Battery cell, battery, battery pack and electric equipment

Abstract

The embodiment of the utility model provides a battery cell, a battery, a battery pack and electric equipment. The battery cell comprises a first heat absorption structure and a plurality of pole pieces, the plurality of pole pieces are stacked along a first direction; the number of the first heat absorption structures is at least one, the at least one first heat absorption structure and the at least one pole piece are adjacently arranged in the first direction, and the first heat absorption structures contain heat absorption materials so as to absorb heat in the battery cell under the condition that the first heat absorption structures are punctured. Therefore, by arranging the first heat absorption structure adjacent to the pole piece, when the first heat absorption structure is punctured, the first heat absorption structure can release the heat absorption material and quickly absorb heat in the battery cell in time, so that thermal runaway of the battery cell is effectively inhibited, and the safety of the battery cell is improved.

Description

Technical Field

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

[0002] With the development of the new energy industry, lithium batteries have attracted widespread attention. Lithium batteries usually include a shell and a battery cell arranged inside the shell, wherein the battery cell includes positive and negative electrodes arranged alternately. When an electric field is applied to the positive and negative electrodes, lithium ions are intercalated and deintercalated between the positive and negative electrodes to achieve charging and discharging.

[0003] However, during the use of lithium batteries, foreign objects may penetrate or even pierce the lithium battery, which may cause partial or complete short circuits of the positive and negative electrodes, and the electrical energy may be converted into heat energy and accumulate and release in a short period of time, which may cause thermal runaway and pose a greater safety hazard to the battery cell. Utility Model Content

[0004] The present application aims to provide a battery cell, a battery, a battery pack and an electrical device to solve the problem that when the existing battery cell is punctured or even penetrated, thermal runaway may occur, resulting in a major safety hazard for the battery cell.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, the present application discloses a battery cell, the battery cell comprising: a first heat absorption structure and a plurality of pole pieces;

[0007] A plurality of pole pieces are stacked along a first direction;

[0008] At least one of the first heat absorbing structures is provided, and at least one of the first heat absorbing structures is arranged adjacent to at least one of the pole pieces along the first direction. The first heat absorbing structure contains heat absorbing material to absorb heat inside the battery core when the first heat absorbing structure is punctured.

[0009] Optionally, the first heat absorbing structure comprises: a first heat absorbing portion and a second heat absorbing portion;

[0010] The first heat absorbing portion and the second heat absorbing portion are adjacently arranged along the first direction;

[0011] The endothermic material includes an endothermic solute and an endothermic solvent. The first endothermic portion is used to accommodate the endothermic solute, and the second endothermic portion is used to accommodate the endothermic solvent. When the first endothermic structure is pierced, the endothermic solute contacts the endothermic solvent and undergoes an endothermic reaction to absorb heat inside the battery core.

[0012] Optionally, the first heat absorbing part and the second heat absorbing part are an integrally formed structure.

[0013] Optionally, the first heat absorbing part and the second heat absorbing part are separately molded structures.

[0014] Optionally, the first heat absorbing structure is a heat absorbing capsule.

[0015] Optionally, the heat-absorbing capsule comprises a capsule wall, and the capsule wall encloses a closed chamber;

[0016] The heat absorbing material is disposed in the chamber.

[0017] Optionally, the heat absorbing capsule further comprises a partition, which is arranged in the chamber to separate the chamber into a first chamber and a second chamber which are independent of each other;

[0018] The endothermic material includes an endothermic solute and an endothermic solvent. The first chamber is used to accommodate the endothermic solute, and the second chamber is used to accommodate the endothermic solvent. When the endothermic capsule is pierced, the endothermic solute contacts the endothermic solvent and undergoes an endothermic reaction to absorb the heat inside the battery core.

[0019] Optionally, the first chamber and the second chamber are arranged sequentially along the first direction.

[0020] Optionally, the endothermic solute is ammonium nitrate and the endothermic solvent is water.

[0021] Optionally, the battery cell further includes a diaphragm, and a plurality of the diaphragms are provided, and the plurality of diaphragms and the plurality of pole pieces are alternately arranged along the first direction;

[0022] The first heat absorption structure is arranged between the diaphragm and the pole piece.

[0023] Optionally, the first heat absorption structure has a first projection perpendicular to the first direction, the diaphragm has a second projection perpendicular to the first direction, and an area of ​​the second projection is greater than or equal to an area of ​​the first projection.

[0024] Optionally, the first heat absorption structure has a first projection perpendicular to the first direction, the pole piece has a third projection perpendicular to the first direction, and an area of ​​the third projection is less than or equal to an area of ​​the first projection.

[0025] In a second aspect, the present application further discloses a battery, comprising:

[0026] A housing, wherein the housing is provided with a receiving cavity;

[0027] And the battery cell described in any of the above items, wherein the battery cell is arranged in the accommodating cavity.

[0028] Optionally, the battery further comprises a second heat absorption structure, which is arranged between the shell and the battery cell and parallel to the pole piece of the battery cell;

[0029] The second heat absorbing structure contains a heat absorbing material to absorb the heat inside the battery core when the second heat absorbing structure is punctured.

[0030] In a third aspect, the present application also discloses a battery pack, which includes the above-mentioned battery.

[0031] In a fourth aspect, the present application further discloses an electrical device, wherein the electrical device comprises the above-mentioned battery pack.

[0032] In the embodiment of the present application, the battery cell includes: a first heat absorbing structure and a plurality of pole pieces; the plurality of pole pieces are stacked along a first direction; at least one first heat absorbing structure is provided, and at least one first heat absorbing structure is arranged adjacent to at least one pole piece along the first direction, and the first heat absorbing structure contains a heat absorbing material to absorb the heat inside the battery cell when the first heat absorbing structure is pierced. Since the first heat absorbing structure is provided, and the first heat absorbing structure is arranged adjacent to the pole piece, when a foreign object penetrates or even pierces the battery cell, causing the first heat absorbing structure to be pierced, the first heat absorbing structure can release the heat absorbing material to absorb the heat inside the battery cell in a timely and rapid manner, thereby effectively suppressing thermal runaway of the battery cell, which is beneficial to improving the safety of the battery cell.

[0033] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0035] Figure 1 It is a structural schematic diagram of a battery cell in the prior art;

[0036] Figure 2 is a schematic diagram of the structure of the heat-absorbing capsule provided in an embodiment of the present application;

[0037] Figure 3 It is a schematic diagram of the partial structure of the battery cell provided in Example 1 of the present application;

[0038] Figure 4 It is a schematic diagram of the partial structure of the battery cell provided in the second embodiment of the present application;

[0039] Figure 5 It is a schematic diagram of the partial structure of the battery cell provided in Example 3 of the present application;

[0040] Figure 6 It is a schematic diagram of the partial structure of the battery provided in the embodiment of the present application.

[0041] Figure numerals: 1. first heat absorption structure, 11. heat absorption capsule, 111. capsule wall, 112. separator, 113. first chamber, 114. second chamber, 2. pole piece, 21. negative pole piece, 22. positive pole piece, 3. diaphragm, 4. shell, 5. second heat absorption structure, X. first direction. DETAILED DESCRIPTION

[0042] The embodiments of the utility model will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0043] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this utility model, unless otherwise specified, "multiple" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Reference Figure 1 , shows a schematic diagram of the structure of a battery cell in the prior art, such as Figure 1 As shown, the battery assembly comprises a housing 4 and a battery cell disposed in the housing 4, the battery cell comprises a separator 3 and a pole piece 2 alternately disposed along a first direction X, wherein the pole piece 2 comprises a negative pole piece 21 and a positive pole piece 22, and the negative pole piece 21 and the positive pole piece 22 are alternately disposed along the first direction X. In order to improve the safety of the battery, before the battery leaves the factory, a needle puncture test is usually used to simulate the state of an internal short circuit when a foreign object pierces the battery, so as to understand the safety performance of the battery.

[0047] GB / T31485-2015 stipulates that the needle puncture test method is to use a Φ5mm~Φ8mm high-temperature resistant steel needle (the cone angle of the needle tip is 45°~60°) at a speed of 25mm / s, penetrate from the direction perpendicular to the battery pole piece, stay for 1 hour, and require that the battery does not catch fire or explode. However, during the needle puncture test, the pole piece 2 is short-circuited, and the electrical energy is converted into heat energy and accumulated and released in large quantities in a short period of time. This may cause the battery cell to smoke or even catch fire and explode in a short period of time, which may cause thermal runaway of the battery cell and pose a major safety hazard. Therefore, it is necessary to add protective measures to the battery cell to avoid or delay the occurrence of smoke or even fire and explosion of the battery, and effectively inhibit the occurrence of thermal runaway of the battery.

[0048] An embodiment of the present application provides a battery cell, and the battery cell of the present application is described in detail below with reference to the accompanying drawings.

[0049] Reference Figure 2 , showing a schematic diagram of the structure of the heat-absorbing capsule provided in the embodiment of the present application, referring to Figure 3 , showing a partial structural schematic diagram of the battery cell provided in Example 1 of the present application, referring to Figure 4 , showing a partial structural schematic diagram of the battery cell provided in the second embodiment of the present application, referring to Figure 5 , showing a partial structural schematic diagram of the battery cell provided in the third embodiment of the present application, referring to Figure 6 , shows a partial structural schematic diagram of a battery provided in an embodiment of the present application. It should be noted that, Figures 3 to 6 The ellipsis in the table represents repeated settings of the same structure.

[0050] like Figures 3 to 5 As shown, the present application provides a battery cell, comprising: a first heat absorption structure 1 and a plurality of pole pieces 2; the plurality of pole pieces 2 are stacked along a first direction X; at least one first heat absorption structure 1 is provided, at least one first heat absorption structure 1 is adjacent to at least one pole piece 2 along the first direction X, the first heat absorption structure 1 contains a heat absorption material, and when the first heat absorption structure 1 is pierced, the first heat absorption structure 1 releases the heat absorption material to absorb heat inside the battery cell.

[0051] In the embodiment of the present application, since the first heat absorption structure 1 is provided, the first heat absorption structure 1 is provided adjacent to the pole piece 2. Thus, when a foreign object penetrates into or even penetrates the battery cell, causing the first heat absorption structure to be pierced, the first heat absorption structure 1 can release the heat absorption material and promptly and quickly absorb the heat inside the battery cell, thereby effectively suppressing the occurrence of thermal runaway of the battery cell, which is beneficial to improving the safety of the battery.

[0052] It should be noted that the battery cell of the embodiment of the present application can be a wound battery cell or a laminated battery cell, which is not limited here. For a wound battery cell, the first direction X is the radial direction of the wound battery cell, and for a laminated battery cell, the first direction X is the thickness direction of the laminated battery cell. It can be understood that the thickness of the laminated battery cell depends on the number of laminated layers. In addition, the first heat absorption structure 1 can be a heat absorption layer, or a heat absorption capsule 11 or other structure that can accommodate heat absorption materials, which is not limited here, and those skilled in the art can adjust it according to actual needs.

[0053] In practical applications, the battery generally includes a shell 4 and a battery cell, wherein the shell 4 is provided with a receiving cavity, and the battery cell is provided in the receiving cavity. The battery cell includes a positive electrode sheet 22 and a negative electrode sheet 21 which are alternately arranged. When an electric field is applied to the positive electrode sheet 22 and the negative electrode sheet 21, lithium ions are intercalated and deintercalated between the positive electrode sheet 22 and the negative electrode sheet 21 to achieve charging and discharging. Therefore, when the number of the first heat absorption structure 1 is small, such as when only one is provided, the effect of suppressing the temperature rise of the battery cell is limited; and when the number of the first heat absorption structure 1 is large, such as when the number of the first heat absorption structure 1 is consistent with the number of the positive electrode sheet 22 or the negative electrode sheet 21, the first heat absorption structure 1 will hinder the migration of lithium ions between the positive electrode sheet 22 and the negative electrode sheet 21 to a certain extent, so that the energy density of the battery is sacrificed greatly. The embodiment of the present application does not limit the number of the first heat absorption structure 1. On the premise of taking into account both temperature rise suppression and energy density, those skilled in the art can adjust it according to actual needs.

[0054] It should be noted that, since the foreign body is pierced from the outside, that is, the pole piece 2 located outside is pierced before the pole piece 2 located inside, therefore, based on the fact that the first heat absorption structure 1 should be arranged at the position where heat absorption is most urgently needed, the first heat absorption structure 1 of the embodiment of the present application is preferentially arranged adjacent to the pole piece 2 located outside. When multiple first heat absorption structures 1 are provided, the multiple first heat absorption structures 1 are arranged according to the principle of dense outside and sparse inside, that is, from the inside to the outside of the battery cell, the arrangement density of the first heat absorption structure 1 increases, thereby improving the overall temperature rise suppression effect of the battery cell, which is conducive to avoiding or delaying the occurrence of battery smoke or even fire and explosion, and effectively suppressing the occurrence of thermal runaway of the battery cell.

[0055] In practical applications, the battery cell further includes a diaphragm 3, and a plurality of diaphragms 3 are provided, and the plurality of diaphragms 3 and the plurality of pole pieces 2 are alternately arranged along the first direction X; the first heat absorption structure 1 is arranged between the diaphragm 3 and the pole piece 2. Specifically, the battery cell includes a plurality of basic units consisting of a diaphragm 3, a negative pole piece 21, a diaphragm 3 and a positive pole piece 22, such as Figure 3 and Figure 4 As shown, the embodiment of the present application provides two positions where the first heat absorption structure 1 is arranged between the negative electrode sheet 21 and the separator 3. Figure 5 As shown, the embodiment of the present application further provides a position in which the first heat absorption structure 1 is arranged between the positive electrode sheet 22 and the diaphragm 3 .

[0056] It should be noted that the embodiment of the present application only provides some possible arrangement positions of the first heat absorption structure 1, and those skilled in the art may make adjustments according to actual needs.

[0057] In some optional embodiments of the present application, the first heat absorption structure 1 includes: a first heat absorption part and a second heat absorption part; the first heat absorption part and the second heat absorption part are adjacently arranged along the first direction X; the heat absorption material includes an endothermic solute and an endothermic solvent, the first heat absorption part is used to accommodate the endothermic solute, and the second heat absorption part is used to accommodate the endothermic solvent. When the first heat absorption structure 1 is pierced, the endothermic solute contacts the endothermic solvent and an endothermic reaction occurs to absorb the heat inside the battery cell.

[0058] In the embodiment of the present application, since the first heat absorption part and the second heat absorption part are provided, the first heat absorption part is used to accommodate the endothermic solute, and the second heat absorption part is used to accommodate the endothermic solvent. In this way, during the normal charge and discharge process of the battery, the endothermic solute and the endothermic solvent are in a mutually isolated state. When a foreign object penetrates or even punctures the battery, causing the first endothermic structure 1 to be punctured, the endothermic solute in the first heat absorption part contacts the endothermic solvent in the second heat absorption part, thereby causing a violent dissolution endothermic reaction, which can promptly and quickly absorb the heat inside the battery cell.

[0059] It should be noted that the first heat absorption part and the second heat absorption part can be an integrally formed structure or a split-formed structure, which is not limited here, and those skilled in the art can make adjustments according to actual needs. It can be understood that when the first heat absorption part and the second heat absorption part are an integrally formed structure, not only can the overall structural strength of the first heat absorption structure 1 be improved, but also the assembly process of the battery cell can be simplified, which is beneficial to improving the assembly efficiency of the battery cell. When the first heat absorption part and the second heat absorption part are split-formed structures, that is, the first heat absorption part and the second heat absorption part are two independent components, the processing difficulty of the first heat absorption structure 1 can be reduced. However, in order to avoid the problem that the first heat absorption part and the second heat absorption part are misaligned, resulting in the inability to puncture both at the same time and causing the inability to reliably absorb the internal heat of the battery cell, during the assembly process of the battery cell, it is usually necessary to accurately stack the first heat absorption part and the second heat absorption part, which will increase the difficulty of assembling the battery cell and cause the assembly efficiency to decrease.

[0060] In some optional embodiments of the present application, the first heat absorption structure 1 is a heat absorption capsule 11. Specifically, the heat absorption capsule 11 includes a capsule wall 111, which encloses a closed chamber; the heat absorption material is arranged in the chamber. In this way, since the heat absorption material is arranged in the chamber, that is, the heat absorption material is only released when the capsule wall 111 is punctured, the influence on the normal charging and discharging of the battery cell can be reduced.

[0061] It should be noted that the endothermic materials in the embodiments of the present application include chemical endothermic materials and physical endothermic materials, wherein the chemical endothermic materials absorb heat through chemical reactions, such as dissolution endothermic reactions, and the physical endothermic materials absorb heat through physical mechanisms, such as phase change. The embodiments of the present application do not limit the types of endothermic materials, and those skilled in the art can choose according to actual needs. It is understandable that in order to adapt to different types of battery cells, the capsule wall 111 of the endothermic capsule 11 is a flexible material, that is, a material that is retractable, bendable, and has a certain degree of flexibility, including but not limited to polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), polypropylene (PP) or other materials.

[0062] In some optional embodiments of the present application, the endothermic capsule 11 further includes a partition 112, which is disposed in the chamber to divide the chamber into a first chamber 113 and a second chamber 114 that are independent of each other; the endothermic material includes an endothermic solute and an endothermic solvent, the first chamber 113 is used to accommodate the endothermic solute, and the second chamber 114 is used to accommodate the endothermic solvent, and when the endothermic capsule 11 is pierced, the endothermic solute contacts the endothermic solvent and undergoes an endothermic reaction to absorb heat inside the battery cell.

[0063] In the embodiment of the present application, due to the provision of a separator 112, the separator 112 divides the chamber into a first chamber 113 and a second chamber 114 which are independent of each other. The first chamber 113 is used to accommodate an endothermic solute, and the second chamber 114 is used to accommodate an endothermic solvent. In this way, during the normal charge and discharge process of the battery, the endothermic solute and the endothermic solvent are in a state of isolation from each other. When a foreign object penetrates or even punctures the battery, the capsule wall 111 and the separator 112 of the endothermic capsule 11 are punctured, and the endothermic solute located in the first chamber 113 contacts the endothermic solvent located in the second chamber 114, thereby causing a violent dissolution endothermic reaction, which can timely and quickly absorb the heat inside the battery cell. Specifically, when the endothermic solute and the endothermic solvent undergo an endothermic reaction, on the one hand, the temperature of the internal structure of the battery cell, such as the pole piece 2, the electrolyte, the diaphragm 3, etc., can be reduced, thereby suppressing the deintercalation of lithium ions and effectively reducing the short-circuit current. On the other hand, the heat generated by the short circuit of the electrode 2 cannot accumulate in a large amount in a short time, thereby suppressing the temperature rise in the battery, so that many processes, such as the release of oxygen from the positive electrode material, the decomposition of the electrolyte to produce hydrogen, methane and other combustible gases, and the melting of the diaphragm 3 are suppressed, thereby effectively avoiding or delaying the occurrence of battery smoking or even fire and explosion, which can greatly limit the probability of thermal runaway of the battery.

[0064] It should be noted that, in order to adapt to different types of battery cells, the separator 112 of the endothermic capsule 11 is a flexible material, that is, a material that is retractable, bendable, and has a certain degree of flexibility, including but not limited to polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), polypropylene (PP) or other materials. It can be understood that the separator 112 is essentially a layer of separation membrane arranged in the chamber, and when the capsule wall 111 and the separator 112 of the endothermic capsule 11 are integrally processed and formed using the same material, the manufacturing cost of the endothermic capsule 11 can be reduced. In one embodiment, the endothermic solute is ammonium nitrate and the endothermic solvent is water. When ammonium nitrate is dissolved in water, a violent endothermic reaction occurs, thereby effectively absorbing the heat inside the battery cell. The embodiment of the present application does not limit the types of endothermic solutes and endothermic solvents. On the basis of satisfying that both can undergo endothermic reactions, those skilled in the art can make a selection according to actual needs.

[0065] In practical applications, when performing the needle puncture test, the steel needle pierces the battery from a direction perpendicular to the pole piece 2. Based on this, in some optional embodiments of the present application, the first chamber 113 and the second chamber 114 are sequentially arranged along the first direction X. In this way, the first chamber 113 and the second chamber 114 can be punctured at the same time, so that the endothermic solute and the endothermic solvent can contact smoothly and undergo an endothermic reaction, which is beneficial to improving the endothermic reliability of the endothermic capsule 11.

[0066] In some optional embodiments of the present application, the first heat absorption structure 1 has a first projection perpendicular to the first direction X, the diaphragm 3 has a second projection perpendicular to the first direction X, and the area of ​​the second projection is greater than or equal to the area of ​​the first projection.

[0067] In the embodiment of the present application, since the area of ​​the second projection of the diaphragm 3 is greater than or equal to the area of ​​the first projection of the first heat absorption structure 1, that is, the diaphragm 3 can completely wrap the first heat absorption structure 1, thereby improving the overall structural strength of the battery cell and facilitating the assembly of the battery cell and the shell 4.

[0068] It should be noted that the wound battery cell is roughly cylindrical. For the wound battery cell, the first projection refers to the side wall projection of the cylindrical wound battery cell, that is, the cross-section of the first heat absorption structure 1 arranged inside the wound battery cell is roughly annular.

[0069] In some optional embodiments of the present application, the first heat absorption structure 1 has a first projection perpendicular to the first direction X, the pole piece 2 has a third projection perpendicular to the first direction X, and the area of ​​the third projection is less than or equal to the area of ​​the first projection.

[0070] In the embodiment of the present application, since the area of ​​the third projection of the pole piece 2 is less than or equal to the area of ​​the first projection of the first heat absorption structure 1, that is, the first heat absorption structure 1 can completely wrap the pole piece 2, so as to prevent foreign objects from only piercing the pole piece 2 but not the first heat absorption structure 1 when piercing the battery, resulting in the first heat absorption structure 1 being unable to absorb heat and unable to suppress the temperature rise, causing the battery to have thermal runaway in a short time.

[0071] It should be noted that the electrode sheet 2 includes positive electrode sheets 22 and negative electrode sheets 21 alternately arranged along the first direction X, and the projection area of ​​the positive electrode sheet 22 along the direction perpendicular to the first direction X is usually smaller than the projection area of ​​the negative electrode sheet 21 along the direction perpendicular to the first direction X. Therefore, when the projection area of ​​the negative electrode sheet 21 along the direction perpendicular to the first direction X is less than or equal to the area of ​​the first projection of the first heat absorption structure 1, it can be satisfied that the positive electrode sheet 22 and the negative electrode sheet 21 in the battery cell are both located within the first projection range of the first heat absorption structure 1, which is beneficial to improving the heat absorption reliability of the first heat absorption structure 1. In addition, since the first heat absorption structure 1 blocks the migration of lithium ions to a certain extent, in order to reduce the processing cost of the battery cell, for the electrode sheet 2 adjacent to the first heat absorption structure 1, the side of the electrode sheet 2 close to the first heat absorption structure 1 may not be coated.

[0072] An embodiment of the present application further provides a battery, comprising: a shell 4, the shell 4 being provided with a receiving cavity; and a battery cell according to any one of the above embodiments, the battery cell being provided in the receiving cavity.

[0073] In the embodiment of the present application, since the first heat absorption structure 1 is provided in the battery cell, when a foreign object penetrates or even pierces the battery, the first heat absorption structure 1 can release the heat absorption material and promptly and quickly absorb the heat inside the battery cell, thereby effectively suppressing the temperature rise of the battery cell, avoiding or delaying the occurrence of smoke or even fire and explosion of the battery, effectively suppressing the occurrence of thermal runaway of the battery cell, and being beneficial to improving the safety of the battery.

[0074] It should be noted that in the embodiment of the present application, the structure of the battery cell is the same as the structure of the battery cell in any of the above embodiments, and its beneficial effects are also similar, which will not be elaborated here.

[0075] In some optional embodiments of the present application, the battery further includes a second heat absorption structure 5, which is disposed between the shell 4 and the battery cell and parallel to the pole piece 2 of the battery cell; the second heat absorption structure 5 contains a heat absorption material to absorb heat inside the battery cell when the second heat absorption structure is punctured.

[0076] In the embodiment of the present application, since a second heat absorption structure 5 is also provided, the second heat absorption structure 5 is provided between the housing 4 and the battery cell and is provided in parallel with the pole piece 2 of the battery cell. In this way, when a foreign object penetrates or even pierces the battery, the second heat absorption structure 5 can be pierced first to absorb heat, which is beneficial to improving the effect of temperature rise suppression and effectively suppressing the occurrence of thermal runaway of the battery.

[0077] It should be noted that the second heat absorption structure 5 is a heat absorption layer or a heat absorption capsule 11. The embodiment of the present application preferably uses a heat absorption capsule 11. The second heat absorption structure 5 can be processed integrally with the battery core or assembled after separate processing. This is not limited here, and those skilled in the art can choose according to their needs.

[0078] An embodiment of the present application also provides a battery pack, which includes the above-mentioned battery.

[0079] It should be noted that in the embodiments of the present application, the structure of the battery is the same as the structure of the battery in any of the above embodiments, and its beneficial effects are also similar, which will not be elaborated here.

[0080] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery pack.

[0081] It should be noted that in the embodiment of the present application, the structure of the battery pack is the same as the structure of the battery pack in any of the above embodiments, and its beneficial effects are also similar, which will not be elaborated here.

[0082] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0083] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: The battery core comprises: a first heat absorption structure and a plurality of pole pieces; A plurality of pole pieces are stacked along a first direction; At least one of the first heat absorbing structures is provided, and at least one of the first heat absorbing structures is arranged adjacent to at least one of the pole pieces along the first direction. The first heat absorbing structure contains heat absorbing material to absorb heat inside the battery core when the first heat absorbing structure is punctured.

2. The battery cell according to claim 1, characterized in that: The first heat absorbing structure comprises: a first heat absorbing portion and a second heat absorbing portion; The first heat absorbing portion and the second heat absorbing portion are adjacently arranged along the first direction; The endothermic material includes an endothermic solute and an endothermic solvent. The first endothermic portion is used to accommodate the endothermic solute, and the second endothermic portion is used to accommodate the endothermic solvent. When the first endothermic structure is pierced, the endothermic solute contacts the endothermic solvent and undergoes an endothermic reaction to absorb heat inside the battery core.

3. The battery cell according to claim 2, characterized in that: The first heat absorbing part and the second heat absorbing part are an integrally formed structure.

4. The battery cell according to claim 2, characterized in that: The first heat absorbing part and the second heat absorbing part are separately formed structures.

5. The battery cell according to claim 1, characterized in that: The first heat absorbing structure is a heat absorbing capsule.

6. The battery cell according to claim 5, characterized in that: The heat-absorbing capsule comprises a capsule wall, and the capsule wall encloses a closed chamber; The heat absorbing material is disposed in the chamber.

7. The battery cell according to claim 6, characterized in that: The heat absorbing capsule further comprises a partition, which is arranged in the chamber to separate the chamber into a first chamber and a second chamber which are independent of each other; The endothermic material includes an endothermic solute and an endothermic solvent. The first chamber is used to accommodate the endothermic solute, and the second chamber is used to accommodate the endothermic solvent. When the endothermic capsule is pierced, the endothermic solute contacts the endothermic solvent and undergoes an endothermic reaction to absorb the heat inside the battery core.

8. The battery cell according to claim 7, characterized in that: The first chamber and the second chamber are arranged sequentially along the first direction.

9. The battery cell according to claim 7, characterized in that: The endothermic solute is ammonium nitrate, and the endothermic solvent is water.

10. The battery cell according to claim 1, characterized in that: The battery cell further includes a diaphragm, wherein a plurality of diaphragms are provided, and the plurality of diaphragms and the plurality of pole pieces are alternately arranged along the first direction; The first heat absorption structure is arranged between the diaphragm and the pole piece.

11. The battery cell according to claim 10, characterized in that: The first heat absorption structure has a first projection perpendicular to the first direction, the diaphragm has a second projection perpendicular to the first direction, and an area of ​​the second projection is greater than or equal to an area of ​​the first projection.

12. The battery cell according to claim 1, characterized in that: The first heat absorption structure has a first projection perpendicular to the first direction, the pole piece has a third projection perpendicular to the first direction, and an area of ​​the third projection is less than or equal to an area of ​​the first projection.

13. A battery, characterized in that: The battery comprises: A housing, wherein the housing is provided with a receiving cavity; And the battery cell according to any one of claims 1 to 12, wherein the battery cell is arranged in the accommodating cavity.

14. The battery according to claim 13, characterized in that The battery further comprises a second heat absorbing structure, which is arranged between the shell and the battery cell and parallel to the pole piece of the battery cell; The second heat absorbing structure contains a heat absorbing material to absorb the heat inside the battery core when the second heat absorbing structure is punctured.

15. A battery pack, characterized in that: The battery pack comprises the battery according to claim 13 or 14.

16. An electrical equipment, characterized in that: The electric device comprises the battery pack according to claim 15.

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