Gel electrolyte, battery and electric device

Abstract

The invention relates to a gel electrolyte, a battery and an electric device. The gel electrolyte comprises an inorganic aerogel material, a flexibilizer and an electrolyte, the toughening agent is in a fibrous shape. When the gel electrolyte is used for preparing a battery, the oxidation stability of the battery can be improved, and the cycle performance of the battery is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a gel electrolyte, a battery and an electrical device. Background Art

[0002] Secondary batteries are increasingly being used due to their clean and renewable characteristics, and have been widely used in consumer electronics, electric vehicles, energy storage and many other fields. With the rapid development of the new energy industry, people's demand for new energy vehicles such as electric vehicles and electric bicycles is increasing. In order to meet the future scenarios with higher energy density requirements, including long-range electric vehicles and electric aircraft, metal lithium secondary batteries with higher energy density have been developed, which are considered to be the most promising next-generation energy storage system.

[0003] Traditional secondary battery systems contain a large amount of organic electrolytes, which have disadvantages such as high volatility and flammability. Especially in lithium metal secondary batteries, lithium dendrites formed by lithium metal can easily pierce the diaphragm and cause internal short circuits. Therefore, semi-solid gel electrolytes with high safety have been developed to prevent lithium dendrites from piercing the traditional diaphragm and causing internal short circuits, and can also block the corrosion of metal lithium by water vapor in the air. However, traditional gel electrolytes have poor oxidation resistance, especially in high-voltage positive electrode systems, traditional gel electrolytes are easily oxidized and cause structural collapse.

[0004] Therefore, the traditional technology needs to be further improved. Summary of the invention

[0005] Based on this, it is necessary to provide a gel electrolyte, a battery and an electrical device, aiming to improve the oxidation stability of the battery and thus improve the cycle performance of the battery.

[0006] The present application is implemented through the following technical solutions.

[0007] In a first aspect of the present application, a gel electrolyte is provided, wherein the gel electrolyte comprises an inorganic aerogel material, a toughening agent and an electrolyte; the toughening agent is in a fibrous shape.

[0008] The above-mentioned gel electrolyte includes specific components, in which the inorganic aerogel material serves as a skeleton structure, and cooperates with the fibrous toughening agent to form a more stable support framework, and the electrolyte is mainly adsorbed on the skeleton structure to form a stable gel state. Among them, the inorganic aerogel material has good antioxidant properties, and after cooperating with the fibrous toughening agent to form a more stable support framework, the overall mechanical structure of the gel electrolyte is more stable and more conducive to film formation. Even if it is subjected to oxidation, its stable structure is not easy to collapse, which further improves the overall antioxidant performance. The various components work together to make the inorganic aerogel material have good structural stability, good film-forming properties and excellent oxidation resistance. When used to prepare batteries, it can increase the oxidation potential of the battery, thereby improving the battery's cycle performance.

[0009] In some embodiments, the inorganic aerogel material and the toughening agent together form a three-dimensional network structure.

[0010] The inorganic aerogel material and toughening agent together form a three-dimensional network structure, which is beneficial to further improve the mechanical stability of the gel electrolyte.

[0011] Furthermore, the toughening agent is interspersed in the pores of the inorganic aerogel material to jointly build a three-dimensional network structure.

[0012] In some embodiments, based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the inorganic aerogel material is 78% to 98%;

[0013] Optionally, the mass proportion of the inorganic aerogel material is 80% to 98%.

[0014] The mass proportion of the inorganic aerogel material is adjusted so that the mass of the inorganic aerogel material is dominant in the supporting structure of the gel electrolyte, forming a supporting structure mainly composed of the inorganic aerogel material, which can better cooperate with the toughening agent to further improve the oxidation resistance of the gel electrolyte.

[0015] In some of the embodiments, based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the toughening agent is 1% to 10%.

[0016] In some embodiments, the toughening agent satisfies at least one of the following conditions (1) to (2):

[0017] (1) The aspect ratio of the toughening agent is 1 to 1000;

[0018] Optionally, the toughening agent has an aspect ratio of 5 to 200;

[0019] Further optionally, the toughening agent has an aspect ratio of 10 to 100;

[0020] (2) The diameter of the toughening agent is 0.05 μm to 1 μm.

[0021] By regulating the aspect ratio of the toughening agent, the integrity of the supporting structure formed by the toughening agent and the inorganic aerogel can be further improved, thereby further improving the cycle performance of the battery.

[0022] In some embodiments, the toughening agent includes at least one of cellulose, asbestos, polyester fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber or polyurethane fiber;

[0023] Optionally, the toughening agent comprises at least one of cellulose or polypropylene fibers.

[0024] In some embodiments, the inorganic aerogel material includes at least one of silicon dioxide aerogel, titanium dioxide aerogel, zirconium dioxide aerogel, aluminum oxide aerogel, magnesium oxide aerogel, vanadium oxide aerogel, boron nitride aerogel or titanium nitride aerogel;

[0025] Optionally, the inorganic aerogel material includes at least one of silica aerogel or alumina aerogel.

[0026] In some embodiments, the gel electrolyte further comprises a binder.

[0027] The binder is helpful to promote the inorganic aerogel material and the toughening agent to build a stable support structure, further improving the mechanical stability of the gel electrolyte.

[0028] In some embodiments, the binder satisfies at least one of the following conditions (1) to (2):

[0029] (1) Based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the binder is 1% to 10%;

[0030] (2) The binder includes at least one of styrene-butadiene rubber, water-based acrylic resin, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-vinyl acetate copolymer, polyacrylic acid, carboxymethyl cellulose, polyvinyl alcohol or polyvinyl butyral.

[0031] In some of the embodiments, in the gel electrolyte, the mass proportion of the electrolyte is 10% to 50%.

[0032] By regulating the mass ratio of the electrolyte in the gel electrolyte, the gel electrolyte can maintain excellent structural stability and oxidation resistance while providing sufficient ion transmission channels inside the gel electrolyte, further improving the performance of the battery.

[0033] In some embodiments, the electrolyte includes an electrolyte salt and an organic solvent;

[0034] Optionally, in the electrolyte, based on the volume of the organic solvent, the concentration of the electrolyte salt is 0.1 mol / L to 10 mol / L.

[0035] According to a second aspect of the present application, a battery is provided, wherein the battery comprises the gel electrolyte according to the first aspect.

[0036] In some embodiments, the battery further comprises a positive electrode sheet and a negative electrode sheet, and the gel electrolyte is placed between the positive electrode sheet and the negative electrode sheet;

[0037] Optionally, in the vertical direction from the positive electrode sheet to the negative electrode sheet, the thickness of the gel electrolyte is 10 μm to 50 μm;

[0038] Further optionally, the thickness of the gel electrolyte is 12 μm to 25 μm.

[0039] Regulate the thickness of the gel electrolyte between the positive and negative electrodes to reduce the ion migration path between the positive and negative electrodes and improve battery performance.

[0040] According to a third aspect of the present application, there is provided an electrical device, wherein the electrical device comprises the battery according to the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0042] Figure 1 is a schematic diagram of one embodiment of a battery cell;

[0043] Figure 2 yes Figure 1 Exploded diagram of

[0044] Figure 3 is a schematic diagram of an embodiment of a battery pack;

[0045] Figure 4 yes Figure 3 Exploded diagram of

[0046] Figure 5 is a schematic diagram of an embodiment of an electrical device in which a battery is used as a power source;

[0047] Figure 6 This is an electron microscope image of a slice of the gel electrolyte prepared in Example 1.

[0048] Description of reference numerals:

[0049] 1. Battery pack; 2. Upper box; 3. Lower box; 4. Battery cell; 41. Shell; 42. Electrode assembly; 43. Cover plate; 5. Electrical device. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In summary, the oxidation resistance of traditional gel electrolytes is poor. Studies have found that traditional gel electrolytes are often formed by the composite of polymers, electrolytes and inorganic fillers to form gel electrolytes, which have good ionic conductivity and mechanical strength. However, the oxidation resistance is poor, especially when a higher energy density is achieved to obtain a high-voltage positive electrode system. Traditional gel electrolytes are easily oxidized, resulting in structural collapse and reducing the cycle performance of the battery.

[0055] Based on this, after a lot of creative research, the gel electrolyte in this application is obtained, which can improve the oxidation stability of the battery and thus improve the cycle performance of the battery.

[0056] In one embodiment of the present application, a gel electrolyte is provided. The components of the gel electrolyte include an inorganic aerogel material, a toughening agent and an electrolyte; the toughening agent is in a fibrous shape.

[0057] The above-mentioned gel electrolyte includes specific components, in which the inorganic aerogel material serves as a skeleton structure, and cooperates with the fibrous toughening agent to form a more stable support framework, and the electrolyte is mainly adsorbed on the skeleton structure to form a stable gel state. Among them, the inorganic aerogel material has good antioxidant properties, and after cooperating with the fibrous toughening agent to form a more stable support framework, the overall mechanical structure of the gel electrolyte is more stable and more conducive to film formation. Even if it is subjected to oxidation, its stable structure is not easy to collapse, which further improves the overall antioxidant performance. The various components work together to make the inorganic aerogel material have good structural stability, good film-forming properties and excellent oxidation resistance. When used to prepare batteries, it can increase the oxidation potential of the battery, thereby improving the battery's cycle performance.

[0058] It is understandable that the meaning of the above-mentioned "fibrous" is the same as the conventional fibrous morphology in the art, which means that the structural morphology of the substance presents the form of fiber strips, fiber filaments or fiber rods.

[0059] In some of the embodiments, the inorganic aerogel material and the toughening agent together form a three-dimensional network structure.

[0060] The inorganic aerogel material and toughening agent together form a three-dimensional network structure, which is beneficial to further improve the mechanical stability of the gel electrolyte.

[0061] Furthermore, the toughening agent is interspersed in the pores of the inorganic aerogel material or carried on the inorganic aerogel material to jointly build a three-dimensional network structure.

[0062] Furthermore, tougheners and tougheners, and tougheners and inorganic aerogels can attract each other through intermolecular forces to form a three-dimensional network structure.

[0063] Specifically, the electrolyte is adsorbed on the three-dimensional network structure formed by the inorganic aerogel material and the toughening agent. For example, the electrolyte salt in the electrolyte will be embedded and accumulated in the holes of the three-dimensional network structure, or adsorbed on the surface of the three-dimensional network structure, and the solvent in the electrolyte will be adsorbed in the three-dimensional network structure.

[0064] In some of the embodiments, based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the inorganic aerogel material is 78% to 98%.

[0065] Optionally, based on the total mass of components in the gel electrolyte excluding the electrolyte, the mass proportion of the inorganic aerogel material is 80% to 98%.

[0066] The mass proportion of the inorganic aerogel material is adjusted so that the mass of the inorganic aerogel material is dominant in the supporting structure of the gel electrolyte, forming a supporting structure mainly composed of the inorganic aerogel material, which can better cooperate with the toughening agent to further improve the oxidation resistance of the gel electrolyte.

[0067] In the above-mentioned "80%~98%", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%; or a range consisting of any two numerical values, for example, it can be 80%~98%, 80%~95%, 80%~90%, 80%~88%, 80%~85%, 85%~98%, 85%~95%, 85%~90%, 85%~88%, 90%~98%, 90%~95%, 90%~93%.

[0068] In some embodiments, the toughening agent has an aspect ratio of 1-1000.

[0069] Optionally, the toughening agent has an aspect ratio of 5-200.

[0070] Further optionally, the aspect ratio of the toughening agent is 10-100.

[0071] By regulating the aspect ratio of the toughening agent, the integrity of the supporting structure formed by the toughening agent and the inorganic aerogel can be further improved, thereby further improving the structural stability of the gel electrolyte.

[0072] It can be understood that the aspect ratio of the toughening agent refers to the ratio of the length of the toughening agent to the diameter of the cross section of the toughening agent.

[0073] In the above "1-1000", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000; or a range consisting of any two values, for example, it can be 1-900. , 1-800, 1-700, 1-600, 1-500, 1-400, 1-300, 1-200, 1-100, 5-900, 5-800, 5-700, 5-600, 5-500, 5-400, 5-300, 5-200, 5-100, 10-900, 10-800, 10-700, 10-600, 10-500, 10-400, 10-300, 10-200, 10-100, 50-900, 50-800, 50-700, 50-600, 50-500, 50-400, 50-300, 50-200, 50-100.

[0074] In some embodiments, the diameter of the toughening agent is 0.05 μm to 1 μm.

[0075] It can be understood that the diameter of the toughening agent refers to the cross-sectional diameter of a single toughening agent. For example, if the toughening agent is in a fibrous form, it refers to the cross-sectional diameter of a single fiber.

[0076] In the above “0.05μm~1μm”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 0.05μm, 0.06μm, 0.07μm, 0.08μm, 0.09μm, 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm; or a range consisting of any two values, for example, 0. 05μm~1μm, 0.05μm~0.9μm, 0.05μm~0.8μm, 0.05μm~0.7μm, 0.05μm~0.6μm, 0.05μm~0.5μm, 0.05μm~0.4μm, 0.05μm~ 0.3μm, 0.05μm~0.2μm, 0.05μm~0.1μm, 0.1μm~0.5μm, 0.1μm~0.7, 0.1μm~0.9, 0.1μm~1, 0.5μm~0.7μm, 0.5μm~1μm.

[0077] In some of the embodiments, the toughening agent includes at least one of cellulose, asbestos, polyester fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber or polyurethane fiber.

[0078] Optionally, the toughening agent comprises at least one of cellulose or polypropylene fibers.

[0079] In some of the embodiments, the porosity of the inorganic aerogel material is 80% to 99%.

[0080] Optionally, the porosity of the inorganic aerogel material is 90% to 95%.

[0081] In the above-mentioned "80%~99%", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%; or a range consisting of any two numerical values, for example, it can be 80%~98%, 80%~95%, 80%~90%, 80%~88%, 80%~85%, 85%~98%, 85%~95%, 85%~90%, 85%~88%, 90%~98%, 90%~95%, 90%~93%.

[0082] In some embodiments, the specific surface area of ​​the inorganic aerogel material is 600 m 2 / g~1200m 2 / g.

[0083] Optionally, the inorganic aerogel material has a specific surface area of ​​800 m 2 / g~1000m 2 / g.

[0084] The specific surface area or porosity of the inorganic aerogel material is further regulated to improve the adsorption of components in the electrolyte by the support structure formed by the inorganic aerogel material and the toughening agent, thereby improving the ion transmission capacity and structural stability of the gel electrolyte.

[0085] The above “600m 2 / g~1200m 2 / g", the value includes the minimum and maximum values ​​of the range, and each value between the minimum and maximum values, and specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 600m 2 / g, 650m 2 / g、700m 2 / g, 750m2 / g、800m 2 / g, 850m 2 / g、900m 2 / g, 950m 2 / g、1000m 2 / g; or a range consisting of any two values, for example, 600m 2 / g~1200m 2 / g, 600m 2 / g~1100m 2 / g, 600m 2 / g~1000m 2 / g, 600m 2 / g~900m 2 / g, 600m 2 / g~800m 2 / g, 600m 2 / g~700m 2 / g、700m 2 / g~1200m 2 / g、700m 2 / g~1100m 2 / g、700m 2 / g~1000m 2 / g、700m 2 / g~900m 2 / g、700m 2 / g~800m 2 / g、800m 2 / g~1200m 2 / g、800m 2 / g~1100m 2 / g、800m 2 / g~1000m 2 / g、800m 2 / g~900m 2 / g.

[0086] In some of the embodiments, the inorganic aerogel material includes at least one of silica aerogel, titania aerogel, zirconium dioxide aerogel, aluminum oxide aerogel, magnesium oxide aerogel, vanadium oxide aerogel, boron nitride aerogel or titanium nitride aerogel.

[0087] Optionally, the inorganic aerogel material includes at least one of silica aerogel or alumina aerogel.

[0088] In some embodiments, the particle size of the inorganic aerogel material is 2 μm to 6 μm.

[0089] The particle size here refers to the average value of the actual particle size tested by the molecular sieve screening method, which can also be considered as the average particle size.

[0090] In some of the embodiments, the components of the gel electrolyte further include a binder.

[0091] The binder is helpful to promote the inorganic aerogel material and the toughening agent to build a stable support structure, further improving the mechanical stability of the gel electrolyte.

[0092] In some of the embodiments, based on the total mass of the components in the gel electrolyte except the electrolyte, the mass proportion of the binder is 1% to 10%.

[0093] In the above “1% to 10%”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%; or a range consisting of any two values, for example, 1% to 10%, 1% to 9%, 1% to 8%, 1% to 7%, 1% to 6 %, 1% to 5%, 1% to 4%, 1% to 3%, 1% to 2%, 2% to 10%, 2% to 9%, 2% to 8%, 2% to 7%, 2% to 6%, 2% to 5%, 2% to 4%, 2% to 3%, 3% to 10%, 3% to 9%, 3% to 8%, 3% to 7%, 3% to 6%, 3% to 5%, 3% to 4%, 5% to 10%, 5% to 9%, 5% to 8%, 5% to 7%, 5% to 6%.

[0094] In some of the embodiments, the binder includes at least one of styrene-butadiene rubber, water-based acrylic resin, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-vinyl acetate copolymer, polyacrylic acid, carboxymethyl cellulose, polyvinyl alcohol or polyvinyl butyral.

[0095] In some of the embodiments, the binder includes at least one of polyvinylidene fluoride or polytetrafluoroethylene.

[0096] In some of the embodiments, based on the total mass of the components in the gel electrolyte except the electrolyte, the mass proportion of the toughening agent is 1% to 10%.

[0097] In the above “1% to 10%”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%; or a range consisting of any two values, for example, 1% to 10%, 1% to 9%, 1% to 8%, 1% to 7%, 1% to 6 %, 1% to 5%, 1% to 4%, 1% to 3%, 1% to 2%, 2% to 10%, 2% to 9%, 2% to 8%, 2% to 7%, 2% to 6%, 2% to 5%, 2% to 4%, 2% to 3%, 3% to 10%, 3% to 9%, 3% to 8%, 3% to 7%, 3% to 6%, 3% to 5%, 3% to 4%, 5% to 10%, 5% to 9%, 5% to 8%, 5% to 7%, 5% to 6%.

[0098] In some of the embodiments, in the gel electrolyte, the electrolyte accounts for 10% to 50% by mass.

[0099] In the above “10% to 50%”, the values ​​include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and the following point values: 10%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 23%, 25%, 27%, 29%, 30%, 31%, 33%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, %, 37%, 39%, 40%, 41%, 43%, 45%, 47%, 49%, 50%; or a range consisting of any two values, for example, 10%-50%, 10%-40%, 10%-30%, 10%-20%, 15%-50%, 15%-40%, 15%-30%, 15%-20%, 20%-50%, 20%-40%, 20%-30%.

[0100] In some of the embodiments, in the gel electrolyte, the mass proportion of the solid component is 50.5% to 95%.

[0101] By regulating the mass proportion of the electrolyte or the mass proportion of the solid component in the gel electrolyte, the gel electrolyte can maintain excellent structural stability and oxidation resistance while providing sufficient ion transmission channels inside the gel electrolyte, thereby further improving the performance of the battery.

[0102] In some of the embodiments, the mass proportion of the solid component in the gel electrolyte can be obtained by testing as follows:

[0103] The gel electrolyte is placed in a vacuum oven at 80° C. for drying to obtain a gel electrolyte dry film. The mass difference between the gel electrolyte and the gel electrolyte dry film is the mass of the organic solvent contained in the gel electrolyte. The mass percentage of the gel electrolyte dry film to the gel electrolyte is the mass content of the solid component in the gel electrolyte.

[0104] It can be understood that in the gel electrolyte, the mass proportion of the solid components is the mass proportion of the solid components in the inorganic aerogel material, toughening agent, binder and electrolyte; the solid components in the electrolyte include electrolyte salts and solid additives.

[0105] In the above-mentioned "50.5%~95%", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values ​​50.5%, 51%, 53%, 55%, 57%, 59%, 60%, 61%, 63%, 65%, 67%, 69%, 70%, 72%, 75%, 79%, 81%, 83%, 85%, 87%, 90%, 91%, 92%, 93%, 94%, 95%; or a range consisting of any two values, for example, it can be 50%~70%, 55%~70%, 60%~70%, 50%~60%, 55%~60%, 70%~80%, 75%~85%, 80%~90%.

[0106] In some of the embodiments, the electrolyte includes an electrolyte salt and an organic solvent.

[0107] In some of the embodiments, in the electrolyte solution, the concentration of the electrolyte salt is 0.1 mol / L to 10 mol / L based on the volume of the organic solvent.

[0108] In the above-mentioned "0.1mol / L~10mol / L", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and the following point values: 0.1mol / L, 0.5mol / L, 1mol / L, 1.5mol / L, 2mol / L, 2.5mol / L, 3mol / L, 3.5mol / L, 4mol / L, 4.5mol / L, 5mol / L, 5.5mol / L, 6mol / L, 6.5mol / L, 7mol / L, 7.5mol / L, 8mol / L, 8.5mol / L, 9mol / L, 9.5mol / L, 10mol / L; or a range consisting of any two values.

[0109] The electrolyte salt and organic solvent in the present application may be various electrolyte salts and organic solvents commonly used in the art. Examples of electrolyte salts and organic solvents are given here, but are not limited to the types specifically described below.

[0110] The electrolyte salt may be an electrolyte lithium salt, an electrolyte sodium salt, or an electrolyte potassium salt.

[0111] In some of these embodiments, the electrolyte salt includes an electrolyte lithium salt.

[0112] In a specific example, the electrolyte salt may include at least one of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorobis(oxalatophosphate) (LiDFOP) or lithium tetrafluorooxalatophosphate (LiTFOP).

[0113] The organic solvent may be at least one of a sulfone solvent, a carbonate solvent, a carboxylate solvent or an ether solvent.

[0114] In some embodiments, the sulfone solvent includes at least one of sulfolane, dimethyl sulfone, methyl ethyl sulfone or diethyl sulfone.

[0115] In some embodiments, the carbonate solvent includes at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, diphenyl carbonate, dibutyl carbonate or butylene carbonate.

[0116] In some embodiments, the carboxylate solvent includes but is not limited to at least one of propyl butyrate, propyl acetate, isopropyl acetate, ethyl propionate, propyl propionate, butyl propionate, isopropyl propionate or ethyl butyrate.

[0117] In some embodiments, the ether solvent includes at least one of methyl ether, propyl ether, butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, crown ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, methyl nonafluoro-n-butyl ether or octafluoropentyl-tetrafluoroethyl ether.

[0118] In any embodiment of the present application, the gel electrolyte may be prepared in the following manner, including the following step S10.

[0119] Step S10: Mix and stir the components of the gel electrolyte to prepare a gel electrolyte.

[0120] One embodiment of the present application further provides a battery, the battery comprising the gel electrolyte of the first aspect.

[0121] In some of the embodiments, the battery may be a secondary battery.

[0122] In some embodiments, the battery is a lithium-ion battery.

[0123] In some embodiments, the battery is a lithium metal battery.

[0124] In some embodiments, the battery further includes a positive electrode sheet and a negative electrode sheet, and the gel electrolyte is disposed between the positive electrode sheet and the negative electrode sheet.

[0125] Optionally, in the vertical direction from the positive electrode sheet to the negative electrode sheet, the thickness of the gel electrolyte is 10 μm to 50 μm.

[0126] It can be understood that in the above battery, the gel electrolyte exists in the form of a gel electrolyte membrane; further, the thickness of the gel electrolyte membrane is 10 μm to 50 μm.

[0127] Further optionally, the thickness of the gel electrolyte is 12 μm to 25 μm.

[0128] Regulate the thickness of the gel electrolyte between the positive and negative electrodes to reduce the ion migration path between the positive and negative electrodes and improve battery performance.

[0129] In the above “10μm~50μm”, the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiment and the following point values: 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm; or any two values. Range, for example: 10μm~50μm, 15μm~50μm, 20μm~50μm, 25μm~50μm, 30μm~50μm, 35μm~50μm, 40μm~50μm, 45μm~50μm, 15μm~45μm, 20μm~45μm, 25μm~45μm, 30μm~45μm, 35μm~45μm, 40μm~45μm.

[0130] The positive electrode sheet and the negative electrode sheet in the present application can be various types of positive electrode sheets and negative electrode sheet systems commonly used in the art. The positive electrode sheet includes a current collector and a positive electrode active layer loaded on the surface of the current collector.

[0131] The components of the positive electrode active layer include positive electrode active materials. The positive electrode active materials can be selected from commonly used positive electrode active materials in the art, including but not limited to: positive electrode active materials for lithium ion batteries, positive electrode active materials for sodium ion batteries, or positive electrode active materials for potassium ion batteries.

[0132] The positive electrode active material of a lithium ion battery, the positive electrode active material of a sodium ion battery and the positive electrode active material of a potassium ion battery are hereinafter referred to as lithium ion active material, sodium ion active material or potassium ion active material, respectively.

[0133] Further, as an example, the lithium ion active material may include at least one of the following materials: lithium phosphates containing olivine structure, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2) or its modified compounds. Examples of lithium-containing phosphates with olivine structure may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4, referred to as LFP), lithium manganese phosphate (such as LiMnPO4) or lithium manganese iron phosphate. In any embodiment of the present application, the molecular formula of the lithium ion active material is: LiFe x Mn (1-x) PO4, x can be any number from 0 to 1.

[0134] It can be understood that when x is 0, LiFe x Mn (1-x) PO4 is LiMnPO4 lithium manganese phosphate. When x is 1, LiFePO4 is LiFePO4 lithium iron phosphate (LFP).

[0135] It should be noted that the lithium content in the positive electrode material exemplified above refers to its content when it is not in use. During the use of the battery, it will be repeatedly used as a battery, and the Li in the positive electrode active material will change during the charging and discharging process, that is, the molar subscript of Li in the positive electrode active material in the battery product will not always remain at 1, but will change; further, the range of change can be (0 to 1.2).

[0136] For example, LiFe x Mn (1-x) PO4 can be further expressed as Li y Fe x Mn (1-x) PO4, y is 0~1.1.

[0137] For example, for the ternary material Li y (Ni a Co b Mn c ) 1-d M d O 2-x A x , y is 0.2~1.2, a+b+c=1, 0≤d≤1, 0≤x<2; M is one or more of Zr, Sr, B, Ti, Mg, Sn and Al, and A is one or more of S, N, F, Cl, Br and I.

[0138] The battery will be accompanied by Li deintercalation and consumption during the charge and discharge process. The molar content of Li is different when the battery is discharged to different states. The above definition of y includes the molar content of Li under different charge and discharge states of the battery; further, the battery voltage is usually between 2-5V.

[0139] In some of the embodiments, the above-mentioned active material includes a high-voltage positive electrode active material; further, the above-mentioned active material includes a nickel-containing active material; for example, it can be at least one of a nickel-containing ternary material, lithium nickel cobalt oxide, lithium nickel manganese oxide or lithium nickel cobalt manganese oxide; more specifically, it can be at least one of lithium nickel manganese cobalt oxide, nickel manganese spinel or nickel-rich lithium manganese oxide.

[0140] The above-mentioned gel electrolyte has excellent oxidizability. When used in the preparation of batteries, especially under high-voltage positive electrode active materials, it can significantly improve the oxidation stability of the battery and improve the cycle performance of the battery.

[0141] As an example, the sodium ion active material may include at least one of the following materials: at least one of a sodium transition metal oxide, a polyanionic compound, and a Prussian blue compound. However, the present application is not limited to these materials, and other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries may also be used.

[0142] As an optional technical solution of the present application, in the sodium transition metal oxide, the transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr or Ce. The sodium transition metal oxide is, for example, Na x MO2, wherein M includes at least one or more of Ti, V, Mn, Co, Ni, Fe, Cr or Cu, and 0<x≤1.

[0143] As an optional technical solution of the present application, the polyanionic compound can be a compound having sodium ions, transition metal ions and tetrahedral (YO4) n- A class of compounds with anionic units. The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr or Ce; Y includes at least one of P, S or Si; n represents (YO4) n- valence state.

[0144] Polyanionic compounds can also be those with sodium ions, transition metal ions, tetrahedral (YO4) n- A class of compounds of anion units and halogen anions. The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr or Ce; Y includes at least one of P, S or Si, and n represents (YO4) n- valence state; the halogen may be at least one of F, Cl or Br.

[0145] Polyanionic compounds can also be sodium ions, tetrahedral (YO4) n- Anion unit, polyhedral unit (ZO y ) m+ and a class of compounds containing an optional halogen anion. Y includes at least one of P, S or Si, and n represents (YO4) n- valence state; Z represents a transition metal, including at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr or Ce, m represents (ZO y ) m+ valence state; the halogen may be at least one of F, Cl or Br.

[0146] Polyanionic compounds include NaFePO4, Na3V2(PO4)3 (sodium vanadium phosphate, abbreviated as NVP), Na4Fe3(PO4)2(P2O7)(NFPP), NaM1PO4F or Na3(VO y )2(PO4)2F (3-2y) At least one of .

[0147] M1 is at least one of V, Fe, Mn and Ni, and 0≤y≤1.

[0148] Prussian blue compounds can be sodium ions, transition metal ions and cyanide ions (CN - ). The transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr or Ce. Prussian blue compounds are, for example, Na a M2 b M3 c (CN)6, wherein M2 and M3 are each independently selected from at least one of Ni, Cu, Fe, Mn, Co or Zn, 0<a≤2, 0<b<1, 0<c<1.

[0149] In any embodiment of the present application, in the positive electrode active layer, the mass proportion of the positive electrode active material is 70% to 99.8%.

[0150] In any embodiment of the present application, the components of the positive electrode active layer further include a conductive agent and a binder.

[0151] The conductive agent may be any commonly used conductive agent in the art, including but not limited to at least one of graphite, carbon nanotubes, nanofibers, carbon black or graphene. Specifically, it may be selected from at least one of SP, KS-6, acetylene black, branched Ketjen black ECP, SFG-6, vapor grown carbon fiber VGCF, carbon nanotubes CNTs or graphene and composite conductive agents thereof.

[0152] The binder can be at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, hydrogenated nitrile rubber, 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) or fluorine-containing acrylate resin.

[0153] Optionally, in the positive electrode active layer, the mass proportion of the conductive agent is 1% to 20%.

[0154] Optionally, in the positive electrode active layer, the mass proportion of the binder is 1% to 10%.

[0155] In some embodiments, the thickness of the positive electrode active layer is 30 μm to 200 μm.

[0156] In any embodiment of the present application, the current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material on a polymer material substrate.

[0157] In some embodiments, the metal material is selected from any one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver or silver alloy.

[0158] In some of the embodiments, the polymer material substrate includes at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS) or polyethylene (PE).

[0159] In any embodiment of the present application, the positive electrode sheet can be prepared by the following method: dispersing the above-mentioned components for preparing the positive electrode sheet in an organic solvent to form a positive electrode slurry; coating the positive electrode slurry on the current collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0160] In some of the embodiments, the solid content of the positive electrode slurry is 40 wt % to 80 wt %, and the viscosity at 25° C. is adjusted to 5000 mPa·s to 25000 mPa·s.

[0161] In some embodiments, the organic solvent includes, but is not limited to, N-methylpyrrolidone.

[0162] In some embodiments, the surface density of the positive electrode active material contained in the positive electrode sheet is 0.018 g / cm 2 ~0.05g / cm 2 .

[0163] The surface density of the positive electrode active material = the mass of the positive electrode active material / the area of ​​the positive electrode sheet.

[0164] Negative electrode sheet: The negative electrode sheet may adopt the negative electrode sheet system of various types of batteries commonly used in the art, and lithium-ion batteries and lithium metal batteries are used as examples below, but are not limited to the following types.

[0165] In some of the embodiments, the battery is a lithium metal battery, and the negative electrode sheet can be a negative electrode sheet that is known in the art and can be used for a lithium metal battery.

[0166] In some embodiments, the negative electrode sheet directly adopts a lithium-containing metal sheet.

[0167] In another embodiment, the negative electrode sheet includes a lithium-containing metal layer and a conductive layer stacked together.

[0168] Furthermore, the lithium-containing metal in the lithium-containing metal sheet and the lithium-containing metal layer may be lithium metal, or an alloy formed by lithium metal and other metal or non-metal elements.

[0169] Further, the other metals include at least one of tin (Sn), zinc (Zn), aluminum (Al), magnesium (Mg), silver (Ag), gold (Au), gallium (Ga), indium (In) or platinum (Pt); the non-metallic elements include at least one of boron (B), carbon (C) or silicon (Si).

[0170] In some of these embodiments, the conductive layer may be a copper foil.

[0171] In any embodiment of the present application, the negative electrode sheet can be prepared in the following manner: directly pressing a lithium-containing metal sheet to obtain the negative electrode sheet, or stacking and pressing the lithium-containing metal layer and the conductive layer to obtain the negative electrode sheet.

[0172] In some of the embodiments, the battery is a lithium-ion battery, and the negative electrode sheet can be a negative electrode sheet known in the art that can be used for a lithium-ion battery.

[0173] In some embodiments, the negative electrode sheet includes a current collector and a negative electrode active layer supported on a surface of the current collector.

[0174] The components of the negative electrode active layer include a negative electrode active material.

[0175] The negative electrode active material mentioned above can adopt the commonly used negative electrode active material in this application.

[0176] In any embodiment of the present application, the above-mentioned negative electrode active material includes at least one of mesophase carbon microbeads, graphite, glassy carbon, carbon nanotubes, carbon-carbon composite materials, carbon fibers, hard carbon, soft carbon, silicon-based materials, tin-based materials, magnesium-based materials or iron-based materials.

[0177] Optionally, specific examples of the above-mentioned negative electrode active materials include, but are not limited to: at least one of mesophase carbon microbeads, natural graphite, artificial graphite, graphene, glassy carbon, carbon nanotubes, carbon fibers, hard carbon, soft carbon, iron oxide, tin oxide, silicon oxide, magnesium oxide, silicon-carbon composites, lithium metal or lithium metal alloys.

[0178] In any embodiment of the present application, the mass proportion of the above-mentioned negative electrode active material in the negative electrode active layer is 70% to 100%.

[0179] In any embodiment of the present application, the components of the negative electrode active layer further include a negative electrode conductive agent and a negative electrode binder.

[0180] In any embodiment of the present application, the above-mentioned negative electrode conductive agent can be a conductive material commonly used in the art, including but not limited to: at least one of graphite, carbon nanotubes, nanofibers, carbon black or graphene. Specifically, it can be selected from SP, KS-6, acetylene black, branched Ketjen black ECP, SFG-6, vapor-grown carbon fiber VGCF, carbon nanotubes CNTs or graphene and at least one of their composite conductive agents.

[0181] The weight ratio of the negative electrode conductive agent in the negative electrode active layer is 0 to 20 wt % based on the total weight of the negative electrode active layer.

[0182] The above-mentioned negative electrode binder can be a commonly used binder in the art, and can 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) or carboxymethyl chitosan (CMCS).

[0183] The weight ratio of the negative electrode binder in the negative electrode active layer is 0 to 30 wt % based on the total weight of the negative electrode active layer.

[0184] In any embodiment of the present application, the negative electrode active layer may further include other additives, such as thickeners, such as sodium carboxymethyl cellulose (CMC-Na), etc. Based on the total weight of the negative electrode active layer, the weight ratio of other additives in the negative electrode active layer is 0-15wt%.

[0185] In any embodiment of the present application, the current collector in the negative electrode sheet may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil.

[0186] The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material on a polymer material substrate.

[0187] In some embodiments, the metal material is selected from any one of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver or silver alloy.

[0188] In some of the embodiments, the polymer material substrate includes at least one of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS) or polyethylene (PE).

[0189] In any embodiment of the present application, the negative electrode sheet can be prepared in the following manner: the above-mentioned components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained.

[0190] In some embodiments, the solvent includes but is not limited to water.

[0191] In some of the embodiments, the solid content of the negative electrode slurry is 30 wt % to 70 wt %, and the viscosity at 25° C. is adjusted to 2000 mPa·s to 10000 mPa·s.

[0192] In some embodiments, the surface density of the negative electrode active material contained in the negative electrode sheet is 0.005 g / cm 2 ~0.03g / cm 2 .

[0193] The surface density of the negative electrode active material = the mass of the negative electrode active material / the area of ​​the negative electrode sheet.

[0194] The present application has no particular limitation on the shape of the battery, and the shape of the battery of the present application can be cylindrical, square, or any other shape. For example, Figure 1 The battery cell 4 is a battery having a square structure as an example.

[0195] In some embodiments, reference Figure 2 The housing may include a shell 41 and a cover plate 43. The shell 41 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 41 has an opening connected to the receiving cavity, and the cover plate 43 can be covered on the opening to close the receiving cavity.

[0196] The positive electrode sheet and the gel electrolyte film negative electrode sheet can be wound or laminated to form an electrode assembly 42, which is packaged in the receiving cavity. The number of electrode assemblies 42 contained in the battery cell 4 can be one or more, which can be adjusted according to needs.

[0197] The battery comprises one or more battery cells 4 .

[0198] The battery may be a battery module or a battery pack; the battery module or battery pack includes at least one battery cell 4. The number of battery cells contained in the battery module may be one or more, and those skilled in the art may select a suitable number according to the application and capacity of the battery module.

[0199] Figure 3 and Figure 4The battery pack 1 is used as an example. The battery pack 1 includes a battery box and one or more battery cells 4 disposed in the battery box. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can cover the lower box body 3 and form a closed space for the battery cells 4.

[0200] The plurality of battery cells 4 may be arranged in the battery box in any manner.

[0201] The present application also provides an electrical device, which includes the above-mentioned battery.

[0202] Furthermore, in the above-mentioned electrical device, the battery may exist in the form of a battery cell, or may be further assembled into a battery pack.

[0203] The above-mentioned battery or the battery pack assembled therefrom can be used as a power source for an electrical device, and can also be used as an energy storage unit for an electrical device.

[0204] The above-mentioned electrical devices may be, but are not limited to, mobile equipment, electric vehicles, electric trains, ships and satellites, energy storage systems, etc.

[0205] In some of these embodiments, the mobile device may be a mobile phone or a laptop computer, etc.

[0206] In some of the embodiments, the electric vehicle includes, but is not limited to, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.

[0207] Figure 5 The power consumption device 5 is taken as an example. The power consumption device 5 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the power consumption device 5's requirements for high power and high energy density of the battery, a battery pack can be used.

[0208] As another example, the power-consuming device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a battery may be used as a power source.

[0209] The present invention will be described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. It should be understood that the attached claims summarize the scope of the present invention. Under the guidance of the concept of the present invention, those skilled in the art should realize that certain changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0210] The following are specific embodiments. Specific embodiments

[0212] Example 1

[0213] 1. Preparation of batteries

[0214] (1) Preparation of gel electrolyte:

[0215] The lithium salt lithium bis(fluorosulfonyl)imide (LiFSI) is dissolved in an organic solvent, and the electrolyte additive lithium difluorooxalate borate is added and stirred evenly to obtain an electrolyte, wherein the concentration of LiFSI is 1 mol / L based on the volume of the organic solvent, the mass proportion of the electrolyte additive is 1 wt%, and the organic solvent is a solution of ethylene carbonate and ethyl methyl carbonate mixed in a volume ratio of 50:50.

[0216] The inorganic aerogel (silicon dioxide aerogel), binder (polytetrafluoroethylene) and toughening agent (polypropylene fiber) were mixed in a mass ratio of 95:3:2 and added into a stirrer. Then, the above electrolyte was added and stirred evenly. The membrane-like gel electrolyte was prepared by rolling with a roller press. The thickness was recorded as H1.

[0217] The above gel electrolyte slice is placed under an electron microscope for observation. The electron microscope image is as follows: Figure 6 As shown, inorganic aerogel and fibrous substances interspersed and mixed in its pores can be seen to form a three-dimensional network structure.

[0218] The ratio of the total mass of the inorganic aerogel, binder and toughening agent to the total mass of the electrolyte is recorded as M1. The average particle size of the inorganic aerogel is 3 μm, the porosity is 95%, and the specific surface area is 800 m 2 / g, the diameter of the toughening agent is 0.5μm and the aspect ratio is 100.

[0219] Taking the total mass of the components in the gel electrolyte excluding the electrolyte as a benchmark, the mass proportion of the inorganic aerogel is recorded as K1, the mass proportion of the toughening agent is recorded as K2, and the mass proportion of the binder is recorded as K3. The specific component types and parameters are shown in Table 1.

[0220] Furthermore, the type and mass proportion of each component in the above-mentioned gel electrolyte can also be tested by characterization and analysis methods commonly used in the field, for example: performing elemental energy spectrum analysis on the gel electrolyte dry film to obtain qualitative and quantitative test results of the main constituent elements of the gel electrolyte dry film, and further analyzing and calculating the type and mass proportion of each component.

[0221] (2) Preparation of negative electrode

[0222] Use a 50μm thick lithium foil and roll it together with a 12μm thick copper foil to serve as the negative electrode.

[0223] (3) Preparation of positive electrode

[0224] The positive electrode active material (lithium nickel cobalt manganese oxide NMC811), the conductive agent Super P, and the binder PVDF were mixed in a mass ratio of 98:1:1, and NMP was added and stirred evenly to obtain a positive electrode slurry (solid content of 75%); the positive electrode slurry was coated on the surface of the positive electrode current collector carbon-coated aluminum foil and dried to obtain a positive electrode sheet. The surface capacity of the positive electrode sheet was 3.5 mAh / cm 2 .

[0225] (4) Preparation of lithium metal battery: The positive and negative electrode sheets are stacked and combined, the positive and negative electrodes are separated by the above-mentioned membrane-like gel electrolyte, and wrapped with aluminum-plastic film bags to form a stacked dry battery cell, which is vacuum packaged and left to stand at room temperature for 6 hours to obtain a lithium metal battery.

[0226] (5) Performance test of lithium metal batteries:

[0227] 1. The lithium metal battery prepared above is charged and discharged at a constant current to a cut-off voltage of 4.3V. The specific process is: 0.5C constant current charging to 4.3V, 0.5C constant current discharging to 2.8V, and charging to a cut-off voltage of 4.3V. If the constant current discharge can be smoothly maintained to 4.3V, a charge and discharge curve is obtained. If it can be successfully discharged to 4.3V, in the charge and discharge curve, there is no current jump peak at the cut-off voltage, it is determined that no oxidation reaction occurs on the positive electrode side of the battery, resulting in interruption of battery charge and discharge, which indicates that the voltage is the electrochemical oxidation potential V0 of the battery.

[0228] 2. Take the above lithium metal battery and perform electrochemical cycling at room temperature of 25°C under the test conditions of 0.33C constant current and constant voltage charging and 0.33C constant current discharge. The cut-off voltages for charging and discharging are set to 4.3V and 2.8V, respectively. Constant current-constant voltage charging is specifically as follows: when 0.33C constant current charging reaches a cut-off voltage of 4.3V, continue to charge at 4.3V constant voltage until the current drops to 0.05C, then discharge at 0.33C constant current to a cut-off voltage of 2.8V. One charge-discharge cycle is one cycle. When the capacity decay rate of the battery after discharge reaches 80%, the battery life is considered to have stopped. Record the number of cycles at this time, recorded as Cy80%.

[0229] Embodiments 2 to 5

[0230] Examples 2 to 5 are basically the same as Example 1, except that in step (1) of preparing the gel electrolyte, the amount of inorganic aerogel or binder or toughening agent added is adjusted differently from that in Example 1. For specific parameters, see Table 1.

[0231] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0232] Embodiments 6 to 8

[0233] Examples 6 to 8 are basically the same as Example 1, except that the thickness H1 of the membrane-shaped gel electrolyte is regulated differently from that of Example 1. For specific parameters, see Table 1.

[0234] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0235] Embodiments 9-10

[0236] Embodiments 9 to 10 are basically the same as Embodiment 1, except that the M1 value is adjusted differently from that in Embodiment 1. For specific parameters, see Table 1.

[0237] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0238] Examples 11-12

[0239] Examples 11 to 12 are basically the same as Example 1, except that: in the preparation of the gel electrolyte in step (1), the type of the toughening agent is adjusted differently from that in Example 1, and the diameter and aspect ratio of the toughening agent are kept the same as those in Example 1: the diameter is 0.5 μm, and the aspect ratio is 100. For specific parameters, see Table 1.

[0240] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0241] Example 13

[0242] Example 13 is basically the same as Example 1, except that in step (1) of preparing the gel electrolyte, the type of the binder is adjusted differently from that in Example 1. For specific parameters, see Table 1.

[0243] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0244] Embodiments 14 to 16

[0245] Examples 14 to 16 are basically the same as Example 1, except that in step (1) of preparing the gel electrolyte, the type of inorganic aerogel material is regulated differently from that in Example 1. For specific parameters, see Table 1.

[0246] The average particle size of the inorganic aerogel in Example 14 is 3 μm, the porosity is 93%, and the specific surface area is 750 m 2 / g; the average particle size of the inorganic aerogel in Example 15 is 3 μm, the porosity is 92.8%, and the specific surface area is 776m 2 / g; the average particle size of the inorganic aerogel in Example 16 is 3 μm, the porosity is 94.5%, and the specific surface area is 790m 2 / g.

[0247] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0248] Examples 17 to 20

[0249] Examples 17 to 20 are substantially the same as Example 1, except that in step (1) of preparing the gel electrolyte, the length of the toughening agent is changed while maintaining the diameter of the toughening agent at 0.5 μm to adjust the aspect ratio of the toughening agent, which is different from that of Example 1. For specific parameters, see Table 1.

[0250] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0251] Comparative Example 1

[0252] Comparative Example 1 is substantially the same as Example 1, except that no toughening agent is added in the preparation of the gel electrolyte in step (1). Specific parameters are shown in Table 1.

[0253] The other step conditions are the same as those in Example 1. The test results are shown in Table 1.

[0254] Comparative Example 2

[0255] Comparative Example 1 is basically the same as Example 1, except that: in the preparation of the gel electrolyte in step (1), the polypropylene fiber is replaced with polypropylene resin particles with an average particle size of 3 μm, and K2 represents the mass percentage of the polypropylene resin particles. For specific parameters, see Table 1.

[0256] The relevant parameters and performance results of each embodiment and comparative example are shown in Table 1. Among them, based on the total mass of the components in the gel electrolyte except the electrolyte, the mass proportion of the inorganic aerogel is recorded as K1, the mass proportion of the toughening agent is K2, and the mass proportion of the binder is K3; the mass content of the solid component in the gel electrolyte is K4; the thickness of the gel electrolyte in the lithium metal battery is H1.

[0257] Table 1

[0258]

[0259]

[0260] In Table 1, “ / ” indicates that the substance or parameter does not exist.

[0261] By analyzing the data in Table 1 and comparing the data in Example 1 with those in Comparative Examples 1 to 2, it can be seen that when the battery is prepared using the gel electrolyte of the present application, the oxidation stability of the battery can be improved, not only a higher oxidation potential can be achieved, but also good oxidation resistance can be maintained during the cycle process, thereby improving the cycle performance of the battery.

[0262] Furthermore, by conducting an intra-group analysis and comparison of the data of Examples 1 to 22, it can be seen that further regulating the amount of inorganic aerogel or binder or toughening agent added, regulating the aspect ratio of the toughening agent, etc., can further improve the oxidation resistance and structural stability of the battery, and further improve the cycle performance of the battery.

[0263] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0264] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A gel electrolyte, characterized in that: The gel electrolyte comprises an inorganic aerogel material, a toughening agent and an electrolyte; the toughening agent is in a fiber shape.

2. The gel electrolyte according to claim 1, characterized in that The inorganic aerogel material and the toughening agent together form a three-dimensional network structure.

3. The gel electrolyte according to claim 1, characterized in that Based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the inorganic aerogel material is 78% to 98%; Optionally, the mass proportion of the inorganic aerogel material is 80% to 98%.

4. The gel electrolyte according to any one of claims 1 to 3, characterized in that Based on the total mass of the components in the gel electrolyte except the electrolyte, the mass proportion of the toughening agent is 1% to 10%.

5. The gel electrolyte according to any one of claims 1 to 3, characterized in that: The toughening agent satisfies at least one of the following conditions (1) to (2): (1) The aspect ratio of the toughening agent is 1 to 1000; Optionally, the toughening agent has an aspect ratio of 5 to 200; Further optionally, the toughening agent has an aspect ratio of 10 to 100; (2) The diameter of the toughening agent is 0.05 μm to 1 μm 。 6. The gel electrolyte according to any one of claims 1 to 3, characterized in that The toughening agent includes at least one of cellulose, asbestos, polyester fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber or polyurethane fiber; Optionally, the toughening agent comprises at least one of cellulose or polypropylene fibers.

7. The gel electrolyte according to any one of claims 1 to 3, characterized in that The inorganic aerogel material includes at least one of silicon dioxide aerogel, titanium dioxide aerogel, zirconium dioxide aerogel, aluminum oxide aerogel, magnesium oxide aerogel, vanadium oxide aerogel, boron nitride aerogel or titanium nitride aerogel; Optionally, the inorganic aerogel material includes at least one of silica aerogel or alumina aerogel.

8. The gel electrolyte according to any one of claims 1 to 3, characterized in that The components of the gel electrolyte also include a binder.

9. The gel electrolyte according to claim 8, characterized in that The binder satisfies at least one of the following conditions (1) to (2): (1) Based on the total mass of the components in the gel electrolyte excluding the electrolyte, the mass proportion of the binder is 1% to 10%; (2) The binder includes at least one of styrene-butadiene rubber, water-based acrylic resin, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-vinyl acetate copolymer, polyacrylic acid, carboxymethyl cellulose, polyvinyl alcohol or polyvinyl butyral.

10. The gel electrolyte according to any one of claims 1 to 3, characterized in that In the gel electrolyte, the mass proportion of the electrolyte is 10% to 50%.

11. The gel electrolyte according to any one of claims 1 to 3, characterized in that: The electrolyte comprises an electrolyte salt and an organic solvent; Optionally, in the electrolyte, based on the volume of the organic solvent, the concentration of the electrolyte salt is 0.1 mol / L to 10 mol / L.

12. A battery, characterized in that: The battery comprises the gel electrolyte according to any one of claims 1 to 12.

13. The battery according to claim 12, characterized in that The battery further comprises a positive electrode sheet and a negative electrode sheet, wherein the gel electrolyte is disposed between the positive electrode sheet and the negative electrode sheet; Optionally, in the vertical direction from the positive electrode sheet to the negative electrode sheet, the thickness of the gel electrolyte is 10 μm to 50 μm; Further optionally, the thickness of the gel electrolyte is 12 μm to 25 μm.

14. An electrical device, characterized in that: The electrical device comprises the battery according to any one of claims 12 to 13.

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