CN218274977U - Battery core, single battery and energy storage equipment - Google Patents

Abstract

The utility model discloses an electricity core, battery cell and energy storage equipment belongs to lithium ion battery technical field. The battery core comprises a connecting sheet and a composite current collector for manufacturing a pole piece, wherein the connecting sheet comprises a first metal sheet, a transition metal sheet and a second metal sheet which are sequentially connected, and the end surface of the second metal sheet is provided with a plurality of riveting columns; the composite current collector comprises a first metal layer, a polymer layer and a second metal layer, wherein a false tab area is arranged on one side of the composite current collector, and a riveting hole is formed in the false tab area; the connecting sheet is configured to be riveted with the false pole lug area through the riveting hole by the riveting column, so that the first metal layer is electrically connected with the second metal layer through the riveting column. Current can flow through the first metal layer and the second metal layer simultaneously, the overcurrent area of the tab is increased, and the contact impedance of the battery cell is reduced; the connecting sheet is firmly connected with the composite current collector by adopting a riveting process; the circuit of the metal layer can be communicated only by one riveting column without adding a plurality of accessories, so that the energy density of the battery cell is improved.

Description

Battery core, single battery and energy storage equipment

Technical Field

The utility model relates to a lithium ion battery technical field especially relates to an electricity core, battery cell and energy storage equipment.

Background

Lithium ion batteries are widely used due to their advantages of stable voltage, high capacity, high energy density, long cycle life, environmental friendliness, and the like. In order to realize the energy storage function of charging and discharging, a current collector tab of a pole core inside the battery (namely, a current collector tab of the battery) must be electrically connected with an external tab well. At present, an aluminum foil is generally adopted as a positive current collector, a copper foil is adopted as a negative current collector, and a tab of the aluminum foil current collector is generally connected with an aluminum connecting sheet of an external tab and a tab of a copper foil current collector is generally connected with a copper connecting sheet of the external tab by welding, so that the electric energy stored in an electric core is released and utilized. With the continuous development of the battery industry, composite current collectors with better performance are appeared, for example, composite current collectors with plastic polymers as the intermediate layer, such as Al/PET/Al, cu/PET/Cu, etc. (PET, i.e., polyethylene terephthalate). The composite current collector has a middle layer made of polymer and a surface layer made of metal conducting layer, and when thermal runaway occurs in the battery core, the surface metal layer shrinks due to heating and the polymeric layer expands due to heating to form internal open circuit, so that the safety performance of the battery is improved.

The composite current collector structure is generally formed by evaporating or sputtering a metal layer on two sides of a middle polymer layer so as to realize the surface conductive function. However, due to the existence of the middle polymer layer, the metal layers on the two sides can not realize circuit communication on the two sides like the conventional current collector when the battery is charged and discharged, and therefore the circuit communication among the multiple layers of pole pieces can not be realized when the conventional current collector tab welding mode is adopted.

At present, a solution to this phenomenon is generally an external false tab, for example, the false tab and a single pole piece are connected by using an ultrasonic welding method, in this way, the length of the battery core tab is increased to occupy the internal space of the battery, which results in a decrease in the energy density of the battery core, and meanwhile, the welding method has low welding efficiency, and the welding strength requirement is difficult to meet due to easy over-welding or insufficient welding in the welding process.

Therefore, it is desirable to provide a battery cell, a single battery and an energy storage device to solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an electricity core, battery cell and energy storage equipment, the pole piece of electricity core adopt the compound mass flow body to make, and the both sides metal level intercommunication of compound mass flow body reduces the flow resistance, and the electric current of being convenient for flows.

In order to realize the purpose, the following technical scheme is provided:

a cell, comprising:

the connecting sheet comprises a first metal sheet, a transition metal sheet and a second metal sheet which are sequentially connected, and a plurality of riveting columns are arranged on the end face of the second metal sheet;

the composite current collector is used for manufacturing a pole piece of the battery cell and comprises a first metal layer, a polymer layer and a second metal layer, a false pole lug area protrudes outwards from one side of the composite current collector, and the false pole lug area is provided with a plurality of riveting holes in a penetrating manner;

the connecting piece is configured to: the riveting column penetrates through the riveting hole and is riveted with the false tab area, so that the first metal layer is electrically connected with the second metal layer through the riveting column.

As an alternative of the battery core, the outer wall surface of the transition metal sheet is provided with a plastic insulating layer.

As an alternative to the battery cell, the plastic insulating layer is at least one of polyethylene terephthalate, polyamide, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyparaphenylene terephthalamide, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl formal, polyvinyl butyral, polyurethane, polyacrylonitrile, polyvinyl acetate, polyoxymethylene, phenol resin, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber, polycarbonate, polysulfone, polyethersulfone, and polyphenylene oxide.

As an alternative of the battery cell, the first metal sheet, the transition metal sheet and the second metal sheet are of an integrated structure.

As an alternative of the battery core, the first metal sheet, the transition metal sheet and the second metal sheet are all at least one of aluminum, copper, nickel, titanium, silver, stainless steel, nickel-copper alloy and aluminum-zirconium alloy.

As an alternative of the battery cell, both the first metal layer and the second metal layer are made of metal aluminum or metal copper.

As an alternative of the battery cell, the number of the rivet columns on the second metal sheet is n, the diameter of the rivet columns is D1, the height of the rivet columns is a, the thickness of the second metal sheet is E, and a model relationship between the current-carrying capacity of the second metal sheet S and the capacity of the battery cell Cp satisfies: nD1 (A + E) S < 4/3Cp.

The battery core comprises a positive plate containing the composite current collector, a diaphragm layer and a negative plate containing the composite current collector, which are laminated in sequence.

The utility model provides a single battery, includes the plastic-aluminum membrane and as above arbitrary electricity core, electric core set up in the plastic-aluminum membrane, the periphery wall of plastic insulation layer with the port department of plastic-aluminum membrane bonds.

An energy storage device comprises a motor and the single battery, wherein the motor is electrically connected with the single battery.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model provides an electric core, adopt the pole piece of compound mass flow body preparation electric core, compound mass flow body includes first metal level, polymer layer and second metal level, the riveting hole has been seted up in the false utmost point ear district of compound mass flow body, the riveting hole runs through first metal level, polymer layer and second metal level in proper order, the riveting post that will be located on the second metal level of connection piece passes the riveting hole and rivets, make the first metal level and the second metal level of compound mass flow body pass through riveting post electric connection, so that electric core when charging and discharging, the electric current can flow through first metal level and second metal level simultaneously, increase the area of overflowing of utmost point ear, reduce the effect of electric core contact impedance; the riveting process is adopted, so that the connection piece and the composite current collector are firmly connected; when the multiple layers of pole pieces are laminated, a plurality of accessories are not required to be added, and the circuit of the metal layers of the multiple layers of pole pieces can be communicated only by one riveting column, so that the energy density of the battery cell is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

Fig. 1 is a schematic structural view of a composite current collector in an embodiment of the present invention;

FIG. 2 is a schematic structural view of a connecting sheet in an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along the line R-R in FIG. 2;

fig. 4 is a schematic structural view of riveting a composite current collector and a connecting sheet in the embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along the line T-T in FIG. 4;

fig. 6 is a schematic structural view of the riveting of the connecting sheet and the positive plate of the battery cell in the embodiment of the present invention;

fig. 7 is a schematic structural diagram of a single battery in an embodiment of the present invention.

Reference numerals are as follows:

100. a positive plate; 200. a separator layer; 300. a negative plate; 400. an aluminum-plastic film;

1. connecting sheets; 2. compounding a current collector;

11. a first metal sheet; 12. a transition metal sheet; 13. a second metal sheet; 14. riveting columns; 15. a plastic insulating layer;

21. a first metal layer; 22. a polymer layer; 23. a second metal layer; 24. a false pole ear region; 25. and riveting the holes.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be further noted that, unless otherwise explicitly stated or limited, the terms "disposed" and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meaning of the above terms in the present invention can be understood as a specific case by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation of the first and second features not being in direct contact, but being in contact with another feature between them. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

The composite current collector structure generally comprises a middle polymer layer, and a metal layer is evaporated or sputtered on two sides of the middle polymer layer so as to realize the surface conduction function. However, due to the existence of the middle polymer layer, the metal layers on the two sides can not realize circuit communication on the two sides like the conventional current collector when the battery is charged and discharged, and therefore the circuit communication among the multiple layers of pole pieces can not be realized when the conventional current collector tab welding mode is adopted.

At present, a solution to this phenomenon is generally an external false tab, for example, the false tab and a single pole piece are connected by means of ultrasonic welding, so that, on one hand, the tab of the battery cell becomes long and occupies the internal space of the battery, resulting in a reduction in the energy density of the battery cell, and on the other hand, the welding mode has low welding efficiency, and the welding strength requirement is difficult to meet due to easy over-welding or insufficient welding in the welding process.

In order to communicate the metal layers on the two sides of the composite current collector of the cell pole piece, reduce the flow resistance, and facilitate the current flow, the embodiment provides a cell, and the details of the embodiment are described in detail below with reference to fig. 1 to 7.

As shown in fig. 1 to 5, the battery cell includes a connecting sheet 1 and a composite current collector 2, where the composite current collector 2 is used to fabricate a pole piece of the battery cell. Specifically, the connecting sheet 1 comprises a first metal sheet 11, a transition metal sheet 12 and a second metal sheet 13 which are connected in sequence, and a plurality of riveting columns 14 are arranged on the end face of the second metal sheet 13; specifically, the first metal sheet 11 is located above the transition metal sheet 12, and the second metal sheet 13 is located below the transition metal sheet 12. The composite current collector 2 comprises a first metal layer 21, a polymer layer 22 and a second metal layer 23, wherein a false tab area 24 protrudes outwards from one side of the composite current collector 2, and the false tab area 24 is provided with a plurality of riveting holes 25 in a penetrating manner; the connecting sheet 1 is configured such that the rivet stud 14 passes through the rivet hole 25 and is riveted to the dummy tab region 24, so that the first metal layer 21 is electrically connected to the second metal layer 23 through the rivet stud 14.

It should be understood that in the present embodiment, the rivet holes are penetrated through the dummy tab regions after lamination, but in other embodiments, the rivet holes may be penetrated through the dummy tab regions before lamination.

In short, in the battery cell provided in this embodiment, the composite current collector 2 is used to manufacture the pole pieces of the battery cell, the composite current collector 2 includes a first metal layer 21, a polymer layer 22, and a second metal layer 23, a rivet hole 25 is formed in a false tab area 24 of the composite current collector 2, the rivet hole 25 sequentially penetrates through the first metal layer 21, the polymer layer 22, and the second metal layer 23, and the rivet stud 14 on the second metal sheet 13 of the connecting sheet 1 penetrates through the rivet hole 25 and is riveted, so that the first metal layer 21 and the second metal layer 23 of the composite current collector 2 are electrically connected through the rivet stud 14, so that when the battery cell is charged and discharged, current can simultaneously flow through the first metal layer 21 and the second metal layer 23, the overcurrent area of the tab is increased, and the effect of reducing the contact impedance of the battery cell is achieved. The riveting process is adopted, so that the connecting sheet 1 and the composite current collector 2 are firmly connected; when the multiple pole pieces are laminated, the circuit of the metal layers of the multiple pole pieces can be communicated only by one riveting column 14 without adding a plurality of accessories, and the energy density of the battery cell is improved.

It is understood that the rivet stem 14 in this embodiment is made of metal.

Further, as shown in fig. 2, the outer wall surface of the transition metal sheet 12 is provided with a plastic insulating layer 15. By arranging the plastic insulating layer 15, the transition metal sheet 12 area of the connecting sheet 1 is conveniently insulated from the outside, and the safety level of the battery cell is improved. Specifically, the transition metal sheet 12 and the plastic insulating layer 15 are formed as an integrated structure by a plastic injection molding process.

As shown in fig. 1, 2, 3 and 5, the length G of the plastic insulating layer 15 of the second metal sheet 13 is greater than the length F of the first metal sheet 11. The relationship among the height A of the rivet column 14 of the second metal sheet 13, the thickness E of the second metal sheet 13, the hole depth C of the riveting hole 25 of the false pole ear region 24 and the total thickness B after riveting satisfies: a is greater than C and E + A is greater than B, because the riveting column 14 can deform and shorten when the riveting column 14 is riveted, A is greater than C and E + A is greater than B, so that the height of the riveting column 14 meets the requirement of a riveting process.

Illustratively, the plastic insulating layer 15 is at least one of polyester terephthalate, polyamide, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyparaphenylene terephthalamide, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl formal, polyvinyl butyral, polyurethane, polyacrylonitrile, polyvinyl acetate, polyoxymethylene, phenol resin, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber, polycarbonate, polysulfone, polyethersulfone, polyphenylene oxide.

Further, the first metal sheet 11, the transition metal sheet 12, and the second metal sheet 13 are an integrated structure. Illustratively, the first metal sheet 11, the transition metal sheet 12, and the second metal sheet 13 are formed into a unified structure through a stamping process, or formed into a unified structure through a multi-layer ultra-thin metal film laminating process.

Further, the first metal sheet 11, the transition metal sheet 12, and the second metal sheet 13 are each at least one of aluminum, copper, nickel, titanium, silver, stainless steel, nickel-copper alloy, and aluminum-zirconium alloy.

Further, the first metal layer 21 and the second metal layer 23 are both metal aluminum or metal copper. When the composite current collector 2 is used for manufacturing the positive plate 100, the first metal layer 21 and the second metal layer 23 are both made of metal aluminum; when the composite current collector 2 is used for manufacturing the negative electrode sheet 300, the first metal layer 21 and the second metal layer 23 are both made of copper.

Further, the number of the rivet columns 14 on the second metal sheet 13 is n, the diameter of the rivet columns 14 is D1, the height of the rivet columns 14 is a, the thickness of the second metal sheet 13 is E, and the current-carrying capacity of the second metal sheet 13 is S and the capacity of the battery cell is satisfied by the model relationship of Cp: nD1 (A + E) S is less than 4/3Cp, and the total cross-sectional area of the rivet column 14 determines the maximum current which can be borne by the charging and discharging of the battery cell, so that the diameter size and the total number of the rivet column 14 are determined by nD1 (A + E) S less than 4/3Cp, and the charging and discharging requirements of the battery cell are further met. Wherein D1, A and E are in mm, S is in A/mm2, and Cp is in A.

Illustratively, the length F of the first metal sheet 11 is 10mm to 60mm, and the length G of the plastic insulating layer 15 is 15mm to 80mm; the total thickness of the first metal sheet 11 is 0.1mm-5mm; the total thickness of the transition metal sheet 12 is 0.1mm-5mm; the thickness E of the second metal sheet 13 is 0.1mm-5mm; the diameter D1 of the riveting column 14 is 1-10mm, preferably 4-8mm; the height a of the stud 14 is 0.05-5mm, preferably 0.1-3mm. In this embodiment, the height and diameter of the rivet columns 14 and the number of the rivet columns 14 are changed to meet the charge and discharge rate requirements of the battery cells of different lithium ion types, so that the weight loss energy density and the volume energy density are not damaged.

Specifically, in this embodiment, referring to fig. 1, fig. 3 and fig. 4, the first metal sheet 11, the transition metal sheet 12 and the second metal sheet 13 of the connecting sheet 1 are made of a sheet structure with a thickness of 2.5mm by stamping a model 1060 aluminum material roll, and the transition metal sheet 12 is covered by a plastic insulating layer 15 made of PP material by using an injection molding process, so as to form a novel tab with a thickness of 3.0 mm. Wherein the length F of the first metal sheet 11 is 45mm, and the length G of the plastic insulating layer 15 is 60mm; the thickness of the second metal sheet 13 is 2.5mm, the diameter D1 of the rivet column 14 is 6mm, and the height a is 0.35mm. After the positive pole piece, the negative pole piece and the diaphragm layer 200 are laminated, a multilayer false tab is formed, a punching process is adopted on the surface of the false tab to form a riveting hole 25 with the diameter D2 of 5.9mm, and an assembly body is formed by the axis positioning of D1 and D2, as shown in figure 4. After the false pole lug and the connecting sheet 1 are assembled, riveting the second surface of the false pole lug by adopting a press riveting process to realize circuit communication.

Further, the battery cell in this embodiment further includes a positive electrode sheet 100 containing the composite current collector 2, a separator layer 200, and a negative electrode sheet 300 containing the composite current collector 2, which are stacked in sequence. The number of the positive electrode sheet 100, the separator layer 200, and the negative electrode sheet 300 stacked is increased according to actual use without much limitation.

In the embodiment, the circuit is communicated by punching the dummy tab area 24 of the laminated battery core, assembling the connecting sheet 1 and the punched position, and riveting the dummy tab area 24 of the composite current collector 2 and the connecting sheet 1 by pressure. By adopting the connection mode, the extra increase of the pole piece lug length caused by the connection of accessories such as false lugs can be avoided, the waste of the internal space of the battery cell is further caused, the whole connection strength and the lug overflowing area are also increased by increasing the number of riveting points and the riveting area, and the effect of reducing the contact impedance of the battery cell is further achieved.

The embodiment further provides a single battery, as shown in fig. 7, the single battery includes an aluminum-plastic film 400 and the above-mentioned battery cell, the battery cell is disposed in the aluminum-plastic film 400, and the peripheral wall of the plastic insulating layer 15 is bonded to the port of the aluminum-plastic film 400, so as to meet the charging and discharging requirements of the single battery.

This embodiment still provides an energy storage equipment, and this energy storage equipment includes motor and battery cell, and the motor is connected with the battery cell electricity.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (8)

1. A battery cell, comprising:

the connecting piece (1) comprises a first metal sheet (11), a transition metal sheet (12) and a second metal sheet (13) which are sequentially connected, and a plurality of riveting columns (14) are arranged on the end face of the second metal sheet (13);

the composite current collector (2) is used for manufacturing a pole piece of the battery core, the composite current collector (2) comprises a first metal layer (21), a polymer layer (22) and a second metal layer (23), a false pole ear area (24) protrudes outwards from one side of the composite current collector (2), and a plurality of riveting holes (25) are formed in the false pole ear area (24) in a penetrating mode;

the connection piece (1) is configured to: the riveting column (14) penetrates through the riveting hole (25) and is riveted with the false tab area (24), so that the first metal layer (21) is electrically connected with the second metal layer (23) through the riveting column (14).

2. The electrical core according to claim 1, characterized in that the outer wall surface of the transition metal sheet (12) is provided with a plastic insulating layer (15).

3. The electrical core according to claim 1, wherein the first metal sheet (11), the transition metal sheet (12) and the second metal sheet (13) are of a unitary structure.

4. The electrical core of claim 1, wherein the first metal layer (21) and the second metal layer (23) are both metallic aluminum or metallic copper.

5. The battery cell according to any one of claims 1 to 4, wherein the number of the rivet columns (14) on the second metal sheet (13) is n, the diameter of the rivet columns (14) is D1, the height of the rivet columns (14) is A, the thickness of the second metal sheet (13) is E, and a model relationship between the current-carrying capacity of the second metal sheet (13) being S and the capacity of the battery cell being Cp satisfies: nD1 (A + E) S < 4/3Cp.

6. The battery cell of claim 5, further comprising a positive plate (100) containing the composite current collector (2), a separator layer (200) and a negative plate (300) containing the composite current collector (2) which are sequentially laminated.

7. A single battery, which is characterized by comprising an aluminum-plastic film (400) and the battery core of any one of claims 1 to 6, wherein the battery core is arranged in the aluminum-plastic film (400), and the peripheral wall of the plastic insulating layer (15) is bonded with the port of the aluminum-plastic film (400).

8. An energy storage device comprising an electric motor and the battery cell of claim 7, the electric motor being electrically connected to the battery cell.

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