CN219575669U - Pole piece of battery and battery thereof - Google Patents

Abstract

The utility model provides a pole piece of a battery, which comprises the following components in the thickness direction: the insulating layer is paved on one side surface of the insulating layer, and the positive current collector is paved on the other side surface of the insulating layer; paving a negative current collector on the other side surface of the insulating layer; the outer surface of the negative electrode current collector is coated with a negative electrode active material; the outer surface of the positive electrode current collector is coated with a positive electrode active material and a positive electrode insulating layer; the pole piece is provided with a positive pole lug area and a negative pole lug area along the width direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector; the positive electrode lug area is welded with a positive electrode lug; the cathode tab area is welded with the anode tab. The pole pieces of the battery provided by the utility model adopt a bipolar pole piece structure which is connected in parallel, the structural design is simple, the complexity of winding or lamination equipment can be reduced, and the production efficiency of the battery core is improved.

Description

Pole piece of battery and battery thereof

Technical Field

The embodiment of the utility model relates to the field of energy, in particular to a pole piece of a battery and the battery thereof.

Background

The secondary battery (rechargeable battery) is also called a rechargeable battery or a storage battery, and is a battery that can be continuously used by activating an active material by charging after discharging the battery. The main rechargeable batteries in the market include nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid (or lead-storage) batteries, lithium ion batteries, polymer lithium ion batteries and the like.

Secondary batteries have become the main stream of electrochemical energy storage as an electrochemical energy storage device. Current lithium ion batteries generally use current collectors for the positive electrode and the negative electrode separately, the current collector of the positive electrode adopts aluminum foil, the current collector of the negative electrode adopts copper foil, the current collector of the positive electrode or the current collector of the negative electrode is coated with diaphragms with the same polarity as the current collector on both sides, and a positive electrode plate and a negative electrode plate are isolated through the diaphragms. For manufacturing of lithium ion batteries, the structure greatly increases the complexity of winding or lamination process in the manufacturing process of the secondary batteries, reduces the production efficiency of the battery cells and increases the production cost.

Disclosure of Invention

In order to solve the above problems, embodiments of the present utility model provide a pole piece of a battery and a battery thereof.

In a first aspect, a pole piece of a battery according to an embodiment of the present utility model includes, in a thickness direction: the insulating layer is paved on one side surface of the insulating layer, and the positive current collector is paved on the other side surface of the insulating layer; paving a negative current collector on the other side surface of the insulating layer; the outer surface of the negative electrode current collector is coated with a negative electrode active material; the outer surface of the positive electrode current collector is coated with a positive electrode active material and a positive electrode insulating layer; the pole piece is provided with a positive pole lug area and a negative pole lug area along the width direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector; the positive electrode lug area is welded with a positive electrode lug; the cathode tab area is welded with the anode tab. Therefore, the parallel bipolar pole piece structure is adopted, the structural design is simple, the complexity of winding or lamination equipment can be reduced, and the production efficiency of the battery cell is improved.

In some embodiments, the surface of the positive current collector of the positive tab area is provided with a positive tab weld; the positive electrode tab is welded and printed for welding the positive electrode tab; the surface of the negative electrode current collector in the negative electrode tab area is provided with a negative electrode tab welding mark; the negative electrode tab is welded and printed for welding the negative electrode tab. Therefore, the welding and printing of the positive electrode tab of the reserved tab area can ensure that the positive electrode and the negative electrode cannot be short-circuited in the tab welding process.

In some embodiments, the positive electrode insulating layers are disposed on both sides of the positive electrode active material, respectively. With this, the negative electrode active material can be ensured to maintain consistent compaction of the negative electrode Overhang region and the negative electrode active material main body region in the rolling process, and the safety performance of the battery can be improved.

In some embodiments, the coating width of the negative electrode active material is wider than the coating width of the positive electrode active material. Therefore, the folds and powder falling caused in the pole piece rolling process can be improved.

In some embodiments, the coating width of the negative electrode active material is equal to the coating width of the positive electrode active material plus the coating width of the positive electrode insulating layers on both sides. Therefore, the folds and powder falling caused in the pole piece rolling process can be improved. In some embodiments, the thickness of the positive electrode insulating layer is less than or equal to the thickness of the positive electrode active material. Therefore, the positive electrode active material can be prevented from being pressed to the designed compaction density due to the fact that the press roller firstly contacts the positive electrode insulating layer in the process of rolling the pole piece, and meanwhile, the safety performance of the battery can be improved.

In some embodiments, the pole piece and the diaphragm form a pole core by winding. Therefore, the existing winding equipment can be adopted to wind the die-cut parallel bipolar pole pieces into battery pole cores, the winding complexity is reduced, and the production efficiency of the battery cells is improved.

In some embodiments, the pole piece and the diaphragm form a pole core by lamination. Therefore, the parallel bipolar pole pieces after die cutting can be laminated into battery pole cores by adopting the existing lamination equipment, the complexity of lamination process is reduced, and the production efficiency of the battery cells is improved.

In some embodiments, the pole piece and the diaphragm form a pole core through winding or lamination, the pole core is packaged with a hard shell or an aluminum plastic film, and the battery is manufactured after electrolyte is injected. Therefore, the bipolar battery pole core connected in parallel can be manufactured into a battery.

In a second aspect, an embodiment of the present utility model provides a battery, including a pole piece and a separator; the pole piece and the diaphragm form a pole core through winding or lamination; the pole core is packaged by a hard shell or an aluminum plastic film, and electrolyte is injected to obtain a battery; wherein the pole piece includes: the insulating layer is paved on one side surface of the insulating layer, and the positive current collector is paved on the other side surface of the insulating layer; paving a negative current collector on the other side surface of the insulating layer; the outer surface of the negative electrode current collector is coated with a negative electrode active material; the outer surface of the positive electrode current collector is coated with a positive electrode active material and a positive electrode insulating layer; the pole piece is provided with a positive pole lug area and a negative pole lug area along the width direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector; the positive electrode lug area is welded with a positive electrode lug; the cathode tab area is welded with the anode tab. The beneficial effects are as described in the first aspect, and are not repeated here.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments disclosed in the present specification, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only examples of the embodiments disclosed in the present specification, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

The drawings that accompany the detailed description can be briefly described as follows.

FIG. 1 is a schematic illustration of a pole piece according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of the positive side after the pole piece die-cutting procedure according to the embodiment of the present utility model;

FIG. 3 is a schematic view of the negative side of a pole piece after a pole piece die cutting process according to an embodiment of the present utility model;

fig. 4 is a schematic diagram of a pole piece winding process according to an embodiment of the present utility model;

FIG. 5 is a top view of the positive surface of a pole piece lamination die cut provided by an embodiment of the utility model;

FIG. 6 is a bottom view of the negative side of a die cut of a pole piece lamination provided by an embodiment of the utility model;

fig. 7 is a schematic diagram of a lamination process of a pole piece according to an embodiment of the present utility model.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be described below with reference to the accompanying drawings.

In describing embodiments of the present utility model, words such as "exemplary," "such as" or "for example" are used to mean serving as examples, illustrations or explanations. Any embodiment or design described herein as "exemplary," "such as" or "for example" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "such as" or "for example," etc., is intended to present related concepts in a concrete fashion.

In the description of the embodiments of the present utility model, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a alone, B alone, and both A and B. In addition, unless otherwise indicated, the term "plurality" means two or more. For example, a plurality of systems means two or more systems, and a plurality of terminals means two or more terminals.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating an indicated technical feature. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

In the description of embodiments of the utility model reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

In the description of the embodiments of the present utility model, the terms "first\second\third, etc." or module a, module B, module C, etc. are used merely to distinguish similar objects and do not represent a particular ordering for the objects, it being understood that particular orders or precedence may be interchanged as allowed so that the embodiments of the present utility model described herein can be implemented in an order other than that illustrated or described herein.

In the description of the embodiment of the present utility model, reference numerals indicating steps, such as S110, S120, … …, etc., do not necessarily indicate that the steps are performed in this order, and the order of the steps may be interchanged or performed simultaneously as allowed.

In the description of the embodiments of the present utility model, the current collector refers to a structure or part for collecting current, and on the lithium ion battery, mainly refers to a metal foil, such as copper foil and aluminum foil.

In the description of the embodiment of the utility model, the electrode lugs are metal conductors for leading out the positive electrode and the negative electrode from the battery core, and the electrode lugs of the positive electrode and the negative electrode of the battery are contact points during charge and discharge.

In the description of the embodiments of the present utility model, pole piece rolling refers to further compaction of the coated pole piece to increase the energy density of the battery, typically after the coating process and before the cutting process.

In the description of the embodiments of the present utility model, pole piece slitting is the continuous slitting of a wider, full roll of pole pieces into a number of narrower pole pieces of the desired width.

In the description of the embodiment of the utility model, pole piece production comprises the steps of welding pole lugs on the pole pieces after cutting, pasting protective gummed paper, encapsulating the pole lugs or cutting and forming the pole lugs by using laser, and the like, and the pole pieces are used for the subsequent winding process.

In the description of the embodiment of the utility model, the pole piece die cutting refers to continuously coating pole pieces with pole lugs at two sides in a coiled manner, forming the pole lugs through a hardware die, and then coiling the pole pieces for subsequent slitting and coiling processes.

In the description of the embodiment of the utility model, pole piece winding refers to winding a pole piece manufactured through a sheet making process or a rolling die cutting into a battery pole core.

In the description of the embodiments of the present utility model, the pole piece lamination refers to lamination of the individual pole pieces cut in the die cutting process into battery pole cores.

In the description of the embodiments of the present utility model, battery packaging refers to the placement of battery cells into a cell housing.

In the description of the embodiments of the present utility model, cell injection refers to the quantitative injection of battery electrolyte into a cell.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein is for the purpose of describing embodiments of the utility model only and is not intended to be limiting of the utility model.

The first scheme adopts a mode of connecting bipolar pole pieces in series inside so as to improve the voltage of the battery cell. The battery cell includes a plurality of electrode assemblies, each of which requires a separate separator for sealing and isolating. One tab is led out between the electrode assemblies with the number of the assemblies being more than or equal to 2, and the polarities of the tabs of the two electrode assemblies are opposite. Each electrode assembly includes a positive electrode sheet, a separator, and a negative electrode sheet. The scheme has the advantages of complex structure, higher realization difficulty and high cost.

The second scheme adopts bipolar electrode, namely, one side of the current collector is coated with positive electrode active material, the other side is coated with negative electrode active material, and the internal series connection of the batteries is realized through the assembly of pole pieces. The battery pole piece of this scheme is through making the positive and negative pole respectively alone the film-forming, the mode that again through bonding and welding is with positive and negative pole piece complex and prepare. This arrangement causes a short circuit between the positive electrode and the negative electrode, and an effective secondary battery cannot be formed.

Fig. 1 is a schematic view of a pole piece according to an embodiment of the present utility model. As shown in fig. 1, the pole piece 10 includes, in the thickness D direction: an insulating layer 101, wherein a positive electrode current collector 102 is paved on one side surface of the insulating layer 101; paving a negative current collector 103 on the other side surface of the insulating layer; the outer surface of the negative electrode current collector 103 is coated with a negative electrode active material 301; the outer surface of the positive electrode current collector 102 is coated with a positive electrode active material 201 and a positive electrode insulating layer 202; the pole piece 10 is provided with a positive pole lug area AA and a negative pole lug area BB along the width H direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector; the positive electrode lug area is welded with a positive electrode lug; the cathode tab area is welded with the anode tab.

According to the pole piece provided by the embodiment of the utility model, the pole piece 10 adopts bipolar cells connected in parallel, and the anode active material 201 and the cathode active material 301 are coated on two sides of the same current collector. The current collector is a composite current collector, the middle layer of the composite current collector is an insulating layer 101, metal conductive layers are arranged on two sides of the insulating layer 101, wherein the metal conductive layer on one side is a positive current collector 102, and the metal conductive layer on the other side is a negative current collector 103.

Fig. 1 shows that the projection area of the positive tab area on the negative side does not intersect the projection area of the negative current collector 103 on the negative side, and the positive tab area is the protruding end of the insulating layer and the positive current collector with respect to the negative current collector. Similarly, the projection area of the negative electrode tab area on the positive electrode side is not intersected with the projection area of the positive electrode current collector 102 on the positive electrode side, and the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector. Therefore, the positive electrode and the negative electrode can be ensured not to be short-circuited in the welding process of the positive electrode tab and the negative electrode tab.

The positive electrode insulating layer 202 can ensure that the negative electrode active material 301 maintains consistent compaction of the negative electrode Overhang region and the negative electrode active material body region during rolling, and the positive electrode insulating layer width a > 0.

In some embodiments, the material of the insulating layer 101 may be a polymer insulating layer, for example: films of polyvinyl chloride, polyethylene, polytetrafluoroethylene, neoprene, polyvinyl acetal, and the like.

In some embodiments, the material of the insulating layer 101 may be a synthetic fiber insulating paper, such as: aromatic polyamide fiber paper, polyester fiber paper, polyaramid fiber paper, polysulfone fiber paper, polyoxadiazole fiber paper, and the like;

in some embodiments, the material of the insulating layer 101 may also be various insulating tapes or the like.

In some embodiments, the thickness of the insulating layer is 1-30mm.

In some embodiments, the positive electrode current collector 102 is typically an aluminum layer or an iron layer for guiding the positive electrode current.

In some embodiments, the negative electrode current collector 103 is a copper layer or an aluminum layer or an iron layer for guiding the negative electrode current.

In some embodiments, the thickness of the positive electrode current collector 102 is 0.5-10mm and the thickness of the negative electrode current collector 103 is 0.5-10mm.

In some embodiments, the positive electrode active material 201 is coated on the surface of the positive electrode current collector 102.

In some embodiments, the positive electrode active material 201 is provided with a positive electrode insulating layer 202 on both sides thereof, the width a (a > 0), and the thickness of the positive electrode insulating layer 202 is less than or equal to the thickness of the positive electrode active material 201. Therefore, the positive electrode active material 201 can be prevented from being pressed to the designed compaction density due to the fact that the press roller firstly contacts the positive electrode insulating layer 202 in the process of rolling the pole piece, and meanwhile the safety performance of the battery can be improved.

In some embodiments, the width a of the positive electrode insulating layer 202 may be 0.5-10mm.

In some embodiments, the positive electrode active material 201 may be formed of one or more of a ternary material, a lithium iron phosphate material, or a positive electrode material of a sodium ion battery. The thickness of the positive electrode active material 201 is 50 to 500 μm.

In some embodiments, the positive electrode material of the sodium ion battery includes sodium vanadium phosphate, sodium vanadium pyrophosphate, prussian blue/white, layered multi-oxides, and the like.

In some embodiments, the anode active material 301 is coated on the surface of the anode current collector 103, and the coating width of the anode active material 301 is wider than that of the cathode active material 201.

In some embodiments, the width of the negative electrode active material 301 and the positive electrode active material 201 plus the width of the positive electrode insulating layers 202 on the left and right sides are equal. Therefore, the folds and powder falling caused in the pole piece rolling process can be improved.

In some embodiments, the anode active material 301 is composed mainly of one or more of graphite-based materials, silicon-based materials, or metal oxides.

In some embodiments, the graphite-based material includes synthetic graphite, natural graphite, hard carbon, soft carbon, and amorphous carbon; silicon-based materials include silicon, silicon monoxide and silicon dioxide; the metal oxide includes lithium titanate.

In the embodiment of the utility model, the pole piece is subjected to a die cutting procedure according to the die cutting size, and after die cutting, a positive pole lug area and a negative pole lug area reserved on the current collector are respectively welded with one current collector in an ultrasonic welding mode to serve as lug welding marks, and the lug welding marks are used for fixing the lugs through ultrasonic or laser welding.

In the die cutting process, the traditional winding adopts double-sided die cutting, the die cutting lugs are different in distance, and Mark holes are arranged at the die cutting positions for positioning; and the lamination adopts unilateral die cutting, and the tab interval is the same, can carry out equidistant cutting off. The two different processes of winding and disc after the die cutting process are respectively described below.

Fig. 2 is a schematic diagram of the positive side of the pole piece after the pole piece die cutting process according to the embodiment of the utility model. As shown in fig. 2, the length of the pole piece is L, and after the die-cutting process, the surface of the positive current collector 102 in the positive tab area of the pole piece is provided with a positive tab solder 204.

The positive electrode insulating layers 202 are provided on both sides of the positive electrode active material 201, respectively.

Fig. 3 is a schematic view of the negative side of the pole piece after the pole piece die cutting process according to the embodiment of the present utility model. As shown in fig. 3, after the pole piece die-cutting process, a negative pole tab welding mark 303 is provided on the surface of the negative pole current collector 103 in the negative pole tab area.

The coating width of the anode active material 301 is wider than that of the cathode active material 201.

In some embodiments, the coating width of the negative electrode active material 301 is equal to the coating width of the positive electrode active material 201 plus the coating width of the positive electrode insulating layers 202 on both sides.

As shown in fig. 2 and 3, the die-cut pole pieces may be welded with the positive electrode tab and the negative electrode tab by ultrasonic or laser welding, and the materials of the welded tabs correspond to those of the positive electrode current collector 102 and the negative electrode current collector 103.

In some embodiments, the positive tab 203 may be welded at the positive tab weld 204. The positive electrode tab 203 is made of aluminum or iron, and the positive electrode tab 203 is a contact point for charging/discharging positive electrode current, corresponding to the material of the positive electrode current collector 102.

In some embodiments, the negative tab 302 may be welded at the negative tab weld 303. The material of the negative electrode tab 302 corresponds to the material of the negative electrode current collector 103, and is a copper layer, an aluminum layer or an iron layer, and the negative electrode tab 302 is a contact point for charging/discharging negative electrode current.

The die-cut pole piece shown in fig. 2 and 3 may be subjected to a single-side winding process based on the currently existing winding apparatus.

Fig. 4 is a schematic diagram of a pole piece winding process according to an embodiment of the present utility model. As shown in fig. 4, the winding needle 401 is a columnar body, and has an elliptical cross section or a circular cross section. The height H of the winding needle 401 corresponds to the width H of the pole piece, the perimeter c of the section corresponds to the length L of the pole piece, L is more than or equal to L, and the pole piece is wound on one side by taking the winding needle 401 as the center to form a pole core.

In some embodiments, the outer surface of the cylindrical body of the winding needle 401 is wrapped with a layer of membrane 1. In winding, a separator 2 is applied to the surface of the negative electrode active material 301 on the negative electrode side of the electrode sheet 10, and then the separator is attached to the outer surface of the cylindrical body of the winding needle 401, and single-layer winding is performed around the winding needle 401. After winding, the separator 1, the separator 2, the pole piece negative electrode side 3, the composite current collector 4 and the pole piece positive electrode side 5 are sequentially arranged outwards by taking the winding needle 401 as a center.

In some embodiments, after a separator 2 is applied to the surface of the negative electrode active material 301 on the negative electrode side of the electrode sheet 10, the separator is attached to the outer surface of the cylindrical body of the winding needle 401, and the separator is wound in a single layer around the winding needle 401 for a plurality of turns. After winding, the diaphragm 1, the diaphragm 2, the pole piece negative electrode side 3, the composite current collector 4, the pole piece positive electrode side 5, the diaphragm 2 and the pole piece negative electrode side 3 … are sequentially arranged outwards by taking the winding needle 401 as a center.

In some embodiments, when winding, a separator 2 is applied to the surface of the positive electrode active material 201 on the positive electrode side of the electrode sheet 10, and then the separator is attached to the outer surface of the cylindrical body of the winding needle 401, and single-layer winding is performed around the winding needle 401. After winding, the separator 1, the separator 2, the positive electrode side 5 of the pole piece, the composite current collector 4 and the negative electrode side 3 of the pole piece are sequentially arranged outwards by taking the winding needle 401 as a center.

In some embodiments, after a separator 2 is applied to the surface of the positive electrode active material 201 on the positive electrode side of the electrode sheet 10, the separator is attached to the outer surface of the cylindrical body of the winding needle 401, and the separator is wound in a single layer around the winding needle 401 for a plurality of turns. After winding, the diaphragm 1, the diaphragm 2, the positive electrode side of the pole piece, the composite current collector, the negative electrode side of the pole piece, the diaphragm 2 and the negative electrode side … are sequentially arranged outwards by taking the winding needle 401 as a center.

The pole piece provided by the utility model is subjected to a lamination process based on the current lamination equipment.

Fig. 5 is a top view of the positive surface of a die cut of a pole piece lamination provided by an embodiment of the utility model. As shown in fig. 5, the outer surface of the positive electrode current collector 102 is coated with a positive electrode active material 201 and a positive electrode insulating layer 202; positive electrode insulating layers 202 are coated on both sides of the positive electrode active material 201 in the width H direction. The width of the positive electrode insulating layer 202 is a (a > 0), and the thickness d1 of the positive electrode insulating layer 202 is less than or equal to the thickness d2 of the positive electrode active material 201.

After the die cutting process, the surface of the positive current collector 102 in the positive tab area of the pole piece is provided with a positive tab welding mark 204; the surface of the negative electrode current collector 103 in the negative electrode tab region is provided with a negative electrode tab welding mark 303. The positive electrode tab and the negative electrode tab can be welded on the tabs of the positive electrode tab area and the negative electrode tab area in an ultrasonic or laser welding mode, and the materials of the welded tabs correspond to the materials of the positive electrode current collector 102 and the negative electrode current collector 103. The materials and welding modes of the positive electrode and the negative electrode tab are shown in fig. 2 and 3, and are not described in detail here.

Fig. 6 is a bottom view of the negative side of a die cut of a pole piece lamination provided in an embodiment of the utility model. As shown in fig. 6, the outer surface of the negative electrode current collector 103 is coated with a negative electrode active material 301; the width of the negative electrode active material 301 and the width of the positive electrode active material 201 are equal to each other plus the width of the positive electrode insulating layers 202 on the left and right sides. Therefore, the folds and powder falling caused in the pole piece rolling process can be improved.

After the die cutting process, the surface of the positive current collector 102 in the positive tab area of the pole piece is provided with a positive tab welding mark 204; the surface of the negative electrode current collector 103 in the negative electrode tab region is provided with a negative electrode tab welding mark 303. The positive electrode tab and the negative electrode tab can be welded on the tabs of the positive electrode tab area and the negative electrode tab area in an ultrasonic or laser welding mode, and the materials of the welded tabs correspond to the materials of the positive electrode current collector 102 and the negative electrode current collector 103. The materials and welding modes of the positive electrode and the negative electrode tab are shown in fig. 2 and 3, and are not described in detail here.

Fig. 7 is a schematic diagram of a lamination process of a pole piece according to an embodiment of the present utility model. As shown in fig. 7, the pole piece provided by the embodiment of the utility model is cut into a plurality of sections of pole pieces according to a specified size, each section of pole piece in the plurality of sections of pole pieces is overlapped, and a separator 2 is arranged between a positive electrode side 5 of a first piece and a negative electrode side 3 of a second piece in the overlapped two sections of pole pieces.

Illustratively, a length L pole piece may be cut into multiple segments of pole pieces at a specified dimension n.

Illustratively, a pole piece of length L may be cut into m pole pieces, each of length L/m.

In some embodiments, each of the multiple segments of pole pieces may be placed in an overlapping relationship with a separator disposed between a negative side surface of a first of the two overlapping segments adjacent to a positive side surface of a second of the segments.

The diaphragm can be arranged between the two overlapped pole pieces in a cutting way, or can be formed by folding a whole piece of diaphragm in a Z shape.

Lamination can be performed based on the current existing equipment to form pole cores, so that the cost is reduced, and the complexity of production equipment is reduced. And (3) winding or laminating the pole piece and the diaphragm after the pole lugs are welded to form a pole core, packaging the pole core by a hard shell or an aluminum plastic film, and injecting electrolyte to manufacture the battery.

In some embodiments, the hard shell comprises an aluminum shell, a steel shell, a plastic shell, or the like.

In the pole core forming process, the coiled positive and negative pole pieces are continuous, the lamination is a sheet material, and under the condition of the same layer number, compared with the coiled battery, the number of pole lugs of the lamination battery is doubled, meanwhile, the tension of the diaphragm is almost zero, and the porosity and the raw materials are kept consistent.

Example 1

The pole piece provided by the embodiment 1 of the utility model adopts PET as an insulating layer of the pole piece, the thickness is 6 mu m, the positive pole current collector adopts an aluminum layer, the thickness is 3 mu m, and the negative pole current collector also adopts an aluminum layer, and the thickness is 3 mu m.

The positive electrode active material was sodium vanadium phosphate, the coating thickness was 170 μm, and the positive electrode insulating layer thickness on both sides of the positive electrode active material was 100 μm. The width of the positive electrode active material was 70mm, and the width a of the positive electrode insulating layer was 5mm.

The negative electrode active material was hard carbon, and the coating thickness was 300. Mu.m. The width of the negative electrode active material was 80mm, which was equal to the width of the positive electrode active material plus the width of the positive electrode insulating layers on the left and right sides.

The pole pieces after die cutting are respectively welded with positive pole lugs and negative pole lugs in positive pole lug areas and negative pole lug areas, the width of the welded pole lugs is 50mm, the height of the pole lugs is 30mm, the welded pole lugs are made of aluminum, and the thickness is 12 mu m.

The diaphragm adopts a PE base film with the thickness of 9 mu m, ceramic layers are coated on two sides of the diaphragm, the thickness of the ceramic layers is 2.5 mu m, and a pole core is formed by adopting a winding mode.

The electrode core is packaged by an aluminum shell, the solute of the electrolyte adopts sodium hexafluorophosphate or sodium perchlorate, the solvent adopts DMC and PC mixed solvent, and the electrolyte is injected to manufacture the battery.

Example 2

The pole piece provided in the embodiment 2 of the utility model adopts synthetic fiber insulating paper as the material of the insulating layer 101 of the pole piece, the thickness is 10 μm, the anode current collector adopts an iron layer, the thickness is 6 μm, and the cathode current collector also adopts an iron layer, and the thickness is 6 μm.

The positive electrode active material is lithium iron phosphate material, the thickness of the coating is 280 mu m, and the thickness of the positive electrode insulating layers at two sides of the positive electrode active material is 180 mu m. The width of the positive electrode active material was 100mm, and the width a of the positive electrode insulating layer was 4mm.

The negative electrode active material was silica, the coating thickness was 270 μm, and the width of the negative electrode active material was 108mm, which was equal to the width of the positive electrode active material plus the width of the positive electrode insulating layers on the left and right sides.

The pole pieces after die cutting are respectively welded with positive pole lugs and negative pole lugs in positive pole lug areas and negative pole lug areas, the width of the welded pole lugs is 40mm, the height of the pole lugs is 25mm, the welded pole lugs are made of iron, and the thickness is 14 mu m.

The pole piece with the length L of 2m is cut into 10 sections of pole pieces according to 200mm sections, each section of pole piece in the 10 sections of pole pieces is overlapped, the positive electrode side of the first piece in the overlapped two sections of pole pieces is adjacent to the negative electrode side of the second piece, and a diaphragm is arranged between the positive electrode side and the negative electrode side of the second piece. The diaphragm adopts a PE base film with the thickness of 15 mu m, ceramic layers are coated on two sides of the diaphragm, and the thickness of the ceramic layers is 3.5 mu m.

The diaphragm can be cut into sections with the same size of 200mm and arranged between the two overlapped sections of pole pieces, or can be formed by folding a whole piece of diaphragm in a Z shape and arranged between the two overlapped sections of pole pieces. The die-cut pole piece is shaped as shown in fig. 5 and 6, and the pole core is formed in a lamination manner, which is not described herein.

And (3) forming a pole core after the pole piece and the diaphragm are welded and pass through the lamination, packaging the pole core through an aluminum plastic film, injecting electrolyte, adopting sodium perchlorate as a solute of the electrolyte, adopting DMC (methyl methacrylate) and PC (polycarbonate) mixed solvent as a solvent, and manufacturing the battery.

Based on the current cell structure design. Meanwhile, the complexity of winding or lamination equipment can be reduced, and the production efficiency of the battery cell is improved.

The foregoing is merely a specific implementation of the embodiment of the present utility model, but the protection scope of the embodiment of the present utility model is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the embodiment of the present utility model, and the changes or substitutions are covered by the protection scope of the embodiment of the present utility model.

Claims (10)

1. A pole piece of a battery, characterized in that the pole piece comprises in the thickness direction:

the positive electrode current collector is paved on one side surface of the insulating layer; paving a negative current collector on the surface of the other side of the insulating layer;

the outer surface of the negative electrode current collector is coated with a negative electrode active material;

the outer surface of the positive electrode current collector is coated with a positive electrode active material and a positive electrode insulating layer;

the pole piece is provided with a positive pole lug area and a negative pole lug area along the width direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector;

the positive electrode tab area is welded with a positive electrode tab; and the anode tab area is welded with the anode tab.

2. The pole piece of the battery according to claim 1, wherein the positive current collector surface of the positive tab area is provided with a positive tab weld; the positive electrode tab welding marks are used for welding the positive electrode tab;

the surface of the negative electrode current collector in the negative electrode tab area is provided with a negative electrode tab welding mark; the negative electrode tab welding marks are used for welding the negative electrode tab.

3. The battery pole piece according to claim 1 or 2, wherein the positive electrode insulating layers are provided on both sides of the positive electrode active material, respectively.

4. The battery pole piece according to claim 1 or 2, wherein the coating width of the negative electrode active material is wider than the coating width of the positive electrode active material.

5. The battery pole piece according to claim 1 or 2, wherein the coating width of the negative electrode active material is equal to the coating width of the positive electrode active material plus the coating width of the positive electrode insulating layers on both sides.

6. The battery pole piece according to claim 1 or 2, wherein the thickness of the positive electrode insulating layer is less than or equal to the thickness of the positive electrode active material.

7. A battery pole piece according to claim 1 or 2, characterized in that the pole piece and the separator form a pole core by winding.

8. A pole piece of a battery according to claim 1 or 2, characterized in that the pole piece and the separator form a pole core by lamination.

9. A battery pole piece according to claim 1 or 2, wherein the pole piece and separator form a pole core by winding or lamination;

and packaging the pole core with a hard shell or an aluminum plastic film, and injecting electrolyte to manufacture the battery.

10. The battery is characterized by comprising a pole piece and a diaphragm; the pole piece and the diaphragm form a pole core through winding or lamination; the pole core is packaged by a hard shell or an aluminum plastic film, and electrolyte is injected to obtain a battery; wherein the pole piece comprises: the positive electrode current collector is paved on one side surface of the insulating layer; paving a negative current collector on the surface of the other side of the insulating layer;

the outer surface of the negative electrode current collector is coated with a negative electrode active material;

the outer surface of the positive electrode current collector is coated with a positive electrode active material and a positive electrode insulating layer;

the pole piece is provided with a positive pole lug area and a negative pole lug area along the width direction; the positive electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the negative electrode current collector; the negative electrode tab area is an extending end of the insulating layer and the positive electrode current collector relative to the positive electrode current collector;

the positive electrode tab area is welded with a positive electrode tab; and the anode tab area is welded with the anode tab.