Battery cell structure, battery cell and battery pack

Abstract

Disclosed in the present application are a battery cell structure, a battery cell and a battery pack. The battery cell structure comprises a plurality of electrode sheets and magnetic members; the plurality of electrode sheets are stacked to form an electrode sheet group, an injection cavity being defined by every two adjacent electrode sheets, each injection cavity being provided with a cavity opening, and each cavity opening being used for electrolyte injection; the sides of every two adjacent electrode sheets that are close to each other are provided with magnetic members, wherein the magnetic members are arranged on the sides of the electrode sheets close to the cavity opening, the magnetic member arranged on one of the electrode sheets is a first magnetic member, the magnetic member arranged on the other electrode sheet is a second magnetic member, and ends of the first magnetic member and the second magnetic member having a same magnetic pole are disposed opposite to each other, such that the cavity opening is at least partially opened. Thus, the repulsive force between the same magnetic poles of the magnetic members can be used to increase the distance between the two electrode sheets at each cavity opening, such that the cavity openings are opened to facilitate electrolyte injection.

Description

Battery cell structure, battery cell and battery pack

[0001] The present application claims priority to the Chinese patent application No. 202411340553.1, filed on September 24, 2024, and entitled "Battery cell structure, battery cell and battery pack", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the technical field of battery, in particular to a battery cell structure, a battery cell and a battery pack. BACKGROUND

[0003] The bipolar battery is usually composed of a positive electrode sheet, a bipolar electrode sheet, a negative electrode sheet, a separator, an electrolyte and a sealing element, and the working voltage is increased by internal series connection. A complete sealing structure is formed between each positive electrode and the opposite negative electrode to prevent electrolyte from leaking and decomposing under high voltage. The bipolar battery has the characteristics of short conductive path and large positive and negative electrode contact area, so it can be charged and discharged at a higher current, which is beneficial to improve the utilization rate of active material.

[0004] In the related art, the four sides of the two bipolar electrode sheets are coated with sealing glue, and the range surrounded by the sealing glue is coated with active material. The two bipolar electrode sheets are fused and fixed by the sealing glue, and an unfused area is reserved in the local section of the sealing glue area, and a liquid injection sleeve is inserted for liquid injection. However, when the liquid injection sleeve is inserted in the above-mentioned way, the liquid injection sleeve needs to be inserted into the narrow area between the positive and negative electrodes, which is difficult to operate and has low efficiency.

[0005] SUMMARY

[0006] The present application aims to provide a battery cell structure, a battery cell and a battery pack, which can solve the problem of high operation difficulty of battery cell liquid injection in the prior art.

[0007] In order to solve the above technical problems, the present application is implemented as follows:

[0008] In a first aspect, the embodiments of the present application provide a battery cell structure, comprising a plurality of electrode sheets and magnetic members; the plurality of electrode sheets are stacked to form an electrode sheet group, and an injection cavity is formed between two adjacent electrode sheets; the injection cavity has a cavity opening, and the cavity opening is used for injecting electrolyte; one side of each of the two adjacent electrode sheets is provided with the magnetic member, and the magnetic member is arranged on the side of the electrode sheet close to the cavity opening; the magnetic member arranged on one of the electrode sheets is a first magnetic member, and the magnetic member arranged on the other electrode sheet is a second magnetic member; the first magnetic member and the second magnetic member are arranged opposite to each other at one end of the same magnetic pole to at least partially open the cavity opening.

[0009] Optionally, a first seal is further included; the first seal is arranged between two adjacent pole pieces, and surrounds part of the pole pieces; the two adjacent pole pieces and the first seal form the liquid injection cavity.

[0010] Optionally, the pole piece includes a current collector and an electrode material layer; at least one side surface of the current collector is provided with a coating area, the coating area is provided with the electrode material layer, and the first seal surrounds part of the coating area.

[0011] Optionally, the plurality of pole pieces include at least one first pole piece and two second pole pieces; the at least one first pole piece is stacked along a first direction to form a sub-pole piece group, and the two second pole pieces are arranged on two sides of the sub-pole piece group along the first direction; the first pole piece is provided with the electrode material layer and the magnetic member on both sides along the first direction, and the second pole piece is provided with the electrode material layer and the magnetic member on a side close to the sub-pole piece group.

[0012] Optionally, the pole piece is provided with a first area and a second area at the cavity opening; the second area is located on a side of the first area away from the liquid injection cavity, the magnetic member is arranged in the second area, and the first area is used to arrange a sealing layer to seal the cavity opening after liquid injection.

[0013] Optionally, a second seal is further included; the second seal is arranged in at least the first area.

[0014] Optionally, a plurality of liquid injection cavities are formed in the pole piece group, and the cavity openings of the plurality of liquid injection cavities are directed to the same direction.

[0015] Optionally, an extension is arranged on the pole piece; the extension extends from the pole piece to a direction away from the liquid injection cavity.

[0016] Optionally, the direction of the cavity opening intersects with the extension direction of the extension.

[0017] Optionally, the extensions of two adjacent pole pieces extend in opposite directions.

[0018] Optionally, the extensions of two adjacent pole pieces extend in the same direction.

[0019] Optionally, the magnetic member is made of at least one of pure iron, low-carbon steel, silicon steel sheet, permalloy, and ferrite.

[0020] Optionally, the coercive force of the magnetic member is less than or equal to 1000 A / m.

[0021] In a second aspect, an electric core is formed by liquid injection according to the structure of the electric core in the above embodiments.

[0022] Optionally, a protective film and a sealing layer are further included; the sealing layer is arranged at the cavity opening of the liquid injection cavity, and two adjacent pole pieces are connected by the sealing layer; and the protective film is wrapped around the pole piece group.

[0023] In a third aspect, the embodiments of the present application provide a battery pack, which comprises the battery cell structure as described in the above embodiments, or the battery cell as described in the above embodiments.

[0024] In the embodiments of the present application, a plurality of pole pieces are stacked to form a pole piece group, and a liquid injection cavity is formed between two adjacent pole pieces; the liquid injection cavity has a cavity opening for injecting electrolyte; one side of each of the two adjacent pole pieces is provided with a magnetic member, the magnetic member is arranged on the side of the pole piece close to the cavity opening, the magnetic member arranged on one of the pole pieces is a first magnetic member, and the magnetic member arranged on the other pole piece is a second magnetic member; and the first magnetic member and the second magnetic member are arranged opposite to each other at the same magnetic pole end to at least partially open the cavity opening. In this way, the repulsion between the magnetic members with the same magnetic pole can expand the distance between the two pole pieces at the cavity opening, so as to open the cavity opening, thereby facilitating the injection of electrolyte without the need for additional manual separation of the cavity opening, and thus reducing the operation difficulty and improving the efficiency of liquid injection.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the description of the embodiments, given in conjunction with the accompanying drawings, in which:

[0027] FIG. 1 is a cross-sectional view of a partial structure of a battery pack according to an embodiment of the present application;

[0028] FIG. 2 is a front cross-sectional view of a battery pack according to an embodiment of the present application;

[0029] FIG. 3 is a side cross-sectional view of a battery pack according to an embodiment of the present application.

[0030] Reference signs: 1-magnetic member; 2-first sealing member; 3-pole piece; 4-pole piece group; 5-second sealing member; 6-first pole piece; 7-second pole piece; 8-protective film; 9-separator; 11-first magnetic member; 12-second magnetic member; 13-first region; 14-second region; 31-current collector; 32-electrode material layer; 33-extension; 41-sub-pole piece group; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, for the purpose of explanation, and are not to be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0032] The terms "first", "second" in the description and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0033] In the description of the present application, it should be understood that 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 indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element 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.

[0034] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] The battery cell structure, battery cell and battery pack provided by the embodiments of the present application will be described in detail below in combination with the drawings and through specific embodiments and their application scenarios.

[0036] As shown in FIGS. 1-3, in a first aspect, the embodiments of the present application provide a battery cell structure, comprising a plurality of pole pieces 3 and magnetic members 1; the plurality of pole pieces 3 are stacked to form a pole piece group 4, and an injection cavity is formed between two adjacent pole pieces 3; the injection cavity has a cavity opening for injecting electrolyte; the two adjacent pole pieces 3 are provided with magnetic members 1 on the side close to each other, and the magnetic members 1 are arranged on the side of the pole pieces 3 close to the cavity opening; the magnetic member 1 arranged on one of the pole pieces 3 is a first magnetic member 11, and the magnetic member 1 arranged on the other pole piece 3 is a second magnetic member 12; the first magnetic member 11 and the second magnetic member 12 are arranged opposite to each other at the same magnetic pole end to at least partially open the cavity opening.

[0037] In the embodiments of the present application, the plurality of pole pieces 3 are stacked to form a pole piece group 4, and an injection cavity is formed between two adjacent pole pieces 3; the two adjacent pole pieces 3 are provided with magnetic members 1 on the side close to each other, and the magnetic members 1 are arranged on the side of the pole pieces 3 close to the cavity opening; the magnetic member 1 arranged on one of the pole pieces 3 is a first magnetic member 11, and the magnetic member 1 arranged on the other pole piece 3 is a second magnetic member 12; the first magnetic member 11 and the second magnetic member 12 are arranged opposite to each other at the same magnetic pole end to at least partially open the cavity opening. In this way, the repulsion between the magnetic members 1 with the same magnetic pole can expand the distance between the two pole pieces 3 at the cavity opening, thereby opening the cavity opening, so as to facilitate the injection of electrolyte without the need for additional manual separation of the cavity opening, thereby reducing the operation difficulty and improving the efficiency of the injection.

[0038] Specifically, the electrolyte can be a liquid electrolyte, i.e., a liquid-state electrolyte formed by dissolving a solid-state electrolyte in a liquid solvent; or the electrolyte used to make the electrolyte can be a phase-changeable electrolyte, for example, the electrolyte is in a liquid state in an initial state, and can gradually change from a liquid state to a gel state under specific light or specific temperature conditions, and finally can change to a solid state. By using such an electrolyte, the electrolyte can be made into a gel state, and then injected into the injection cavity, and then the liquid-state electrolyte in the injection cavity can be converted into a solid-state electrolyte by using light or temperature.

[0039] In some embodiments, the two adjacent pole pieces 3 can form the injection cavity by direct connection, for example, by welding to form the injection cavity. The injection cavity can also be formed by indirect connection, for example, by arranging a sealant between the two adjacent pole pieces 3 to form the injection cavity by adhesion.

[0040] In some embodiments, the first magnetic member 11 and the second magnetic member 12 each have S and N poles, and the S pole of the first magnetic member 11 and the S pole of the second magnetic member 12 are arranged oppositely, so that repulsion is generated between the first magnetic member 11 and the second magnetic member 12, thereby driving the respective pole pieces 3 away from each other, and further opening the cavity. Of course, the N pole of the first magnetic member 11 and the N pole of the second magnetic member 12 can also be arranged oppositely to generate repulsion between them.

[0041] It should be noted that the relative arrangement of the same poles of the first magnetic member 11 and the second magnetic member 12 herein refers to that the projections of the first magnetic member 11 and the second magnetic member 12 in a plane perpendicular to the first direction X at least partially coincide.

[0042] In addition, as shown in FIGS. 1 and 2, the stacking direction of the plurality of pole pieces 3 is the first direction X, the direction of liquid injection is the third direction Z, and the direction perpendicular to the first direction X and the third direction Z is the second direction Y.

[0043] Preferably, as shown in FIG. 3, the projections of the first magnetic member 11 and the second magnetic member 12 in a plane perpendicular to the first direction X coincide.

[0044] Optionally, as shown in FIG. 2, the first sealing member 2 is further included; the first sealing member 2 is arranged around part of the periphery of the pole piece 3, and the adjacent two pole pieces 3 and the first sealing member 2 form a liquid injection cavity.

[0045] In the embodiments of the present application, the first sealing member 2 is arranged between the adjacent two pole pieces 3, the first sealing member 2 is arranged around part of the periphery of the pole piece 3, and the adjacent two pole pieces 3 and the first sealing member 2 form a liquid injection cavity. In this way, the adjacent two pole pieces 3 are sealed and fused by the first sealing member 2 to form the liquid injection cavity, so as to facilitate the storage of electrolyte through the liquid injection cavity.

[0046] In some embodiments, as shown in FIG. 2, the surface of each pole piece 3 has four edges, at least three of which are provided with the first sealing member 2, and the adjacent two pole pieces 3 can be fused and fixed together by the first sealing member 2, thereby forming a liquid injection cavity; the position of the cavity opening of the liquid injection cavity corresponds to the side of the pole piece 3 on which the first sealing member 2 is not arranged. Of course, the adjacent two pole pieces 3 can also be partially sealed by the second sealing member 5 to form the cavity opening of the liquid injection cavity; the embodiments of the present application do not limit this.

[0047] It should be noted that the first sealing member 2 can include a sealing adhesive layer arranged between the two pole pieces 3, and the connection and fixation of the pole pieces 3 are realized by an adhesive medium such as a sealing adhesive or a sealing frame.

[0048] Optionally, as shown in FIG. 1 and FIG. 2, the pole piece 3 comprises a current collector 31 and an electrode material layer 32; at least one side surface of the current collector 31 is provided with a coating area, and the coating area is provided with the electrode material layer 32; and the first sealing member 2 is arranged around part of the coating area.

[0049] In the embodiment of the present application, the coating area is provided on at least one side surface of the current collector 31, and the coating area is provided with the electrode material layer 32. In this way, the chemical reaction between the electrode material layer 32 and the electrolyte can be facilitated to generate electrons or current; in addition, the first sealing member 2 is arranged around part of the coating area. In this way, the electrolyte is sealed in the liquid injection cavity where the coating area is located, and the electrolyte is prevented from overflowing to the first sealing member 2, thereby improving the chemical reaction rate of the electrolyte and the electrode material layer 32.

[0050] Specifically, the current collector 31 functions to collect the current generated by the reaction between the electrolyte and the electrode material layer 32 to form a larger current, thereby realizing the process of converting chemical energy into electrical energy. The current collector 31 not only serves as a carrier of the electrode material layer 32, but also serves as a carrier for collecting and transmitting positive and negative electrode electrons.

[0051] In some embodiments, the cell structure further comprises a separator 9, and the separator 9 is arranged between every two adjacent pole pieces 3; the separator 9 is provided with a porous structure for allowing the chemical substances in the electrolyte to pass through.

[0052] Optionally, as shown in FIG. 3, the plurality of pole pieces 3 comprises at least one first pole piece 6 and two second pole pieces 7; the at least one first pole piece 6 is stacked along the first direction X to form a sub-pole piece group 41; the two second pole pieces 7 are arranged on the two sides of the sub-pole piece group 41 along the first direction X; the first pole piece 6 is provided with the electrode material layer 32 and the magnetic member 1 on the two sides thereof along the first direction X; and the second pole piece 7 is provided with the electrode material layer 32 and the magnetic member 1 on the side thereof close to the sub-pole piece group 41.

[0053] In the embodiment of the present application, the at least one first pole piece 6 is stacked along the first direction X to form the sub-pole piece group 41, and the two second pole pieces 7 are arranged on the two sides of the sub-pole piece group 41; the first pole piece 6 is provided with the electrode material layer 32 and the magnetic member 1 on the opposite two sides thereof along the first direction X; and the second pole piece 7 is provided with the electrode material layer 32 and the magnetic member 1 on the side thereof close to the sub-pole piece group 41. In this way, the bipolar pole piece is used in the middle part of the pole piece group 4, and the magnetic member is arranged on the two sides of the bipolar pole piece to expand the cavity opening between the two adjacent bipolar pole pieces and the cavity opening between the unipolar pole piece and the bipolar pole piece. In addition, the present application forms the pole piece group 4 stacked in the order of the second pole piece 7-separator 9-(first pole piece 6-separator 9)n-second pole piece 7, and when the pole piece group 4 is injected with the electrolyte, a plurality of cavity openings can be opened at the same time to improve the injection efficiency of the injection equipment.

[0054] In some embodiments, the first pole piece 6 is a bipolar pole piece, and the second pole piece 7 is a unipolar pole piece, of which one is a positive pole piece and the other is a negative pole piece. For example, as shown in FIG. 3, the second pole piece 7 on the right side of FIG. 3 is a positive pole piece, and the second pole piece 7 on the left side of FIG. 3 is a negative pole piece. The current collector 31 in the positive pole piece is a positive current collector, and the side of the positive current collector facing the first pole piece 6 is coated with a positive material layer. The current collector 31 in the negative pole piece is a negative current collector, and the side of the negative current collector facing the first pole piece 6 is coated with a negative material layer. The current collector 31 in the first pole piece 6 is a composite current collector, and the side of the composite current collector facing the positive pole piece is coated with a negative material layer, and the side of the composite current collector facing the negative pole piece is coated with a positive material layer, thereby forming the pole piece group 4 shown in FIG. 3, which is a positive current collector-positive material layer-separator 9-(negative material layer-composite current collector-positive material layer-separator 9)n-negative material layer-negative current collector.

[0055] It should be noted that a plurality of first pole pieces 6 or one first pole piece 6 can be arranged in the sub-pole piece group 41, which is not limited in the embodiments of the present application.

[0056] Optionally, as shown in FIG. 2, the pole piece 3 is provided with a first region 13 and a second region 14 at the cavity opening. The second region 14 is located on the side of the first region 13 away from the liquid injection cavity, and the magnetic member 1 is arranged on the second region 14. The first region 13 is used to arrange a sealing layer to seal the completed liquid injection cavity opening.

[0057] In the embodiments of the present application, the first region 13 and the second region 14 are arranged at the cavity opening of the pole piece 3. The second region 14 is located on the side of the first region 13 away from the liquid injection cavity, and the magnetic member 1 is arranged on the second region 14. The first region 13 is used to arrange a sealing layer to seal the completed liquid injection cavity opening. In this way, the second region 14 provided with the magnetic member 1 can be cut off, and the cavity opening can be sealed by arranging a sealing layer on the first region 13, thereby avoiding the problem that the sealed cavity opening is opened due to the presence of the magnetic member 1.

[0058] It should be noted that the first region 13 can not be provided with a sealing member, and the cavity opening can be sealed by welding.

[0059] Optionally, the second sealing member 5 is further included, and the second sealing member 5 is arranged at least in the first region 13.

[0060] In the embodiments of the present application, the second sealing member 5 is arranged at least in the first region 13. In this way, the cavity opening can be sealed and blocked by the second sealing member 5, which is simple and convenient to operate.

[0061] The second seal 5 arranged between the two pole pieces is connected with only one of the pole pieces 3, and a gap exists between the second seal 5 and the other pole piece to form an open structure, so that the electrolyte is injected into the liquid injection cavity. After the liquid injection is completed, the two pole pieces 3 are close to each other and contact each other, and the second seal 5 is bonded and fixed to the two pole pieces 3 on both sides by heating and melting, so that a sealing layer is formed between the two adjacent pole pieces, and the electrolyte is sealed in the liquid injection cavity.

[0062] In some embodiments, the second seal 5 can also be arranged in the second area 14, and the magnetic member 1 is arranged between the pole piece 3 and the second seal 5. In this way, by arranging the magnetic member 1 between the pole piece 3 and the second seal 5, the connection strength between the magnetic member 1 and the pole piece 3 is enhanced, the magnetic member 1 is prevented from falling off the pole piece 3 due to external force during the liquid injection process, and the stability of the liquid injection is improved.

[0063] In some embodiments, when the pole piece 3 is produced, the magnetic member 1 can be pasted to a preset position of the pole piece 3 in advance, the preset position corresponds to the cavity opening of the liquid injection cavity, and then the second seal 5 is pasted to the preset position of the pole piece 3 to cover the magnetic member 1, so as to improve the subsequent liquid injection efficiency. In addition, the second seal 5 can prevent the magnetic member 1 from being in contact with the electrolyte and causing the magnetic member 1 to fail.

[0064] Optionally, as shown in FIG. 2, the magnetic member 1 can also be arranged on the second seal 5 located on the second area 14.

[0065] In the embodiments of the present application, the magnetic member 1 is arranged on the second seal 5 located on the second area 14. In this way, after the liquid injection is completed, the magnetic member 1 can be removed from the second seal 5, and then the second seal 5 can be used to bond and close the cavity opening, which is simple and convenient to operate.

[0066] In some embodiments, the magnetic member 1 can be arranged on the side of the second seal 5 away from the pole piece 3, for example, the magnetic member 1 is pasted to the surface of the second seal 5 by using a double-sided adhesive or the like. In this way, after the liquid injection is completed, the magnetic member 1 can be torn off from the second seal 5, which is convenient to operate.

[0067] In still other embodiments, the magnetic member 1 can also be at least partially embedded in the second seal 5. In this way, by embedding the magnetic member 1, the displacement of the magnetic member 1 in the second direction Y and the third direction Z can be limited, so that the magnetic member 1 is prevented from falling off the second seal 5.

[0068] In still other embodiments, as shown in FIG. 2, the magnetic member 1 can be arranged near the midpoint of the second seal 5, or can be arranged around the second seal 5.

[0069] Optionally, a plurality of liquid injection cavities are formed in the pole piece group 4, and the cavity openings of the plurality of liquid injection cavities are oriented in the same direction.

[0070] In the embodiment of the present application, a plurality of liquid injection cavities are formed in the pole piece group 4, and the cavity openings of the plurality of liquid injection cavities are oriented in the same direction. In this way, when liquid injection is performed by using a liquid injection device, the plurality of liquid injection openings of the liquid injection device can be used to inject liquid into the liquid injection cavities in the same direction, so as to improve the efficiency of liquid injection.

[0071] Optionally, as shown in FIG. 3, the pole piece 3 is provided with an extension 33 extending away from the liquid injection cavity.

[0072] In the embodiment of the present application, the extension 33 is arranged on the pole piece 3 and extends away from the liquid injection cavity. In this way, the adjacent pole pieces 3 can be electrically connected through the extension 33, so as to connect a plurality of pole pieces 3 in series to form a complete loop.

[0073] In some embodiments, each pole piece 3 can extend in a different direction to form the extension 33, and the length of the extension 33 can be selected according to requirements, which is not limited in the embodiment of the present application.

[0074] Optionally, as shown in FIG. 2 and FIG. 3, the orientation of the cavity opening intersects with the extension direction of the extension 33.

[0075] In the embodiment of the present application, the orientation of the cavity opening intersects with the extension direction of the extension 33. In this way, during the liquid injection process, the extension 33 can avoid interfering with the liquid injection at the cavity opening, and at the same time, the electrolyte can also avoid polluting the extension 33 to cause damage to the pole piece 3.

[0076] It should be noted that the liquid injection cavity has a cavity bottom arranged opposite to the cavity opening, and the direction from the cavity bottom to the cavity opening is the orientation of the cavity opening.

[0077] For example, as shown in FIG. 3, the extension 33 can extend along the second direction Y, and as shown in FIG. 2, the orientation of the cavity opening can be arranged along the third direction Z, i.e., the cavity opening can be arranged on any side of the electrode material layer 32 along the third direction Z.

[0078] Optionally, as shown in FIG. 3, the extensions 33 of the adjacent two pole pieces 3 extend in opposite directions.

[0079] In the embodiment of the present application, since the pole pieces 3 are electrically connected through the extensions 33, heat will be generated when electrons are transmitted. By arranging the extensions 33 of the adjacent two pole pieces 3 to extend in opposite directions, the extensions 33 can be arranged in an up-and-down staggered manner to increase the distance between the adjacent two extensions 33, so as to facilitate heat dissipation.

[0080] For example, as shown in FIG. 3, the second pole piece 7 located at the rightmost side of FIG. 3 extends upward to form an extension 33; from right to left, the first first pole piece 6 extends downward to form an extension 33, the second first pole piece 6 extends upward to form an extension 33, and the extensions 33 of the second first pole piece 6 and the extension 33 of the second pole piece 7 constitute two adjacent extensions 33. Through this arrangement, the distance between the two adjacent extensions 33 can be increased.

[0081] Optionally, the extensions 33 of the two adjacent pole pieces 3 extend towards the same direction.

[0082] In the embodiment of the present application, the extensions 33 of the two adjacent pole pieces 3 extend towards the same direction. In this way, all the extensions 33 are arranged on the same side, facilitating the connection between the extensions 33.

[0083] Optionally, the magnetic member 1 is made of at least one of pure iron, low-carbon steel, silicon steel sheet, permalloy, and ferrite.

[0084] In the embodiment of the present application, the magnetic member 1 made of pure iron, low-carbon steel, silicon steel sheet, permalloy, or ferrite has good stability and good corrosion resistance. In this way, when liquid injection is performed, the problem that the magnetic force disappears due to the contact between the magnetic member 1 and the electrolyte and the cavity opening cannot be opened can be avoided.

[0085] Optionally, the coercive force of the magnetic member 1 is less than or equal to 1000 A / m.

[0086] In the embodiment of the present application, by setting the coercive force of the magnetic member 1 to be less than or equal to 1000 A / m, the problem that the cavity opening is excessively opened due to excessive coercive force, thereby causing the pole piece 3 to be excessively deformed and broken can be avoided.

[0087] For example, the coercive force of the magnetic member 1 can be set to be 100 A / m, 200 A / m, 300 A / m, 400 A / m, 500 A / m, 600 A / m, 700 A / m, 800 A / m, 900 A / m, 1000 A / m, or any value or a range between any two values.

[0088] In a second aspect, the embodiment of the present application provides an electric core formed by injecting liquid into the electric core structure according to any one of the above embodiments.

[0089] In the embodiments of the present application, the plurality of pole pieces 3 are stacked to form a pole piece group 4, and the injection cavity is formed by the adjacent two pole pieces 3. The adjacent two pole pieces 3 are provided with the magnetic members 1 on the side close to each other. The magnetic members 1 are arranged on the side of the pole pieces 3 close to the cavity opening. The magnetic member 1 arranged on one of the pole pieces 3 is the first magnetic member 11, and the magnetic member 1 arranged on the other pole piece 3 is the second magnetic member 12. The first magnetic member 11 and the second magnetic member 12 are arranged opposite to each other at the same magnetic pole end to at least partially open the cavity opening. In this way, the repulsion between the magnetic members 1 with the same magnetic pole can expand the distance between the two pole pieces 3 at the cavity opening, so as to open the cavity opening, thereby facilitating the injection of the electrolyte without the need for additional manual separation of the cavity opening, thereby reducing the operation difficulty and improving the injection efficiency.

[0090] Optionally, as shown in FIGS. 1-3, the battery cell further comprises a protective film 8 and a sealing layer. The sealing layer is arranged at the cavity opening of the injection cavity, and the adjacent two pole pieces 3 are connected by the sealing layer. The protective film 8 is wrapped around the pole piece group 4.

[0091] In the embodiments of the present application, the sealing layer is arranged at the cavity opening of the injection cavity, and the adjacent two pole pieces 3 are connected by the sealing layer. The protective film 8 is wrapped around the pole piece group 4. In this way, the sealing property of the injection cavity can be further enhanced to avoid the liquid in the injection cavity from flowing out through the gap of the injection cavity and causing damage to the battery cell.

[0092] In some embodiments, the sealing layer can be formed by the second sealing members 5 as shown in FIG. 2. During the injection, the adjacent two second sealing members 5 can be pre-stuck at the cavity opening position of the current collector 31. After the injection is completed, the adjacent two second sealing members 5 are fused to seal the cavity opening.

[0093] In other embodiments, the protective film 8 can be made of a material with strong insulation performance, for example, the protective film 8 is made of an aluminum plastic film made of aluminum plastic composite material.

[0094] In a third aspect, the embodiments of the present application provide a battery pack comprising the battery cell structure as in the above-mentioned embodiments of the present application; or the battery cell as in the above-mentioned embodiments of the present application.

[0095] In the embodiments of the present application, the pole pieces 3 are stacked to form a pole piece group 4, and the liquid injection cavity is formed between the adjacent two pole pieces 3. The adjacent two pole pieces 3 are provided with the magnetic members 1 on the side close to each other, and the magnetic members 1 are arranged on the side of the pole pieces 3 close to the cavity opening. The magnetic member 1 arranged on one of the pole pieces 3 is the first magnetic member 11, and the magnetic member 1 arranged on the other pole piece 3 is the second magnetic member 12. The first magnetic member 11 and the second magnetic member 12 are arranged in opposite ends of the same magnetic pole to at least partially open the cavity opening. In this way, the repulsion between the magnetic members 1 with the same magnetic pole can expand the distance between the two pole pieces 3 at the cavity opening, so as to open the cavity opening, thereby facilitating the injection of the electrolyte without the need of manually separating the cavity opening, and reducing the operation difficulty and improving the efficiency of the liquid injection.

[0096] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" 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. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0097] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An electric cell structure, wherein, The plurality of pole pieces (3) and the magnetic member (1) are included. The plurality of pole pieces (3) are stacked to form a pole piece group (4), and an injection cavity is formed between two adjacent pole pieces (3). The injection cavity has a cavity opening for injecting electrolyte. The two adjacent pole pieces (3) are provided with the magnetic member (1) on one side close to each other. The magnetic member (1) is arranged on the side of the pole piece (3) close to the cavity opening. The magnetic member (1) arranged on one of the pole pieces (3) is a first magnetic member (11), and the magnetic member (1) arranged on the other pole piece (3) is a second magnetic member (12). The first magnetic member (11) and the second magnetic member (12) are arranged opposite to the same magnetic pole end to at least partially open the cavity opening.

2. The cell structure of claim 1, wherein, The first sealing member (2) is further included. The first sealing member (2) is arranged around part of the pole piece (3), and the two adjacent pole pieces (3) and the first sealing member (2) form the injection cavity.

3. The cell structure of claim 2, wherein, The pole piece (3) includes a current collector (31) and an electrode material layer (32). At least one side surface of the current collector (31) is provided with a coating area, and the electrode material layer (32) is arranged in the coating area. The first sealing member (2) is arranged around part of the coating area.

4. The cell structure of claim 3, wherein, The plurality of pole pieces (3) includes at least one first pole piece (6) and two second pole pieces (7). At least one first pole piece (6) is stacked along a first direction to form a sub-pole piece group (41), and two second pole pieces (7) are arranged on both sides of the sub-pole piece group (41) along the first direction. The first pole piece (6) is provided with the electrode material layer (32) and the magnetic member (1) on both sides along the first direction. The second pole piece (7) is provided with the electrode material layer (32) and the magnetic member (1) on the side close to the sub-pole piece group (41).

5. The cell structure of claim 1, wherein, The pole piece (3) is provided with a first area (13) and a second area (14) at the cavity opening. The second area (14) is located on the side of the first area (13) away from the injection cavity. The magnetic member (1) is arranged on the second area (14). The first area (13) is used to arrange a sealing layer to plug the completed injection cavity.

6. The cell structure of claim 5, wherein, The second sealing member (5) is further included. The second sealing member (5) is arranged in at least the first area (13).

7. The cell structure of any one of claims 1-6, wherein, A plurality of injection cavities are formed in the pole piece group (4), and the cavity openings of the plurality of injection cavities are directed to the same direction.

8. The cell structure of claim 1, wherein, The pole piece (3) is provided with an extension (33). The extension (33) extends from the pole piece (3) in a direction away from the injection cavity.

9. The cell structure of claim 8, wherein, The direction of the cavity opening intersects with the extension direction of the extension (33).

10. The cell structure of claim 8, wherein, The extensions (33) of the two adjacent pole pieces (3) extend in opposite directions.

11. The cell structure of claim 8, wherein, The extensions (33) of the two adjacent pole pieces (3) extend in the same direction.

12. The cell structure of claim 1, wherein, The magnetic member (1) is made of at least one of pure iron, low-carbon steel, silicon steel sheet, permalloy, and ferrite.

13. The cell structure of claim 1, wherein, The coercive force of the magnetic member (1) is less than or equal to 1000 A / m.

14. An electric cell, wherein, The liquid injection is formed by using the structure of the battery cell according to any one of claims 1-13.

15. The electric cell of claim 14, wherein, Further comprising a protective film (8) and a sealing layer; The sealing layer is arranged at the cavity opening of the liquid injection cavity, and two adjacent pole pieces (3) are connected by the sealing layer, and the protective film (8) is wrapped around the pole piece group (4).

16. A battery pack, wherein, The battery cell comprises the structure of the battery cell according to any one of claims 1-13, or the battery cell according to any one of claims 14-15.

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