Electrolytes, secondary batteries and power consumption devices

Abstract

The present application provides an electrolyte, a secondary battery, and a power consumption device. The electrolyte includes a cyclic sulfate ester compound represented by Formula I and a metal ion additive. The cyclic sulfate ester compound and the metal ion additive are useful for forming a stable SEI film and further for improving the battery's power-consumption performance.

Description

[Technical Field]

[0001] The present application relates to the field of secondary battery technology, and in particular to electrolytes, secondary batteries and power consuming devices. [Background technology]

[0002] In recent years, with the development of secondary battery technology, secondary batteries have been widely applied in energy storage power systems such as hydroelectric power, thermal power, wind power and solar power plants, as well as in multiple fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. As the application fields of secondary batteries have made great progress, the requirements for their battery performance have also increased.

[0003] During the charging process, the electrolyte is continuously recycled at the negative electrode. To reduce side reactions at the negative electrode, researchers have attempted to form a passivation layer on the negative electrode surface by adding various compounds to the electrolyte. This passivation layer is also known as a solid electrolyte interfacial film (SEI). Research has shown that forming a solid electrolyte interfacial film (SEI) with uniform, dense, stable properties, low impedance, and good adhesion is beneficial for improving the electrochemical performance of the battery and enhancing battery performance. However, conventional electrolyte systems have high impedance and cannot meet the demand for improved battery performance. Summary of the Invention

[0004] The present application has been made in view of the above-mentioned problems, and its object is to provide an electrolyte solution containing a cyclic sulfate ester compound represented by Formula I and a metal ion additive. The cyclic sulfate ester compound and the metal ion additive are useful for forming a stable SEI film and further for improving the battery's power-saving performance.

[0005] A first aspect of the present application provides an electrolyte solution, the electrolyte solution comprising a cyclic sulfate ester compound represented by Formula I and a metal ion additive,

[0006] [ka]

[0007] In Formula I, R1, R2, R3, and R4 are each independently selected from the structure shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group; and R1, R2, R3, and R4 are not simultaneously selected from a hydrogen atom; In Formula II, R5 and R6 are each independently selected from the group consisting of a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and the wavy line represents the bond position.

[0008] On the one hand, the introduction of cyclic sulfate ester compounds into the electrolyte is advantageous for forming a stable SEI film. During the battery charging process, the cyclic sulfate ester groups serve to form an inorganic sulfite film between the electrolyte and the negative electrode plate, and the R1, R2, R3, or R4 groups serve to form an elastic organic film between the electrolyte and the negative electrode plate. For example, introducing alkyl / alkoxy groups into the R1, R2, R3, or R4 groups can form an elastic SEI film with longer organic chains on the negative electrode side, which can avoid or reduce the breakdown of the SEI film due to the volume change that occurs on the negative electrode side during cycling and improve the stability of the SEI film. In addition, the introduction of F- or N-containing elements into the R1, R2, R3, or R4 groups can participate in the film formation on the negative electrode side, forming an SEI film rich in inorganic components such as LiF or Li3N, which can improve the mechanical strength of the SEI film and further improve the stability of the SEI film on the negative electrode side. On the other hand, by introducing metal ion additives into the electrolyte, they act synergistically with the cyclic sulfate ester compound, participate in the formation of an inorganic film, and further help form a stable SEI film, further blocking electron tunneling, reducing interfacial impedance, and significantly improving the battery's power efficiency.

[0009] In any embodiment, R1, R2, R3, and R4 are each independently selected from one of the structures shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, and a cyano group.

[0010] R1, R2, R3, and R4 are each independently selected from the structure shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, and a cyano group. During the battery charging process, R1, R2, R3, or R4 separates from the cyclic sulfate ester group to form an organic film, which increases the interfacial stability between the electrolyte and the negative electrode plate and is beneficial to improving the battery's charging performance.

[0011] In either embodiment, R1 is selected from a hydrogen atom or a C1-C3 alkyl group; R2 is selected from a C1-C3 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a cyano group, or the structure shown in Formula II; R3 is selected from a hydrogen atom or a C1-C3 alkyl group; and R4 is selected from a C1-C3 alkyl group, a halogen atom, a C1-C3 alkoxy group, or the structure shown in Formula II.

[0012] In any embodiment, R1 is selected from a hydrogen atom or a methyl group, R2 is selected from a methyl group, an ethyl group, a fluorine atom, a trifluoromethyl group, a cyano group, or the structure shown in Formula II, R3 is selected from a hydrogen atom, and R4 is selected from a methyl group, an ethyl group, a propyl group, a fluorine atom, an ethoxy group, or the structure shown in Formula II.

[0013] In either embodiment, R1 and R3 are hydrogen atoms, and R2 and R4 are methyl groups, ethyl groups, fluorine atoms, or the structure shown in Formula II; or R2 is a methyl group or the structure shown in Formula II, and R4 is a methyl group.

[0014] In either embodiment, R1 and R3 are hydrogen atoms, and R2 and R4 are methyl groups or the structure shown in Formula II.

[0015] In any embodiment, R5 and R6 are each independently selected from one of a hydrogen atom and a C1-C3 alkyl group.

[0016] In any embodiment, the cyclic sulfate ester compound is the compound shown below:

[0017] [ka]

[0018] The compound is selected from one or more of the following:

[0019] By adding the above cyclic sulfate ester compound to the electrolyte, an SEI film is formed in which the organic film and the inorganic film are mixed together, forming a more stable interface and helping to improve the battery's power efficiency.

[0020] In any embodiment, the mass content W of the cyclic sulfate ester compound based on the total mass of the electrolyte solution satisfies 0.001%≦W≦20%, and optionally is 0.1% to 5%.

[0021] By controlling the mass content of the cyclic sulfate ester compound within an appropriate range, it is possible not only to meet the demand for increasing the battery's power-scaling performance, but also to avoid or reduce the impact on the ion transmission rate caused by an excessively high mass content of the cyclic sulfate ester compound.

[0022] In any embodiment, the metal ion additive comprises one or more of an alkali metal ion, an alkaline earth metal ion, and a valent metal ion.

[0023] In any embodiment, the alkali metal ions include one or more of sodium ions, lithium ions, and potassium ions; and / or Based on the total mass of the electrolyte, the mass content of the alkali metal ions is 30 ppm to 3000 ppm, and optionally 50 ppm to 2000 ppm.

[0024] The introduction of alkali metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and by controlling the mass content of alkali metal ions, a stable SEI film can be formed, and the influence of the introduction of alkali metal ions on the electrolyte system can be avoided or reduced.

[0025] In any embodiment, the high-valent metal ions include one or more of aluminum ions and copper ions; and / or Based on the total mass of the electrolyte, the mass content of the high-valent metal ions is 0.5 ppm to 300 ppm, and optionally 15 ppm to 200 ppm.

[0026] Introducing high-valent metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and controlling the mass content of the high-valent metal ions allows for the formation of a stable SEI film, and also avoids or reduces the influence of the introduction of high-valent metal ions on the electrolyte system.

[0027] In any embodiment, the alkaline earth metal ions include one or more of magnesium ions and calcium ions; and / or Based on the total mass of the electrolyte, the mass content of the alkaline earth metal ions is 0.5 ppm to 500 ppm, and optionally 13 ppm to 400 ppm.

[0028] The introduction of alkaline earth metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and by controlling the mass content of alkaline earth metal ions, a stable SEI film can be formed, and the influence of the introduction of alkaline earth metal ions on the electrolyte system can be avoided or reduced.

[0029] In any embodiment, the electrolyte solution further comprises an electrolyte salt, the electrolyte salt comprising a lithium salt or a sodium salt; the lithium salt comprises one or more of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorobis(oxalato)phosphate, and lithium bis(oxalato)borate; The sodium salts include one or more of sodium hexafluorophosphate, sodium difluoro(oxalato)borate, sodium perchlorate, sodium bisfluorosulfonylimide, sodium bistrifluoromethanesulfonylimide, and sodium trifluoromethanesulfonate.

[0030] The lithium salt or sodium salt has good compatibility with the cyclic sulfate ester compound, and by introducing an appropriate amount of the cyclic sulfate ester compound into the electrolyte, the lithium salt or sodium salt is not affected.

[0031] A second aspect of the present application provides a secondary battery, which includes a negative electrode plate and the electrolyte solution according to the first aspect.

[0032] In any embodiment, the secondary battery includes a sodium battery or a lithium battery.

[0033] In any embodiment, the negative electrode plate includes a negative electrode active material, and the negative electrode active material includes one or more of artificial graphite, natural graphite, hard carbon, soft carbon, mesocarbon microbeads, carbon fiber, carbon nanotubes, elemental silicon, silicon oxide, silicon carbon composite, silicon alloy, elemental tin, tin oxide, and titanium composite.

[0034] The above negative electrode active materials all have excellent gram capacities and relatively high specific surface areas, which allow the battery to have a relatively high energy density.

[0035] In any embodiment, the active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound are 0.0002 cm 2 / g≦W×A≦0.04cm 2 / g, optionally 0.02cm 2 / g≦W×A≦0.1cm 2 / g.

[0036] When the active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound satisfy a certain relationship, a stable SEI film is formed, and at the same time, the battery's power supply performance and cycle performance are both achieved, allowing the battery's capacity to be fully utilized.

[0037] In any embodiment, the active specific surface area A of the negative electrode plate is A≦20 cm 2 / g, and optionally 5cm 2 / g~15cm 2 / g.

[0038] By controlling the active specific surface area A of the negative electrode plate within an appropriate range, it is possible to avoid or reduce the impact on the volatilization of battery capacity caused by increased battery polarization due to an excessively small active specific surface area of ​​the negative electrode plate, and it is also possible to avoid or reduce the impact on the cycle performance and storage performance of the battery caused by increased interfacial side reactions due to an excessively large active specific surface area of ​​the negative electrode plate. By having an active specific surface area A within an appropriate range, it is possible to achieve both good cycle performance, good storage performance, and good capacity of the battery.

[0039] A third aspect of the present application provides a power consuming device, the power consuming device including the secondary battery of the second aspect of the present application. [Brief explanation of the drawings]

[0040] [Figure 1] 1 is a schematic diagram of a secondary battery cell according to an embodiment of the present application; [Figure 2] FIG. 2 is an exploded view of the secondary battery cell shown in FIG. 1 according to the embodiment of the present application. [Figure 3]1 is a schematic diagram of a battery module according to an embodiment of the present application; [Figure 4] 1 is a schematic diagram of a battery pack according to an embodiment of the present application; [Figure 5] FIG. 5 is an exploded view of the battery pack according to the embodiment of the present application shown in FIG. 4. [Figure 6] 1 is a schematic diagram of a power consumption device in which a secondary battery according to an embodiment of the present application is used as a power source; DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, with appropriate reference to the drawings, embodiments specifically disclosing the electrolyte, secondary battery, and power consumption device of the present application will be described in detail. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters and redundant description of actually identical structures may be omitted. This is to avoid the following description becoming unnecessarily long and to facilitate understanding by those skilled in the art. Note that the drawings and the following description are provided to enable those skilled in the art to fully understand the present application, and are not intended to limit the subject matter described in the claims.

[0042] The "ranges" disclosed in this application are defined in the form of lower and upper limits, and a given range is defined by selecting one lower limit and one upper limit, and the selected lower and upper limits define the boundaries of the particular range. Such defined ranges may be inclusive or exclusive of the end values, and any combination is possible; i.e., any lower limit can be combined with any upper limit to form a single range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also possible. Furthermore, if 1 and 2 are listed as minimum range values ​​and 3, 4, and 5 are listed as maximum range values, the ranges 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5 are all possible. In this application, unless otherwise specified, a numerical range "a to b" is a shorthand notation for any combination of real numbers a to b, where a and b are both real numbers. For example, the numerical range "0-5" represents that the present specification has already listed all real numbers between "0-5," and "0-5" is merely a shorthand representation of combinations of these numbers. Also, expressing a parameter as an integer ≧2 is equivalent to disclosing that this parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0043] Unless otherwise stated, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0044] Unless otherwise stated, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0045] Unless otherwise specified, all steps in this application may be performed in order or randomly, and are preferably performed in order. For example, when the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed in order, or steps (b) and (a) performed in order. For example, when the method mentioned above may further include step (c), it means that step (c) may be added to the method in any order, and for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0046] Unless otherwise specified, the terms "comprise" and "include" used in this application may be open-ended or closed-ended. For example, the terms "comprise" and "include" may further include or include other components not listed, or may include or include only the listed components.

[0047] Unless otherwise stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, "A or B" is satisfied when A is true (or exists) and B is false (or does not exist), when A is false (or does not exist) but B is true (or exists), or when both A and B are true (or exist).

[0048] Currently, electrolytes present many problems. Taking lithium batteries as an example, electrolytes typically contain ester-based solvents (e.g., vinylene carbonate). These solvents are prone to side reactions with the lithium reaction interface, forming SEI films rich in organic components such as alkyllithium, which increase impedance and affect the battery's power performance. At the same time, excessive impedance can lead to lithium precipitation from the anode, further shortening the battery's lifespan. Therefore, it is necessary to design electrolytes that can meet the application needs of new-generation electrochemical systems.

[0049] [Electrolyte] Based on this, the present application provides an electrolyte solution, the electrolyte solution comprising a cyclic sulfate ester compound shown in Formula I and a metal ion additive,

[0050] [ka]

[0051] In Formula I, R1, R2, R3, and R4 are each independently selected from the structure shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group; and R1, R2, R3, and R4 are not simultaneously selected from a hydrogen atom; In Formula II, R5 and R6 are each independently selected from the group consisting of a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and the wavy line represents the bond position.

[0052] As used herein, the term "C1-C6 alkyl group" refers to a straight or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, the group being free of unsaturation, having from 1 to 6 carbon atoms, and attached to the remainder of the molecule by a single bond. Examples of C1-C6 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, n-pentyl, and n-hexyl groups.

[0053] As used herein, the term "cyclic sulfate compound" refers to a cyclic compound that contains a sulfate group and in which the two oxygen atoms and the sulfur atom in the sulfate group form a five-membered ring structure.

[0054] As used herein, the term "metal ion additive" refers to a salt added to an electrolyte in an amount of 5% or less, consisting entirely of metal cations and anions, and liquid at or near room temperature, where the metal cations include, but are not limited to, sodium, lithium, potassium, aluminum, copper, magnesium, or calcium ions. Room temperature is 25°C ± 5°C.

[0055] As used herein, the term "C1-C3 alkyl group" refers to a straight or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, the group being free of unsaturation, having from 1 to 3 carbon atoms, and attached to the remainder of the molecule by a single bond. Examples of C1-C3 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, and 1-methylethyl (isopropyl).

[0056] As used herein, the term "halogen atom" refers to periodic group VIIA elements, including, but not limited to, F, Cl, Br, I, and At.

[0057] As used herein, the term "C1-C3 haloalkyl group" refers to a C1-C3 alkyl group in which at least one hydrogen atom has been replaced with a halogen atom, including, but not limited to, trichloromethane, difluoroethylene, and 3-fluoropropylene.

[0058] As used herein, the term "C1-C3 alkoxy group" refers to a C1-C3 alkyl group and an oxygen atom, including, but not limited to, methoxy (CHO-), ethoxy (CHO-), and propoxy (CHO-).

[0059] As used herein, the term "C1-C3 haloalkoxy group" refers to a C1-C3 alkoxy group in which at least one hydrogen atom is replaced with a halogen atom, including, but not limited to, 1,1,1,2,2-pentafluoro-2-(2,2,2-trifluoroethoxy)ethane, 1-(2,2-difluoroethoxy)-2-(2,2,2-trifluoroethoxy)ethane, and 1,2-bis(2-fluoroethoxy)ethane.

[0060] As used herein, the term "double bond" refers to a heavy bond between two atoms in a compound molecule that is made up of two shared electron pairs, i.e., a carbon-carbon double bond.

[0061] As used herein, the term "ester group" refers to a group consisting of -COOR 10 is a group, where R 10 is a substituted or unsubstituted C 1-5 As used herein, the term "C1-C5 alkyl group" refers to a straight or branched hydrocarbon chain group consisting solely of carbon and hydrogen atoms, the group being free of unsaturation, having from 1 to 5 carbon atoms and attached to the remainder of the molecule by a single bond.

[0062] As used herein, the term "cyano" refers to a -CN group.

[0063] As used herein, the term "sulfonic acid group" refers to a -SO3H group.

[0064] As used herein, the term "bonding position" refers to the position at which a bond is formed between the structure shown in Formula II and the structure shown in Formula I.

[0065] On the one hand, the introduction of cyclic sulfate ester compounds into the electrolyte is advantageous for forming a stable SEI film. During the battery charging process, the cyclic sulfate ester groups serve to form an inorganic sulfite film between the electrolyte and the negative electrode plate, and the R1, R2, R3, or R4 groups serve to form an elastic organic film between the electrolyte and the negative electrode plate. For example, introducing alkyl / alkoxy groups into the R1, R2, R3, or R4 groups can form an elastic SEI film with longer organic chains on the negative electrode side, which can avoid or reduce the breakdown of the SEI film due to the volume change that occurs on the negative electrode side during cycling and improve the stability of the SEI film. In addition, the introduction of F- or N-containing elements into the R1, R2, R3, or R4 groups can participate in the film formation on the negative electrode side, forming an SEI film rich in inorganic components such as LiF or Li3N, which can improve the mechanical strength of the SEI film and further improve the stability of the SEI film on the negative electrode side. On the other hand, by introducing metal ion additives into the electrolyte, they act synergistically with the cyclic sulfate ester compound, participate in the formation of an inorganic film, and further help form a stable SEI film, further blocking electron tunneling, reducing interfacial impedance, and significantly improving the battery's power efficiency.

[0066] On the other hand, by introducing metal ion additives into the electrolyte, they act synergistically with the cyclic sulfate ester compound, participate in the formation of an inorganic film, and further help form a stable SEI film, further blocking electron tunneling, reducing interfacial impedance, and significantly improving the battery's power efficiency.

[0067] In some embodiments, R1, R2, R3, and R4 are each independently selected from one of the structures shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, and a cyano group.

[0068] R1, R2, R3, and R4 are each independently selected from the structure shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, and a cyano group. During the battery charging process, R1, R2, R3, or R4 separates from the cyclic sulfate ester group to form an organic film, which increases the interfacial stability between the electrolyte and the negative electrode plate and is beneficial to improving the battery's charging performance.

[0069] In some embodiments, R1 is selected from a hydrogen atom, a C1-C3 alkyl group, R2 is selected from a C1-C3 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a cyano group, or a structure shown in Formula II, R3 is selected from a hydrogen atom, a C1-C3 alkyl group, and R4 is selected from a C1-C3 alkyl group, a halogen atom, a C1-C3 alkoxy group, or a structure shown in Formula II.

[0070] In some embodiments, R1 is selected from a hydrogen atom or a methyl group; R2 is selected from a methyl group, an ethyl group, a fluorine atom, a trifluoromethyl group, a cyano group, or the structure shown in Formula II; R3 is selected from a hydrogen atom; and R4 is selected from a methyl group, an ethyl group, a propyl group, a fluorine atom, an ethoxy group, or the structure shown in Formula II.

[0071] In some embodiments, R1 and R3 are hydrogen atoms, and R2 and R4 are methyl groups, ethyl groups, fluorine atoms, or the structure shown in Formula II; or R2 is a methyl group or the structure shown in Formula II, and R4 is a methyl group.

[0072] In some embodiments, R1 and R3 are hydrogen atoms, and R2 and R4 are methyl groups or the structure shown in Formula II.

[0073] In some embodiments, R5 and R6 are each independently selected from one of a hydrogen atom and a C1-C3 alkyl group.

[0074] In some embodiments, the cyclic sulfate compound is the compound shown below:

[0075] [ka]

[0076] The compound is selected from one or more of the following:

[0077] By adding the above cyclic sulfate ester compound to the electrolyte, an SEI film is formed in which the organic film and the inorganic film are mixed together, forming a more stable interface and helping to improve the battery's power efficiency.

[0078] In some embodiments, the mass content W of the cyclic sulfate ester compound based on the total mass of the electrolyte solution satisfies 0.001%≦W≦20%, and optionally is 0.1% to 5%.

[0079] In some embodiments, the mass content W of the cyclic sulfate ester compound, based on the total mass of the electrolyte solution, is optionally 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 2%, 4%, 5%, 6%, 8%, 10%, 12%, 14%, 15%, 16%, 18%, 20%, or a value in a range consisting of any two of the above points.

[0080] By controlling the mass content of the cyclic sulfate ester compound within an appropriate range, it is possible not only to meet the demand for increasing the battery's power-scaling performance, but also to reduce or diminish the impact on the ion transmission rate caused by an excessively high mass content of the cyclic sulfate ester compound.

[0081] In some embodiments, the metal ion additive comprises one or more of an alkali metal ion, an alkaline earth metal ion, and a valent metal ion.

[0082] In some embodiments, the alkali metal ions include one or more of sodium ions, lithium ions, and potassium ions.

[0083] In some embodiments, the mass content of alkali metal ions is between 30 ppm and 3000 ppm, and optionally between 50 ppm and 2000 ppm, based on the total mass of the electrolyte.

[0084] In some embodiments, the mass content of alkali metal ions, based on the total mass of the electrolyte, is optionally 30 ppm, 50 ppm, 100 ppm, 200 ppm, 400 ppm, 500 ppm, 600 ppm, 800 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm, or a range consisting of any two of the above points.

[0085] As can be seen, the alkali metal ions in the metal ion additive are involved in the formation of the SEI film, and by consuming some of the alkali metal ions, the mass content of the alkali metal ions in the electrolyte can be reduced. For example, if the mass content of the alkali metal ions in the electrolyte is 30 ppm, the mass content of the alkali metal ions based on the total mass of the electrolyte is 30 ppm to 3000 ppm, both of which are within the range protected by the embodiments of the present application.

[0086] The introduction of alkali metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and by controlling the mass content of alkali metal ions, a stable SEI film can be formed, and the influence of the introduction of alkali metal ions on the electrolyte system can be avoided or reduced.

[0087] In some embodiments, the high-valent metal ions include one or more of aluminum ions and copper ions.

[0088] In some embodiments, the mass content of the high-valent metal ions is between 0.5 ppm and 300 ppm, and optionally between 15 ppm and 200 ppm, based on the total mass of the electrolyte.

[0089] In some embodiments, the mass content of the high-valent metal ions, based on the total mass of the electrolyte, is optionally 0.5 ppm, 1 ppm, 5 ppm, 10 ppm, 15 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, or a range consisting of any two of the above points.

[0090] As can be seen, the high-valent metal ions in the metal ion additive are involved in the formation of the SEI film, and by consuming some of the high-valent metal ions, the mass content of the high-valent metal ions in the electrolyte can be reduced. For example, if the mass content of the high-valent metal ions in the electrolyte is 0.5 ppm, the mass content of the high-valent metal ions based on the total mass of the electrolyte is 0.5 ppm to 300 ppm, both of which are within the range protected by the embodiments of the present application.

[0091] Introducing high-valent metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and controlling the mass content of the high-valent metal ions allows for the formation of a stable SEI film and can also reduce or eliminate the impact of the introduction of high-valent metal ions on the electrolyte system.

[0092] In some embodiments, the alkaline earth metal ions include one or more of magnesium ions and calcium ions.

[0093] In some embodiments, the mass content of alkaline earth metal ions is between 0.5 ppm and 500 ppm, and optionally between 13 ppm and 400 ppm, based on the total mass of the electrolyte.

[0094] In some embodiments, the mass content of alkaline earth metal ions, based on the total mass of the electrolyte, is optionally 0.5 ppm, 1 ppm, 5 ppm, 10 ppm, 13 ppm, 15 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, 350 ppm, 400 ppm, 450 ppm, 500 ppm, or a range consisting of any two of the above points.

[0095] As can be seen, the alkaline earth metal ions in the metal ion additive are involved in the formation of the SEI film, and some of the alkaline earth metal ions are consumed, thereby reducing the mass content of the alkaline earth metal ions in the electrolyte. For example, if the mass content of the alkaline earth metal ions in the electrolyte is 0.5 ppm, then the mass content of the alkaline earth metal ions based on the total mass of the electrolyte is 0.5 ppm to 500 ppm, both of which are within the range protected by the embodiments of the present application.

[0096] The introduction of alkaline earth metal ions into the electrolyte helps to form an inorganic SEI film with stronger electron blocking ability, and by controlling the mass content of alkaline earth metal ions, a stable SEI film can be formed, and the influence of the introduction of alkaline earth metal ions on the electrolyte system can be reduced or minimized.

[0097] The metal ions can be introduced into the electrolyte in the form of adding a salt containing the selected metal ion, which can be a hexafluorophosphate salt, such as sodium hexafluorophosphate.

[0098] The mass content of the metal ions in the metal ion additive in the electrolyte can be detected using instruments and methods known in the art, including, but not limited to, using an ICP (Inductive Coupled Plasma Emission Spectrometer) in accordance with the standard operating flow recommended by the instrument manufacturer or the industry practice.

[0099] In some embodiments, the electrolyte solution further comprises an electrolyte salt, the electrolyte salt comprising a lithium salt or a sodium salt; the lithium salt comprises one or more of lithium hexafluorophosphate (LiPF), lithium perchlorate (LiClO), lithium tetrafluoroborate (LiBF), lithium hexafluoroarsenate (LiAsF), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium difluorobis(oxalato)phosphate (LiDFOP), lithium bis(oxalato)borate (LiBOB); The sodium salts include one or more of sodium hexafluorophosphate (NaPF6), sodium difluoro(oxalato)borate (NaDFOB), sodium perchlorate (NaClO4), sodium bisfluorosulfonylimide (NaFSI), sodium bistrifluoromethanesulfonylimide (NaTFSI), sodium trifluoromethanesulfonate (NaOTf).

[0100] In some embodiments, the concentration of the electrolyte salt is between 0.1 mol / L and 5 mol / L, and optionally between 0.7 mol / L and 1.2 mol / L. In some embodiments, the concentration of the electrolyte salt is optionally 0.1 mol / L, 0.2 mol / L, 0.4 mol / L, 0.5 mol / L, 0.7 mol / L, 0.8 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 5.5 mol / L, 5 mol / L, or a range consisting of any two of the above points.

[0101] The lithium salt or sodium salt has good compatibility with the cyclic sulfate ester compound, and by introducing an appropriate amount of the cyclic sulfate ester compound into the electrolyte, the lithium salt or sodium salt is not affected.

[0102] In some embodiments, the electrolyte solution may further optionally contain additives. For example, the additives may include a negative electrode film-forming additive, a positive electrode film-forming additive, and may further include additives that can improve some battery performance, such as an additive that improves the overcharge performance of the battery, or an additive that improves the high-temperature or low-temperature performance of the battery.

[0103] [Positive electrode plate] The positive electrode plate includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector. The positive electrode film layer includes a positive electrode active material, a conductive agent, and an adhesive.

[0104] For example, the positive electrode current collector has two surfaces that face each other in the thickness direction of the positive electrode current collector, and the positive electrode film layer is disposed on either one or both of the two facing surfaces of the positive electrode current collector.

[0105] In some embodiments, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, aluminum foil may be used as the metal foil sheet. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0106] In some embodiments, the positive electrode active material may be any positive electrode active material known in the art for batteries. For example, the positive electrode active material may include at least one of a lithium-containing phosphate having an olivine structure, a lithium metal oxide, and a modified compound thereof. However, the present application is not limited to these materials, and other conventional materials usable as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of lithium metal oxides include lithium cobalt oxide (e.g., LiCoO), lithium nickel oxide (e.g., LiNiO), lithium manganese oxide (e.g., LiMnO, LiMnO), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM 333 (may be abbreviated as "LiNi") 0.5 Co 0.2 Mn 0.3 O2(NCM 523 (may be abbreviated as "LiNi") 0.5 Co 0.25 Mn 0.25 O2(NCM 211 (may be abbreviated as "LiNi") 0.6 Co 0.2 Mn 0.2 O2(NCM622 (may be abbreviated as "LiNi") 0.8 Co 0.1 Mn 0.1 O2(NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05 Examples of the lithium-containing phosphate having an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0107] In some embodiments, the conductive agent may be any conductive agent known in the art for batteries, including, by way of example, at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0108] In some embodiments, the adhesive may include any battery adhesive known in the art. By way of example, the adhesive may include polyvinylidene fluoride.

[0109] In some embodiments, a positive electrode plate can be manufactured as follows: Components for manufacturing the positive electrode plate, such as a positive electrode active material, a conductive agent, an adhesive, and any other components, are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry, which is then coated onto a positive electrode current collector, and the positive electrode plate is obtained after processes such as drying and cold pressing.

[0110] [Negative electrode plate] The negative electrode plate includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material.

[0111] For example, the negative electrode current collector has two surfaces that face each other in the thickness direction thereof, and the negative electrode film layer is disposed on either one or both of the two facing surfaces of the negative electrode current collector.

[0112] In some embodiments, the negative electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be copper foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0113] In some embodiments, the negative electrode plate comprises an active negative electrode material, the active negative electrode material comprising one or more of artificial graphite, natural graphite, hard carbon, soft carbon, mesocarbon microbeads, carbon fibers, carbon nanotubes, elemental silicon, silicon oxide, silicon carbon composite, silicon alloy, elemental tin, tin oxide, and titanium composite.

[0114] In some embodiments, the titanium composite material comprises lithium titanate.

[0115] The above negative electrode active materials all have excellent gram capacities and relatively high specific surface areas, which allow the battery to have a relatively high energy density.

[0116] In some embodiments, the active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound are 0.0002 cm 2 / g≦W×A≦0.04cm 2 / g, optionally 0.02cm 2 / g≦W×A≦0.1cm 2 / g.

[0117] As used herein, the term "active specific surface area" refers to the ratio of the active surface area of ​​a negative electrode plate to the mass of the negative electrode plate, and may be used to reflect the number of active sites on the negative electrode plate during charging and discharging. The larger the active specific surface area of ​​the negative electrode plate, the more active sites there are on the negative electrode plate.

[0118] In this specification, the active specific surface area of ​​the negative electrode plate can be tested using any known method. For example, the active specific surface area of ​​the negative electrode plate is calculated based on the Randles-Sevcik equation, combining the mass of the negative electrode plate. The negative electrode plate is used as the cathode, and a metallic lithium sheet is used as the anode. Ferrocene is added to the electrolyte (the same as the electrolyte used in the battery manufacturing process) at a concentration of 50 mmol / L, and the resulting assembly is a button-type half-cell. Four parallel samples are scanned at scan rates (v) of 0.1 mV / s, 0.3 mV / s, 0.5 mV / s, and 1 mV / s, respectively, to obtain cyclic voltammetry curves at different scan rates. The peak currents (ip) of the cyclic voltammetry curves are extracted using EC-Lab software. A linear graph of the cyclic voltammetry curve (ip) versus the square root of the scan rate (v) is plotted, with the square root of the scan rate (v) as the abscissa and the peak current (ip) as the ordinate, and the slope (K) is obtained.

[0119] The slope is found based on the Randles-Sevcik equation, where n represents the electron transfer number, which is related to the type of probe molecule and has a value of 1; c represents the concentration of ferrocene and has a value of 50 mmol / L; and D is the diffusion coefficient of ferrocene and has a value of 2.1 × 10 -6 cm 2 / s, the active surface area of ​​the negative electrode plate A = K / (2.69 × 10 5 ×n 2 / 3 CD 1 / 2 ) and the ratio of the active surface area A of the negative electrode plate to the weight m of the negative electrode plate is the active specific surface area of ​​the negative electrode plate.

[0120] In some embodiments, the product of the active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound is optionally 0.0002 cm 2 / g, 0.0005cm 2 / g, 0.002cm 2 / g, 0.005cm 2 / g, 0.02cm 2 / g, 0.022cm 2 / g, 0.024cm 2 / g, 0.025cm 2 / g, 0.026cm 2 / g, 0.028cm 2 / g, 0.03cm 2 / g, 0.032cm 2 / g, 0.034cm 2 / g, 0.035cm 2 / g, 0.036cm 2 / g, 0.038cm 2 / g, 0.04cm 2 / g, or a range consisting of any two of the above points.

[0121] When the active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound satisfy the above-mentioned relationship, a stable SEI film is formed, and at the same time, both the battery's power supply performance and cycle performance are achieved, enabling the battery to fully utilize its capacity.

[0122] In some embodiments, the active specific surface area A of the negative electrode plate is A≦20 cm 2 / g, and optionally 5cm 2 / g~15cm 2 / g.

[0123] In some embodiments, the active specific surface area A of the negative electrode plate is optionally 1 cm 2 / g, 2cm 2 / g, 4cm 2 / g, 5cm 2 / g, 6cm 2 / g, 8cm 2 / g, 10cm 2 / g, 11cm 2 / g, 12cm2 / g, 13cm 2 / g, 14cm 2 / g, 15cm 2 / g, or a range consisting of any two of the above points.

[0124] By controlling the active specific surface area A of the negative electrode plate within an appropriate range, it is possible to avoid or reduce the impact on the volatilization of battery capacity caused by increased battery polarization due to an excessively small active specific surface area of ​​the negative electrode plate, and it is also possible to avoid or reduce the impact on the cycle performance and storage performance of the battery caused by increased interfacial side reactions due to an excessively large active specific surface area of ​​the negative electrode plate. By having an active specific surface area A within an appropriate range, it is possible to achieve both good cycle performance, good storage performance, and good capacity of the battery.

[0125] In some embodiments, the negative electrode membrane layer optionally further comprises an adhesive, which may be selected from at least one 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).

[0126] In some embodiments, the negative electrode film layer further optionally includes a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0127] In some embodiments, the negative electrode membrane layer optionally further comprises other additives, such as a thickener (eg, carboxymethylcellulose sodium (CMC-Na)).

[0128] In some embodiments, the negative electrode plate can be manufactured in the following manner: Components for manufacturing the negative electrode plate, such as a negative electrode active material, a conductive agent, an adhesive, and any other components, are dispersed in a solvent (e.g., deionized water) to form a negative electrode slurry, which is then coated onto a negative electrode current collector, and the negative electrode plate is obtained after processes such as drying and cold pressing.

[0129] [Separator] In some embodiments, the secondary battery further includes a separator, which may be selected from any known porous structure separator with good chemical and mechanical stability.

[0130] In some embodiments, the separator may be made of at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different.

[0131] In some embodiments, the positive and negative electrodes and the separator can be fabricated into an electrode assembly by a winding or lamination process.

[0132] In some embodiments, the secondary battery may include an exterior body, which may be used to package the electrode assembly and electrolyte.

[0133] In some embodiments, the exterior of the secondary battery may be a hard case, such as a hard plastic case, an aluminum case, a steel case, etc. The exterior of the secondary battery may be a pouch, such as a bag-shaped pouch. The pouch may be made of plastic, such as polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0134] [Secondary battery] In the present application, the shape of the secondary battery includes, but is not limited to, a cylindrical shape, a rectangular shape, or any other shape. For example, FIG. 1 shows an example of a rectangular secondary battery 5. The secondary battery may be a sodium ion secondary battery, a magnesium ion secondary battery, or a potassium ion secondary battery.

[0135] In some embodiments, the secondary battery includes an electrolyte according to the present application. In some embodiments, the secondary battery includes a negative electrode plate according to the present application.

[0136] In some embodiments, referring to FIG. 2 , the exterior body may include a case 51 and a cover plate 53. Here, the case 51 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate together form a surrounding accommodating cavity. The case 51 has an opening communicating with the accommodating cavity, and the cover plate 53 can cover the opening to seal the accommodating cavity. The positive electrode plate, the negative electrode plate, and the separator may be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is packaged within the accommodating cavity. An electrolyte is impregnated 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 the number according to actual needs.

[0137] [Battery module] In some embodiments, the secondary batteries may be assembled into a battery module, and the number of secondary batteries included in the battery module may be one or more, with the specific number being selectable by those skilled in the art depending on the application and capacity of the battery module.

[0138] Fig. 3 shows an example of a battery module 4. Referring to Fig. 3, in the battery module 4, a plurality of secondary batteries 5 may be arranged in order along the longitudinal direction of the battery module 4. Of course, they may be arranged in any other manner. Furthermore, the plurality of secondary batteries 5 may be fixed by fasteners.

[0139] Optionally, the battery module 4 may further include a housing having an accommodating space, and the plurality of secondary batteries 5 are accommodated in this accommodating space.

[0140] [Battery pack] In some embodiments, the battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, the specific number of which can be selected by those skilled in the art depending on the application and capacity of the battery pack.

[0141] 4 and 5 show an example of a battery pack 1. Referring to FIGS. 4 and 5, the battery pack 1 may include a battery box and a plurality of battery modules 4 installed in the battery box. The battery box includes an upper housing 2 and a lower housing 3, and the upper housing 2 covers the lower housing 3 to form a sealed space for accommodating the battery modules 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.

[0142] [Power consumption equipment] In one embodiment of the present application, there is provided a power consumption device, which includes at least one of the secondary battery of any of the embodiments, the battery module of any of the embodiments, or the battery pack of any of the embodiments.

[0143] The power consuming device includes at least one of a secondary battery, a battery module, or a battery pack according to the present application. The secondary battery, the battery module, or the battery pack may be used as a power source for the power consuming device or as an energy storage unit for the power consuming device. The power consuming device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, energy storage systems, etc.

[0144] The power consumption device can be selected from a secondary battery, a battery module, or a battery pack depending on its usage needs.

[0145] 6 shows an example of a power consuming device, such as a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the demand for high power output and high energy density of secondary batteries in the power consuming device, a battery pack or battery module may be employed.

[0146] Other examples of the device may be a mobile phone, a tablet computer, a notebook computer, etc. These devices are generally required to be thin, and may use a secondary battery as a power source.

[0147] Example The following describes examples of the present application. The examples described below are illustrative and are intended to interpret the present application, but should not be understood as limitations on the present application. If no specific techniques or conditions are described in the examples, they are carried out according to the techniques, conditions, or product specifications described in documents within the field. If no manufacturer is specified for the reagents or equipment used, they are all ordinary products that are commercially available.

[0148] 1. Manufacturing method Example 1 1) Production of cyclic sulfate ester compounds 364.3 g (2 mol) of galactitol was added to a 4 L three-necked flask, stirring was started, and 784.5 g (6.6 mol) of thionyl chloride was added dropwise to the three-necked flask. The temperature was controlled at about 15°C during the addition, and after the addition was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution. After cooling, 1 L of deionized water was slowly added dropwise, and the reaction system was rapidly stirred and dispersed. The solid obtained by filtration was slurried and washed several times with deionized water until the pH became neutral, and the filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0149] A 4 L three-neck flask was charged with 140 g (0.4 mol) of the above intermediate product, 1000 mL of acetonitrile, and 110 mg of ruthenium trichloride trihydrate catalyst. The system was then purged with nitrogen gas. The system was then cooled to 20°C, stirring was started, and 1500 g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 15°C. After the addition was completed, the mixture was stirred at 15°C for 10 minutes, and the solution was separated. The organic phase was quenched with aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The solution was then separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-1.

[0150] [ka]

[0151] 2) Manufacturing of positive electrode plates 2.5 wt% polyvinylidene fluoride adhesive was thoroughly dissolved in N-methylpyrrolidone (NMP), and then 2.0 wt% Super P, 1.0 wt% carbon nanotubes, and 94.5 wt% lithium iron phosphate (LiFePO4), the positive electrode active material, were added and stirred uniformly to obtain a positive electrode slurry. The slurry was evenly applied to the surface of an aluminum foil current collector and then transferred to a vacuum drying oven for complete drying. The dried electrode plate was rolled and punch-diced to obtain a positive electrode plate.

[0152] 3) Manufacturing of negative electrode plates The active material, artificial graphite, conductive agent, carbon black, adhesive, styrene butadiene rubber (SBR), and thickener, sodium hydroxymethylcellulose (CMC), were dissolved in deionized water in a weight ratio of 96.2:0.8:0.8:1.2 and mixed uniformly to form a negative electrode slurry. The negative electrode slurry was then uniformly coated onto a negative electrode current collector copper foil one or more times, followed by drying, cold pressing, and slitting to obtain a negative electrode plate. The active specific surface area of ​​the negative electrode plate was 8 cm. 2 / g.

[0153] 4) Electrolyte In an argon gas atmosphere glove box (HO<0.1 ppm, O<0.1 ppm), lithium hexafluorophosphate LiPF6, a lithium salt, a cyclic sulfate ester compound having the structure shown in Formula I-1, and sodium hexafluorophosphate NaPF6, a metal ion additive, were dissolved in a mixed system of organic solvents: ethylene carbonate / dimethyl carbonate / ethyl methyl carbonate (EC:DMC:EMC in a mass ratio of 1:1:1), and the solution was stirred uniformly to obtain an electrolyte solution with a lithium salt concentration of 1 mol / L.

[0154] 5) Separator A polypropylene film was used as a separator.

[0155] 6) Battery manufacturing A positive electrode plate, a separator, and a negative electrode plate were stacked in this order, and a separator was placed between the positive and negative electrodes to provide isolation. The stack was then wound to obtain an electrode assembly. The electrode assembly was then placed in a battery case, dried, and then an electrolyte was injected. After sequential steps such as standing, hot and cold pressing, chemical formation, shaping, and capacity testing, the lithium battery product of Example 1 was obtained.

[0156] Example 2 The battery of Example 2 is manufactured in a manner similar to that of Example 1, but the manufacturing method of the cyclic sulfate ester compound is adjusted, and the specific manufacturing method is as follows.

[0157] 392.4 g (2 mol) of solid 1,2,3,4,5,6-heptanehexaol was added to a 4 L three-neck flask, stirring was started, and 784.5 g (6.6 mol) of thionyl chloride was added dropwise to the three-neck flask. The temperature was controlled at about 15°C during the addition process, and after the addition was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution. After cooling, 1 L of deionized water was slowly added dropwise, and the reaction system was rapidly stirred and dispersed. The solid obtained by filtration was slurried and washed several times with deionized water until the pH became neutral. The filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0158] A 4L three-neck flask was charged with 140g (0.4mol) of the intermediate product, 1000mL of acetonitrile, and 110mg of ruthenium trichloride trihydrate catalyst. The system was then purged with nitrogen gas, and the temperature of the system was lowered to 20°C. Stirring was started, and 1500g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 15°C. After the addition was completed, the mixture was stirred at 15°C for 10 minutes, and the solution was separated. The organic phase was quenched using aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The solution was separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-2.

[0159] [ka]

[0160] Example 3 The battery of Example 3 is manufactured in a manner similar to that of Example 1, but the manufacturing method of the cyclic sulfate ester compound is adjusted, and the specific manufacturing method is as follows.

[0161] Add 484g (2mol) of solid octitol into a 2L three-neck flask, start stirring, add 1046g (8.8mol) of thionyl chloride dropwise to the three-neck flask, control the temperature at about 15℃ during the addition, and after the addition is completed, keep the temperature at 45℃ for 4 hours to react, and a large amount of paste-like solid precipitates from the reaction solution. After cooling, add 1L of deionized water slowly dropwise, stir the reaction system quickly, disperse, filter, and the obtained solid is slurried and washed several times with deionized water until the pH becomes neutral. The filter cake is dried under reduced pressure at 60℃ to obtain an intermediate product.

[0162] A 4L three-neck flask was charged with 183.2g (0.4mol) of the intermediate product, 1000mL of acetonitrile, and 150mg of ruthenium trichloride trihydrate catalyst. The system was then purged with nitrogen gas. The system was then cooled to 20°C, stirring was started, and 2000g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 10-20°C. After the addition was complete, the mixture was stirred at 10-20°C for 10 minutes, and the solution was separated. The organic phase was quenched using an aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The solution was then separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-5.

[0163] [ka]

[0164] Example 4 The battery of Example 4 is manufactured in a manner similar to that of Example 1, but the manufacturing method of the cyclic sulfate ester compound is adjusted, and the specific manufacturing method is as follows.

[0165] 300 g (2 mol) of solid 1,6-dideoxygalactitol was added to a 3 L three-neck flask, stirring was started, and 523 g (4.4 mol) of thionyl chloride was added dropwise to the three-neck flask. The temperature was controlled at about 15°C during the addition process, and after the addition was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution. After cooling, 1 L of deionized water was slowly added dropwise, and the reaction system was rapidly stirred and dispersed. The solid obtained by filtration was slurried and washed several times with deionized water until the pH became neutral, and the filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0166] A 3L three-neck flask was charged with 184.2g (0.8mol) of the above intermediate product, 1000mL of acetonitrile, and 80mg of ruthenium trichloride trihydrate catalyst. The system was then replaced with nitrogen gas, and the system was cooled to 20°C, stirring was started, and 2000g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 15°C, and after the addition was completed, the mixture was stirred at 15°C for 10 minutes, separated, and the organic phase was quenched using aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The mixture was then separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain a white powder solid, namely, the above compound I-6. 1H-NMR, CD3CN, δ ppm 5.42-5.39(m, 2H), 5.36-5.34(m, 2H), 1.67-1.65(d, 6H).

[0167] [ka]

[0168] Example 5 The battery of Example 5 is manufactured in a manner similar to that of Example 1, but the manufacturing method of the cyclic sulfate ester compound is adjusted, and the specific manufacturing method is as follows.

[0169] 356.5g (2mol) of solid 3,4,5,6-octanolol was added to a 2L three-necked flask, stirring was started, 523g (4.4mol) of thionyl chloride was added dropwise to the three-necked flask, the temperature was controlled to about 15°C during the dropping process, and after the dropping was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution, after cooling, 1L of deionized water was slowly added dropwise, the reaction system was quickly stirred and dispersed, and the solid obtained by filtration was slurried and washed several times with deionized water until the pH became neutral, and the filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0170] 216.2 g (0.8 mol) of the above intermediate product was added to a 3 L three-neck flask, 1000 mL of acetonitrile was added, and 80 mg of ruthenium trichloride trihydrate catalyst was added. The system was then purged with nitrogen gas, and the system was cooled to 20°C, stirring was started, and 2000 g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 15°C, and after the addition was completed, the mixture was stirred at 15°C for 10 minutes, separated, and the organic phase was quenched using aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The mixture was then separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-7.

[0171] [ka]

[0172] Example 6 The battery of Example 6 is manufactured in a manner similar to that of Example 1, but the manufacturing method of the cyclic sulfate ester compound is adjusted, and the specific manufacturing method is as follows.

[0173] 328.4 g (2 mol) of solid 2,3,4,5-heptetrol was added to a 2 L three-neck flask, stirring was started, and 523 g (4.4 mol) of thionyl chloride was added dropwise to the three-neck flask. The temperature was controlled at about 15°C during the addition process, and after the addition was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution. After cooling, 1 L of deionized water was slowly added dropwise, and the reaction system was rapidly stirred and dispersed. The solid obtained by filtration was slurried and washed several times with deionized water until the pH was neutral. The filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0174] 205g (0.8mol) of the above intermediate product was placed in a 3L three-neck flask, and 1000mL of acetonitrile was added. The mixture was stirred until the solid was completely dissolved. 80mg of ruthenium trichloride trihydrate catalyst was added. The system was purged with nitrogen gas, and the temperature of the system was lowered to 20°C. Stirring was started, and 2000g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 10-20°C. After the addition was completed, the mixture was stirred at 10-20°C for 10 minutes, and the mixture was separated. The organic phase was quenched with aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The mixture was separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-8.

[0175] [ka]

[0176] Examples 7 to 29 The batteries of Examples 7 to 29 were manufactured using a method similar to that of Example 4, but the mass content of the cyclic sulfate ester compound, the type and mass content of the metal ion, or the type of negative electrode active material was adjusted. The specific parameters are shown in Table 1.

[0177] Example 30 1) Production of cyclic sulfate ester compounds 364.3 g (2 mol) of galactitol was added to a 4 L three-necked flask, stirring was started, and 784.5 g (6.6 mol) of thionyl chloride was added dropwise to the three-necked flask. The temperature was controlled at about 15°C during the addition, and after the addition was completed, the mixture was kept at 45°C for 4 hours to react, causing a large amount of paste-like solid to precipitate from the reaction solution. After cooling, 1 L of deionized water was slowly added dropwise, and the reaction system was rapidly stirred and dispersed. The solid obtained by filtration was slurried and washed several times with deionized water until the pH became neutral, and the filter cake was dried under reduced pressure at 60°C to obtain an intermediate product.

[0178] A 4 L three-neck flask was charged with 140 g (0.4 mol) of the above intermediate product, 1000 mL of acetonitrile, and 110 mg of ruthenium trichloride trihydrate catalyst. The system was then purged with nitrogen gas. The system was then cooled to 20°C, stirring was started, and 1500 g of 20% aqueous sodium hypochlorite solution was added dropwise within 1 hour. The reaction temperature was controlled at 15°C. After the addition was completed, the mixture was stirred at 15°C for 10 minutes, and the solution was separated. The organic phase was quenched with aqueous sodium sulfite solution until the starch potassium iodide test paper no longer turned blue. The solution was then separated again, the organic layer was concentrated, and the acetonitrile was crystallized to obtain compound I-1.

[0179] 2) Manufacturing of positive electrode plates The positive electrode active material, NaFePO4, the conductive agent, acetylene black, and the adhesive, polyvinylidene fluoride (PVDF), were mixed in a mass ratio of 80:10:10 in an N-methylpyrrolidone solvent system with sufficient stirring to obtain a positive electrode slurry. The slurry was then uniformly applied to the surface of an aluminum foil current collector and transferred to a vacuum drying oven for complete drying. The dried electrode plate was then rolled and punch-diced to obtain a positive electrode plate.

[0180] 3) Manufacturing of negative electrode plates The negative electrode active material, hard carbon, the conductive agent, acetylene black, and the adhesive, polyacrylic acid, were mixed in a mass ratio of 88:2:10 in deionized water solvent and thoroughly stirred to form a negative electrode slurry. The negative electrode slurry was then uniformly coated onto a negative electrode current collector copper foil one or more times, followed by drying, cold pressing, and slitting to obtain a negative electrode plate. The active specific surface area of ​​the negative electrode plate was 8 cm. 2 / g.

[0181] 4) Electrolyte In an argon gas atmosphere glove box (H2O<0.1 ppm, O2<0.1 ppm), sodium hexafluorophosphate NaPF6 (a sodium salt), a cyclic sulfate ester compound having the structure shown in Formula I-1, and metal ion additive lithium hexafluorophosphate LiPF6 were dissolved in a mixed system of organic solvents, ethylene carbonate / dimethyl carbonate / ethyl methyl carbonate (EC:DMC:EMC in a mass ratio of 1:1:1), and the solution was stirred uniformly to obtain an electrolyte solution with a sodium salt concentration of 1 mol / L.

[0182] 5) Separator A polypropylene film was used as a separator.

[0183] 6) Battery manufacturing A positive electrode plate, a separator, and a negative electrode plate are stacked in this order, with a separator positioned between the positive and negative electrodes to provide isolation, and then wound to obtain an electrode assembly. The electrode assembly is then placed in a battery case, dried, and then an electrolyte is injected. After sequential steps such as standing, hot and cold pressing, chemical forming, shaping, and capacity testing, the sodium battery product of Example 33 is obtained.

[0184] Examples 31 to 41 The batteries of Examples 31 to 41 were manufactured using a method similar to that of Example 30, but the type and mass content of the cyclic sulfate ester compound and the type of metal ion were adjusted. Specific parameters are shown in Table 1.

[0185] Examples 42 to 44 The batteries of Examples 42 to 44 were manufactured in a similar manner to that of Example 4, but the active specific surface area of ​​the negative electrode plate was adjusted. Specific parameters are as shown in Table 1.

[0186] Comparative Example 1 The battery of Comparative Example 1 was manufactured in a similar manner to that of Example 1, but the electrolyte did not contain any metal ion additives. The specific parameters are as shown in Table 1.

[0187] Comparative Example 2 The battery of Comparative Example 2 was manufactured in a similar manner to that of Example 33, but the electrolyte did not contain any metal ion additives. The specific parameters are as shown in Table 1.

[0188] Comparative Example 3 The battery of Comparative Example 3 was manufactured using a method similar to that of Example 1, but the electrolyte did not contain a cyclic sulfate ester compound. Specific parameters are as shown in Table 1.

[0189] Comparative Example 4 The battery of Comparative Example 4 was manufactured using a method similar to that of Example 33, but the electrolyte did not contain a cyclic sulfate ester compound. Specific parameters are as shown in Table 1.

[0190] Comparative Example 5 The battery of Comparative Example 5 was manufactured using a method similar to that of Example 1, except that the sulfate ester compound used was the commercially available compound 4,4'-bi-1,3,2-dioxathiolane 2,2,2'-2'-tetraoxide (CAS No. 1431298-10-0, commercially available). The structural formula of 4,4'-bi-1,3,2-dioxathiolane 2,2,2'-2'-tetraoxide is shown in Formula III. Specific parameters are listed in Table 1.

[0191] [ka]

[0192] Comparative Example 6 The battery of Comparative Example 6 was manufactured in a similar manner to that of Comparative Example 5, but the type of electrolyte salt in the electrolyte solution was adjusted. Specific parameters are as shown in Table 1.

[0193] 2. Performance test 1. Negative electrode plate performance test 1) Active specific surface area test The negative electrode plates prepared in the examples and comparative examples were used as the cathode, and a metallic lithium sheet was used as the anode. The electrolyte (the same as that used in the battery manufacturing process) was mixed with 50 mmol / L of ferrocene and assembled into button-type half-cells. Four parallel samples were taken and scanned at scan rates (v) of 0.1 mV / s, 0.3 mV / s, 0.5 mV / s, and 1 mV / s, respectively, to obtain cyclic voltammetry curves at different scan rates. The peak currents (ip) of the cyclic voltammetry curves were extracted using EC-Lab software. A linear graph of the cyclic voltammetry curve (ip) versus the square root of the scan rate (v) was plotted, with the square root of the scan rate (v) as the abscissa and the peak current (ip) as the ordinate, and the slope (K) was obtained.

[0194] The slope is found based on the Randles-Sevick equation, where n represents the electron transfer number, which is related to the type of probe molecule and has a value of 1; c represents the concentration of ferrocene and has a value of 50 mmol / L; and D is the diffusion coefficient of ferrocene and has a value of 2.1 × 10 -6 cm 2 / s, the active surface area of ​​the negative electrode plate A = K / (2.69 × 10 5 ×n 2 / 3 CD 1 / 2 ) and the ratio of the active surface area A of the negative electrode plate to the weight m of the negative electrode plate is the active specific surface area of ​​the negative electrode plate.

[0195] 2. Battery performance test 1) Test the number of cycles required to achieve 80% capacity retention at 25°C The test process for the number of cycles required to reach 80% capacity retention was as follows: the fabricated battery was charged at 25°C to 3.65 V at a constant current of 1 C, then further charged at a constant voltage of 3.65 V until the current decreased to 0.1 C, and then discharged at 1 C to 2.5 V, and the resulting capacity was designated as the initial capacity (C0). The same battery was repeated, and the discharge capacity (Cn) of the battery after the nth cycle was recorded. The battery capacity retention after each cycle was calculated as Pn = Cn / C0 × 100%, and the number of cycles at which Pn decreased to 80% was recorded.

[0196] 2) Magnification performance test At 25°C, the fabricated batteries were charged to 3.65V at a constant current of 0.5C, then charged at a constant voltage of 3.65V until the current decreased to 0.05C and allowed to rest for 5 minutes. The batteries were then discharged to 2.5V at different rates of 0.2C, 1.0C, 1.5C, and 2.0C, and allowed to rest for 5 minutes after each discharge. The discharge capacities of the batteries were recorded. Five parallel samples were prepared for each group, with the discharge capacity at 0.2C as the standard, and the average value was taken. The discharge capacity ratios of the batteries at different discharge rates were calculated using the following formula:

[0197] Battery multiplication discharge capacity ratio (%) = (discharge capacity at corresponding multiplication / discharge capacity at 0.2C multiplication) x 100%

[0198] 3. Analysis of the test results of each example and comparative example According to the above method, the batteries of the examples and comparative examples were manufactured, and the performance parameters were measured. The results are shown in Tables 1 and 2 below.

[0199] [Table 1-1]

[0200] [Table 1-2]

[0201] [Table 1-3]

[0202] [Table 1-4]

[0203] [Table 1-5]

[0204] [Table 2-1]

[0205] [Table 2-2]

[0206] As can be seen from the above results, the electrolyte solutions in Examples 1 to 41 all contain a cyclic sulfate ester compound and a metal ion additive as shown in Formula I, wherein R1, R2, R3, and R4 are each independently selected from the structure shown in Formula II, a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and R1, R2, R3, and R4 are not simultaneously selected from a hydrogen atom, In Formula II, R5 and R6 are each independently selected from the group consisting of a hydrogen atom, a C1-C6 alkyl group, a halogen atom, a C1-C3 haloalkyl group, a C1-C3 alkoxy group, a C1-C3 haloalkyl group, a C1-C3 haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and the wavy line represents the bond position.

[0207] As can be seen from the comparison between Examples 1 to 29 and Comparative Examples 1 and 3, and between Examples 30 to 41 and Comparative Examples 2 and 4, compared to an electrolyte containing only the cyclic sulfate ester compound represented by Formula I or a metal ion additive, the electrolyte of the present application simultaneously contains the cyclic sulfate ester compound represented by Formula I and a metal ion additive, which is advantageous in improving the ratio of the discharge capacity at 1.5C and 2C multiplication rates to the discharge capacity at 0.2C of the battery, thereby improving the multiplication performance of the battery.

[0208] As can be seen from a comparison between Examples 1 to 29 and Comparative Example 5, and between Examples 30 to 41 and Comparative Example 6, compared to an electrolyte containing a cyclic sulfate ester compound represented by Formula III and a metal ion additive, the electrolyte of the present application simultaneously contains a cyclic sulfate ester compound represented by Formula I and a metal ion additive, which is advantageous in improving the number of cycles at 80% capacity retention of the battery and the ratio of the discharge capacity at multiplication rates of 1.5C and 2C to the discharge capacity at 0.2C, thereby improving the cycle performance and multiplication rate performance of the battery.

[0209] As can be seen from a comparison between Examples 1 to 6 and Comparative Example 5, and between Examples 33 to 38 and Comparative Example 6, the inclusion of a cyclic sulfate ester compound represented by formula I-1, I-2, I-6, I-7, I-8, or I-11 in the electrolyte is advantageous for improving the number of cycles until 80% capacity retention of the battery and the ratio of the discharge capacity at 1.5C and 2C to the discharge capacity at 0.2C, compared to the inclusion of a cyclic sulfate ester compound represented by formula III in the electrolyte.

[0210] As can be seen from Examples 4, 7-10, 33, and 36-39, by controlling the mass content W of the cyclic sulfate ester compound to satisfy 0.001%≦W≦20%, based on the total mass of the electrolyte, the batteries had a relatively high 80% capacity retention cycle number and the ratio of the discharge capacity at 0.2C, 1C, 1.5C, and 2C to the discharge capacity at 0.2C. As can be seen from a comparison of Examples 4, 8-9 with Examples 7, 10, and Examples 33, 37-38 with Examples 36 and 39, further controlling the mass content W of the cyclic sulfate ester compound to satisfy 0.1%≦W≦5%, based on the total mass of the electrolyte, is advantageous in further significantly increasing the ratio of the discharge capacity at 1C to the discharge capacity at 0.2C.

[0211] As can be seen from Examples 4, 11 to 15, by controlling the mass content of alkali metal ions to 30 ppm to 3000 ppm based on the total mass of the electrolyte, the battery had a relatively high 80% capacity retention cycle number and a high ratio of discharge capacity at 0.2 C, 1 C, 1.5 C, and 2 C to discharge capacity at 0.2 C. As can be seen from a comparison between Examples 4, 12 to 14 and Examples 11 and 15, further controlling the mass content of alkali metal ions to 50 ppm to 2000 ppm is advantageous in further improving the ratio of discharge capacity at 1 C to discharge capacity at 0.2 C.

[0212] As can be seen from Examples 4, 16 to 20, the mass content of the high-valent metal ions was controlled to 15 ppm to 300 ppm based on the total mass of the electrolyte, so that the battery had a relatively high 80% capacity retention cycle number and a high ratio of the discharge capacity at 0.2C, 1C, 1.5C and 2C to the discharge capacity at 0.2C.

[0213] As can be seen from Examples 4, 21 to 26, the mass content of alkaline earth metal ions was controlled to 13 ppm to 500 ppm based on the total mass of the electrolyte, so that the battery had a relatively high cycle number of 80% capacity retention and a high ratio of discharge capacity at 0.2C, 1C, 1.5C and 2C to discharge capacity at 0.2C.

[0214] As can be seen from a comparison of Examples 4, 27 to 29 with Comparative Example 1, and Examples 40 and 41 with Comparative Example 2, the metal ion additives include sodium ions, copper ions, calcium ions, lithium ions, aluminum ions, or magnesium ions, and all of these are advantageous in increasing the number of cycles at 80% capacity retention of the battery and the ratio of the discharge capacity at 1C, 1.5C, and 2C to the discharge capacity at 0.2C.

[0215] As can be seen from Examples 4 and 42 to 44, the active specific surface area of ​​the negative electrode plate is A≦20 cm 2 / g, the battery had a relatively high 80% capacity retention cycle number and the ratio of discharge capacity at 0.2C, 1C, 1.5C, and 2C to the discharge capacity at 0.2C. As can be seen from a comparison of Examples 4, 42, 43, and 44, the active specific surface area of ​​the negative electrode plate was controlled to 5 cm 2 / g~15cm 2 / g is advantageous in further increasing the number of cycles at which the battery maintains 80% capacity.

[0216] It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any embodiment that has substantially the same configuration as the technical idea and achieves the same effects within the scope of the technical solution of the present application is included within the technical scope of the present application. In addition, various modifications that a person skilled in the art can make to the embodiments and other methods that are constructed by combining some of the components of the embodiments are also included within the scope of the present application, as long as they do not deviate from the spirit of the present application. [Explanation of symbols]

[0217] 1 battery pack, 2 upper housing, 3 lower housing, 4 battery module, 5 secondary battery, 51 case, 52 electrode assembly, 53 cover plate.

Claims

1. An electrolyte solution comprising a cyclic sulfate ester compound according to Formula I and a metal ion additive, 【Chemistry 1】 In Formula I, R １ , R ２ , R ３ , R ４ each independently represents a structure shown in formula II, a hydrogen atom, C １ -C ６ Alkyl group, halogen atom, C １ -C ３ Haloalkyl group, C １ -C ３ Alkoxy group, C １ -C ３ is selected from one of a haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and R １ , R ２ , R ３ and R ４ are not simultaneously selected from hydrogen atoms, In formula II, R ５ , R ６ are each independently a hydrogen atom, C １ -C ６ Alkyl group, halogen atom, C １ -C ３ Haloalkyl group, C １ -C ３ Alkoxy group, C １ -C ３ An electrolyte solution, characterized in that the alkoxy group is selected from one of a haloalkoxy group, a double bond, an ester group, a cyano group, and a sulfonic acid group, and the wavy line represents the bonding position.

2. R １ , R ２ , R ３ , R ４ each independently represents a structure shown in formula II, a hydrogen atom, C １ -C ６ Alkyl group, halogen atom, C １ -C ３ Haloalkyl group, C １ -C ３ 2. The electrolyte solution of claim 1, wherein the group is selected from the group consisting of an alkoxy group and a cyano group.

3. R １ is a hydrogen atom, C １ -C ３ alkyl groups, R ２ is C １ -C ３ Alkyl group, halogen atom, C １ -C ３ selected from a haloalkyl group, a cyano group, or the structure shown in formula II, R ３ is a hydrogen atom, C １ -C ３ alkyl groups, R ４ is C １ -C ３ Alkyl group, halogen atom, C １ -C ３ 3. The electrolyte solution according to claim 1, wherein the alkoxy group is selected from the group consisting of alkoxy groups and the structures shown in formula II.

4. R １ is selected from a hydrogen atom or a methyl group, R ２ is selected from a methyl group, an ethyl group, a fluorine atom, a trifluoromethyl group, a cyano group, or a structure shown in formula II, R ３ is selected from a hydrogen atom, R ４ The electrolyte solution according to any one of claims 1 to 3, wherein is selected from a methyl group, an ethyl group, a propyl group, a fluorine atom, an ethoxy group, or a structure represented by formula II.

5. R １ and R ３ is a hydrogen atom, R ２ and R ４ is a methyl group, an ethyl group, a fluorine atom, or the structure shown in formula II, or R ２ is a methyl group or the structure shown in formula II, and R ４ The electrolyte solution according to any one of claims 1 to 4, wherein is a methyl group.

6. R １ and R ３ is a hydrogen atom, R ２ and R ４ The electrolyte solution according to any one of claims 1 to 5, wherein is a methyl group or a structure shown in formula II.

7. R ５ , R ６ are each independently a hydrogen atom and a C １ -C ３ 7. The electrolyte solution according to claim 1, wherein the alkyl group is selected from the group consisting of the alkyl groups listed above.

8. The cyclic sulfate ester compound is the compound shown below: 【Chemistry 2】 8. The electrolyte solution according to claim 1, wherein the electrolyte is selected from one or more of the following:

9. The electrolyte solution according to any one of claims 1 to 8, characterized in that, based on the total mass of the electrolyte solution, a mass content W of the cyclic sulfate ester compound satisfies 0.001%≦W≦20%, and optionally is 0.1% to 5%.

10. 10. The electrolyte solution according to claim 1, wherein the metal ion additive comprises one or more of an alkali metal ion, an alkaline earth metal ion, and a high-valence metal ion.

11. the alkali metal ions include one or more of sodium ions, lithium ions, and potassium ions; and / or 11. The electrolyte of claim 10, wherein the mass content of the alkali metal ions is 30 ppm to 3000 ppm, and optionally 50 ppm to 2000 ppm, based on the total mass of the electrolyte.

12. the high-valent metal ions include one or more of aluminum ions and copper ions; and / or 12. The electrolyte solution according to claim 10, wherein the mass content of the high-valence metal ions is 0.5 ppm to 300 ppm, and optionally 15 ppm to 200 ppm, based on the total mass of the electrolyte solution.

13. the alkaline earth metal ions include one or more of magnesium ions and calcium ions; and / or 13. The electrolyte according to claim 10, wherein the mass content of the alkaline earth metal ions is 0.5 ppm to 500 ppm, and optionally 13 ppm to 400 ppm, based on the total mass of the electrolyte.

14. the electrolytic solution further includes an electrolyte salt, the electrolyte salt including a lithium salt or a sodium salt; the lithium salt comprises one or more of lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorobis(oxalato)phosphate, lithium bis(oxalato)borate; 14. The electrolyte solution of claim 1, wherein the sodium salt comprises one or more of sodium hexafluorophosphate, sodium difluoro(oxalato)borate, sodium perchlorate, sodium bisfluorosulfonylimide, sodium bistrifluoromethanesulfonylimide, and sodium trifluoromethanesulfonate.

15. A secondary battery comprising a negative electrode plate and the electrolyte solution according to any one of claims 1 to 14.

16. 16. The secondary battery according to claim 15, wherein the secondary battery comprises a sodium battery or a lithium battery.

17. 17. The secondary battery according to claim 15 or 16, wherein the negative electrode plate includes a negative electrode active material, and the negative electrode active material includes one or more of artificial graphite, natural graphite, hard carbon, soft carbon, mesocarbon microbeads, carbon fiber, carbon nanotubes, silicon elemental, silicon oxide, silicon carbon composite, silicon alloy, tin elemental, tin oxide, and titanium composite material.

18. The active specific surface area A of the negative electrode plate and the mass content W of the cyclic sulfate ester compound are 0.0002 cm ２ / g≦W×A≦0.04 cm ２ / g, optionally 0.02 cm ２ / g≦W×A≦0.1 cm ２ 18. The secondary battery according to claim 15, wherein the following is satisfied: / g.

19. The active specific surface area A of the negative electrode plate is A≦20 cm ２ / g, and optionally 5 cm ２ / g ~ 15cm ２ 19. The secondary battery according to claim 18, wherein the ZnO content is 1 / g.

20. A power consuming device comprising the secondary battery according to any one of claims 15 to 19.

Images