Sealing element for solid-state battery, solid-state battery, battery pack and electric equipment

Abstract

The utility model discloses a sealing element for a solid-state battery, the solid-state battery, a battery pack and a vehicle, the sealing element is suitable for covering the peripheral surface of a battery cell of the solid-state battery, and the sealing element comprises a buffer layer, a sealing layer and a sealing layer, and the sealing layer is arranged on one side of the buffer layer in the thickness direction. According to the sealing element disclosed by the utility model, the sealing performance of the battery cell of the battery can be improved, the expansion of the battery cell can be buffered, and the service life of the battery is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially is related to a sealing element for solid state battery, solid state battery, battery pack and electric equipment. BACKGROUND

[0002] At present, global electric vehicles have been applied on a large scale, but the existing liquid lithium ion battery is approaching its energy density limit, and safety problems need to be solved, especially the liquid lithium ion battery of high energy density system, its safety hidden danger cannot be ignored. Therefore, under the promotion of the demand for high energy density, high safety and long service life battery, solid state battery such as all-solid-state battery is regarded as an innovative technology to accelerate the popularization of electric vehicles. By adopting solid electrolyte to replace flammable electrolyte and diaphragm, all-solid-state battery has high safety.

[0003] Sulfide solid electrolyte is widely concerned due to its high ionic conductivity. Sulfide all-solid-state battery is the all-solid-state battery system developed by domestic leading lithium battery enterprises, Japan, South Korea and other places. Sulfide solid electrolyte has poor chemical stability, and H2S gas will be generated when it meets moisture in the air. In this process, the ionic conductivity of sulfide solid electrolyte will decrease, thereby deteriorating the performance of all-solid-state battery. Therefore, the environment control is relatively harsh when preparing sulfide all-solid-state battery, such as the need for dew point production environment above-50 DEG C, which will bring a substantial increase in production cost. Moreover, the sealing performance of the traditional battery is poor, which is not conducive to the long-term stable use of sulfide solid electrolyte.

[0004] In addition, the positive electrode, the negative electrode and the electrolyte layer are all solid-solid contact interfaces. In order to avoid the loss of contact of the interface caused by the continuous expansion and shrinkage of the positive electrode material and the negative electrode material in the cycle process, thereby causing the significant decrease of the battery capacity and the rate performance. Generally, all-solid-state battery needs to work under a certain pressure. In the cycle process, the expansion and shrinkage of the positive electrode material and the negative electrode material are easy to cause the cracking and material falling of the end of the battery cell due to stress or uneven stress. SUMMARY

[0005] The utility model aims at solving one of the technical problems in the prior art. Therefore, one purpose of the utility model is to provide a sealing element for solid state battery. The sealing element can improve the sealing performance of the battery cell, buffer the expansion of the battery cell, and prolong the service life of the battery.

[0006] Another purpose of the utility model is to provide a solid state battery using the above sealing element.

[0007] Another purpose of the utility model is to provide a battery pack using the above solid state battery.

[0008] Another purpose of the utility model lies in providing a power consumption device using the above solid-state battery or battery pack.

[0009] According to the sealing piece for the solid-state battery provided by the utility model, the sealing piece is suitable for covering the outer circumferential surface of the battery cell of the solid-state battery, and the sealing piece comprises: a buffer layer; and a sealing layer arranged on one side of the thickness direction of the buffer layer.

[0010] According to the sealing piece for the solid-state battery provided by the utility model, the sealing piece is simple in structure, high in production and processing efficiency, and convenient to use. When the sealing piece is used for the solid-state battery, the buffer layer can be used for buffering the expansion of the positive electrode and the negative electrode of the battery cell, so that the cracking of the edge part of the positive electrode sheet and the negative electrode sheet due to local stress unevenness is avoided, the self-discharge of the solid-state battery is reduced, short circuit is avoided, and the service life of the solid-state battery is prolonged. In addition, the sealing layer can play the effect of water isolation at the battery cell level, and also has the function of moisture-proof, so that the subsequent process can be carried out in a slightly lower dew point environment, and the production cost can be significantly reduced. In addition, from the perspective of use safety, the moderate sealing and moisture-proof of the battery cell can slow down the speed of the solid-state electrolyte contacting the water in the environment and reacting when the shell of the solid-state battery is accidentally damaged, so as to provide valuable buffer time for safety warning and safety protection measures.

[0011] According to some embodiments of the utility model, the sealing layer is connected to the side of the buffer layer away from the battery cell.

[0012] According to some embodiments of the utility model, the thickness of the buffer layer is d1, and the thickness of the sealing layer is d2, wherein the d1 and d2 satisfy: 0 < d1 / d2 < 2.

[0013] According to some embodiments of the utility model, the thickness of the buffer layer is d1, wherein the d1 satisfies: 0.1mm < d1 < 10mm; and / or, the thickness of the sealing layer is d2, wherein the d2 satisfies: 1mm < d2 < 10mm.

[0014] According to some embodiments of the utility model, the buffer layer comprises a polyurethane foam piece, a polystyrene foam piece, a polyvinyl chloride foam piece or a phenolic foam piece.

[0015] According to some embodiments of the present application, the buffer layer further comprises a fiber piece, an inorganic nanometer material piece or a hollow microbead piece, the fiber piece comprises a plant fiber piece, a polyester fiber piece, a nylon fiber piece, a polyacrylonitrile fiber piece or a glass fiber piece, the inorganic nanometer material piece comprises an aluminum oxide piece, a zirconium oxide piece, a silicate piece or a silicon dioxide piece, and the hollow microbead piece comprises a glass microbead, a polystyrene microbead, an aluminum oxide microbead, a zirconium oxide microbead, a silicon carbide microbead or a boron carbide microbead.

[0016] According to the solid-state battery of the second aspect of the present application, the sealing piece is arranged between the outer circumferential surface of the battery cell and the inner wall surface of the shell.

[0017] According to some embodiments of the present application, the side surface of the battery cell along the circumferential direction perpendicular to the stacking direction of the plurality of pole pieces of the battery cell is connected to the buffer layer of the sealing piece, and the inner wall surface of the shell is connected to the sealing layer of the sealing piece.

[0018] According to some embodiments of the present application, the battery cell comprises: a plurality of positive pole pieces, the plurality of positive pole pieces being arranged along the thickness direction of the positive pole pieces; a plurality of negative pole pieces, the plurality of negative pole pieces being arranged alternately with the plurality of positive pole pieces along the thickness direction of the positive pole pieces, and a solid-state electrolyte layer being arranged between the negative pole pieces and the adjacent positive pole pieces, and the sealing piece covers at least the side surface of the battery cell along the circumferential direction perpendicular to the thickness direction of the positive pole pieces.

[0019] According to the battery pack of the third aspect of the present application, the battery pack comprises a plurality of solid-state batteries according to the second aspect of the present application.

[0020] According to the electric device of the fourth aspect of the present application, the electric device comprises a solid-state battery according to the second aspect of the present application or a battery pack according to the third aspect of the present application.

[0021] Additional aspects and advantages of the present application will be given in part in the following description, and will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings, in which:

[0023] Figure 1 is an assembly view of the sealing piece and the battery cell according to the embodiments of the present application.

[0024] Figure 2 is another assembly view of the sealing member and the battery cell according to an embodiment of the present application;

[0025] Figure 3 is a schematic view of a solid-state battery according to an embodiment of the present application.

[0026] Reference signs:

[0027] 100, sealing member; 200, solid-state battery;

[0028] 1, buffer layer; 2, sealing layer;

[0029] 3, battery cell; 31, positive electrode sheet; 32, negative electrode sheet;

[0030] 33, solid-state electrolyte layer; 34, tab. DETAILED DESCRIPTION

[0031] Embodiments of the present application will be described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary, and the following description is made below with reference to Figures 1-3 A sealing member 100 for a solid-state battery 200 according to a first aspect embodiment of the present application is described. The following description in the present application is described by taking the sealing member 100 for the solid-state battery 200 as an example.

[0032] As shown in Figure 1 and Figure 2 , the sealing member 100 for the solid-state battery 200 according to the first aspect embodiment of the present application is adapted to cover the outer circumferential surface of the battery cell 3 of the solid-state battery 200. For example, the battery cell 3 is arranged inside a housing (not shown in the figure) of the solid-state battery 200. The sealing member 100 is located between the outer circumferential surface of the battery cell 3 and the inner wall surface of the housing, so as to cover the outer circumferential surface of the battery cell 3.

[0033] Specifically, the sealing member 100 includes a buffer layer 1 and a sealing layer 2, and the sealing layer 2 is arranged on one side in the thickness direction of the buffer layer 1. For example, in the example of Figure 1 and Figure 2 , the sealing member 100 is a layered structure member, including the buffer layer 1 and the sealing layer 2 stacked together, and the stacking direction of the buffer layer 1 and the sealing layer 2 is the thickness direction of the buffer layer 1 or the sealing layer 2.

[0034] The arrangement of the buffer layer 1 and the sealing layer 2 includes the following cases, for example, the buffer layer 1 is arranged between the sealing layer 2 and the battery cell 3. That is, from the direction of the battery cell 3 to the shell, the sequence is: the battery cell 3, the buffer layer 1, the sealing layer 2, and the shell. In this way, the buffer layer 1 is directly in contact with the outer circumferential surface of the battery cell 3, and the buffer layer 1 can be used to buffer the expansion of the positive electrode tab 31 and the negative electrode tab 32 of the battery cell 3, avoiding the occurrence of cracking of the edge part of the positive electrode tab 31 and the negative electrode tab 32 due to local stress unevenness, and the active material is not easy to fall off from the current collector, reducing the self-discharge of the solid-state battery 200, and also avoiding short circuit, prolonging the service life of the solid-state battery 200. In addition, the sealing layer 2 can play a role in bonding and sealing the side of the battery cell 3, that is, the battery cell 3 can be bonded into a whole with the shell through the sealing layer 2, playing a role in isolating moisture at the battery cell 3 level, and also having a moisture-proof effect, which can ensure that the subsequent processes, such as shell sleeving, tab welding, and sealing inspection, can be carried out in a slightly lower dew point environment (in the early stage of the production of the electrode tab of the solid-state battery 200 and the lamination section, a dew point environment of-50°C or above is required), which can significantly reduce production costs. In addition, from the perspective of use safety, the moderate sealing and moisture-proof of the battery cell 3 can slow down the speed of contact between the solid-state electrolyte and the moisture in the environment and the deterioration reaction when the shell of the solid-state battery 200 is accidentally damaged, providing valuable buffer time for safety warning and safety protection measures. Therefore, it is necessary to seal at the battery cell 3 level. Moreover, the sealing piece 100 has a simple structure, high production and processing efficiency, and is convenient to use.

[0035] In addition, the following cases are also included, for example, the sealing layer 2 is arranged between the buffer layer 1 and the battery cell 3. That is, from the direction of the battery cell 3 to the shell, the sequence is: the battery cell 3, the sealing layer 2, the buffer layer 1, and the shell. In this way, in addition to improving the moisture-proof and sealing performance of the battery cell 3 and buffering the expansion of the positive electrode tab 31 and the negative electrode tab 32 of the battery cell 3, the buffer layer 1 can reduce the risk of material falling off of the battery cell 3 caused by vibration between the battery cell 3 and the shell, that is, the shell will vibrate during use, and the battery cell 3 is connected to the shell through the sealing piece 100, and the buffer layer 1 is connected to the inner wall surface of the shell, improving the overall stability of the solid-state battery 200, and the battery cell 3 is not easy to fall off, which is conducive to the long-term stable use of the battery cell 3, and also prolongs the service life of the solid-state battery 200.

[0036] According to the sealing piece 100 for the solid-state battery 200, the sealing piece 100 has simple structure, high production and processing efficiency, and is convenient to use. When the sealing piece 100 is used for the solid-state battery 200, the buffer layer 1 can be used to buffer the expansion of the positive pole piece 31 and the negative pole piece 32 of the battery cell 3, avoid the edge part of the positive pole piece 31 and the negative pole piece 32 from cracking due to uneven local stress, reduce the self-discharge of the solid-state battery 200, avoid short circuit, and prolong the service life of the solid-state battery 200. In addition, the sealing layer 2 can play a role in isolating moisture at the battery cell 3 level, has a moisture-proof effect, and can ensure that the subsequent processes can be carried out in a slightly lower dew point environment, thereby significantly reducing the production cost. In addition, from the perspective of use safety, the moderate sealing and moisture-proof of the battery cell 3 can slow down the speed of the solid-state electrolyte contacting the moisture in the environment and reacting when the shell of the solid-state battery 200 is accidentally damaged, thereby providing valuable buffer time for safety warning and safety protection measures.

[0037] According to some embodiments of the present application, Figure 1 The sealing layer 2 is connected to the side of the buffer layer 1 away from the battery cell 3. That is, the preferred scheme of the sealing piece 100 in the present application is that the sealing layer 2 is connected to the side of the buffer layer 1 away from the battery cell 3. The buffer layer 1 covers the outer circumferential surface of the battery cell 3, one side of the sealing layer 2 is connected to the buffer layer 1, and the other side of the sealing layer 2 is bonded to the inner wall surface of the shell.

[0038] Therefore, the buffer layer 1 directly contacts the outer circumferential surface of the battery cell 3, the buffer layer 1 can be used to buffer the expansion of the positive pole piece 31 and the negative pole piece 32 of the battery cell 3, avoid the edge part of the positive pole piece 31 and the negative pole piece 32 from cracking due to uneven local stress, prevent the active material from falling off the current collector, reduce the self-discharge of the solid-state battery 200, avoid short circuit, and prolong the service life of the solid-state battery 200. In addition, the sealing layer 2 can play a role in bonding and sealing the side of the battery cell 3, that is, the battery cell 3 can be integrated with the shell through the sealing layer 2, play a role in isolating moisture at the battery cell 3 level, have a moisture-proof effect, and ensure that the subsequent processes, such as shell sleeving, pole ear welding, and sealing inspection, can be carried out in a slightly lower dew point environment (the dew point environment needs to be above-50 DEG C in the early stage of the production of the pole piece of the solid-state battery 200 and the lamination section), thereby significantly reducing the production cost. In addition, from the perspective of use safety, the moderate sealing and moisture-proof of the battery cell 3 can slow down the speed of the solid-state electrolyte contacting the moisture in the environment and reacting when the shell of the solid-state battery 200 is accidentally damaged, thereby providing valuable buffer time for safety warning and safety protection measures. Therefore, it is necessary to seal the battery cell 3 level. Moreover, the sealing piece 100 has simple structure, high production and processing efficiency, and is convenient to use.

[0039] The thickness of the buffer layer 1 and the sealing layer 2 is not particularly limited and can also be adjusted according to actual needs. For example, in some examples, the thickness of the buffer layer 1 is d1, and the thickness of the sealing layer 2 is d2, wherein d1, d2 satisfy: 0 < d1 / d2 ≤ 2. In this way, the thickness of the sealing layer 2 and the buffer layer 1 is more reasonable, so as to ensure that the buffer layer 1 can buffer the expansion of the positive electrode plate 31 and the negative electrode plate 32, while also avoiding the cracking of the sealing layer 2, thereby further improving the waterproof and moisture-proof performance of the sealing layer 2, and ensuring that the subsequent processes, such as casing, welding of the tab, checking of the sealing performance, etc. can be carried out in a slightly lower dew point environment (in the early production of the solid-state battery 200 and the lamination segment, a dew point environment of-50°C or above is required).

[0040] According to some embodiments of the present application, the thickness of the buffer layer 1 is d1, wherein d1 satisfies: 0.1mm ≤ d1 ≤ 10mm. And / or, the thickness of the sealing layer 2 is d2, wherein d2 satisfies: 1mm ≤ d2 ≤ 10m.

[0041] For example, the thickness of the buffer layer 1 and the thickness of the sealing layer 2 are set to include the following cases: first, only the thickness d1 of the buffer layer 1 satisfies 0.1mm ≤ d1 ≤ 10mm, and the thickness of the sealing layer 2 is not limited. Second, only the thickness d2 of the sealing layer 2 satisfies 1mm ≤ d2 ≤ 10mm, and the thickness of the buffer layer 1 is not limited. Third, the thickness d1 of the buffer layer 1 and the thickness d2 of the sealing layer 2 respectively satisfy: 0.1mm ≤ d1 ≤ 10mm, 1mm ≤ d2 ≤ 10mm.

[0042] When the thickness of the buffer layer 1 is less than 0.1mm, the buffer layer 1 is thin, which is not conducive to the uniform coverage of the buffer layer 1 on the outer circumferential surface of the battery cell 3, and also reduces the buffering effect of the buffer layer 1. When the thickness of the buffer layer 1 is greater than 10mm, the thickness of the buffer layer 1 is large, thereby increasing the space occupied by the sealing member 100 in the shell of the solid-state battery 200. Therefore, by setting the thickness d1 of the buffer layer 1 to satisfy 0.1mm ≤ d1 ≤ 10mm, the thickness of the buffer layer 1 is reasonable, so that the buffer layer 1 has a good buffering effect while also reducing the space occupied by the sealing member 100 in the shell.

[0043] When the thickness of the sealing layer 2 is less than 1 mm, the thickness of the sealing layer 2 is small, which is not conducive to uniformly covering the side surface in the thickness direction of the buffer layer 1 to form the sealing layer 2, thereby reducing the waterproof and moisture-proof performance of the sealing layer 2. When the thickness of the sealing layer 2 is greater than 10 mm, the thickness of the sealing layer 2 is large, which increases the overall thickness of the sealing member 100, increases the space occupied by the sealing member 100 in the shell, and also increases the production cost of the sealing member 100. Therefore, by setting the thickness d2 of the sealing layer 2 to satisfy 1 mm≤d2≤10 mm, the thickness of the sealing layer 2 is reasonable, so that the sealing layer 2 has good waterproof and moisture-proof performance, while also reducing the space occupied by the sealing member 100 in the shell, and further reducing the production cost of the sealing member 100.

[0044] According to some embodiments of the present application, the buffer layer 1 comprises a polyurethane foam piece, a polystyrene foam piece, a polyvinyl chloride foam piece or a phenolic foam piece. That is, the buffer layer 1 can be a coating made of polyurethane foam (containing many repeating -NHCOO- groups on the high molecular chain of polyurethane), polystyrene foam, polyvinyl chloride foam or phenolic foam, and then the coating is adhered to the four side surfaces of the battery cell 3 by spraying to form the buffer layer 1. Preferably, the buffer layer 1 is a polyurethane foam piece. In this way, the material for making the buffer layer 1 is easy to purchase and convenient to use, and at the same time, the polyurethane foam piece, the polystyrene foam piece, the polyvinyl chloride foam piece or the phenolic foam piece has excellent compression and rebound ability. When the positive electrode sheet 31 and the negative electrode sheet 32 expand, the buffer layer 1 can be compressed and rebound to the original shape after compression. When the positive electrode sheet 31 and the negative electrode sheet 32 shrink, the buffer layer 1 can be stretched and then rebound to the original state. It should be noted that the buffer layer 1 can be directly made of a purchased polyurethane foam piece, a polystyrene foam piece, a polyvinyl chloride foam piece or a phenolic foam piece with a suitable thickness.

[0045] According to some embodiments of the utility model, the buffer layer 1 further comprises a fiber piece, an inorganic nanometer material piece or a hollow microbead piece, the fiber piece comprises a plant fiber piece, a polyester fiber piece, a nylon fiber piece, a polyacrylonitrile fiber piece or a glass fiber piece, the inorganic nanometer material piece comprises an alumina piece (Al2O3), a zirconia piece (ZrO2), a silicate piece or a SiO2 silicon dioxide piece, and the hollow microbead piece comprises a glass microbead, a polystyrene microbead, an alumina (Al2O3) microbead, a zirconia (ZrO2) microbead, a silicon carbide (SiC) microbead or a boron carbide (B4C) microbead. That is, part of reinforcing materials such as granular materials, textile materials and shear thickening materials, for example, plant fibers, polyester fibers, nylon fibers, polyacrylonitrile fibers and glass fibers, can be added to the above-mentioned materials for preparing the buffer layer 1. The inorganic nanometer material piece is, for example, alumina (Al2O3), zirconia (ZrO2), silicate or SiO2. The hollow microbead piece is, for example, a glass microbead, a polystyrene microbead, an alumina (Al2O3) microbead, a zirconia (ZrO2) microbead, a silicon carbide (SiC) microbead or a boron carbide (B4C) microbead. The use of the above-mentioned materials can improve the structural strength of the buffer layer 1, increase the continuous and long-term compression resilience of the buffer layer 1, and further improve the use performance of the sealing piece 100.

[0046] According to some embodiments of the utility model, the sealing layer 2 comprises a thermosetting resin piece, a thermoplastic resin piece or a photocuring resin piece. Alternatively, the material of the sealing layer 2 is selected from a thermosetting resin, a thermoplastic resin or a photocuring resin. Thus, the sealing layer 2 has good waterproof and moisture-proof performance, good sealing performance, and also has adhesive performance, so that the inner wall surface of the shell can be adhered, thereby making the connection of the electric core 3 and the shell more firm.

[0047] According to the solid-state battery 200 of the second aspect of the utility model, Figure 1 and Figure 2 comprise a shell (not shown in the figure), an electric core 3 and a sealing piece 100, the electric core 3 is arranged in the shell, and the sealing piece 100 is the sealing piece 100 for the solid-state battery 200 according to the above-mentioned first aspect of the utility model, and the sealing piece 100 is arranged between the outer peripheral surface of the electric core 3 and the inner wall surface of the shell.

[0048] For example, the shell can be a square shell or a cylindrical shell, and the following description takes the square shell as an example. The battery cell 3 is arranged in the shell, the sealing member 100 is arranged between the inner wall surface of the shell and the outer peripheral surface of the battery cell 3, and the sealing member 100 covers the outer peripheral surface of the battery cell 3. The above-mentioned covering refers to that the sealing member 100 can cover only a part of the outer peripheral surface of the battery cell 3, or cover all of the outer peripheral surface of the battery cell 3. In this way, the sealing performance of the solid-state battery 200 is improved, which is equivalent to double insurance for the solid-state battery 200, so that when the shell is accidentally damaged, the solid-state electrolyte in the battery cell 3 is exposed to the air to cause a safety accident, and the safety performance of the solid-state battery 200 is improved. In addition, the stability of the solid-state battery 200 during long-term use is also improved, and the service life of the solid-state battery 200 is prolonged.

[0049] According to some embodiments of the present application, Figures 1-3 The side surface of the battery cell 3 around the circumference perpendicular to the direction in which the plurality of pole pieces of the battery cell 3 are stacked is connected to the buffer layer 1 of the sealing member 100, and the inner wall surface of the shell is connected to the sealing layer 2 of the sealing member 100. For example, in the example of Figures 1-3 The large surface of the battery cell 3 is the surface that approaches or moves away from each other when the pole pieces of the battery cell 3 are stacked, and the side surface around the circumference perpendicular to the direction in which the plurality of pole pieces of the battery cell 3 are stacked is the four side surfaces around the four large surfaces of the battery cell 3. That is, the buffer layer 1 covers at least the above-mentioned four side surfaces of the battery cell 3, for example, the four side surfaces of Figure 2 The tab 34 of the battery cell 3 is arranged on the upper surface of the battery cell 3, and the two side surfaces of the sealing layer 2 in the thickness direction are respectively connected to the buffer layer 1 and the inner wall surface of the shell. In this way, the solid-state electrolyte of the battery cell 3 can be protected to a greater extent, the solid-state electrolyte is prevented from contacting the moisture in the air, the sealing performance of the sealing member 100 is improved, and the effects of moisture-proofing and short-circuit prevention are achieved. Moreover, the position of the sealing member 100 is reasonably arranged, the material usage of the sealing member 100 is reduced, and the production cost of the sealing member 100 is reduced.

[0050] According to some embodiments of the present application, Figure 3 The plurality of pole pieces include a plurality of positive pole pieces 31 and a plurality of negative pole pieces 32. The plurality of positive pole pieces 31 are arranged along the thickness direction of the positive pole piece 31, and the plurality of negative pole pieces 32 are alternately arranged with the plurality of positive pole pieces 31 along the thickness direction of the positive pole piece 31. The solid-state electrolyte layer 33 is arranged between the negative pole piece 32 and the adjacent positive pole piece 31, and the sealing member 100 covers at least the side surface of the battery cell 3 around the circumference perpendicular to the thickness direction of the positive pole piece 31.

[0051] For example, in the example of Figure 3In the example shown in FIG. 1, the plurality of positive electrode sheets 31 and the plurality of negative electrode sheets 32 are arranged alternately, and the solid-state electrolyte layer 33 is arranged between adjacent positive electrode sheet 31 and negative electrode sheet 32. That is, for the solid-state electrolyte layer 33, both sides of the thickness direction of the solid-state electrolyte layer 33 are in contact with the positive electrode sheet 31 and the negative electrode sheet 32 respectively, and the remaining four sides are exposed to the outside of the battery cell 3. The sealing member 100 covers at least the four sides of the battery cell 3. In this way, while ensuring the use performance of the sealing member 100, the amount of material used by the sealing member 100 can be reduced, and the space occupied by the sealing member 100 in the shell can also be reduced, so that the arrangement of each component of the solid-state battery cell 3 is more reasonable.

[0052] For example, the positive active material can be a conventional positive material, including LiMO2, M including at least one of Ni, Co, Mn, Ti, Mg, Si, V, Zr, Al, and W. LiFe x Mn 1-x PO4, 0≤x≤1, LiM2O4, M including at least one of Ni, Co, Mn, Ti, Mg, Si, V, Zr, Al, and W. Li2MnO3-LiMO2, sulfide solid-state electrolyte including Li6PS5Cl, Li3MCl6, M selected from at least one of Y, In, Si, Sc, and Er. And Li2S-P2S5. The negative electrode material can be selected from conventional lithium ion battery negative electrode materials, such as lithium titanate Li4Ti5O 12 , silicon-carbon, silicon, graphite, etc.

[0053] The battery pack (not shown in the figure) according to the third aspect of the present application comprises a plurality of solid-state batteries 200 according to the second aspect of the application.

[0054] The battery pack according to the present application improves the use performance of the battery pack and prolongs the service life of the battery pack by using the above-mentioned solid-state battery 200.

[0055] The power equipment (not shown in the figure) according to the fourth aspect of the present application comprises a solid-state battery 200 according to the second aspect of the application or a battery pack according to the third aspect of the application.

[0056] The vehicle according to the present application improves the use performance of the power equipment by using the above-mentioned solid-state battery 200 or battery pack. For example, the power equipment includes a vehicle, an aircraft, a ship, a computer, an energy storage cabinet, etc.

[0057] The embodiments of the present application are described in detail below. It should be noted that the embodiments described below are exemplary and are used to explain the present application, and should not be construed as limiting the present application. In addition, if not specifically stated, all reagents used in the following examples are commercially available or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also readily available to those skilled in the art.

[0058] The sealing member 100, the battery cell 3 and the solid-state battery 200 of the present application are described by way of example with reference to the specific embodiments and comparative examples. The performance of the solid-state battery 200 of the embodiments and comparative examples is tested as follows:

[0059] Moisture resistance test

[0060] The moisture resistance test method is as follows: the battery cell 3 is sealed in a container with an inner cavity volume of 0.125m 3 at a dew point of -30℃, and the mass of H2S released by the battery cell 3 after 24h of storage is tested (the mass fraction of H2S gas in the gas in the inner cavity of the container is tested by gas chromatography, and the capacity of the battery cell 3 is combined to calculate the volume of H2S released per unit capacity of the battery cell 3, i.e. 1Ah of the battery cell 3).

[0061] DC resistance test

[0062] The battery cell 3 stored in a sealed state is packaged in a battery shell, and the DC resistance of the battery is tested. The test method for DC resistance is as follows: the battery is charged at 0.1C and discharged at 0.1C, and charged and discharged at 2.5-4.25V for one cycle, and the constant volume capacity C of the battery is recorded. Then the battery is adjusted to 50% SOC (discharged to 50% of the constant volume capacity), and after standing for 1 hour, charged at 1C rate for 30s, and the voltage V1 before 1C charging, the voltage V2 at the end of charging, and the test current I are recorded, and then the DC resistance R is calculated as [(V2-V1)xC] / I.

[0063] Cycle performance test

[0064] The battery is charged at 1C constant current and constant voltage, discharged at 1C, and cycled at 2.5-4.25V and 25℃ for 300 cycles. The first cycle discharge capacity C1 and the 300th cycle discharge capacity C2 of the battery are recorded, and the capacity retention rate of the battery is calculated as C2 / C1.

[0065] Example 1

[0066] The polyurethane: solvent (dimethylacetamide): surfactant (silicone oil): catalyst (stannous octoate): dichloromethane is stirred at high speed for 10 min at a mass ratio of 30:100:0.5:0.4:10. Then it is sprayed on the outer side end face of the battery cell 3 to form the buffer layer 1. After the battery cell 3 is dried at 130°C for 100s, the thermosetting resin epoxy resin (sealing layer 2 material) and the polyamine curing agent are mixed at a ratio of 10:3 and then coated on the aforementioned buffer layer 1 to form the sealing layer 2. Thus, a battery cell 3 with a sealing member 100 of the present application is obtained, with a buffer layer 1 thickness of 3mm and a sealing layer 2 thickness of 3mm.

[0067] The preparation method of the battery cell 3 is as follows:

[0068] Preparation of the positive electrode sheet 31. The ternary positive electrode active material (specifically, LiNi 0.8 Co 0.1 Mn 0.1 O2), the argyrodite sulfide solid-state electrolyte (specifically, Li6PS6Cl), the binder PVDF, and the conductive agent carbon black are mixed uniformly at a ratio of 80:20:1.5:1 to form a sheet.

[0069] Preparation of the solid-state electrolyte layer 33. The solid-state electrolyte and the binder PVDF are mixed at a ratio of 100:1 to form a solid-state electrolyte sheet, which is the solid-state electrolyte layer 33.

[0070] Preparation of the negative electrode sheet 32. The negative electrode active material (silicon-carbon) and the binder hydrogenated nitrile rubber (HNBR) are mixed uniformly at a ratio of 100:2 to form the negative electrode sheet 32.

[0071] The lamination process. The positive electrode sheet 31, the solid-state electrolyte layer 33, and the negative electrode sheet 32 are sequentially laminated, and the battery cell 3 is pressed into shape under a certain pressure after the lamination. Then, the buffer layer 1 is pasted on the four side end faces of the battery cell 3 by spraying, and the sealing layer 2 is pasted on the surface of the buffer layer 1 by spraying, dipping, or other methods. The method of forming the sealing layer 2 is not particularly limited, for example, methods such as capillary bottom filling, injection molding, transfer molding, or impregnation molding can be used. The method used in this embodiment is spraying.

[0072] Example 2

[0073] The main difference from Example 1 is that 5% by mass of glass fibers are added to the polyurethane. The glass fibers have a diameter of 10-20μm and a length of 0.1-10mm.

[0074] Example 3

[0075] The main difference from Example 1 is that the buffer layer 1 is a phenolic foam piece. Specifically, phenolic resin, n-pentane (blowing agent), Tween 80 (surfactant) are mixed at 100:40:1, and then it is sprayed on the outer lateral end face of the cell 3.

[0076] Example 4

[0077] The main difference from Example 1 is that the buffer layer 1 is a polystyrene foam piece. Specifically, polystyrene and pentane are mixed at 100:50, and then it is sprayed on the outer lateral end face of the cell 3.

[0078] Example 5

[0079] The main difference from Example 1 is that the buffer layer 1 is a polyvinyl chloride foam piece. Specifically, polystyrene and azodicarbonamide are mixed at 100:20, and then it is sprayed on the outer lateral end face of the cell 3.

[0080] Example 6

[0081] The main difference from Example 1 is that the sealing layer 2 is a thermoplastic material 1 (styrene-butadiene rubber-30) with 6 wt% dicumyl peroxide as a crosslinking agent, using a heat-cured way (100°C, 30 min).

[0082] Example 7

[0083] The main difference from Example 1 is that the buffer layer 1 is 0.5 mm thick and the sealing layer 2 is 3 mm thick.

[0084] Example 8

[0085] The main difference from Example 1 is that the buffer layer 1 is 10 mm thick and the sealing layer 2 is 3 mm thick.

[0086] Example 9

[0087] The main difference from Example 1 is that the buffer layer 1 is 3 mm thick and the sealing layer 2 is 10 mm thick.

[0088] Example 10

[0089] The main difference from Example 1 is that the buffer layer 1 is 3 mm thick and the sealing layer 2 is 1 mm thick.

[0090] Comparative Example 1

[0091] The seal 100 does not contain the sealing layer 2.

[0092] Comparative Example 2

[0093] The seal 100 does not contain the buffer layer 1.

[0094] Comparative Example 3

[0095] The solid-state battery 200 does not contain the sealing member 100 proposed in the present application.

[0096] Table 1 Performance test results of examples and comparative examples

[0097]

[0098] Table 1 gives the performance comparison of the batteries of various examples and comparative examples in moisture-proof performance and cycle performance of the battery cell 3. It can be seen that the use of the sealing member 100 proposed in the present application can significantly improve the moisture-proof performance of the battery cell 3. When there is no sealing member 100, such as comparative example 3, because the battery does not have sufficient moisture-proof function, therefore in the case of insufficient dew point, the sulfide electrolyte in the battery cell 3 contacts the moisture in the air, generating H2S harmful gas. When the sealing member 100 of the present application is added, the battery cell 3 can have good moisture-proof effect and no H2S gas is generated. At the same time, when the electrolyte absorbs water, because the performance of the electrolyte is changed, the DCIR of the battery is also significantly increased. The sealing member 100 proposed in the present application can significantly inhibit the increase of DCIR caused by the water absorption of the battery cell 3 compared with comparative example 3. In addition, the sealing member 100 proposed in the present application can also significantly improve the cycle performance compared with comparative example 3. When a certain amount of fiber component is added to the buffer layer 1 or the thickness of the buffer layer is appropriately increased, the cycle performance of the battery can be further improved. However, considering the influence on the energy density of the battery, the thickness of the buffer layer 1 and the sealing layer 2 should not be too thick.

[0099] Other configurations of the battery 200, the battery pack and the vehicle according to the embodiments of the present application and the operation are known to those skilled in the art, and will not be described in detail here.

[0100] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0101] In the description of the present application, the meaning of "a plurality of" is two or more.

[0102] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0103] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A seal for a solid-state battery, characterized in that: The sealing member is suitable for covering the outer peripheral surface of the battery cell of the solid-state battery, and the sealing member includes: buffer layer; A sealing layer is provided on one side of the buffer layer in a thickness direction.

2. The seal for a solid-state battery according to claim 1, characterized in that: The sealing layer is connected to a side of the buffer layer away from the battery core.

3. The seal for a solid-state battery according to claim 1, wherein: The thickness of the buffer layer is d1, and the thickness of the sealing layer is d2, wherein d1 and d2 satisfy: 0<d1 / d2≤2.

4. The seal for a solid-state battery according to claim 1, wherein The thickness of the buffer layer is d1, wherein d1 satisfies: 0.1 mm ≤ d1 ≤ 10 mm; and / or, The thickness of the sealing layer is d2, wherein d2 satisfies: 1mm≤d2≤10mm.

5. The seal for a solid-state battery according to claim 1, wherein: The buffer layer includes a polyurethane foam piece, a polystyrene foam piece, a polyvinyl chloride foam piece or a phenolic foam piece.

6. The seal for a solid-state battery according to claim 5, characterized in that: The buffer layer also includes fiber parts, inorganic nanomaterial parts or hollow microbead parts, the fiber parts include plant fiber parts, polyester fiber parts, nylon fiber parts, polyacrylonitrile fiber parts or glass fiber parts, the inorganic nanomaterial parts include aluminum oxide parts, zirconium oxide parts, silicate parts or silicon dioxide parts, and the hollow microbead parts include glass microbeads, polystyrene microbeads, aluminum oxide microbeads, zirconium oxide microbeads, silicon carbide microbeads or boron carbide microbeads.

7. The seal for a solid-state battery according to any one of claims 1 to 6, characterized in that: The sealing layer includes a thermosetting resin, a thermoplastic resin or a light-curing resin.

8. A solid-state battery, characterized in that: include: case; a battery cell, the battery cell being arranged in the housing; A seal, wherein the seal is a seal for a solid-state battery according to any one of claims 1 to 7, and the seal is arranged between the outer peripheral surface of the battery cell and the inner wall surface of the shell.

9. The solid-state battery according to claim 8, characterized in that The side surface of the battery core in a circumferential direction perpendicular to the stacking direction of the multiple pole pieces of the battery core is connected to the buffer layer of the seal, and the inner wall surface of the shell is connected to the sealing layer of the seal.

10. The solid-state battery according to claim 9, characterized in that The plurality of pole pieces include: A plurality of positive electrode sheets, wherein the plurality of positive electrode sheets are arranged along the thickness direction of the positive electrode sheets; A plurality of negative electrode sheets are arranged alternately with the plurality of positive electrode sheets along the thickness direction of the positive electrode sheets, a solid electrolyte layer is provided between the negative electrode sheets and the adjacent positive electrode sheets, and the seal at least covers the circumferential side surfaces of the battery cell perpendicular to the thickness direction of the positive electrode sheets.

11. A battery pack, characterized in that: Comprising a plurality of solid-state batteries according to any one of claims 8-10.

12. An electrical device, characterized in that: Comprising the solid-state battery according to any one of claims 8 to 10, or the battery pack according to claim 11.

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