CN216818393U

CN216818393U - Composite current collector, pole piece, battery and device using battery

Info

Publication number: CN216818393U
Application number: CN202120367411.XU
Authority: CN
Inventors: 张万财; 吴婷婷; 冯俊敏
Original assignee: Xiamen Haichen New Energy Technology Co Ltd
Current assignee: Xiamen Hithium Energy Storage Technology Co Ltd
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2022-06-24
Anticipated expiration: 2031-02-07

Abstract

The application provides a device of compound mass flow body, pole piece, battery and use battery relates to battery technical field. The composite current collector comprises a first conducting layer, a base film and a second conducting layer which are sequentially arranged in a stacking mode, the composite current collector is provided with a coating area used for coating active materials and a lug area used for forming a lug, the base film in the coating area is made of insulating materials, and the first conducting layer and the second conducting layer are conducted in the lug area. The first conducting layer and the second conducting layer of the composite current collector are separated by a base film made of an insulating material in a coating area, and the first conducting layer and the second conducting layer respectively react to generate current. The first conducting layer and the second conducting layer are conducted in the pole lug area, so that current is converged in the pole lug area, the metal foil does not need to be additionally welded to collect the current, the adapter plate is directly welded to the pole lug area, the converging structure is simplified, the manufacturing efficiency is improved, the manufacturing cost is reduced, and the large-scale use is facilitated.

Description

Composite current collector, pole piece, battery and device using battery

Technical Field

The application relates to the technical field of batteries, in particular to a composite current collector, a pole piece, a battery and a device using the battery.

Background

The rapid development of lithium ion batteries is promoted by the current reasons of global ecological environment destruction, energy shortage, new energy policy development of all countries in the world and the like. The lithium ion battery has excellent electrochemical properties such as high power density, high working voltage, long service life and the like, so that the lithium ion battery is widely applied to the fields of 3C digital products, new energy automobiles, energy storage and the like.

The lithium ion cell is an important constituent unit of the lithium ion battery and is formed by combining a current collector, positive and negative active materials, a diaphragm and electrolyte. Usually, a metal foil is selected as a current collector, wherein the positive current collector is selected from an aluminum foil, and the negative current collector is selected from a copper foil. The current collector of the lithium electronic battery mainly collects the current generated by the active substances of the positive and negative electrodes and utilizes the conductive performance of the current collector to collect the current into large current which is output outwards. Therefore, according to the electrical principle, sufficient contact between the current collector and the active material is required to ensure that the internal resistance is as small as possible.

However, the inventors found in the research process that the current collectors in the prior art mainly have the following problems during the use process: (1) conventional current collectors generally use metal foils as current collectors, and then directly coat the active material on the surface thereof. The surface of the metal current collector is smooth, so that the adhesive cannot play the adhesive role if the amount of the adhesive is small or the preparation process fails in the manufacturing process of the pole piece, and the active substance is firmly adhered to the current collector. And (2) when the traditional current collector is used in the lithium ion battery, the current collector in the battery is soaked in the proton organic electrolyte for a long time to generate corrosion, so that the current collector loses, collects and conducts large current. (3) In the normal charge and discharge process of the active material, the crystal lattice of the active material stretches due to charge and discharge so as to separate the active material from the current collector, and finally the battery core fails.

In order to improve the energy density and safety of the battery, attention is paid to a composite current collector obtained by compounding a polymer film and a metal coating. The conducting layer of this compound mass flow body both sides is separated by the insulating layer for the conducting layer of insulating layer both sides can't switch on, consequently need make the compound mass flow body earlier and roll up the core after when doing utmost point ear, and use the one end of two metal foils to weld the two sides of compound mass flow body respectively, then weld the one end coincidence of two metal foils, make the electric current of the conducting layer of compound mass flow body both sides converge together, at last through the adaptor piece welding to the electric core.

The composite current collector has the defects of complex manufacturing process and high cost, and is difficult to realize large-scale use.

SUMMERY OF THE UTILITY MODEL

An object of this application embodiment is to provide a device of compound mass flow body, pole piece, battery and use battery, its technical problem that can improve the electric current of compound mass flow body and be difficult to collect.

In a first aspect, an embodiment of the present application provides a composite current collector, which includes a first conductive layer, a base film, and a second conductive layer, which are sequentially stacked, where the composite current collector has a coating area for coating an active material and a tab area for forming a tab, the base film in the coating area is made of an insulating material, and the first conductive layer and the second conductive layer are conducted in the tab area.

In the implementation process, the coating areas on the two sides of the composite current collector are respectively used for coating active materials, and the tab areas are used for forming tabs and are directly connected with the adapter plate. The first conducting layer and the second conducting layer of the composite current collector are separated by a base film made of an insulating material in a coating area, and the first conducting layer and the second conducting layer respectively react to generate current. The first conducting layer and the second conducting layer are conducted in the pole lug area, so that current is converged in the pole lug area, the metal foil does not need to be additionally welded to collect the current, the adapter plate is directly welded to the pole lug area, the converging structure is simplified, the manufacturing efficiency is improved, the manufacturing cost is reduced, and the large-scale use is facilitated.

In one possible embodiment, the base film of the coating region is made of a polymer material, and the base film of the extreme ear region is made of a polymer material dispersed with conductive particles.

In the above-mentioned realization process, the base film in coating district is made by insulating macromolecular material for the first conducting layer and the second conducting layer of base film both sides can't switch on in coating district, and the electrically conductive particle of dispersion can make the base film in utmost point ear district have electric conductivity in the macromolecular material, and then makes first conducting layer and second conducting layer switch on in utmost point ear district.

In one possible embodiment, the polymeric material is polypropylene, polyethylene terephthalate, polyimide, polyamide, polyethylene naphthalate, polyphenylene sulfide, polyvinyl chloride, or polyvinylidene chloride.

The conductive particles are metal conductive particles or carbon-based conductive particles, the metal conductive particles are made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy, and the carbon-based conductive particles are made of graphite, acetylene black, graphene or carbon nanotubes.

In one possible embodiment, the mass of the conductive particles in the base film of the extreme ear region is 1 to 99 wt% of the mass of the high molecular material.

Optionally, the mass of the conductive particles is 10-50 wt% of the mass of the polymer material.

In the above implementation process, when the mass of the conductive particles in the base film part region is 1 to 99 wt% of the mass of the polymer material, the base film part region can be made conductive.

In one possible embodiment, the conductive particles have a particle size of 0.01 to 12 μm.

Optionally, the conductive particles have a particle size of 0.1 to 2 μm.

In the implementation process, the particle size of the conductive particles is 0.01-12 microns, so that the conductive particles are uniformly distributed in the high polymer material.

In one possible embodiment, the thickness of the base film is 0.9 to 20 μm.

In one possible embodiment, the material of the first conductive layer and the second conductive layer is aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy.

In a second aspect, embodiments of the present application provide a pole piece, which includes the composite current collector described above, and a coating region of the surfaces of the first conductive layer and the second conductive layer is provided with an active material.

In a third aspect, an embodiment of the present application provides a battery, which includes a casing and the above-mentioned pole piece, where the pole piece is disposed in the casing.

In a fourth aspect, the present application provides a device using a battery, which includes the above battery, and the battery is used for providing electric energy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a cross-sectional view of a prior art composite current collector of the present application;

FIG. 2 is a cross-sectional view of a prior art pole piece of the present application;

fig. 3 is a cross-sectional view of a first composite current collector of an embodiment of the present application;

FIG. 4 is a front view of a first base film of an embodiment of the present application;

FIG. 5 is a front view of a laminated pole piece of an embodiment of the present application;

FIG. 6 is a front view of a wound pole piece according to an embodiment of the present application;

fig. 7 is a cross-sectional view of a second composite current collector of an embodiment of the present application;

FIG. 8 is a front view of a second base film of an embodiment of the present application;

FIG. 9 shows a cut pole piece according to an embodiment of the present application;

FIG. 10 is a cross-sectional view of a pole piece of an embodiment of the present application;

FIG. 11 is a front view of a pole piece of an embodiment of the present application;

fig. 12 is a schematic structural diagram of a battery according to an embodiment of the present application.

Icon: 10-a composite current collector; 100-a first conductive layer; 200-a base film; 201-a coating zone; 202-polar ear region; 300-a second conductive layer; 400-pole ear; 500-an active material; 20-pole piece; 30-a battery; 610-a shell body; 620-shell cover; 621-positive pole column; 622-cathode terminal; 623-explosion-proof valve.

Detailed Description

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

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

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 application, it should be noted that the terms "upper", "lower", "inner", "outer", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings or orientations or positional relationships conventionally placed when products of the application are used, and are only used for convenience of description and simplification of the description, but do not indicate or imply that the devices or elements referred to must have specific orientations, be constructed in specific orientations, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is further noted that, unless expressly stated or limited otherwise, the terms "disposed," "mounted," and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Referring to fig. 1 and 2, a conventional composite current collector 10 includes a first conductive layer 100, a base film 200, and a second conductive layer 300, which are sequentially stacked.

Wherein the base film 200 is made of an insulating material, resulting in that the first conductive layer 100 and the second conductive layer 300 cannot be conducted. Therefore, the current collector 10 needs to additionally manufacture the tab 400, before the tab 400 is manufactured, the current collector 10 needs to be manufactured into a roll core, then one ends of two metal foils are used to weld the surfaces of the first conductive layer 100 and the second conductive layer 300 respectively, and one ends of the two metal foils are welded in an overlapping manner, so that the currents of the first conductive layer 100 and the second conductive layer 300 on the two sides of the current collector 10 are gathered together, and finally the current collector is welded to a battery cell through an adapter plate.

However, the conventional composite current collector 10 has the disadvantages of complicated manufacturing process and high cost, and is difficult to realize large-scale use.

Referring to fig. 3 and 4, an embodiment of the present application provides a composite current collector 10, which includes a first conductive layer 100, a base film 200, and a second conductive layer 300, which are sequentially stacked.

The composite current collector 10 has a coating region 201 and a tab region 202, the base film 200 of the coating region 201 is made of an insulating material, and the base film 200 of the tab region 202 is made of a conductive material, such that the first conductive layer 100 and the second conductive layer 300 are conducted in the tab region 202.

The coating regions 201 on both sides of the composite current collector 10 are used to coat the active material 500, and the tab regions 202 are used to form the tabs 400 and directly connect the tabs. The first conductive layer 100 and the second conductive layer 300 of the composite current collector 10 of the present application are separated by the base film 200 made of an insulating material in the coating region 201, and the first conductive layer 100 and the second conductive layer 300 respectively react to generate an electric current. And the first conductive layer 100 and the second conductive layer 300 are conducted in the tab area 202, so that current is converged in the tab area 202, and a tab 400 is not required to be additionally installed to collect the current. The composite current collector 10 can directly weld the adapter sheet on the lug area 202, simplifies the confluence structure, improves the manufacturing efficiency, reduces the manufacturing cost and is beneficial to large-scale use.

The base film 200 is made of a high polymer material, the high polymer material of the base film 200 of the coating area 201 does not contain conductive particles, the base film 200 of the tab area 202 is made of conductive resin, and the conductive resin is the high polymer material dispersed with the conductive particles, so that the base film 200 can freely realize the effect that a part of the conductive part is not conducted, and the base film 200 can be more freely implemented in the fields of lithium batteries 30 and the like.

The base film 200 is made of an insulating polymer material, and the polymer material of the base film 200 of the coating region 201 has no conductive particles therein, so that the first conductive layer 100 and the second conductive layer 300 on both sides of the base film 200 cannot be conducted in the coating region 201. The conductive particles dispersed in the polymer material can make the base film 200 of the tab region 202 conductive, so that the first conductive layer 100 and the second conductive layer 300 are conducted in the tab region 202.

The high polymer material is polypropylene (PP), polyethylene terephthalate (PET), Polyimide (PI), Polyamide (PA), Polyethylene (PE), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyvinyl chloride (PVC) or polyvinylidene chloride (PVDC).

And, the process of forming the base film 200 using the polymer material as a raw material includes biaxial stretching or tape casting. For example, the base film 200 includes a biaxially oriented polypropylene film (BOPP), a cast polypropylene film (CPP), a biaxially oriented polyethylene terephthalate film (BOPET), or a cast polyethylene terephthalate film (CPET).

The conductive particles are metal conductive particles or carbon-based conductive particles.

The metal conductive particles are made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy, and the carbon-based conductive particles are made of graphite, acetylene black, graphene or carbon nanotubes.

The particle size of the conductive particles is 0.01-12 mu m, which is beneficial to the uniform distribution of the conductive particles in the high polymer material.

Optionally, the conductive particles have a particle size of 0.1 to 2 μm.

In one embodiment of the present application, the conductive particles may have a particle size of 1 μm. In some other embodiments of the present application, the conductive particles may also have a particle size of 0.01 μm, 0.05 μm, 0.1 μm, 0.5 μm, 1.2 μm, 1.5 μm, or 2 μm.

The mass of the conductive particles in the base film 200 of the extreme ear region 202 is 1-99 wt% of the mass of the polymer material.

In one embodiment of the present application, the mass of the conductive particles may be 25 wt% of the mass of the polymer material. In some other embodiments herein, the mass of the conductive particles is 1 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, or 99 wt% of the mass of the polymeric material.

It should be noted that the conductive particles need to be added to the polymer material before the polymer material is molded, and the mixture is sufficiently stirred to uniformly disperse the conductive particles in the polymer material. However, during the stirring process, care must be taken to remove air to prevent the formation of bubbles.

The base film 200 can be prepared by spraying, rolling, splicing and the like.

The thickness of the base film 200 is 0.9 to 20 μm.

In one embodiment of the present application, the thickness of the base film 200 may be 10 μm. In other embodiments of the present application, the thickness of the base film 200 may also be 0.9 μm, 1 μm, 5 μm, 8 μm, 12 μm, 15 μm, 18 μm, or 20 μm.

The first conductive layer 100 is made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy.

The second conductive layer 300 is made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy.

The material of the first conductive layer 100 and the material of the second conductive layer 300 may be the same or different, and the material of the first conductive layer 100 and the thickness of the second conductive layer 300 may be the same or different.

Meanwhile, the active material 500 applied to the coating region 201 on the surface of the first conductive layer 100 needs to be matched with the material and thickness of the first conductive layer 100, and the active material 500 applied to the coating region 201 on the surface of the second conductive layer 300 needs to be matched with the material and thickness of the second conductive layer 300.

The particle diameters of the active material 500 coated on the surface of the first conductive layer 100 and the active material 500 coated on the surface of the second conductive layer 300 may be the same or different, the specific surface area may be the same or different, the gram volume may be the same or unknown, the coating thickness/weight may be the same or different, and the coating may be carbon-coated or uncoated.

In the production of the current collector, please continue to refer to fig. 3 and fig. 4, an entire base film 200 may be produced, and the composite current collector 10 has only one conductive region and one non-conductive region, the non-conductive region is located at the top end of the base film 200, the first conductive layer 100 and the second conductive layer 300 are bonded to both sides of the base film 200 to obtain the composite current collector 10, and the coating region 201 of the composite current collector 10 is further coated with the active material 500 to obtain the pole piece 20.

Selecting how to cut the pole pieces 20 according to the types of the pole pieces 20, referring to fig. 5, if the laminated pole pieces 20 are needed, cutting the pole pieces 20 to form a plurality of identical pole pieces 20, and simultaneously cutting the same position of the pole ear region 202 of each pole piece 20 to form a tab 400, wherein after the plurality of pole pieces 20 are laminated, the plurality of tabs 400 are also laminated; referring to fig. 6, if a wound pole piece 20 is required, a tab 400 is cut at the tab region 202 of the pole piece 20 to form a space, and a plurality of tabs 400 of the wound pole piece 20 are overlapped.

Referring to fig. 7 to 9, a whole base film 200 may be produced, and the base film 200 has only a plurality of conductive regions and a plurality of non-conductive regions, each conductive region corresponds to each non-conductive region one by one, the first conductive layer 100 and the second conductive layer 300 are bonded to two sides of the base film 200 to obtain the composite current collector 10, and further, the coating region 201 of the composite current collector 10 is coated with an active material 500 to obtain a pole piece 20, and a plurality of pole pieces 20 are obtained by cutting.

The choice of how to clip the pole pieces 20 is then based on the type of pole piece 20.

Referring to fig. 10 and 11, an example of the present application further provides a pole piece 20, which includes the composite current collector 10, and the coating area 201 of the surfaces of the first conductive layer 100 and the second conductive layer 300 is provided with an active material 500.

The pole piece 20 of the present application does not require additional tab 400 welding, but rather directly welds the interposer to the tab region 202.

Referring to fig. 12, the embodiment of the present application further provides a battery 30, which includes a housing and the above-mentioned pole piece 20, wherein the pole piece 20 is disposed in the housing.

Wherein the casing includes casing body 610 and cap 620, with the pole piece 20 of this application embodiment, electrolyte and diaphragm combination form the battery 30 subassembly, set up the battery 30 subassembly in casing body 610, cap 620 is provided with anodal utmost point post 621, negative pole post 622 and explosion-proof valve 623, is connected the anodal utmost point ear 400 and the anodal utmost point post 621 of battery 30 subassembly, is connected the negative pole ear 400 and the negative pole post 622 of battery 30 subassembly to obtain battery 30 with cap 620 sealing connection in casing body 610.

The device using the battery 30 in the embodiment of the present application includes the battery 30 described above, and the battery 30 is used for supplying electric energy.

In the present embodiment, the device using the battery 30 is not limited, and any device that supplies electric energy using the battery 30 of the present embodiment can be used as the device using the battery 30 of the present embodiment.

For example, the device using the battery 30 in the embodiment of the present application includes a new energy automobile, where the new energy automobile is provided with the battery 30 on a chassis, and the battery 30 supplies electric energy to a driving motor of the electric automobile, and the motor converts the electric energy of the power supply into mechanical energy.

In summary, the coating regions 201 of the composite current collector 10 according to the embodiment of the present disclosure are respectively used for coating the active material 500, and the tab regions 202 are used for forming the tabs 400 and directly connecting the interposer. The first conductive layer 100 and the second conductive layer 300 of the composite current collector 10 of the present application are separated by the base film 200 made of an insulating material in the coating region 201, and the first conductive layer 100 and the second conductive layer 300 respectively react to generate an electric current. The first conductive layer 100 and the second conductive layer 300 are conducted in the tab area 202, so that current is converged in the tab area 202, and a transition piece is directly welded on the tab area 202 without additionally welding a metal foil to converge the current, so that the converging structure is simplified, the manufacturing efficiency is improved, the manufacturing cost is reduced, and the large-scale use is facilitated.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The utility model provides a composite current collector, its characterized in that, composite current collector is including first conducting layer, base film and the second conducting layer that stacks gradually the arrangement, composite current collector has the district of coating that is used for coating active material and the utmost point ear district that is used for forming utmost point ear, the base film in coating district is made by insulating material, first conducting layer with the second conducting layer is in utmost point ear district switches on.

2. The composite current collector of claim 1, wherein the base film of the coating zone is made of a polymeric material and the base film of the polar ear zone is made of a conductive resin.

3. The composite current collector of claim 2, wherein the polymeric material is polypropylene, polyethylene terephthalate, polyimide, polyamide, polyethylene naphthalate, polyphenylene sulfide, polyvinyl chloride, or polyvinylidene chloride;

the conductive particles in the conductive resin are metal conductive particles or carbon-based conductive particles, the metal conductive particles are made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy or aluminum-zirconium alloy, and the carbon-based conductive particles are made of graphite, acetylene black, graphene or carbon nanotubes.

4. The composite current collector of claim 3, wherein the conductive particles have a particle size of 0.01 to 12 μm.

5. The composite current collector of claim 4, wherein the conductive particles have a particle size of 0.1 to 2 μm.

6. The composite current collector of claim 1, wherein the base film has a thickness of 0.9 to 20 μm.

7. The composite current collector of claim 1, wherein the first and second conductive layers are made of aluminum, copper, nickel, titanium, silver, nickel-copper alloy, or aluminum-zirconium alloy.

8. A pole piece comprising the composite current collector of any one of claims 1 to 7, wherein the coated areas of the surfaces of the first and second conductive layers are provided with an active material.

9. A battery comprising a housing and the pole piece of claim 8, wherein the pole piece is disposed within the housing.

10. A battery-operated device, characterized in that it comprises a battery according to claim 9, said battery being intended to provide electric energy.