubstituted C 6-20 halogenated arylene group.

[0155] In the present application, the halogen atom in the halogenated alkylene group may be one or more of fluorine, chlorine, bromine, and iodine, and may further be fluorine. The number of halogen atoms in the halogenated alkylene group may be one or more.

[0156] In the present application, the halogen atom in the halogenated arylene group may be one or more of fluorine, chlorine, bromine, and iodine, and may further be fluorine. The number of halogen atoms in the halogenated arylene group may be one or more.

[0157] In some embodiments, any one of R is independently an Rc-substituted or unsubstituted C 1-10 alkylene group, an Rc-substituted or unsubstituted C 1-10 halogenated alkylene group, an Rc-substituted or unsubstituted C 6-20 arylene group, and an Rc-substituted or unsubstituted C 6-20 halogenated arylene group. The Rc-substituted C 1-10 substituent in the alkylene group, the Rc-substituted C 1-10 substituent in the halogenated alkylene group, the Rc-substituted C 6-20 substituent in the arylene group and the Rc-substituted C 6-20 substituent in the halogenated arylene group are each independently a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC=(O)R 41 , -C=(O)OR 42 , C 1-10 alkyl group, C 2-10 alkenyl group, C2-10 It may contain one or more of the substituents such as alkynyl and C 2-10 alkoxy groups. However, R 41 and R 42 are each independently a C 1-6 alkyl group, such as a methyl group, an ethyl group, etc. However, the substituent in the Rc-substituted C 1-10 alkylene group, the substituent in the Rc-substituted C 1-10 halogenated alkylene group, the substituent in the Rc-substituted C 6-20 arylene group and the Rc substituent in the Rc-substituted C 6-20 halogenated arylene group are each independently a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC=(O)R 41 , -C=(O)OR 42 , C 1-10 alkyl group, C 2-10 alkenyl group, C 2-10 alkynyl and C 2-10 It may be selected from one or more of the substituents such as alkoxy groups. However, R 41 and R 42 are each independently a C 1-6 alkyl group, such as a methyl group, an ethyl group, etc. In the present application, unless otherwise explained, when the substituent R C is included in R, the number of R C may be one or more.

[0158] In some embodiments, in the non-aqueous electrolyte, M in M a+ includes one or more of Li, Na, K, Rb, Cs, Mg, Ca, Ba, Al, Fe, Cu, and Ni.

[0159] In some embodiments, a, b, and c are each independently selected from 1, 2, or 3.

[0160] In some embodiments, m is 1, 2, or 3.

[0161] In some embodiments, n is 0 or 1 - 4, and may further be 0, 1, 2, 3, or 4.

[0162] In some embodiments, the second additive includes one or more of lithium difluorophosphate, lithium monofluorophosphate, lithium tetrafluoroborate, lithium fluorosulfonate, and sodium fluorosulfonate. Further, it may be one or more of lithium difluorophosphate, lithium monofluorophosphate, lithium tetrafluoroborate, lithium fluorosulfonate, and sodium fluorosulfonate.

[0163] In some embodiments, the mass ratio (which may be denoted as W2) of the second additive in the non-aqueous electrolyte is 0 - 11%. The mass ratio W2 of the second additive in the non-aqueous electrolyte may be any one of 0, 0.005%, 0.01%, 0.015%, 0.02%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 11%, etc., and may also be selected from the intervals composed of any two of the above-mentioned percentages. For example, it may be 0.005% - 11%, 0.01% - 11%, 0 - 10%, 0.005% - 10%, 0.01% - 10%, 0.05% - 10%, 0.05% - 5%, etc. When W2 is 0, that is, the second additive is not added to the non-aqueous electrolyte.

[0164] By introducing diisocyanate, which is the first additive, the impedance of the formed SEI film may be increased. By introducing the second additive into the non-aqueous electrolyte, an SEI film with a high content of inorganic substances on the negative electrode can be formed, the rapid charging performance of the secondary battery can be improved, and the cycle performance of the secondary battery can also be further improved.

[0165] In some embodiments, the volume average particle size D of the negative electrode active material v 50 ≧ 6 μm, and D v50 refers to the particle size corresponding to when the cumulative volume distribution percentage of the substance or material reaches 50%, and optionally, the volume average particle size D of the negative electrode active material v 50 is 6 μm to 20 μm, and further optionally, the volume average particle size D of the negative electrode active material v 50 is 15 μm to 20 μm. The D of the negative electrode active material v 50 may further be any one of sizes such as 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 16 μm, 18 μm, 20 μm, or may be an interval composed of any two of the above-mentioned sizes

[0166] In the specification of the present application, the volume cumulative distribution particle size D v N (where N represents any numerical value selected from 0 to 100) can be adopted to characterize the particle size of the substance or material, and refers to the particle size corresponding to when the cumulative volume distribution percentage of the substance or material reaches N%, and the occupied volume ratio where the particle size is D v is N% when it is N or less. D v N may be obtained from the volume cumulative distribution curve of the particle size of the substance or material. Without other explanations, the volume cumulative distribution curve accumulates from 0 on the small particle size side v Taking D v 50 as an example, D v 50 refers to the particle size corresponding to when the cumulative volume distribution percentage of the substance or material reaches 50%. Taking D v 50 as an example, the particle size of the particles occupying 50% of the volume of the substance or material is D v is 50 or less, and represents that the particle size of the particles occupying 50% of the volume of the substance or material is greater than D v Those skilled in the art can understand the meaning of D

[0167] By controlling the particle size of the negative electrode active material to have a relatively large particle size, the contact area between the negative electrode material and the electrolytic solution can be reduced. As a result, the probability of a side reaction occurring between the solvent and the negative electrode surface is reduced, which is further advantageous for reducing the swelling rate of the tab and can better improve the cycle performance of the cell.

[0168] In some embodiments, the BET specific surface area of the negative electrode active material is 0.5 m 2 / g to 2.0 m 2 / g, and optionally, the BET specific surface area of the negative electrode active material is 0.8 m 2 / g to 1.5 m 2 / g. The BET specific surface area of the negative electrode active material may be any one of the values such as 0.5 m 2 / g, 0.6 m 2 / g, 0.8 m 2 / g, 1 m 2 / g, 1.5 m 2 / g, 1.8 m 2 / g, 2 m 2 / g, or may be selected from the intervals composed of any two of the above-mentioned numerical values.

[0169] In the present application, the BET specific surface area of the negative electrode active material may be obtained by testing in the following methods, but is not limited thereto. Test by the nitrogen gas adsorption specific surface area analysis test method and calculate by the BET (Brunauer Emmett Teller) method. The nitrogen gas adsorption specific surface area analysis test may be performed with a Tri Star II type specific surface and pore analyzer manufactured by Micromeritics, USA, and the test steps may refer to GB / T 19587-2004. The sample to be measured is the negative electrode active material raw material or the negative electrode active material sampled from the negative electrode active material layer of the negative electrode tab. The analysis method of the test is as follows. The sample to be measured is dried in a vacuum oven at 200 °C for 2 hours, and then argon gas is used as the adsorption gas, and the adsorption and desorption curve with a relative pressure P / P0 of 0 to 0.99 is mapped with a specific surface and pore analyzer. P is the equilibrium adsorption pressure, P0 is the saturated vapor pressure, and the specific surface area of the negative electrode active material is calculated by the BET method.

[0170] By controlling the particle size of the negative electrode active material to have a certain specific surface area, the surface area of the negative electrode material can be reduced, the contact area between the negative electrode material and the electrolyte can be reduced, the occurrence of side reactions of the solvent on the negative electrode surface can be reduced, and the cycle performance of the cell can be improved better.

[0171] <Negative electrode tab> In the present application, the negative electrode tab in the secondary battery includes a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material includes a graphite material.

[0172] In some embodiments, the negative electrode tab includes a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector, the negative electrode film layer includes a negative electrode active material layer, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material includes a graphite material.

[0173] In some embodiments, the weight percentage of the graphite material in the negative electrode active material is ≧ 50%. The weight percentage of the graphite material in the negative electrode active material may further be any one of 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, etc., or any one of the above percentages or more, or a range from any one of the above percentages to 100%, or a range composed of any two of the above percentages. In some embodiments, the weight percentage of the graphite material in the negative electrode active material is ≧ 80%. In some embodiments, the weight percentage of the graphite material in the negative electrode active material is 100%.

[0174] As a non-limiting example, the negative electrode current collector has two surfaces facing each other in its own thickness direction, and the negative electrode film layer is provided on either one or both of the two opposing surfaces of the negative electrode current collector.

[0175] In some embodiments, the negative electrode current collector may employ a metal foil sheet or a composite current collector. For example, a copper foil may be employed as the metal foil sheet. The composite current collector may include a polymer material-based layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be obtained by forming a metal material on the polymer material substrate. In the negative electrode current collector, non-limiting examples of the metal material may include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. In the negative electrode current collector, non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0176] In some embodiments, the graphite material in the negative electrode active material may include one or more of artificial graphite and natural graphite. The negative electrode active material may further include other well-known negative electrode active materials used in batteries in this field. As non-limiting examples, the negative electrode active material may further include one or more of materials such as soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may include one or more of elemental silicon, silicon oxide, silicon carbon composite, silicon nitride composite, and silicon alloy. The tin-based material may include one or more of elemental tin, tin acid compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as the negative electrode active material of the battery may be used, as long as a graphite material is included therein. These negative electrode active materials may be used alone with only one type of graphite material, or may be used in combination of two or more types (in this case, at least including a graphite material).

[0177] In some embodiments, the negative electrode active material includes artificial graphite.

[0178] In some embodiments, the negative electrode film layer optionally further includes a binder. The binder may include one or more of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0179] In some embodiments, the negative electrode film layer optionally further includes a conductive agent. The conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon spot, carbon nanotube, graphene, and carbon nanofiber.

[0180] In some embodiments, the negative electrode film layer optionally further includes other auxiliaries, such as a thickening agent. Non-limiting examples of the thickening agent may include sodium carboxymethyl cellulose (CMC-Na).

[0181] In some embodiments, the negative electrode tab can be manufactured as follows. Components for manufacturing the negative electrode tab described above, such as a negative electrode active material, a conductive agent, a binder, and any other components, are dispersed in a solvent (a non-limiting example of the solvent is deionized water) to form a negative electrode slurry. The negative electrode slurry is applied to at least one surface of the negative electrode current collector, and through processes such as drying and densification (cold pressing method may be adopted for densification), a negative electrode tab can be obtained. The surface of the negative electrode current collector to which the negative electrode slurry is applied may be a single surface of the negative electrode current collector or two surfaces of the negative electrode current collector. The solid content of the negative electrode slurry may be 40 wt% to 60 wt%. The press density of the negative electrode tab may be 1.4 g / cm 3 ~1.95 g / cm 3 and may further be selected as 1.5 g / cm 3 ~1.8 g / cm 3 In the present application, wt% represents the percentage of the weight content.

[0182] <Positive electrode tab> In the present application, the positive electrode tab includes a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material layer, and further, the positive electrode active material layer includes a positive electrode active material.

[0183] As a non-limiting example, the positive electrode current collector has two surfaces facing each other in its own thickness direction, and the positive electrode film layer is provided on either one or both of the two opposing surfaces of the positive electrode current collector.

[0184] In some embodiments, the positive electrode current collector may employ a metal foil sheet or a composite current collector. For example, as the metal foil sheet, an aluminum foil may be employed. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material on a polymer material substrate, and the metal material may include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc. Non-limiting examples of the polymer material substrate include substrates made of materials such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0185] In some embodiments of the present application, the positive electrode active material includes a lithium ion material, and further, the secondary battery is a lithium ion secondary battery.

[0186] In some embodiments of the present application, the secondary battery is a lithium ion secondary battery. The lithium ion secondary battery realizes the charging and discharging process by utilizing the intercalation and deintercalation of lithium ions into and from the electrodes and the transport in the electrolyte. Usually, the active ions in the lithium ion secondary battery are lithium ions, but are not limited thereto.

[0187] The positive electrode active material may adopt well-known positive electrode active materials used in batteries in this field. As non-limiting examples, the positive electrode active material may include one or more of materials or substances such as lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials or substances, and other conventional materials or substances used as the positive electrode active material of the battery may also be used. Only one type of these positive electrode active materials may be used alone, or two or more types may be used in combination. However, non-limiting examples of lithium transition metal oxides may include one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds, but are not limited thereto. Non-limiting examples of lithium cobalt oxide include LiCoO2, non-limiting examples of lithium nickel oxide include LiNiO2, non-limiting examples of lithium manganese oxide include LiMnO2, LiMn2O4, etc., and non-limiting examples of lithium nickel cobalt manganese oxide include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which may simply be called NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which may simply be called NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which may simply be called NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which may simply be called NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which may simply be called NCM 811 ), etc. Non-limiting examples of lithium nickel cobalt aluminum oxide include LiNi 0.85 Co 0.15 Al0.05 It contains O2. Non-limiting examples of the lithium-containing phosphate having an olivine structure may include one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon, but are not limited thereto. Non-limiting examples of lithium iron phosphate include LiFePO4 (which may be simply referred to as LFP), and non-limiting examples of lithium manganese phosphate include LiMnPO4.

[0188] In some embodiments, the positive electrode active material may include one or more of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, sodium oxide, potassium oxide, and a material composed of any one of the above substances and a doping element, but is not limited thereto. Further, the doping element in any one of the positive electrode active materials independently includes one or more of a transition metal element and a non-transition metal element.

[0189] In some embodiments, the positive electrode film layer optionally further includes a binder. As non-limiting examples, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0190] In some embodiments, the positive electrode film layer optionally further includes a conductive agent. As non-limiting examples, the conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon spot, carbon nanotube, graphene, and carbon nanofiber.

[0191] In some embodiments, the positive electrode tab can be manufactured as follows. The components for manufacturing the positive electrode tab described above, such as the positive electrode active material, the conductive agent, the binder, and any other components, are dispersed in a solvent to form a positive electrode slurry. The positive electrode slurry is applied to the surface of at least one side of the positive electrode current collector, and through processes such as drying and consolidation (the consolidation may adopt a cold pressing method), a positive electrode tab can be obtained. The type of the solvent may include any one of those in the above embodiments, but is not limited thereto. For example, it may be N-methylpyrrolidone (NMP). The surface of the positive electrode current collector to which the positive electrode slurry is applied may be a single surface of the positive electrode current collector or two surfaces of the positive electrode current collector. The solid content of the positive electrode slurry may be 40 wt% to 80 wt%. The press density of the positive electrode tab may be 3.0 to 3.6 g / cm 3 and may also be selected as 3.3 to 3.5 g / cm 3 .

[0192] <Electrolyte> The electrolyte has the role of transmitting active ions between the positive electrode tab and the negative electrode tab. The electrolyte in the present application includes an electrolytic solution.

[0193] In some embodiments, the electrolytic solution is a non-aqueous electrolyte. The non-aqueous electrolyte may include an electrolyte salt and a solvent. In a lithium-ion secondary battery, the electrolyte salt may include an electrolyte lithium salt.

[0194] In some embodiments, the electrolyte lithium salt may include one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide (LiFSI), lithium bistrifluoromethanesulfonylimide (LiTFSI), lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalateborate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluorooxalatophosphate.

[0195] In some embodiments, the solvent is an organic solvent.

[0196] In the present application, the solvent in the non-aqueous electrolyte includes a chain carboxylic acid ester (referred to as the first solvent). The definition of the first solvent is as described above.

[0197] In some embodiments, in addition to including the first solvent, the solvent may further include one or more of an ether-based solvent and a carbonate-based solvent. The carbonate-based solvent may include one or more of a carbonate and a halogenated carbonate. Non-limiting examples include, for example, ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), and one or more of fluorides of any one of the above.

[0198] In some other embodiments, in addition to containing the first solvent, the solvent may further contain one or more of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluorinated ethylene carbonate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, ethyl methyl sulfone, and diethyl sulfone.

[0199] In some embodiments, in addition to containing the first solvent, the solvent may further contain one or more of ethylene carbonate (EC) and ethyl methyl carbonate (EMC). In some examples, the solvent contains ethylene carbonate. In some examples, the solvent contains ethyl methyl carbonate. In some examples, the solvent contains ethylene carbonate and ethyl methyl carbonate, and further, the occupied volume ratio of ethylene carbonate to ethyl methyl carbonate may be 3:7, but is not limited thereto.

[0200] In some embodiments, the solvent is a combination of the first solvent, ethylene carbonate, and ethyl methyl carbonate.

[0201] In some embodiments, the electrolyte may optionally further contain an additive. For example, the additive may include a negative electrode film-forming additive and a positive electrode film-forming additive, and may further include an additive that can improve certain performance of the battery, such as an additive that improves the overcharge performance of the battery, an additive that improves the high-temperature or low-temperature performance of the battery, and the like.

[0202] In some embodiments, the additive may include one or more of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoromethyl group ethylene carbonate (TFPC), methylene methanedisulfonic acid ester (MMDS), 1-propylene-1,3-sultone (PST), ethylene sulfite (ES), propylene sulfite (PS), ethylene sulfate (DTD), succinonitrile (SN), adiponitrile (AND), sulfonic acid ester cyclic quaternary ammonium salt, tris(trimethylsilyl) phosphate (TMSP), tris(trimethylsilyl) borate (TMSB), and anisole.

[0203] In some embodiments, the additive includes one or more of a first additive and a second additive.

[0204] In some embodiments, the additive includes the first additive.

[0205] In some embodiments, the additive includes the second additive.

[0206] In some embodiments, the additive includes the first additive and the second additive.

[0207] The definitions (including but not limited to the types and usage amounts) of the first additive and the second additive are as described above. Separator

[0208] In some embodiments, the secondary battery further includes a separator. In the present application, there is no particular limitation on the type of the separator, and any well-known separator with a porous structure and excellent chemical and mechanical stability may be selected and used.

[0209] In some embodiments, the material of the separator may include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0210] <Electrode assembly, electrochemical energy storage device, secondary battery> In some embodiments, the positive electrode tab, the negative electrode tab, and the separator can be manufactured as an electrode assembly by a winding process or a lamination process.

[0211] In some embodiments, the electrochemical energy storage device may include an exterior body. The exterior body may be used to package the above electrode assembly and electrolyte.

[0212] In some embodiments, the secondary battery may include an exterior body. The exterior body may be used to package the above electrode assembly and electrolyte.

[0213] In some embodiments, the exterior body of the secondary battery may be a hard case, such as a hard plastic case, an aluminum case, a steel case, etc. The exterior body of the secondary battery may be a soft pack, such as a bag-type soft pack. The material of the soft pack may be plastic, and further, non-limiting examples of the plastic may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0214] The present application does not particularly limit the shape of the secondary battery, and it may be cylindrical, rectangular, or any other arbitrary shape. For example, FIG. 1 shows a rectangular-structured secondary battery 5 as an example.

[0215] In some embodiments, as shown in FIG. 2, the exterior body may include a case 51 and a cover 53. However, the case 51 may include a bottom plate and side plates connected to the bottom plate, and an accommodation chamber is formed by being surrounded by the bottom plate and the side plates. The case 51 has an opening communicating with the accommodation chamber, and the cover 53 can be crowned on the opening to close the accommodation chamber. The positive tab, the negative tab, and the separator can form an electrode assembly 52 by a winding process or a lamination process. The electrode assembly 52 is packaged in the accommodation chamber. The electrolytic solution is infiltrated into the electrode assembly 52. The number of electrode assemblies 52 included in the secondary battery 5 may be one or more, and those skilled in the art can select according to actual needs.

[0216] In some embodiments, the secondary battery has one or more of the following effects.

[0217] Regarding the rapid charging time, the rapid charging time ≤ 35 min, and may further be ≤ 33 min, may further be ≤ 32 min, may further be ≤ 30 min, may further be ≤ 28 min.

[0218] Regarding the expansion of the negative tab, when cycling up to SOH 80% at 45°C, the expansion rate of the negative tab ≤ 36%, and may further be ≤ 35.5%, may further be ≤ 33%, may further be ≤ 32%, may further be ≤ 30%, may further be ≤ 258%.

[0219] Regarding the cycle performance, when cycling up to SOH 80% at 45°C, the corresponding number of cycles ≥ 800, and may further be ≥ 900, may further be ≥ 950, may further be ≥ 1000, may further be ≥ 1100, may further be ≥ 1150, may further be ≥ 1200.

[0220] Regarding the gas generation performance, when stored at 60°C for 30 days, the expansion rate of the cell is ≤9%, and it may further be ≤8%, or even further ≤7.5%, or even further ≤7%.

[0221] In some embodiments, the secondary battery has excellent comprehensive performance of rapid charging ability, cycle performance, and safety performance, and further has excellent storage performance. In some examples, when stored at 60°C for 30 days, the capacity retention rate is ≥85%, and it may further be ≥88%, or even further ≥90%, or even further ≥95%.

[0222] In some examples, the rapid charging time is ≤35 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤33%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥900, the expansion rate of the cell when stored at 60°C for 30 days is ≤8%, and further, the capacity retention rate when stored at 60°C for 30 days satisfies ≥88%.

[0223] In some examples, the rapid charging time is ≤33 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤32%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥1000, the expansion rate of the cell when stored at 60°C for 30 days is ≤8%, and further, the capacity retention rate when stored at 60°C for 30 days satisfies ≥90%.

[0224] In some examples, the rapid charging time is ≤30 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤30%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥950, the expansion rate of the cell when stored at 60°C for 30 days is ≤8%, and further, the capacity retention rate when stored at 60°C for 30 days satisfies ≥90%.

[0225] In some embodiments, the fast charging time is ≤ 35 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤ 32%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥ 900, the expansion rate of the cell when stored at 60°C for 30 D is ≤ 7%, and further, the capacity retention rate when stored at 60°C for 30 D satisfies ≥ 88%.

[0226] In some embodiments, the fast charging time is ≤ 30 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤ 30%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥ 1000, the expansion rate of the cell when stored at 60°C for 30 D is ≤ 7%, and further, the capacity retention rate when stored at 60°C for 30 D satisfies ≥ 90%.

[0227] In some embodiments, the fast charging time is ≤ 32 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤ 33%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥ 1100, the expansion rate of the cell when stored at 60°C for 30 D is ≤ 7.5%, and further, the capacity retention rate when stored at 60°C for 30 D satisfies ≥ 90%.

[0228] In some embodiments, the fast charging time is ≤ 28 min, the expansion rate of the negative electrode tab when cycling to SOH 80% at 45°C is ≤ 28%, the number of cycles corresponding to cycling to SOH 80% at 45°C is ≥ 1200, the expansion rate of the cell when stored at 60°C for 30 D is ≤ 7.5%, and further, the capacity retention rate when stored at 60°C for 30 D satisfies ≥ 95%.

[0229] According to a second aspect, the present application provides a power consumption device including the secondary battery described in the first aspect of the present application.

[0230] The secondary battery may be used as a power source for the power-consuming device or as an energy storage unit of the power-consuming device. The power-consuming device may include, but is not limited to, mobile devices, electric vehicles, trains, ships, and satellites, energy storage systems, etc. The mobile device may be, for example, a mobile phone, a notebook computer, etc., and the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric motorcycle, an electric scooter, an electric golf cart, an electric truck, etc., but is not limited thereto.

[0231] As the power-consuming device, a secondary battery can be selected according to the needs of its use.

[0232] FIG. 3 shows a power-consuming device 6 as an example. The power-consuming device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the high power and high energy density requirements of the power-consuming device for the secondary battery, a battery pack or a battery module may be adopted.

[0233] Another example of the device may be a mobile phone, a tablet, a notebook computer, etc. The device is usually required to be thin and light, and a secondary battery may be adopted as a power source.

[0234] Hereinafter, some embodiments of the present application will be described. The embodiments described below are exemplary and are merely used for interpreting the present application and should not be understood as a limitation to the present application. When the technology or conditions are not clearly shown in the embodiments, they are carried out according to the previous description, or according to the technology or conditions described in the literature in this field, or according to the product specification. When the manufacturer of the reagent or equipment used is not shown, they are commercially available general products or can be purchased from the market and combined in a general manner.

[0235] Example 1. 1. Manufacture of the negative electrode tab 1.1. Select the type of negative electrode active material according to Table 1, and select a negative electrode active material having a certain volume average particle size D v 50 and a BET specific surface area.

[0236] (1) Particle size test Regarding the production of the sample, the negative electrode active material raw material may be the negative electrode active material sampled from the negative electrode active material layer of the negative electrode tab. In order to avoid the aggregation during the drying process from affecting the particle size test, a washed wet sample was taken for the dispersion test.

[0237] Regarding the type of particle size, the volume average particle size D v 50 test was carried out.

[0238] The instrument model number is a Malvern 3000 (MasterSizer 3000) laser particle size analyzer, and GB / T19077-2016 / ISO 13320:2009, which is the reference standard flow, was referred to.

[0239] The test flow was as follows. An appropriate amount of the sample to be measured (the concentration of the sample only needs to meet the light extinction of 8% - 12%) was taken, 20 mL of anhydrous ethanol was injected, ultrasonic treatment was carried out for 5 min (53KHz / 120W) to completely disperse the sample. Then, the sample was measured according to the GB / T19077-2016 / ISO 13320:2009 standard.

[0240] (2) BET specific surface area test of negative electrode active material Regarding the production of the sample, the negative electrode active material raw material may be the negative electrode active material sampled from the negative electrode active material layer of the negative electrode tab.

[0241] The test method was as follows. The test was carried out by the nitrogen gas adsorption specific surface area analysis test method and calculated by the BET (Brunauer Emmett Teller) method. The nitrogen gas adsorption specific surface area analysis test may be carried out with a Tri StarII type specific surface and pore analyzer manufactured by Micromeritics Company, USA, and the test steps may refer to GB / T 19587-2004.

[0242] The detailed steps were as follows. The sample to be measured was dried in a vacuum oven at 200 °C for 2 hours, and argon gas was used as the adsorption gas. The adsorption / desorption curve with a relative pressure P / P0 of 0 to 0.99 was mapped using a specific surface area and pore analyzer. P is the equilibrium adsorption pressure, P0 is the saturated vapor pressure, and the specific surface area of the negative electrode active material was calculated by the BET method.

[0243] 1.2. Manufacture of the negative electrode tab Artificial graphite as the negative electrode active material, carbon black as the conductive agent, styrene-butadiene rubber (SBR) as the binder, and sodium carboxymethyl cellulose (CMC-Na) as the thickener were dissolved in deionized water as the solvent at a weight ratio of 90:4:4:2 and uniformly mixed. Then, a negative electrode slurry (with a solid content of 48%) was manufactured, and the negative electrode slurry was uniformly applied to the surfaces on both sides of the copper foil of the negative electrode current collector once or multiple times, followed by drying, cold pressing, and slitting to obtain the negative electrode tab. The press density of the negative electrode tab was 1.65 g / cm 3 was obtained.

[0244] However, the OI value of the graphite particles, D v 50, the porosity of the negative electrode tab, the press density of the negative electrode tab, the components, types, and contents of the negative electrode tab, etc., were used to adjust and control the OI value of the negative electrode tab by at least one parameter.

[0245] Regarding the test of the OI value of the negative electrode tab, an X-ray powder diffractometer (X´pert PRO) was used to test the intensities of the diffraction peaks at the 004 crystal plane and the 110 crystal plane. An X-ray diffraction spectrum was obtained according to the general rules of X-ray diffraction analysis method and the lattice constant measurement method of graphite JIS K 0131-1996, JB / T4220-2011. Then, according to OI = I 004 / I 110 the ratio of the intensities of the diffraction peaks at the 004 crystal plane and the 110 crystal plane of the negative electrode active material layer was obtained. I 004 is the intensity of the diffraction peak at the 004 crystal plane, and I 110was the intensity of the diffraction peak on the 110 crystal plane.

[0246] Regarding the test of the resistance value R of the negative electrode tab, the test was conducted using a BER1300 multi-functional tab resistance meter. First, the negative electrode tab was cut into a sample to be measured with a certain size (a small circular sheet with a diameter of 40 mm), the sample to be measured was placed between two probes, and the test results were recorded. Multiple (≥5) samples to be measured were taken, and the average value of the multiple samples to be measured was calculated as the test result.

[0247] 2. Preparation of the electrolyte (non-aqueous electrolyte) In a glove box under an argon atmosphere (H2O < 0.1 ppm, O2 < 0.1 ppm), ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were uniformly mixed at an occupied volume ratio of 3:7. Among them, 60 wt% of methyl acetate based on the total weight of the solvent was added. Then, lithium hexafluorophosphate (LiPF6) was added and dissolved in the organic solvent to make the concentration of LiPF6 12.5 wt%, and it was uniformly stirred to obtain the electrolyte.

[0248] 3. Manufacture of the positive electrode tab Lithium iron phosphate positive electrode material, acetylene black as a conductive agent, and polyvinylidene fluoride (PVDF) as a binder were put into a solvent N-methylpyrrolidone (NMP) at a weight ratio of 90:5:5 and stirred sufficiently to be uniformly mixed. Then, a positive electrode slurry (the solid content was 67%) was obtained. And the positive electrode slurry was uniformly coated on the surfaces on both sides of the positive electrode current collector. The coating weight on one side was about 22.7 mg / cm 2 (For example, 350 mg / 1540.25 mm 2 ) and then, through drying, cold pressing, and slitting, the positive electrode tab was obtained.

[0249] 4. Separator A generally commercially available polypropylene film was used as the separator.

[0250] 5. Assembly of the secondary battery The positive electrode tab (width 87 mm × length 605 mm), separator (width 98 mm × length 1896 mm), and negative electrode tab (width 93 mm × length 735 mm) were stacked in sequence, and the separator was positioned between the positive and negative tabs to serve the role of separation. Then, it was wound up to obtain an electrode assembly, the electrode assembly was placed in a battery case, and after drying, 12.0 g of electrolyte solution (3 Ah, injection coefficient 4.0 g / Ah) was injected. Furthermore, a lithium-ion battery was manufactured through processes such as formation and standing.

[0251] Examples 2 to 41 and Comparative Examples 1 - 9 adopted substantially the same method as Example 1. The differences lie in one or more parameters among the type of negative electrode active material, the OI value of the negative electrode tab, the resistance value R of the negative electrode tab, the type and usage amount of the first solvent (chain carboxylic acid ester), the type and usage amount of the first additive, the type and usage amount of the second additive, the D v 50, and the specific surface area (BET), and Tables 1 and 2 can be referred to.

[0252]

Table 1

[0253] In Table 1, W0 is the mass ratio of the first solvent in the electrolyte solvent.

[0254]

Table 2

[0255] In Table 2, W1 is the mass ratio of the first additive in the electrolyte solution (non-aqueous electrolyte), and W2 is the mass ratio of the second additive in the electrolyte solution (non-aqueous electrolyte).

[0256] Test analysis method 1. Test of rapid charging performance At 25°C, a charge-discharge test was conducted on the battery after capacity grading at voltages ranging from 2.5 V to 3.65 V. The test steps were as follows: First, it was charged at a constant current of 3C until the state of charge (SOC) reached 30%, then charged at a constant current of 2C until the SOC reached 60%, and then charged at a constant current of 1C and a constant voltage until the SOC reached 80%. The cut-off current was 0.01C, and it was left to stand for 5 minutes. Then, it was discharged at a constant current of 1C until the voltage reached 2.0 V and left to stand for 5 minutes. The time taken to charge the battery to 80% SOC was measured.

[0257] SOC represents the status of the remaining capacity of the battery. The value ranges from 0 to 100%. When SOC = 0, it indicates that the battery is completely discharged, and when SOC = 100%, it indicates that the battery is completely charged.

[0258] 2. Test of the tab expansion rate (tab expansion rate when cycling at 45°C until 80% state of health (SOH)) At 45°C, the lithium-ion battery was charged at a constant current of 0.5C until the voltage reached 3.65 V. Then, it was charged at a constant voltage of 3.65 V until the current became less than 0.05C. Subsequently, the lithium-ion battery was discharged at a constant current of 0.5C until the voltage reached 2.5 V. This was one charge-discharge process (i.e., one cycle). The thickness L0 of the negative tab was measured using a micrometer (Mitutoyo 293-100, with a precision of 0.01 mm). Charging and discharging were repeated in this way, and the thickness L1 of the negative tab when the capacity retention rate was 80% was recorded. The expansion rate of the negative tab when cycling at 45°C until 80% SOH was (L1 / L0 - 1) × 100%.

[0259] 3. Test of cycle performance At 45 °C, the lithium-ion battery was charged at a constant current of 0.5C until 3.65V, and then charged at a constant voltage of 3.65V until the current became less than 0.05C. Then, the lithium-ion battery was discharged at a constant current of 0.5C until 2.5V. This was one charge-discharge process (i.e., one cycle). Charging and discharging were repeated in this way, and the number of cycles when the capacity retention rate was 80% was recorded. It was denoted as "the number of cycles corresponding to cycling to SOH 80% at 45 °C".

[0260] 4. Test of gas generation performance The lithium-ion secondary battery was charged at a constant current of 0.33C until 3.65V, and then charged at a constant voltage of 3.65V until the current reached 0.05C, fully charging the lithium-ion battery. The volume of the battery was tested by the water replacement method, and this volume was taken as the volume before storage. Then, the lithium-ion battery was stored at 60 °C for 30 days. After the storage was completed, the lithium-ion secondary battery was placed in an environment of 25 °C, and the volume of the battery was tested by the water replacement method, and this volume was taken as the volume after storage. The volume expansion rate of the battery was calculated according to the following formula.

[0261] Battery volume expansion rate = (Volume after storage / Volume before storage - 1) × 100%.

[0262] It was denoted as "the expansion rate of the cell when stored at 60 °C for 30 days". The lower this value, the lower the gas generation amount, and the better the gas generation performance.

[0263] 5. Test of storage performance At 25°C, the lithium-ion battery was charged at a constant current of 0.33C until 3.65V, and then charged at a constant voltage of 3.65 until the current became less than 0.05C. Then, the lithium-ion battery was discharged at a constant current of 0.33C until 2.5V (the discharge capacity of the battery was recorded as C0). The fully charged battery was placed in an oven at 60°C for 30 days and then taken out. The battery was placed in an environment at 25°C and discharged at 0.33C, and the discharge capacity was recorded as C1. The capacity retention rate = (C1 / C0)×100%, and it was denoted as "capacity retention rate when stored at 60°C for 30D".

[0264] Results of test analysis The results of the test can be referred to Table 3.

[0265] The secondary batteries manufactured in Examples 1 to 41 obtained excellent comprehensive performance in terms of rapid charging ability, low expansion of the negative electrode tab, and battery cycle performance. The expansion rate of the cell in the gas generation test at high temperature further reflects the gas generation performance. Data on the rapid charging time, expansion rate of the negative electrode tab when cycling to 80% SOH at 45°C, the number of cycles corresponding to cycling to 80% SOH at 45°C, and the expansion rate of the cell when stored at 60°C for 30D can be referred to. In addition, the secondary batteries manufactured in Examples 1 to 41 further have excellent storage performance (data on the capacity retention rate when stored at 60°C for 30D can be referred to).

[0266] W0×100 / (R×OI) in Comparative Examples 1 to 9 is less than 0.08 or greater than 5. From this, the comprehensive performance of the rapid charging ability, cycle performance, and safety performance of the secondary battery is significantly inferior to that of Examples 1 to 41.

[0267] Regarding the OI values, the resistance value R of the negative electrode tab, and W0 in Comparative Examples 1 to 5, although the values of any single parameter can be used in the technical solution of the present application, the relationship of their combination does not satisfy 0.08 ≦ W0 × 100 / (R × OI) ≦ 5. From this, it is difficult to achieve both excellent rapid charging ability, low tab swelling, low gas generation, low cell swelling, and excellent cycle performance. At least one of the performance parameters of rapid charging ability, low tab swelling, low cell swelling, and excellent cycle performance is clearly not good or has not been improved. In Comparative Example 1, W0 × 100 / (R × OI) is greater than 5, the negative electrode tab is peeled off, and the cell cannot operate. The swelling of the negative electrode tab in Comparative Example 2 is clearly large, the swelling of the cell in Comparative Example 3 is clearly large, and the rapid charging ability in Comparative Examples 4 to 5 is significantly deteriorated.

[0268] The OI value in Comparative Example 6 is slightly large, but W0 × 100 / (R × OI) is too small. The resistance R value of the negative electrode tab in Comparative Example 7 is slightly low, but W0 × 100 / (R × OI) is too large. The R value in Comparative Example 8 is slightly high, but W0 × 100 / (R × OI) is too small. The content of the chain carboxylic acid ester (the first solvent) in Comparative Example 9 is slightly high, but W0 × 100 / (R × OI) is too large. As a result, in Comparative Examples 6 to 9, it is impossible to achieve an excellent comprehensive effect in terms of rapid charging ability, cycle performance, and safety performance.

[0269] In Comparative Examples 7 and 9, they have a short rapid charging time, but in exchange, the swelling of the tab is deteriorated, the cycle performance is significantly deteriorated, the swelling of the cell after generating gas at high temperature is clearly large, and the storage performance is not good.

[0270] In Comparative Example 8, the swelling of the tab is suppressed, but in exchange, the rapid charging ability is reduced, the cycle performance is significantly deteriorated, and the swelling of the cell after generating gas is still large.

[0271]

Table 3

[0272] Each technical feature of the embodiments described above can be arbitrarily combined. For the sake of simplicity of description, not all possible combinations of each technical feature in the above embodiments are described. However, as long as these combinations of technical features do not conflict, they should be regarded as being within the scope described in this specification.

[0273] It should be noted that the present application is not limited to the above embodiments. The above embodiments are merely examples, and embodiments having substantially the same configuration as the technical idea and exhibiting the same effects within the scope of the technical solution of the present application are all included within the technical scope of the present application. The embodiments described above merely represent some embodiments of the present application, and their descriptions are detailed, but they should not be understood as limiting the scope of the claims. It should be noted that within the scope not departing from the gist of the present application, other forms created by performing various modifications that can be conceived by those skilled in the art on the embodiments or by combining some components in the embodiments are also included within the scope of the present application. It should be pointed out that those skilled in the art may make some modifications and improvements on the premise of not departing from the idea of the present application, and all of these belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be in accordance with the scope of the claims, and the specification and drawings can be used to interpret the content of the claims.

Explanation of Reference Numerals

[0274] 5 Secondary battery 51 Case 52 Electrode assembly 53 Cover 6 Power consumption device

Claims

1. A secondary battery comprising: a positive electrode tab; a negative electrode tab; and a non-aqueous electrolyte, wherein the negative electrode tab contains a negative electrode active material, the negative electrode active material contains a graphite material, the non-aqueous electrolyte contains a solvent, the solvent contains a first solvent, the first solvent is a chain carboxylic acid ester, and the OI value of the negative electrode tab, the resistance value R of the negative electrode tab, and the mass ratio W0 of the first solvent in the solvent satisfy the relationship: 0.08 / mΩ ≤ W0 × 100 / (R × OI) ≤ 5 / mΩ. Here, the OI value of the negative electrode tab refers to the ratio of the diffraction peak intensity at the 004 crystal plane of the graphite material to the diffraction peak intensity at the 110 crystal plane, and the unit of R is mΩ. A secondary battery.

2. 6 ≤ OI ≤ 25, optionally, 6 ≤ OI ≤ 18, more optionally, 12 ≤ OI ≤ 18. The secondary battery according to Claim 1.

3. 1 mΩ ≤ R ≤ 50 mΩ, optionally, 5 mΩ ≤ R ≤ 30 mΩ, more optionally, 10 mΩ ≤ R ≤ 20 mΩ. The secondary battery according to Claim 1 or 2.

4. 10% ≤ W0 ≤ 80%, optionally, 20% ≤ W0 ≤ 80%, more optionally, 30% ≤ W0 ≤ 70%, and further optionally, 50% ≤ W0 ≤ 70%. Also, optionally, 10% ≤ W0 ≤ 60%, more optionally, 20% ≤ W0 ≤ 60%. The secondary battery according to any one of Claims 1 to 3.

5. 0.67 ≤ W0 × 100 / OI ≤ 10, optionally, 1 ≤ W0 × 100 / OI ≤ 10, more optionally, 1 ≤ W0 × 100 / OI ≤ 5, and further optionally, 3 ≤ W0 × 100 / OI ≤ 5. Also, optionally, 0.67 ≤ W0 × 100 / OI ≤ 4, more optionally, 1 ≤ W0 × 100 / OI ≤ 4. The secondary battery according to any one of Claims 1 to 4.

6. 0.1 / mΩ ≤ W0 × 100 / (R × OI) ≤ 5 / mΩ, optionally, 0.1 / mΩ ≤ W0 × 100 / (R × OI) ≤ 2 / mΩ. The secondary battery according to any one of Claims 1 to 5.

7. 6 ≤ OI ≤ 18, 10 mΩ ≤ R ≤ 20 mΩ, and 10% ≤ W0 ≤ 80%, optionally, 12 ≤ OI ≤ 18, 10 mΩ ≤ R ≤ 20 mΩ, and 10% ≤ W0 ≤ 60%, more optionally, 20% ≤ W0 ≤ 60%. Alternatively, optionally, a secondary battery according to any one of claims 1 to 6, wherein 12 ≦ OI ≦ 18, 10 mΩ ≦ R ≦ 20 mΩ, and 50% ≦ W0 ≦ 70%.

8. The first solvent contains a compound whose structure is represented by formula (1), Here, R １ and R ２ are each independently a C １－３ alkyl group or a C １－３ haloalkyl group, Optionally, R １ and R ２ are each independently a C １－３ alkyl group or a C １－３ fluorinated alkyl group, Further selectively, R １ and R ２ are each independently one of a methyl group, an ethyl group, a propyl group, a fluoromethyl group, a fluoroethyl group, and a fluoropropyl group, Also, more selectively, R １ and R ２ are each independently one of a methyl group, an ethyl group, a fluoromethyl group, and a fluoroethyl group, Alternatively, optionally, the first solvent further contains one or more of the compounds methyl acetate, ethyl acetate, methyl difluoroacetate, and ethyl difluoroacetate, a secondary battery according to any one of claims 1 to 7.

9. The non-aqueous electrolyte further contains a first additive, and the first additive is a diisocyanate, a secondary battery according to any one of claims 1 to 8.

10. The first additive contains a compound whose structure is represented by formula (2), Here, R ３ is an unsubstituted or Ra-substituted C １－１８ hydrocarbylene group, and Ra contains one or more of the substituents of a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC(=O)R １１ , R １２ OC(=O)-, C １－１０ alkyl group, C ２－１０ alkenyl group, C ２－１０ alkynyl and C ２－１０ oxaalkyl group, and R １１ and R １２ are each independently an alkyl group or a halogenated alkyl group. Optionally, R ３ is a C ２－１０ alkylene group, a C ２－１０ heteroalkylene group, a C ６－１８ arylene group, a C ２－１８ heteroarylene group, a C ３－１８ alicyclic or a C ３－１８ heteroalicyclic, and any one of the above-mentioned groups is unsubstituted or substituted with Ra Alternatively, optionally, R ３ is an unsubstituted or Ra-substituted C ２－１０ alkylene group, an unsubstituted or Ra-substituted C ３－１８ divalent cycloalkyl or an unsubstituted or Ra-substituted C ６－１８ arylene group, and further optionally, R ３ is a C ２－１０ alkylene group, a C ６－１８ divalent cycloalkyl or a C ６－１８ arylene group, and also further optionally, R ３ is a C ４－１０ alkylene group, a C ６－１４ divalent cycloalkyl or a C ６－１４ arylene group, and also further optionally, R ３ is a C ４－１０ alkylene group, a C ６－１０ divalent cycloalkyl or a C ６－１０ arylene group, and also further optionally, R ３ is a C ４－８ hexylene group, a C containing a hexyl ring ６－１０ divalent cycloalkyl or a C containing a benzene ring ６－１０ arylene group, Alternatively, optionally, the first additive contains one or more of the compounds hexamethylene diisocyanate, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, and 2,4-diisocyanate-1-toluene, a secondary battery according to any one of claims 1 to 8.

11. The mass ratio of the first additive in the non-aqueous electrolyte is 0 to 11%, Optionally, the mass ratio of the first additive in the non-aqueous electrolyte is 0.005% to 11%, Further optionally, the mass ratio of the first additive in the non-aqueous electrolyte is 0.005% to 10%, Alternatively, further optionally, the mass ratio of the first additive in the non-aqueous electrolyte is 0.01% to 10%, Alternatively, further optionally, the mass ratio of the first additive in the non-aqueous electrolyte is 0.1% to 5%, Alternatively, further optionally, the mass ratio of the first additive in the non-aqueous electrolyte is 1% to 5%, a secondary battery according to any one of claims 8 to 10.

12. The non-aqueous electrolyte further contains a second additive, and the second additive contains one or more of lithium monofluorophosphate, lithium difluorophosphate, lithium tetrafluoroborate, the compound represented by formula (3), and fluorosulfonate, In formula (3), a, b, and c are each independently a positive integer, m is an integer selected from 1 - 3, n is an integer selected from 0 - 4, q is 0 or 1, and M ａ＋ is a metal ion having an a-valent positive charge, any one of Y is independently a boron atom or a phosphorus atom, X is a halogen atom, and any one of R is independently a substituted or unsubstituted C １－１０ alkylene group, a substituted or unsubstituted C １－１０ halogenated alkylene group, a substituted or unsubstituted C ６－２０ arylene group, and a substituted or unsubstituted C ６－２０ halogenated arylene group, and is one of them Optionally, any one of Rs is independently a C which is Rc-substituted or unsubstituted １－１０ an alkylene group, a C which is Rc-substituted or unsubstituted １－１０ a halogenated alkylene group, a C which is Rc-substituted or unsubstituted ６－２０ an arylene group, and a C which is Rc-substituted or unsubstituted ６－２０ is one of a halogenated arylene group, and the Rc-substituted C １－１０ a substituent in the alkylene group, an Rc-substituted C １－１０ a substituent in the halogenated alkylene group, an Rc-substituted C ６－２０ a substituent in the arylene group and an Rc-substituted C ６－２０ The Rc-substituents in the halogenated arylene group are each independently a halogen atom, -CN, -NCO, -OH, -COOH, -SOOH, -OC=(O)R ４１ , -C=(O)OR ４２ , C １－１０ an alkyl group, C ２－１０ an alkenyl group, C ２－１０ an alkynyl and C ２－１０ may contain one or more of the substituents of an alkoxy group, provided that R ４１ and R ４２ are each independently a C １－６ alkyl group Optionally, in the non-aqueous electrolyte, M ａ＋ wherein M includes one or more of Li, Na, K, Rb, Cs, Mg, Ca, Ba, Al, Fe, Cu, and Ni, Optionally, a, b, and c are each independently selected from 1, 2, or 3, a secondary battery according to any one of claims 1 to 11.

13. The secondary battery according to claim 12, wherein the second additive contains one or more of lithium difluorophosphate, lithium monofluorophosphate, lithium tetrafluoroborate, lithium fluorosulfonate, and sodium fluorosulfonate.

14. The mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 11%, Optionally, the mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 11%, Furthermore, the mass ratio of the second additive in the non-aqueous electrolyte is 0.005% to 10%, Also, optionally further, the mass ratio of the second additive in the non-aqueous electrolyte is 0.05% to 5%. The secondary battery according to any one of claims 12 to 13.

15. The volume average particle diameter D of the negative electrode active material ｖ is 50 ≧ 6 μm, provided that D ｖ 50 represents the particle diameter corresponding when the distribution percentage of the integrated volume of the substance or material reaches 50%, Optionally, the volume average particle diameter D of the negative electrode active material ｖ 50 is from 6 μm to 20 μm, More selectively, the volume average particle diameter D of the negative electrode active material ｖ 50 is 15 μm to 20 μm, and the secondary battery according to any one of claims 1 to 14.

16. The BET specific surface area of the negative electrode active material is 0.5 m ２ / g to 2.0 m ２ / g, and Optionally, the BET specific surface area of the negative electrode active material is 0.8 m ２ / g to 1.5 m ２ / g, and the secondary battery according to any one of claims 1 to 15.

17. The graphite material contains one or more of artificial graphite and natural graphite, Optionally, the graphite material contains artificial graphite. The secondary battery according to any one of claims 1 to 16.

18. The weight percentage of the graphite material in the negative electrode active material is ≧50%, Optionally, the weight percentage of the graphite material in the negative electrode active material is ≧80%, Optionally further, the weight percentage of the graphite material in the negative electrode active material is 100%. The secondary battery according to any one of claims 1 to 17.

19. The secondary battery according to any one of claims 1 to 18, wherein the secondary battery is a lithium-ion secondary battery.

20. A power consumption device including the secondary battery according to any one of claims 1 to 19.

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