Laminated cell and battery

Abstract

The utility model discloses a laminated battery cell and a battery, the laminated battery cell comprises a battery cell body, and two opposite side surfaces of the battery cell body are respectively provided with a single-sided pole piece; and the two supporting sheets are respectively positioned on two opposite sides of the battery cell body, and each supporting sheet is correspondingly attached to one single-sided pole piece. According to the laminated battery cell disclosed by the utility model, under the supporting action of the supporting sheets, the single-sided pole pieces of the battery cell body can be kept in a flat state, and the peripheries of the single-sided pole pieces are tightly attached, so that lithium precipitation caused by warping of the single-sided pole pieces in a later cycle process is prevented, and the cycle performance of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a laminated battery core and a battery. Background Art

[0002] Lithium battery refers to a battery containing lithium (including metallic lithium, lithium alloys, lithium ions, and lithium polymers) in the electrochemical system and is widely used in digital products and other fields.

[0003] The mainstream types of lithium batteries on the market include wound type and stacked type. Among them, stacked batteries can better improve battery performance compared to wound batteries and have advantages in energy density, safety and other aspects.

[0004] At present, in laminated cells, the outermost layer of the cell body is a single-sided electrode (i.e., the current collector of the electrode is coated with an active material layer on only one side), such as a cathode single-sided electrode or an anode single-sided electrode. Figure 1 As shown, the single-sided electrode will warp significantly after rolling, resulting in a loose fit in the battery cell body. The loosely fitted area is prone to lithium deposition during the later cycle process, resulting in poor battery cell cycle performance. Utility Model Content

[0005] The main purpose of the utility model is to provide a laminated battery core, aiming to solve the technical problem that single-sided pole pieces in the current laminated battery core are not tightly fitted due to warping and are prone to lithium deposition.

[0006] To achieve the above object, the utility model provides a laminated battery core, which comprises:

[0007] A battery cell body, wherein two opposite side surfaces of the battery cell body are respectively provided with single-sided pole pieces;

[0008] Two support sheets, the two support sheets are respectively located on two opposite sides of the battery cell body, and each support sheet is correspondingly attached to one of the single-sided pole sheets.

[0009] In some embodiments, the two support sheets are connected via a connecting structure to clamp the battery cell body.

[0010] In some embodiments, the connection structure includes adhesive tape, and the adhesive tape is respectively bonded to the two support sheets.

[0011] In some embodiments, a plurality of adhesive tapes are provided, and the plurality of adhesive tapes are arranged along the circumference of the two support sheets.

[0012] In some embodiments, the connection structure includes a connection sheet;

[0013] One end of the connecting piece is welded and fixed on one of the two supporting pieces, and the other end of the connecting piece is welded and fixed on the other of the two supporting pieces.

[0014] In some embodiments, a plurality of the connecting sheets are provided, and the plurality of the connecting sheets are arranged along the circumference of the two supporting sheets.

[0015] In some embodiments, the outer diameter of the support sheet is equal to or greater than the outer diameter of the single-sided pole sheet.

[0016] In some embodiments, the support sheet has a thickness of 0.1 mm to 1 mm.

[0017] In some embodiments, the support sheet is square; or,

[0018] The supporting sheet is in a square frame shape.

[0019] The utility model also provides a battery, which comprises a shell and the laminated battery core as described above, wherein the laminated battery core is arranged in the shell.

[0020] The laminated cell of the utility model technical solution is provided with two support sheets, which are respectively located on opposite sides of the cell body, and each support sheet is correspondingly attached to a single-sided pole piece. Under the support of the support sheet, the single-sided pole piece of the cell body can be kept flat, and a tight fit is achieved on all sides, thereby preventing the single-sided pole piece from warping and causing lithium deposition in the later cycle process, thereby improving the cell cycle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a stack of battery cells in the prior art;

[0022] Figure 2 This is a schematic diagram of the structure of a laminated battery cell in one embodiment of the utility model;

[0023] Figure 3 for Figure 2 A schematic diagram of the structure of the laminated battery cell in the embodiment from another perspective;

[0024] Figure 4 This is a schematic diagram of the structure of a laminated battery cell in another embodiment of the utility model;

[0025] Figure 5 It is a schematic structural diagram of a laminated battery cell in another embodiment of the present utility model. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the scheme in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0029] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0030] like Figure 1 As shown, in the laminated battery cell, the single-sided pole piece 110 is usually arranged at the outermost side of the battery cell body 100, and the current collector 111 thereof is coated with the active material layer 112 on only one side, and the active material layer 112 of the single-sided pole piece 110 faces the separator 120 of the battery cell body. The single-sided pole piece 110 will be warped significantly after rolling, resulting in a loose fit in the battery cell body 100. The loosely fitted area is prone to lithium deposition during the later cycle process, resulting in poor battery cell cycle performance.

[0031] Based on the above-mentioned problems currently existing, an embodiment of the utility model proposes a laminated battery cell to prevent lithium deposition in the later cycle process due to warping of a single-sided electrode sheet in the laminated battery cell, thereby improving the cycle performance of the battery cell.

[0032] Reference Figure 2The laminated battery cell of this embodiment includes: a battery cell body 100 and two support sheets 200 , and the two opposite side surfaces of the battery cell body 100 respectively have single-sided pole sheets 110 ; the two support sheets 200 are respectively located on the opposite sides of the battery cell body 100 , and each support sheet 200 corresponds to and fits a single-sided pole sheet 110 .

[0033] Specifically, the battery cell body 100 includes two single-sided pole pieces 110, a diaphragm 120, and a pole piece group formed by stacking double-sided pole pieces 130. The two single-sided pole pieces 110 are respectively located on the opposite sides of the battery cell body 100, that is, the single-sided pole piece 110 is located at the outermost side of the pole piece group, and a diaphragm 120 is provided between the single-sided pole piece 110 and the pole piece group. Optionally, the diaphragm 120 is folded in a Z-shape, and several double-sided pole pieces 130 of the pole piece group are inserted into the diaphragm 120 and are alternately stacked with the diaphragm 120. Among them, the double-sided pole pieces 130 involved are coated with active material layers on both sides of the current collector. The two opposite outermost sides of the pole piece group are distributed with single-sided pole pieces 110, and a diaphragm 120 is provided between the single-sided pole piece 110 and the double-sided pole pieces 130 in the pole piece group and adjacent to and opposite to it.

[0034] Among them, the single-sided pole piece 110 is usually a square sheet, such as a rectangular sheet, and its length and width are not limited here. The single-sided pole piece 110 includes a current collector 111 and an active material layer 112. The active material layer 112 is arranged on one side of the current collector 111. In the battery body 100, the active material layer 112 of the single-sided pole piece 110 faces the diaphragm 120. The single-sided pole piece 110 can be a positive single-sided pole piece 110 or a negative single-sided pole piece 110, and this embodiment does not limit this. When the single-sided pole piece 110 is a positive single-sided pole piece 110, the current collector 111 can be made of aluminum foil, and the active material layer 112 can be made of a positive active coating material, such as lithium cobalt oxide, etc.; when the single-sided pole piece 110 is a negative single-sided pole piece 110, the current collector 111 can be made of copper foil, and the active material layer 112 can be made of a negative active coating material, such as graphite, etc.

[0035] There are two support sheets 200, and the two support sheets 200 are correspondingly located on the opposite sides of the battery body 100, and are respectively fitted with the single-sided pole pieces 110 on the opposite sides of the battery body 100. Optionally, the support sheet 200 only contacts the single-sided pole piece 110 but is not connected to it, thereby achieving a fitting arrangement with the single-sided pole piece 110. Alternatively, the support sheet 200 is bonded to the single-sided pole piece 110 to form a connection therewith, thereby achieving a fitting arrangement with the single-sided pole piece 110. Optionally, the outer shape of the support sheet 200 is the same as the outer shape of the single-sided pole piece 110. Among them, the support sheet 200 can be made of polymer materials such as PE (polyethylene), PP (polypropylene), PMMA (polymethyl methacrylate), PU (polyurethane), etc., and can also be supported by metal materials (such as aluminum metal), and can also be made of ceramic materials (such as alumina ceramics). The support sheet 200 plays a certain supporting role on the single-sided pole piece 110. The single-sided pole piece 110 is not easy to warp and deform due to the restriction of the support sheet 200. That is, under the support of the support sheet 200, the single-sided pole piece 110 of the battery body 100 can be kept flat and tightly fitted around, thereby preventing the single-sided pole piece 110 from warping and causing lithium deposition in the later cycle process, thereby improving the battery cycle performance.

[0036] In some embodiments, the two support sheets 200 are connected by a connection structure to clamp the battery body 100. In this embodiment, the two support sheets 200 are connected by setting a connection structure. Under the connection of the connection structure, the two support sheets 200 are relatively close to each other, thereby clamping the battery body 100 and achieving a close fit with the corresponding single-sided pole piece 110, which is not easy to loosen.

[0037] The connection structure can take many structural forms, such as:

[0038] In some embodiments, reference Figure 2 and Figure 3 The connection structure includes adhesive tape 10, and the adhesive tape 10 is respectively bonded to the two support sheets 200. Optionally, adhesive tape 10 is provided on the sides of the two support sheets 200, one end of the adhesive tape 10 is bonded and fixed to one of the two support sheets 200, and the other end of the adhesive tape 10 is bonded and fixed to the other of the two support sheets 200. The type of adhesive tape 10 can be selected according to actual conditions and is not limited thereto. The two support sheets 200 are connected by the adhesive tape 10, and the disassembly and assembly operation is simple and convenient to use.

[0039] Further, refer to Figure 3, a plurality of adhesive tapes 10 are provided, and the plurality of adhesive tapes 10 are provided along the circumference of the two support sheets 200. By providing a plurality of adhesive tapes 10 along the circumference of the two support sheets 200 to connect the two support sheets 200, the connection stability between the two support sheets 200 can be ensured. Optionally, the two support sheets 200 have four sides, namely, upper, lower, left and right sides, and adhesive tapes 10 are distributed on each side to connect the two. For example, an adhesive tape 10 is provided on the upper and lower sides of the two support sheets 200, respectively, and the adhesive tape 10 is located in the middle position of the sides of the two support sheets 200, so as to connect the upper and lower sides of the two support sheets 200 correspondingly. Two adhesive tapes 10 are provided on the left and right sides of the two support sheets 200, respectively, and the two adhesive tapes 10 are located near the two ends of the sides of the two support sheets 200, so as to connect the left and right sides of the two support sheets 200 correspondingly.

[0040] In addition to the above configuration, the adhesive tape 10 may be wrapped around the two support sheets 200 from the periphery of the two support sheets 200 to connect the two support sheets 200 and allow the two support sheets 200 to firmly clamp the battery cell body 100 .

[0041] In some embodiments, reference Figure 4 The connection structure includes a connection sheet 20; one end of the connection sheet 20 is welded and fixed to one of the two support sheets 200, and the other end of the connection sheet 20 is welded and fixed to the other of the two support sheets 200. Optionally, the connection sheet 20 is made of metal. The two support sheets 200 are connected by welding the connection sheet 20, and the connection is stable. Optionally, the connection sheet 20 can be a U-shaped connection sheet 20.

[0042] Further, refer to Figure 4 , a plurality of connecting pieces 20 are provided, and the plurality of connecting pieces 20 are provided along the circumference of the two support pieces 200. By providing a plurality of connecting pieces 20 along the circumference of the two support pieces 200 to connect the two support pieces 200, the connection stability between the two support pieces 200 can be ensured. Optionally, the two support pieces 200 have four sides, namely, upper, lower, left, and right, and each side is provided with connecting pieces 20 to connect the two. For example, a connecting piece 20 is provided on each of the four sides, namely, upper, lower, left, and right, of the two support pieces 200, and the connecting piece 20 is located in the middle of the sides of the two support pieces 200, so as to connect the four sides, namely, upper, lower, left, and right, of the two support pieces 200 accordingly.

[0043] In addition to the above-mentioned welding connection, the connecting piece 20 and the supporting piece 200 can also be connected by snap-fit ​​connection, etc. For example, the two supporting pieces 200 are respectively configured with slots, and the two ends of the connecting piece 20 are respectively configured with holding protrusions, and the connecting piece 20 forms a holding match with the slots on the two supporting pieces 200 through the holding protrusions at both ends of the connecting piece 20, thereby connecting with the two supporting pieces 200. Of course, this is only exemplary and not restrictive.

[0044] In some embodiments, the outer diameter of the support sheet 200 is equal to or greater than the outer diameter of the single-sided pole piece 110. In this embodiment, optionally, the outer diameter of the support sheet 200 can be set equal to the outer diameter of the single-sided pole piece 110, or the outer diameter of the support sheet 200 can be set greater than the outer diameter of the single-sided pole piece 110. In this way, the support portion of the support sheet 200 for the single-sided pole piece 110 can cover the peripheral area of ​​the single-sided pole piece 110, thereby ensuring that the single-sided pole piece 110 is in close contact with the battery body 100, and preventing the single-sided pole piece 110 from warping and deformation.

[0045] In the technical solution of the utility model, it is considered that if the support sheet 200 is too thin, the support strength may be insufficient, and if it is too thick, the volume of the battery cell will be increased, affecting the energy density of the battery cell. In some embodiments, the thickness of the support sheet 200 is 0.1mm to 1mm. That is, the thickness of the support sheet 200 can be set within the range of 0.1mm to 1mm, for example, the thickness of the support sheet 200 can be set to 0.1mm, 0.55mm or 1mm. Optionally, the thickness of the support sheet 200 can be set with reference to the degree of warping of the single-sided pole sheet 110. For example, when the degree of warping of the single-sided pole sheet 110 is small, the thickness of the support sheet 200 can be set to 0.1mm; when the degree of warping of the single-sided pole sheet 110 is medium, the thickness of the support sheet 200 can be set to 0.55mm; when the degree of warping of the single-sided pole sheet 110 is large, the thickness of the support sheet 200 can be set to 1mm.

[0046] In some embodiments, reference Figure 3 and Figure 4 The support sheet 200 is a square structure. The support sheet 200 is a square structure for supporting the single-sided pole piece 110 on the whole surface, ensuring the flat state of the single-sided pole piece 110 and achieving close fit on all sides. Figure 5 The support sheet 200 is a square frame-shaped annular structure, which supports the periphery of the single-piece pole piece, keeps the single-sided pole piece 110 flat, and achieves tight fit around the periphery, which can save materials and reduce costs.

[0047] The utility model also provides a battery, which includes a housing and a laminated battery core as described in the above embodiment, and the laminated battery core is arranged in the housing. The specific structure of the laminated battery core refers to the above embodiment. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0048] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. A laminated battery cell, characterized in that: include: A battery cell body, wherein two opposite side surfaces of the battery cell body are respectively provided with single-sided pole pieces; Two support sheets, the two support sheets are respectively located on two opposite sides of the battery cell body, and each support sheet is correspondingly attached to one of the single-sided pole sheets.

2. The laminated battery cell according to claim 1, characterized in that: The two support sheets are connected via a connecting structure to clamp the battery core body.

3. The laminated battery cell according to claim 2, characterized in that: The connection structure comprises adhesive tape, and the adhesive tape is respectively bonded and connected to the two support sheets.

4. The laminated battery cell according to claim 3, characterized in that: A plurality of adhesive tapes are provided, and the plurality of adhesive tapes are arranged along the circumference of the two support sheets.

5. The laminated battery cell according to claim 2, characterized in that: The connection structure includes a connection piece; One end of the connecting piece is welded and fixed on one of the two supporting pieces, and the other end of the connecting piece is welded and fixed on the other of the two supporting pieces.

6. The laminated battery cell according to claim 5, characterized in that: A plurality of the connecting sheets are provided, and the plurality of the connecting sheets are arranged along the circumferential direction of the two supporting sheets.

7. The laminated battery cell according to claim 1, characterized in that: The outer diameter of the support sheet is equal to or greater than the outer diameter of the single-sided pole sheet.

8. The laminated battery cell according to claim 1, characterized in that: The thickness of the support sheet is 0.1 mm to 1 mm.

9. The laminated battery cell according to claim 1, characterized in that: The supporting sheet is square; or, The supporting sheet is in a square frame shape.

10. A battery, characterized in that: It comprises a shell and a laminated battery core as described in any one of claims 1 to 9, wherein the laminated battery core is arranged in the shell.

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