Electrolyte, battery and electrical device

Abstract

An electrolyte, a battery and an electrical device. The electrolyte comprises an inhibitor, and the inhibitor comprises at least one of a zinc salt, a tin salt, and a silver salt.

Description

Electrolytes, batteries and electrical equipment

[0001] This application claims priority to Chinese Patent Application No. 202410857318.5, filed on June 27, 2024, entitled "Electrolyte, Battery and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of batteries, specifically, it relates to an electrolyte, a battery, and an electrical device. Background Technology

[0003] Lithium-ion batteries are widely used in electric vehicles, smartphones, and other fields. Among them, lithium-ion battery cathode materials rich in manganese (Mn) are widely used due to their low cost and high voltage performance.

[0004] In practical applications, manganese-rich cathode materials, during long-term battery cycling or high-temperature storage, [require Mn]. 2+ Ions easily dissolve from the positive electrode and are conducted to the negative electrode through the electrolyte, where they deposit. This not only affects the stability of the battery but also causes a significant decrease in battery capacity, reducing the battery's lifespan and cycle performance. Summary of the Invention

[0005] One objective of this application is to provide a new technical solution for electrolytes, batteries, and electrical devices.

[0006] According to a first aspect of the embodiments of this application, an electrolyte is provided, comprising:

[0007] The lithium salt, the inhibitor, and the solvent, wherein the inhibitor includes at least one of zinc salt, tin salt, and silver salt.

[0008] Optionally, the zinc salt includes one or more combinations of zinc chloride, zinc nitrate, zinc sulfate, zinc hexafluorophosphate, zinc tetrafluoroborate, zinc perchlorate, zinc trifluoromethanesulfonate, zinc bis(trifluoromethanesulfonate)imide, and zinc bis(fluorosulfonyl)imide.

[0009] Optionally, the tin salt includes one or more combinations of tin nitrate, tin nitrous nitrate, and tin chloride.

[0010] Optionally, the silver salt includes one or more combinations of silver nitrate, silver bis(fluorosulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, silver tetrafluoroborate, silver perchlorate, silver hexafluorophosphate, and silver trifluoromethanesulfonate.

[0011] Optionally, the inhibitor comprises silver bis(fluorosulfonyl)imide and / or silver bis(trifluoromethyl)sulfonyl)imide.

[0012] Optionally, based on the mass of the electrolyte, the solvent has a mass percentage of 60%-85%, the lithium salt has a mass percentage of 7%-40%, and the inhibitor has a mass percentage of 0.2%-6%.

[0013] Optionally, the inhibitor is 2%-6% by mass.

[0014] Optionally, the solvent includes at least one of carbonate solvents, carboxylic acid ester solvents, and ether solvents.

[0015] Optionally, the ether solvent includes one or more combinations of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1,3-dioxolane, dimethoxymethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, isosorbide dimethyl ether, and dipropylene glycol dimethyl ether.

[0016] Optionally, the ether solvent includes fluorinated ethers, which include one or more of the following: 1,1,2,2-tetrafluoroethyl ethyl ether, hexafluoroisopropyl ethyl ether, tetrafluoroethyl-tetrafluoropropyl ether, 2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, difluoromethyl-2,2,3,3-tetrafluoropropyl ether, 2,2,3,3,3-pentafluoropropyl methyl ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1,1,2,3,3,3-pentafluoropropyl difluoromethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, and bis(2,2,2-trifluoroethyl) ether.

[0017] Optionally, the carbonate solvent includes one or more of ethylene carbonate, propylene carbonate, butene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, and ethyl propyl carbonate.

[0018] Optionally, the carboxylic acid ester solvent includes one or more of methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, and butyl butyrate.

[0019] Optionally, the lithium salt includes one or more combinations of lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalate)borate, lithium difluorooxalateborate, lithium difluorodioxalate phosphate, lithium difluorophosphate, lithium hexafluoroantimonyate, lithium fluoride, lithium sulfonyl fluoride, lithium trifluoromethyl, lithium perfluoroethyl, and lithium trifluoromethyl.

[0020] Optionally, the electrolyte further includes additives, which include one or more combinations of 1,3-propanesulfonyl lactone, 1,3-propenesulfonyl lactone, 1,4-butanesulfonyl lactone, vinylene carbonate, fluoroethylene carbonate, methylene disulfonate, and vinyl sulfate.

[0021] Optionally, the additive is 1.7%-5% by mass.

[0022] According to a second aspect of the embodiments of this application, a battery is provided, the battery comprising:

[0023] The positive electrode and the electrolyte described in the first aspect;

[0024] The positive electrode includes a manganese-based positive electrode material.

[0025] Optionally, the manganese-based cathode material includes LiMn2O4, Li2MnO3, and LiNi. a Mn b O4(0.3≤a≤0.7, 1.3≤b≤1.7), LiFe x Mn (1-x) One or more of PO4 (0.1≤x≤0.8) and LiMnPO4.

[0026] Optionally, the battery further includes a casing, a negative electrode, and a separator;

[0027] The diaphragm is disposed between the positive electrode and the negative electrode, and the electrolyte is disposed in the housing.

[0028] Optionally, the negative electrode active material of the negative electrode sheet includes one or a combination of lithium metal and lithium alloy.

[0029] According to a third aspect of the embodiments of this application, an electrical device is provided, the electrical device including the battery described in the second aspect.

[0030] One technical advantage of this application is:

[0031] This application provides an electrolyte that includes an inhibitor, which includes at least one of zinc salt, tin salt, and silver salt. During long-term cycling or high-temperature storage of a battery containing this electrolyte, the inhibitor can reduce the deposition of manganese ions from the positive electrode after dissolving from the positive electrode, thus ensuring the stability of the battery, improving the battery capacity, and guaranteeing the battery's lifespan and cycle performance. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0033] Figure 1 is a schematic diagram of a battery provided in one embodiment of this application.

[0034] The reference numerals in the attached diagram are explained as follows: 1-Electrolyte; 2-Shell; 3-Positive electrode; 4-Negative electrode; 5-Separator. Detailed Implementation

[0035] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0036] The embodiments of this application will now be described in detail, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] The term "and / or" in the specification and claims of this application means at least one of the defined objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0038] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", etc., indicate the orientation or sequence relationship based on the orientation or sequence relationship shown in the drawings or methods, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, sequence, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0040] In batteries containing manganese as the cathode material, under conditions of long-term cycling or high-temperature storage, Mn 2+ Ions readily dissolve from the positive electrode and tend to deposit towards the negative electrode; the electrolyte provided in this application includes inhibitors such as zinc salts, tin salts, and silver salts, which can inhibit Mn. 2+ Ions deposited on the negative electrode ensure the stability and charge / discharge capacity of the battery.

[0041] This application provides an electrolyte for use in a battery containing a manganese-based cathode material, the electrolyte comprising:

[0042] Lithium salt, inhibitor, and solvent, wherein the inhibitor includes at least one of zinc salt, tin salt, and silver salt.

[0043] In this embodiment, the inhibitor is used to suppress the deposition of manganese in the manganese-based cathode material at the anode. In the battery in which this electrolyte is applied, referring to Figure 1, the active material of the cathode sheet contains a manganese-based cathode material, which can be LiMn2O4, Li2MnO3, or LiNi. a Mn b O4(0.3≤a≤0.7, 1.3≤b≤1.7), LiFe x Mn (1-x) Manganese can effectively improve the conductivity of cathode materials and the migration rate of lithium ions by combining one or more of PO4 (0.1≤x≤0.8) and LiMnPO4, thereby increasing the discharge capacity and charging rate of the battery, enabling the battery to store and release more electrical energy.

[0044] In this embodiment, inhibitors such as zinc salts, tin salts, and silver salts are added to the electrolyte. The reactivity of zinc, tin, and silver ions in these inhibitors is lower than that of manganese (Mn), meaning that zinc, tin, and silver ions are more likely to deposit on the negative electrode than Mn. Once Mn occurs on the positive electrode in the battery... 2+ The dissolution of Mn 2+ When there is a tendency for Mn to deposit towards the negative electrode, the deposition and occupancy of metal ions such as Zn (zinc), Sn (tin), and Ag (silver) at the negative electrode will prevent it from depositing. 2+ Mn is deposited at the negative electrode, meaning even if Mn occurs at the positive electrode. 2+ Dissolution will not be due to Mn 2+ Deposition at the negative electrode affects its capacity. Silver salts are preferred as inhibitors because they are easier to deposit at the negative electrode, reducing the deposition of manganese ions dissolved from the positive electrode and thus ensuring battery stability.

[0045] In addition, due to the lower negative electrode potential of the battery, metal ions such as Zn, Sn and Ag are deposited on the negative electrode surface earlier than Mn. Furthermore, these three metal ions have an inductive effect on lithium deposition, which is beneficial for lithium ion intercalation or alloying, thus avoiding the formation of lithium dendrites on the negative electrode and ensuring the battery's charge and discharge capacity and cycle life.

[0046] This application provides an electrolyte that includes an inhibitor, which includes at least one of zinc salt, tin salt, and silver salt. The inhibitor is used to suppress the dissolution of manganese in the manganese-based cathode material. During long-term cycling or high-temperature storage of a battery containing this electrolyte, the inhibitor can reduce the deposition of Mn2+ ions from the cathode material after dissolution from the cathode on the anode, thus ensuring the stability of the battery, improving the battery capacity, and guaranteeing the battery's lifespan and cycle performance.

[0047] In one embodiment, the inhibitor comprises a zinc salt, which includes one or more combinations of zinc chloride, zinc nitrate, zinc sulfate, zinc hexafluorophosphate, zinc tetrafluoroborate, zinc perchlorate, zinc trifluoromethanesulfonate, zinc bis(trifluoromethanesulfonate)imide, and zinc bis(fluorosulfonyl)imide.

[0048] In this embodiment, the zinc salt may specifically include one or more combinations of zinc chloride (ZnCl2), zinc nitrate (Zn(NO3)2), zinc sulfate (ZnSO4), zinc hexafluorophosphate (Zn(PF6)2), zinc tetrafluoroborate (Zn(BF4)2), zinc perchlorate (Zn(ClO4)2), zinc trifluoromethanesulfonate (Zn(CF3SO3)2), zinc bis(trifluoromethanesulfonate)imide (Zn(TFSI)2), and zinc bis(fluorosulfonyl)imide (Zn(FSI)2). The zinc ions in the zinc salt have lower reactivity than manganese, meaning that when manganese and zinc coexist, zinc is more likely to deposit on the negative electrode. The deposition of zinc on the negative electrode occupies a site, thus preventing manganese deposition and ensuring the battery's charge and discharge capacity. Zinc bis(trifluoromethanesulfonate)imide (Zn(TFSI)2) is preferred.

[0049] In one embodiment, the inhibitor comprises a tin salt, which includes one or more combinations of tin nitrate, tin nitrous nitrate, and tin chloride.

[0050] In this embodiment, the tin salt may specifically include one or more combinations of tin nitrate (Sn(NO3)4), stannous nitrate (Sn(NO3)2), and tin chloride (SnCl4). The tin ions in the tin salt have lower reactivity than manganese, meaning that when manganese and tin coexist, tin is more likely to deposit on the negative electrode. The tin deposition site on the negative electrode can prevent manganese from depositing there, thus ensuring the battery's charge and discharge capacity. Tin nitrate (Sn(NO3)4) is preferred.

[0051] In one embodiment, the inhibitor comprises a silver salt, which includes one or more combinations of silver nitrate, silver bis(fluorosulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, silver tetrafluoroborate, silver perchlorate, silver hexafluorophosphate, and silver trifluoromethanesulfonate.

[0052] In this embodiment, the silver salt may specifically include one or more combinations of silver nitrate (AgNO3), silver bis(fluorosulfonyl)imide (AgFSI), silver bis(trifluoromethanesulfonyl)imide (AgTFSI), silver tetrafluoroborate (AgBF4), silver perchlorate (AgClO4), silver hexafluorophosphate (AgPF6), and silver trifluoromethanesulfonate (Ag(CF3SO3)). The reactivity of silver ions in the silver salt is lower than that of manganese. That is, when manganese and silver coexist, silver is more likely to be deposited on the negative electrode. Because the deposition site of silver on the negative electrode can prevent manganese from being deposited on the negative electrode, the charge and discharge capacity of the battery is guaranteed.

[0053] In one embodiment, the inhibitor comprises silver bis(fluorosulfonyl)imide and / or silver bis(trifluoromethyl)sulfonyl)imide.

[0054] In this embodiment, the silver ions in bis(fluorosulfonyl)imide silver and / or bis(trifluoromethyl)sulfonyl)imide silver have lower reactivity than iron, which can inhibit the deposition of manganese and iron at the negative electrode, thus further ensuring the capacity utilization of the negative electrode.

[0055] In one embodiment, based on the mass of the electrolyte, the solvent is 60%-85% by mass, the lithium salt is 7%-40% by mass, and the inhibitor is 0.2%-6% by mass.

[0056] In this embodiment, the solvent serves as the dissolving medium in the electrolyte, ensuring that the electrolyte is uniformly distributed within the electrolyte and guaranteeing its stability and reliability. The mass percentage of the solvent can be, but is not limited to, 60%, 65%, 70%, 75%, 80%, or 85%. Lithium salts possess advantages such as high conductivity, high stability, and a wide electrochemical window, which helps improve the conductivity of the electrolyte. The mass percentage of lithium salts can be, but is not limited to, 7%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%. The inhibitor includes at least one of zinc, tin, and silver salts. When the mass percentage of the inhibitor is controlled within the range of 0.2% to 6%, the deposition of Mn2+ ions dissolved from the positive electrode and deposited on the negative electrode can be effectively reduced, ensuring the stability of the battery. The mass percentage of the inhibitor can be, but is not limited to, 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 6%.

[0057] In one embodiment, the mass percentage of the inhibitor is 2%-6%.

[0058] The mass percentage of the inhibitor in the electrolyte can be 2.0%, 3.0%, 4.0%, 5.0%, or 6.0%. The inhibitor can reduce the Mn content in the cathode material. 2+ The deposition of ions from the positive electrode onto the negative electrode after dissolving allows the proportion of manganese on the negative electrode to be limited to below ppm, thus ensuring the capacity of the negative electrode material.

[0059] In one embodiment, the inhibitor is 0.2%-2% by mass. This is to reduce Mn content in the cathode material by using the inhibitor. 2+ After ions dissolve from the positive electrode, they are deposited on the negative electrode, ensuring the content of solvent and lithium salt in the electrolyte.

[0060] In one embodiment, the solvent includes at least one selected from carbonate solvents, carboxylic acid ester solvents, and ether solvents. In this embodiment, the carbonate solvent, carboxylic acid ester solvent, and ether solvent serve as dissolving media in the electrolyte, enabling the electrolyte to be uniformly distributed within the electrolyte and ensuring the stability and reliability of the electrolyte.

[0061] In one embodiment, the ether solvent includes one or more combinations of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1,3-dioxolane, dimethoxymethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, isosorbide dimethyl ether, and dipropylene glycol dimethyl ether.

[0062] In this embodiment, adding ether solvents to the electrolyte helps to improve the specific capacity, first-efficiency and rate performance of manganese-based cathode materials, thereby increasing the energy density of the battery and realizing the preparation of high-energy-density batteries with manganese-based cathodes.

[0063] In one embodiment, the ether solvent includes fluorinated ethers, which include one or more of 1,1,2,2-tetrafluoroethyl ethyl ether, hexafluoroisopropyl ethyl ether, tetrafluoroethyl-tetrafluoropropyl ether, 2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, difluoromethyl-2,2,3,3-tetrafluoropropyl ether, 2,2,3,3,3-pentafluoropropyl methyl ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1,1,2,3,3,3-pentafluoropropyl difluoromethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, and bis(2,2,2-trifluoroethyl) ether. Fluorinated ethers have high thermal stability and can remain stable at high temperatures, which helps improve battery performance in high-temperature environments.

[0064] In one embodiment, the carbonate solvent includes one or more of ethylene carbonate, propylene carbonate, butene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, and ethyl propyl carbonate; carbonate solvents can provide a higher electrochemical window and a higher redox potential, which makes the battery more voltage stable.

[0065] In one embodiment, the carboxylic acid ester solvent includes one or more of methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, and butyl butyrate. The presence of carboxylic acid ester solvents can improve the chemical stability of the electrolyte, reduce its decomposition reactions during battery operation, and thus extend the battery's lifespan.

[0066] Moreover, the aforementioned ether solvents, carbonate solvents, and carboxylic acid ester solvents have high dielectric constants and large polarity, which can improve the solubility of lithium salts in solvents.

[0067] In one embodiment, the lithium salt includes one or more combinations of lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalate)borate, lithium difluorooxalateborate, lithium difluorodioxalate phosphate, lithium difluorophosphate, lithium hexafluoroantimonyate, lithium fluoride, lithium sulfonyl fluoride, lithium trifluoromethyl, lithium perfluoroethyl, and lithium trifluoromethyl.

[0068] In this embodiment, the lithium salt may specifically include one or more combinations of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(oxalate-borate) (LiBOB), lithium difluorooxalate-borate (LiDFOB), lithium difluorodioxalate-phosphate (LiDFOP), lithium difluorophosphate (LiPO2F2), lithium hexafluoroantimony oxide (LiSbF6), lithium fluoride (LiAsF6), lithium sulfonyl fluoride (LiN(SO2F)2), lithium trifluoromethyl (LiN(SO2CF3)2), lithium perfluoroethyl (LiN(SO2C2F5)2), and lithium trifluoromethyl (LiC(SO2CF3)3). The above lithium salts can improve the lithium insertion / extraction capability of the cathode material, thereby improving the charge / discharge capacity of the battery.

[0069] In one embodiment, the electrolyte further includes additives, including one or more combinations of 1,3-propanesulfonyl lactone, 1,3-propenesulfonyl lactone, 1,4-butanesulfonyl lactone, vinylene carbonate, fluoroethylene carbonate, methanedisulfonate, and vinyl sulfate. In this embodiment, the above-mentioned additives can improve the physical and chemical properties of the electrolyte, thereby enhancing the performance and stability of the battery.

[0070] In one embodiment, the mass percentage of the additive is 1.7%-5%. The additive is used to improve the electrochemical performance of the electrolyte and improve the cathode deposition quality. When the mass percentage of the additive is in the range of 1.7%-5%, the cycle stability of the battery can be improved while ensuring the battery charge and discharge rate. The mass percentage of the additive may be, but is not limited to, 1.7%, 2%, 3%, 4%, or 5%.

[0071] Referring to Figure 1, an embodiment of this application provides a battery, which includes:

[0072] Positive electrode 3 and the electrolyte 1 described above;

[0073] The positive electrode 3 includes a manganese-based positive electrode material, and the electrolyte inhibitor is used to inhibit the deposition of manganese in the manganese-based positive electrode material.

[0074] In this embodiment, the manganese-based cathode material can be a cathode active material containing manganese.

[0075] The electrolyte 1 of the battery includes an inhibitor, which includes at least one of zinc salt, tin salt and silver salt; the inhibitor is used to inhibit the dissolution of manganese in the manganese-based cathode material; during long-term cycling or high-temperature storage of the battery containing this electrolyte, the inhibitor can reduce the deposition of Mn2+ ions from the cathode material after dissolution from the cathode on the anode, thus ensuring the stability of the battery, improving the battery capacity, and guaranteeing the battery's service life and cycle performance.

[0076] In one embodiment, the manganese-based cathode material includes LiMn2O4 and LiNi. a Mn b O4(0.3≤a≤0.7, 1.3≤b≤1.7), LiFe x Mn (1-x) One or more of PO4 (0.1≤x≤0.8) and LiMnPO4.

[0077] In this embodiment, manganese can effectively improve the conductivity of the cathode material and the migration rate of lithium ions, thereby increasing the battery's discharge capacity and charging rate, enabling the battery to store and release more electrical energy.

[0078] In one embodiment, referring to Figure 1, the battery further includes a housing 2, a negative electrode 4, and a separator 5;

[0079] The diaphragm 5 is disposed in the housing 2 between the positive electrode 3 and the negative electrode 4, and the electrolyte 1 is disposed in the housing 2.

[0080] In this embodiment, the electrolyte 1 of the battery is disposed in the casing 2, and the inhibitor in the electrolyte 1 includes at least one of zinc salt, tin salt, and silver salt; the inhibitor is used to inhibit the dissolution of manganese in the manganese-based cathode material; during long-term cycling or high-temperature storage of the battery containing this electrolyte, the inhibitor can reduce the amount of Mn in the cathode material. 2+ The deposition of ions at the negative electrode after they dissolve from the positive electrode ensures the stability of the battery, improves its capacity, and guarantees its lifespan and cycle performance.

[0081] In one embodiment, the negative electrode comprises one or a combination of lithium metal and lithium alloy.

[0082] In this embodiment, a positive electrode containing manganese-based cathode material is combined with a negative electrode containing high-capacity materials such as lithium metal and / or lithium alloy to achieve the fabrication of a high-energy-density battery and ensure the battery's charge and discharge capacity.

[0083] This application provides an electrical device that includes the battery described above.

[0084] The technical solution of this application will be further illustrated below through specific embodiments and comparative examples.

[0085] Example 1

[0086] Preparation of electrolyte: In an argon-filled glove box, triethylene glycol dimethyl ether and 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether were mixed at a mass ratio of 1:4. Lithium difluorosulfonyl imide (25% by weight of the electrolyte) and vinylene carbonate (2% by weight of the electrolyte) were slowly added to the mixed solvent.

[0087] Then add 2.0 wt% bis(trifluoromethanesulfonyl)imide silver (silver salt) based on the total weight of the electrolyte to the electrolyte, and stir evenly to obtain the electrolyte.

[0088] Example 2

[0089] The difference from Example 1 is that 0.2 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) based on the total weight of the electrolyte was added to the electrolyte.

[0090] Example 3

[0091] The difference from Example 1 is that 6.0 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) based on the total weight of the electrolyte was added to the electrolyte.

[0092] Example 4

[0093] The difference from Example 1 is that 1.0 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) and 1.0 wt% of zinc chloride (zinc salt) based on the total weight of the electrolyte are added to the electrolyte.

[0094] Example 5

[0095] The difference from Example 1 is that 1.0 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) and 1.0 wt% of tin nitrate (tin salt) based on the total weight of the electrolyte are added to the electrolyte.

[0096] Example 6

[0097] The difference from Example 1 is that 0.1 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) based on the total weight of the electrolyte was added to the electrolyte.

[0098] Example 7

[0099] The difference from Example 1 is that 8.0 wt% of bis(trifluoromethanesulfonyl)imide silver (silver salt) based on the total weight of the electrolyte was added to the electrolyte.

[0100] Example 8

[0101] The difference from Example 1 is that 2.0 wt% of zinc bis(trifluoromethanesulfonate) amide (zinc salt) based on the total weight of the electrolyte is added to the electrolyte.

[0102] Example 9

[0103] The difference from Example 1 is that 2.0 wt% tin nitrate (tin salt) based on the total weight of the electrolyte was added to the electrolyte.

[0104] Comparative Example 1

[0105] The difference from Example 1 is that no inhibitor was added.

[0106] The electrolytes prepared in the above examples and comparative examples were injected into fully dried LMFP (lithium manganese iron phosphate) positive electrode and silicon-carbon negative electrode batteries. The batteries were then subjected to 25°C for 48 hours, formation and high-temperature baking in the fixture, secondary sealing and conventional capacity testing to obtain the batteries.

[0107] Performance testing

[0108] ambient temperature cycling test

[0109] The battery underwent a room temperature cycle test at 25°C:

[0110] The battery was subjected to 800 charge-discharge cycles at a 1C current and a voltage window of 2.0V-4.3V.

[0111] 800-cycle capacity retention rate (%) = (800th discharge retention capacity / 1st discharge capacity) × 100%.

[0112] Manganese deposition ICP test

[0113] The cycled battery was disassembled, the negative electrode was removed and cleaned with dimethyl carbonate (DMC), the powder on the negative electrode was scraped off, and the Mn content was tested by ICP-OES. The test results are shown in Table 1.

[0114] Table 1

[0115] As can be seen from Table 1, in the batteries of Examples 1 to 9, adding an inhibitor to the electrolyte can reduce the Mn content in the cathode material. 2+ The deposition of ions on the negative electrode after dissolving from the positive electrode allows the battery to retain more than 59% of its capacity after 800 cycles, and the manganese content in the negative electrode can be reduced to below 133 ppm.

[0116] In contrast, no inhibitor was added to the electrolyte in Comparative Example 1, resulting in a capacity retention rate of only 53% after 800 cycles and a manganese content of 172 ppm in the negative electrode.

[0117] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An electrolyte, wherein, It includes lithium salts, inhibitors, and solvents, wherein the inhibitors include at least one of zinc salts, tin salts, and silver salts.

2. The electrolyte according to claim 1, wherein, The zinc salts include one or more combinations of zinc chloride, zinc nitrate, zinc sulfate, zinc hexafluorophosphate, zinc tetrafluoroborate, zinc perchlorate, zinc trifluoromethanesulfonate, zinc bis(trifluoromethanesulfonate)imide, and zinc bis(fluorosulfonyl)imide.

3. The electrolyte according to claim 1, wherein, The tin salt includes one or more combinations of tin nitrate, stannous nitrate, and tin chloride.

4. The electrolyte according to claim 1, wherein, The silver salt includes one or more combinations of silver nitrate, silver bis(fluorosulfonyl)imide, silver bis(trifluoromethanesulfonyl)imide, silver tetrafluoroborate, silver perchlorate, silver hexafluorophosphate, and silver trifluoromethanesulfonate.

5. The electrolyte according to claim 4, wherein, The inhibitors include silver bis(fluorosulfonyl)imide and / or silver bis(trifluoromethyl)sulfonyl)imide.

6. The electrolyte according to claim 1, wherein, Based on the mass of the electrolyte, the solvent accounts for 60%-85% by mass, the lithium salt accounts for 7%-40% by mass, and the inhibitor accounts for 0.2%-6% by mass.

7. The electrolyte according to claim 6, wherein, Based on the mass of the electrolyte, the mass percentage of the inhibitor is 2%-6%.

8. The electrolyte according to claim 1, wherein, The solvent includes at least one of carbonate solvents, carboxylic acid ester solvents, and ether solvents.

9. The electrolyte according to claim 8, wherein, The ether solvents include one or more combinations of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1,3-dioxolane, dimethoxymethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, isosorbide dimethyl ether, and dipropylene glycol dimethyl ether.

10. The electrolyte according to claim 8, wherein, The ether solvents include fluorinated ethers, which include one or more of the following: 1,1,2,2-tetrafluoroethyl ethyl ether, hexafluoroisopropyl ethyl ether, tetrafluoroethyl-tetrafluoropropyl ether, 2,2,2-trifluoroethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, difluoromethyl-2,2,3,3-tetrafluoropropyl ether, 2,2,3,3,3-pentafluoropropyl methyl ether, 1,1,2,3,3,3-hexafluoropropyl ethyl ether, 1,1,2,3,3,3-pentafluoropropyl difluoromethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether, and bis(2,2,2-trifluoroethyl) ether.

11. The electrolyte according to claim 8, wherein, The carbonate solvents include one or more of ethylene carbonate, propylene carbonate, butene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, and ethyl propyl carbonate.

12. The electrolyte according to claim 8, wherein, The carboxylic acid ester solvents include one or more of methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, and butyl butyrate.

13. The electrolyte according to claim 8, wherein, The lithium salt includes one or more combinations of lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalate)borate, lithium difluorooxalateborate, lithium difluorodioxalate phosphate, lithium difluorophosphate, lithium hexafluoroantimonyate, lithium fluoride, lithium sulfonyl fluoride, lithium trifluoromethyl, lithium perfluoroethyl, and lithium trifluoromethyl.

14. The electrolyte according to claim 1, wherein, The electrolyte also includes additives, which include one or more combinations of 1,3-propanesulfonyl lactone, 1,3-propenesulfonyl lactone, 1,4-butanesulfonyl lactone, vinylene carbonate, fluoroethylene carbonate, methylene disulfonate, and vinyl sulfate.

15. The electrolyte according to claim 14, wherein, The additive is 1.7%-5% by mass.

16. A battery, wherein, It includes a positive electrode (3) and an electrolyte (1) as described in any one of claims 1-15; The positive electrode (3) includes a manganese-based positive electrode material.

17. The battery according to claim 16, wherein, The manganese-based cathode material includes LiMn2O4, Li2MnO3, and LiNi. a Mn b O4(0.3≤a≤0.7, 1.3≤b≤1.7), LiFe x Mn (1-x) One or more of PO4 (0.1≤x≤0.8) and LiMnPO4.

18. The battery according to claim 17, wherein, The battery also includes a casing (2), a negative electrode (4), and a separator (5); The diaphragm (5) is spaced between the positive electrode (3) and the negative electrode (4), and the electrolyte (1) is disposed in the housing (2).

19. The battery according to claim 18, wherein, The negative electrode (4) includes one or a combination of lithium metal and lithium alloy.

20. An electrical appliance, wherein, Includes the battery as described in any one of claims 16-19.

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