Battery pack and electric equipment with same

Abstract

The utility model relates to the technical field of batteries, and provides a battery pack and electric equipment with the same. The battery pack comprises at least two battery cells; the sealing ring is located between the two adjacent battery cells, and the sealing ring and the two adjacent battery cells jointly define a closed space; the heat absorption phase change material layer is located in the closed space and meets the condition that V-V1 is larger than or equal to w * Vcell, V represents the volume of the closed space, V1 represents the volume of the heat absorption phase change material layer, w represents the volume expansion rate of the battery cell, and Vcell represents the volume of the battery cell. By the adoption of the battery pack, the energy density of the battery pack is not affected, meanwhile, the heat absorption phase change material can be effectively sealed, and the reliability is improved.

Description

Technical Field

[0001] The present application generally relates to the field of battery technology, and specifically to a battery pack and an electrical device having the same. Background Art

[0002] With the gradual depletion of oil resources and the increasing awareness of environmental protection, recyclable rechargeable batteries have received more and more attention. In order to suppress the thermal diffusion of rechargeable batteries in the case of thermal runaway, related technologies use endothermic phase change materials to remove the heat between cells, and use sealing films to encapsulate the endothermic phase change materials to avoid material reduction and failure.

[0003] However, sealing film packaging will not only reduce the energy density of the battery pack, but also seriously affect the heat absorption effect of the phase change material due to its large thermal resistance, resulting in low reliability. Utility Model Content

[0004] In view of the above-mentioned defects or deficiencies in the related art, it is desired to provide a battery pack and an electrical device having the same, which does not affect the energy density of the battery pack and can effectively seal the heat-absorbing phase change material to improve reliability.

[0005] In a first aspect, the present application provides a battery pack, the battery pack comprising:

[0006] At least two cells;

[0007] A sealing ring, wherein the sealing ring is located between two adjacent battery cells and together with the two adjacent battery cells forms a closed space;

[0008] The heat-absorbing phase-change material layer is located in the enclosed space and satisfies V-V1≥w*V cell , where V represents the volume of the enclosed space, V1 represents the volume of the endothermic phase change material layer, w represents the volume expansion rate of the battery core, V cell Indicates the volume of the battery cell.

[0009] Optionally, in some embodiments of the present application, the sealing ring is arranged on the edge of the outer surface of the battery cell.

[0010] Optionally, in some embodiments of the present application, the heat-absorbing phase change material layer covers at least the center of the outer surface of the battery core.

[0011] Optionally, in some embodiments of the present application, the volume V1 of the heat-absorbing phase change material layer satisfies the following formula: 0.2*A*B≤V1≤0.3C*A*B;

[0012] In the formula, A represents the length of the battery cell, B represents the width of the battery cell, and C represents the thickness of the battery cell. A, B, and C are measured in millimeters.

[0013] Optionally, in some embodiments of the present application, 70mm≤A≤1500mm, 30mm≤B≤500mm, and 6mm≤C≤50mm.

[0014] Optionally, in some embodiments of the present application, along the length direction of the battery cell, the length of the sealing ring is equal to the length of the battery cell.

[0015] Optionally, in some embodiments of the present application, along the width direction of the battery cell, the width y of the sealing ring satisfies the following formula: 2mm≤y≤20mm;

[0016] And / or, along the arrangement direction of the two adjacent battery cells, the thickness z of the sealing ring satisfies the following formula: 0.2 mm≤z≤10 mm.

[0017] Optionally, in some embodiments of the present application, along the arrangement direction of the two adjacent battery cells, the thickness x of the heat-absorbing phase change material layer satisfies the following formula: α*z≤x≤z;

[0018] Wherein, α represents the deformation coefficient of the sealing ring under the action of 1 MPa.

[0019] Optionally, in some embodiments of the present application, there is a weak portion on the sealing ring.

[0020] Optionally, in some embodiments of the present application, the weak portion and the explosion-proof valve of the battery cell are located on the same side.

[0021] Optionally, in some embodiments of the present application, the heat-absorbing phase change material layer is a hydrogel.

[0022] In a second aspect, the present application provides an electrical device, wherein the electrical device comprises a battery pack as described in any one of the first aspects.

[0023] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0024] The embodiment of the present application provides a battery pack and an electric device having the same. The battery pack is provided with a heat-absorbing phase-change material layer between two adjacent battery cells and in a closed space formed by the sealing ring, so that no additional attachment is required on the heat-absorbing phase-change material layer. The structure is simple, and the energy density of the battery pack is not affected. At the same time, there is no thermal resistance, and the heat absorption effect of the phase-change material is not affected. In addition, a space for the battery cell volume to expand is reserved in the closed space formed by the outer surface of the two adjacent battery cells and the sealing ring, thereby preventing the battery cell from squeezing the phase-change material when it expands and causing it to break through the sealing ring, thereby achieving effective and reliable sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0026] Figure 1 A schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the distribution of a heat-absorbing phase change material layer and a sealing ring provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the dimensions of a heat-absorbing phase change material layer and a sealing ring provided in an embodiment of the present application;

[0029] Figure 4 A structural block diagram of an electrical device provided in an embodiment of the present application.

[0030] Reference numerals:

[0031] 1-battery pack, 11-battery cell, 12-sealing ring, 13-heat-absorbing phase change material layer, 2-electrical equipment. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the application described can be implemented in an order other than those illustrated or described herein.

[0034] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0035] For ease of understanding and explanation, the following Figures 1 to 4 The battery pack and the electrical equipment having the same provided by the embodiments of the present application are described in detail.

[0036] Please refer to Figure 1 , which is a schematic diagram of the structure of a battery pack provided in an embodiment of the present application. The battery pack 1 includes at least two battery cells 11, a sealing ring 12 and an endothermic phase change material layer 13. The sealing ring 12 is located between two adjacent battery cells 11 and together with the two adjacent battery cells 11, forms a closed space. The endothermic phase change material layer 13 is located in the closed space and satisfies V-V1≥w*V cell ; Wherein, V1 represents the volume of the endothermic phase change material layer 13; w represents the volume expansion rate of the battery cell 11, V cell represents the volume of the battery cell 11 ; V represents the volume of the enclosed space, and its value is equal to V2-V3, V2 represents the gap volume between the outer surfaces of two adjacent battery cells 11 , and V3 represents the volume of the sealing ring 12 .

[0037] It should be noted that, since the battery cell 11 has a certain volume expansion in the EOL (End of Life) state, assuming that the volume expansion rate is w, and the volume V1' of the same battery cell 11 in the BOL (Begin of Life) state and the volume V2' in the EOL state are tested by the drainage method, the volume expansion rate w of the battery cell 11 in the EOL state is (V2'-V1') / V1', and 2%≤w≤20%. Among them, the battery conditions in the BOL state and the battery conditions in the EOL state are determined in the battery specifications.

[0038] For example, the sealing ring 12 and the endothermic phase change material layer 13 in the embodiment of the present application are arranged in the following five ways, but are not limited to: For example, the sealing ring 12 can be arranged at the outer surface edge of the battery cell 11 (such as Figure 2 As shown in the figure, for example, the outer surface of the battery cell 11 can be the large surface of the battery cell. The advantage of such a setting is that the movable space range of the heat-absorbing phase change material layer 13 can be increased to prevent it from breaking through the sealing ring 12 when it is squeezed by the battery cell expansion. For another example, the heat-absorbing phase change material layer 13 at least covers the center of the outer surface of the battery cell 11 (as shown in the figure). Figure 2 As shown in the figure, for example, the outer surface of the battery cell 11 can also be the large surface of the battery cell. The advantage of such a setting is that since the heat diffuses from the center of the outer surface of the battery cell to the surroundings, that is, the heat is concentrated in the center, so this setting of the heat-absorbing phase change material layer 13 can greatly absorb the heat of the battery cell and effectively inhibit heat diffusion. For another example, a blank area is also provided between the sealing ring 12 and the heat-absorbing phase change material layer 13. The advantage of such a setting is that when the battery cell 11 expands and squeezes the phase change material, the phase change material can fill the blank area, thereby further preventing the phase change material from breaking through the sealing ring 12, thereby improving reliability.

[0039] For another example, in the embodiment of the present application, a sealing ring 12 and a heat-absorbing phase change material layer 13 (such as Figure 2As shown), for example, the outer surface of the battery cell 11 can be the large surface of the battery cell. The advantage of such an arrangement is that the distance between the two battery cells 11 is short, which is convenient for reducing the volume of the battery pack. In addition, in some embodiments of the present application, a sealing ring 12 and a heat-absorbing phase change material layer 13 can be provided on the outer surfaces of two adjacent battery cells 11. For example, the outer surface of the battery cell 11 can be the large surface of the battery cell. The advantage of such an arrangement is that the phase change material can quickly absorb the heat of the corresponding battery cell 11 to prevent heat diffusion. At the same time, the structure of each battery cell 11 is consistent, which is convenient for processing and greatly improves the manufacturing efficiency.

[0040] Combine the following Figure 3 As shown, the structure and parameter information of the sealing ring 12 and the endothermic phase change material layer 13 in the embodiment of the present application are described. For example, the endothermic phase change material layer 13 in the embodiment of the present application includes but is not limited to hydrogel, that is, the heating and vaporization process of water is used to take away the heat generated inside the battery cell 11. For example, the hydrogel is attached to the outer surface of the battery cell, and a sealing ring 12 is arranged around the hydrogel, so that the contact between the hydrogel and the air can be effectively isolated to prevent the hydrogel from failing. In addition, in other embodiments, the endothermic phase change material layer 13 can also use superabsorbent polymer materials or other absorbent materials loaded with liquid, such as any suitable hydrogel polymer or superabsorbent polymer. Exemplarily, hydrophilic or water-absorbent or lyophilic polymer materials include but are not limited to polyacrylic acid, such as acrylic acid copolymers of acrylic acid and salts. Suitable materials include but are not limited to alkali metal salts of polyacrylic acid, polyacrylamide, polyvinyl alcohol, ethylene maleic anhydride copolymers, polyvinyl ethers, hydroxypropyl cellulose, polyvinyl morpholinone, vinyl sulfonic acid, polyacrylates, polyacrylamide, polymers and copolymers of polyvinyl pyridine, etc. Other suitable polymers include, but are not limited to, hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, carboxymethyl cellulose, isobutylene maleic anhydride copolymer, and mixtures thereof. Other suitable polymers include, but are not limited to, inorganic polymers, such as polyphosphazene, etc. Alternatively, it may be a solid phase change material, such as paraffin; or, in addition to water, it may also contain other liquid phase change materials, such as ethanol.

[0041] For another example, the volume V1 of the heat-absorbing phase change material layer 13 in the embodiment of the present application satisfies 0.2*A*B≤V1≤0.3C*A*B, wherein A represents the length of the battery cell 11, B represents the width of the battery cell 11, and C represents the thickness of the battery cell 11. A, B, and C are measured in millimeters. For example, 70mm≤A≤1500mm, 30mm≤B≤500mm, and 6mm≤C≤50mm. This ensures that the phase change material can effectively absorb the heat of the battery cell and will not break through the sealing ring 12 when the phase change material is squeezed by the expansion of the battery cell.

[0042] It can be understood that in the embodiment of the present application, the volume of the heat-absorbing phase change material layer 13 should satisfy 0.2*A*B≤V1≤0.3C*A*B and V-V1≥w*V cell , thereby taking into account both that the phase change material effectively absorbs the heat of the battery cell and does not break the sealing ring 12, greatly enhancing reliability.

[0043] For another example, taking the length direction of the battery cell 11 (i.e., the X direction) as a reference, the length of the sealing ring 12 in the embodiment of the present application is equal to the length of the battery cell 11, for example, the length of the sealing ring 12 is A, the width is y, and the thickness is z. The advantage of such a setting is that the phase change material has a large movable space range, which avoids damage to the sealing ring 12. Alternatively, taking the length direction of the battery cell 11 (i.e., the X direction) as a reference, in some embodiments of the present application, the length of the sealing ring 12 is equal to the width of the battery cell 11, for example, the length of the sealing ring 12 is B, the width is y, and the thickness is z. This meets the diverse usage requirements and has strong flexibility.

[0044] For another example, taking the width direction of the battery cell 11 (i.e., the Y direction) as a reference, the width y of the sealing ring 12 in the embodiment of the present application satisfies 2mm≤y≤20mm. Alternatively, taking the arrangement direction of two adjacent battery cells 11 (i.e., the Z direction) as a reference, the thickness z of the sealing ring 12 in some embodiments of the present application satisfies 0.2mm≤z≤10mm. Alternatively, taking the width direction of the battery cell 11 (i.e., the Y direction) as a reference, in other embodiments of the present application, the width y of the sealing ring 12 satisfies 2mm≤y≤20mm, and taking the arrangement direction of two adjacent battery cells 11 (i.e., the Z direction) as a reference, the thickness z of the sealing ring 12 satisfies 0.2mm≤z≤10mm, which has a wide range of applications.

[0045] For another example, the sealing ring 12 in the embodiment of the present application includes but is not limited to a rubber ring, a foam ring, a plastic ring and an adhesive ring, such as a nitrile rubber ring, a silicone rubber ring, a butyl rubber ring, a fluororubber ring, a fluoroplastic ring and a nylon ring. Furthermore, the sealing ring 12 can be connected to the battery cell 11 by bonding, compression or adsorption to achieve sealing. Since the sealing ring 12 has a certain viscoelasticity and will deform during the compression process, the initial thickness of the sealing ring 12 should be greater than or equal to the thickness of the endothermic phase change material layer 13, that is, along the arrangement direction of the two adjacent battery cells 11 (i.e., the Z direction), the thickness x of the endothermic phase change material layer 13 satisfies α*z≤x≤z, where α represents the deformation coefficient of the sealing ring 12 under the action of 1MPa, and 0<α≤1. It should be noted that the thickness z of the sealing ring 12 is the thickness measured after the sealing ring 12 is taken out from between the two adjacent battery cells 11. When the sealing ring 12 is located between two adjacent battery cells 11 , the thickness of the sealing ring 12 is equal to the distance between the outer surfaces of the two adjacent battery cells 11 .

[0046] For example, in the embodiment of the present application, there is a weak part on the sealing ring 12. The advantage of such a setting is that it can be exhausted quickly to ensure safe use. Furthermore, the weak part can be located on the same side as the explosion-proof valve of the battery cell 11, so that it can share the exhaust channel in the battery pack with the explosion-proof valve, which helps the orderly eruption of steam during thermal runaway, and the changes to the battery pack are small and do not affect other components. For example, the thickness of the sealing ring 12 is reduced or additives are added therein, thereby reducing the strength of the weak part.

[0047] The battery pack provided in the embodiment of the present application has a heat-absorbing phase-change material layer disposed between two adjacent battery cells and in a closed space formed by the sealing ring, so that no additional attachment is required on the heat-absorbing phase-change material layer. The structure is simple, and the energy density of the battery pack is not affected. At the same time, there is no thermal resistance, and the heat absorption effect of the phase-change material is not affected. In addition, a space for the battery cell volume to expand is reserved in the closed space formed by the outer surface of the two adjacent battery cells and the sealing ring, thereby preventing the battery cell from squeezing the phase-change material when it expands and causing it to break through the sealing ring, thereby achieving effective and reliable sealing.

[0048] As another aspect, the present application provides an electrical device. Figure 4 , which is a structural block diagram of an electric device provided in an embodiment of the present application, the electric device 2 may include Figures 1 to 3 The battery pack 1 of the corresponding embodiment. For example, the electrical equipment 2 includes but is not limited to a pure electric vehicle (Battery Electric Vehicle, BEV) and a hybrid electric vehicle (Hybrid Electric Vehicle, HEV).

[0049] It should be noted that, for the description of the same contents in this embodiment as those in other embodiments, reference can be made to the description in other embodiments and will not be repeated here.

[0050] The electric device provided in the embodiment of the present application has a battery pack in which a heat-absorbing phase-change material layer is arranged between two adjacent battery cells and in a closed space formed by the battery pack and the sealing ring, so that no additional attachment is required on the heat-absorbing phase-change material layer. The structure is simple, and the energy density of the battery pack is not affected. At the same time, there is no thermal resistance, and the heat absorption effect of the phase-change material is not affected. In addition, a space for the battery cell volume to expand is reserved in the closed space formed by the outer surface of the two adjacent battery cells and the sealing ring, thereby preventing the battery cell from squeezing the phase-change material when it expands and causing it to break through the sealing ring, thereby achieving effective and reliable sealing.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack, characterized in that: The battery pack (1) comprises: at least two battery cells (11); A sealing ring (12), the sealing ring (12) being located between two adjacent battery cells (11) and enclosing together with the two adjacent battery cells (11) to form a closed space; The heat-absorbing phase-change material layer (13) is located in the closed space and satisfies V-V1≥w*V cell , where V represents the volume of the enclosed space, V1 represents the volume of the endothermic phase change material layer, w represents the volume expansion rate of the battery core, V cell Indicates the volume of the battery cell.

2. The battery pack according to claim 1, characterized in that: The sealing ring (12) is arranged on the edge of the outer surface of the battery core (11).

3. The battery pack according to claim 1, characterized in that: The heat-absorbing phase-change material layer (13) at least covers the center of the outer surface of the battery core (11).

4. The battery pack according to claim 1, characterized in that: The volume V1 of the heat-absorbing phase-change material layer (13) satisfies the following formula: 0.2*A*B≤V1≤0.3*C*A*B; In the formula, A represents the length of the battery cell, B represents the width of the battery cell, and C represents the thickness of the battery cell. A, B, and C are measured in millimeters.

5. The battery pack according to claim 4, characterized in that: 70mm≤A≤1500mm, 30mm≤B≤500mm, and 6mm≤C≤50mm.

6. The battery pack according to claim 1, characterized in that: Along the length direction of the battery core (11), the length of the sealing ring (12) is equal to the length of the battery core (11).

7. The battery pack according to claim 6, characterized in that: Along the width direction of the battery core (11), the width y of the sealing ring (12) satisfies the following formula: 2mm≤y≤20mm; And / or, along the arrangement direction of the two adjacent battery cells (11), the thickness z of the sealing ring (12) satisfies the following formula: 0.2 mm ≤ z ≤ 10 mm.

8. The battery pack according to claim 1, characterized in that: Along the arrangement direction of the two adjacent battery cells (11), the thickness x of the heat-absorbing phase change material layer (13) satisfies the following formula: α*z≤x≤z; Wherein, α represents the deformation coefficient of the sealing ring under the action of 1 MPa.

9. The battery pack according to claim 1, characterized in that: There is a weak portion on the sealing ring (12).

10. The battery pack according to claim 9, characterized in that: The weak portion and the explosion-proof valve of the battery core (11) are located on the same side.

11. The battery pack according to any one of claims 1 to 10, characterized in that: The heat-absorbing phase-change material layer (13) is a hydrogel.

12. An electrical equipment, characterized in that: The electrical device (2) comprises the battery pack (1) according to any one of claims 1 to 11.

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