Current collector assembly, secondary battery and electronic equipment

Abstract

The utility model provides a current collector assembly, secondary battery and electronic equipment, the assembly comprises laminated composite current collectors, each composite current collector comprises a polymer base material and conductive metal layers at two sides, in any two connected composite current collectors, the contacted conductive metal layers form a first conductive path, and the conductive metal layers form a second conductive path. The non-contact conductive metal layer forms a second conductive path; any connected composite current collectors are respectively provided with any one of a first interpenetrating area and a second interpenetrating area, the first interpenetrating area is divided into at least two movable end pieces, at least one movable end piece enables the conductive metal layers forming the first conductive paths to abut against each other, and the first conductive paths are electrically communicated. And at least one movable end sheet is inserted into the adjacent second insertion area, so that the non-contact conductive metal layers forming the second conductive paths are propped against each other, and the second conductive paths are electrically communicated. According to the current collector assembly, the secondary battery and the electronic equipment, the overall thickness of the battery can be reduced, and the battery performance is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to secondary battery technical field, concretely relates to a current collector assembly, secondary battery and electronic equipment. BACKGROUND

[0002] With the scale use of traditional fossil fuels leading to resource shortage and environmental pollution, the development of energy storage systems such as power batteries and wind power photovoltaic green energy is vigorously promoted. Among them, lithium ion battery as a kind of secondary battery, because of its high energy density, long cycle life, good rate performance, low cost and other advantages, is widely used in 3C products, energy storage systems and power batteries. Among the various materials that make up lithium ion batteries, aluminum foil and copper foil are widely used as current collectors of positive and negative electrodes. Although the stability of the battery has been greatly improved, but after being pierced by impact, the positive and negative electrodes are likely to catch fire, so the current collector composed of polymer and metal is considered to be an effective solution to improve the safety of the battery.

[0003] But the composite current collector substrate is mostly two-sided metalized polymer, and due to the excellent insulation ability of non-polar polymer, additional welding process is needed to make both sides conductive, so the total tab thickness welded is much higher than the composite current collector tab thickness, which is not conducive to the size design of the battery cell and the shell process of the laminated body. SUMMARY

[0004] The utility model provides a kind of current collector assembly, secondary battery and electronic equipment, can guarantee that all insertion area double-sided conduction is under the premise of forming tab, does not increase tab thickness. Compared with switching welding process, the thickness of tab area is lower, the overall size of laminated body is smaller, and the damage of switching welding process to tab and the heating problem of welding point position are avoided, improve battery safety and cycle performance.

[0005] To solve the above technical problems, the utility model is realized through the following technical solutions.

[0006] The utility model provides a kind of current collector assembly, including the composite current collector that is sequentially laminated, the composite current collector includes polymer substrate and the conductive metal layer being arranged at the two sides of the polymer substrate, wherein in any two interfaces the composite current collector, two contact the conductive metal layer constitutes first electrically conducting path, two non-contact the conductive metal layer constitutes second electrically conducting path;

[0007] Any one of the first interpenetration region or the second interpenetration region is arranged on any one of the composite current collector, the first interpenetration region on the composite current collector is divided into at least two movable end pieces, at least one of the movable end pieces makes two conductive metal layers constituting the first electric conduction path abut to realize electric connection of the first electric conduction path, and at least one of the movable end pieces interpenetrates the adjacent second interpenetration region to make two non-contact conductive metal layers constituting the second electric conduction path abut to realize electric connection of the second electric conduction path.

[0008] In an embodiment of the present application, the composite current collector is further provided with a pole piece region in a region outside the first interpenetration region or the second interpenetration region, and a surface of the conductive metal layer in the pole piece region is coated with an active layer.

[0009] In an embodiment of the present application, a direction parallel to a boundary of the interpenetration region and the pole piece region is a length direction, the movable end piece of the first interpenetration region is divided along the length direction, a length of the movable end piece of the first interpenetration region is less than a length of the first interpenetration region, and the length of the movable end piece of the first interpenetration region is greater than or equal to a length of the second interpenetration region.

[0010] In an embodiment of the present application, a direction parallel to a boundary of the interpenetration region and the pole piece region is a length direction, the movable end piece of the first interpenetration region is divided along the length direction, the second interpenetration region on the composite current collector is divided into at least two movable end pieces along the length direction, and a movable end of the movable end piece of the second interpenetration region is arranged opposite to a movable end of the movable end piece of the first interpenetration region.

[0011] In an embodiment of the present application, the length of the first interpenetration region and the length of the second interpenetration region are equal and coincide along the length direction, the length of the movable end piece of the first interpenetration region is less than the length of the first interpenetration region, the length of the movable end piece of the second interpenetration region is less than the length of the second interpenetration region, and the sum of the length of the movable end piece of the first interpenetration region and the length of the movable end piece of the second interpenetration region is greater than or equal to the length of the first interpenetration region.

[0012] In an embodiment of the present application, the length of the first interpenetration region and the length of the second interpenetration region are equal and coincide along the length direction, the length of the movable end piece of the first interpenetration region is equal to one half of the length of the first interpenetration region, and the length of the movable end piece of the second interpenetration region is equal to one half of the length of the second interpenetration region.

[0013] In an embodiment of the utility model, the length of the movable end piece of at least one second insertion area is zero.

[0014] In an embodiment of the utility model, the width of the movable end piece of at least one second insertion area is equal to the width of the movable end piece of the first insertion area.

[0015] The utility model also provides a secondary battery comprising the current collector assembly.

[0016] The utility model also provides an electronic device comprising the secondary battery.

[0017] In summary, the utility model provides a current collector assembly, a secondary battery and an electronic device, by adopting composite current collector, can improve the stability of current collector, low permeability, strong adaptability and adjustability, improve the safety and cycle life of secondary battery. And do not need to carry out switching welding every piece of composite current collector, can guarantee that all insertion areas are double-sided conductive under the premise of forming the lug, do not increase the thickness of lug. Compared with switching welding process, the thickness of lug area is lower, the overall size of the laminated core is smaller, and the damage of switching welding process to the lug and the heating problem of the welding point position are avoided, the safety and cycle performance of the battery are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0019] Figure 1 It is a secondary battery schematic diagram in an embodiment.

[0020] Figure 2 It is the schematic diagram of the electrode assembly of the laminated stack in an embodiment.

[0021] Figure 3 It is the schematic diagram of the positive pole piece in an embodiment.

[0022] Figure 4 It is the cross-sectional schematic diagram of the positive pole piece in an embodiment.

[0023] Figure 5 It is the cross-sectional schematic diagram of the negative pole piece in an embodiment.

[0024] Figure 6 It is the schematic diagram of the first insertion area on the partial pole piece area in an embodiment.

[0025] Figure 7Schematic diagram of the first interpenetration region on part of the tab region in another embodiment.

[0026] Figure 8 Schematic diagram of the second interpenetration region on part of the tab region in an embodiment.

[0027] Figure 9 Schematic diagram of the second interpenetration region on part of the tab region in another embodiment.

[0028] Figure 10 Schematic diagram of the second interpenetration region on part of the tab region in another embodiment.

[0029] Figure 11 Schematic diagram of the second interpenetration region on part of the tab region in another embodiment.

[0030] Figure 12 Schematic diagram of the connection between the first interpenetration region and the second interpenetration region in an embodiment.

[0031] Figure 13 Schematic diagram of the connection between the first interpenetration region and the second interpenetration region in another embodiment.

[0032] Figure 14 Schematic diagram of the connection between the first interpenetration region and the second interpenetration region in another embodiment.

[0033] Figure 15 Schematic diagram of the connection between the first interpenetration region and the second interpenetration region in another embodiment.

[0034] Figure 16 Test results of the tab overall thickness and the tab resistance in Embodiments 1-2 and Comparative Example 1.

[0035] Explanation of reference numerals:

[0036] 10, housing; 11, first electrode; 12, second electrode; 13, explosion-proof valve; 14, liquid injection hole; 100, positive tab; 101, positive tab region; 102, positive interpenetration region; 110, positive current collector; 111, first polymer base material; 112, first conductive metal layer; 120, positive active layer; 200, negative tab; 210, negative current collector; 211, second polymer base material; 212, second conductive metal layer; 220, negative active layer; 201, negative tab region; 202, negative interpenetration region; 130, first interpenetration region; 131, first movable end piece; 132, second movable end piece; 133, third movable end piece; 140, second interpenetration region; 141, fourth movable end piece; 142, fifth movable end piece; 143, sixth movable end piece; 300, separator. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. The present application can also be implemented or applied through different specific embodiments, and various modifications or changes can be made to the details in the specification without departing from the spirit of the present application.

[0038] It should be understood that the structures, proportions, sizes, etc. shown in the drawings of the specification are only used to understand and read the disclosed content by those skilled in the art, and are not used to limit the implementation conditions of the present application, and therefore do not have technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the disclosed technology. At the same time, the terms such as "upper", "lower", "left", "right", "middle", "below", "lower", "first", "second", and "one" in the specification are only for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the implementation of the present application.

[0039] The technical solutions of the present application will be further described in detail below in combination with the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0040] The present application provides an electronic device, which includes at least one secondary battery for providing electric energy. The electronic device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. In an embodiment of the present application, the vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc. The above electric devices are not specially limited in the present application.

[0041] Please refer to Figure 1As shown in the utility model one embodiment, provide a kind of secondary battery, can be used for above-mentioned electronic equipment, secondary battery includes shell 10 and the electrode assembly (not shown in drawing) being arranged in shell 10.Wherein, the utility model does not limit the type and shape of secondary battery, for example, soft pack battery, cylindrical battery or square shell battery etc., again, for example, sodium ion secondary battery or lithium ion secondary battery etc., in the embodiment, for example, with lithium ion secondary battery as example is described.

[0042] Please refer to Figure 1 As shown in the utility model one embodiment, when secondary battery is for example square shell battery, square shell battery is for example including shell 10, first electrode 11, second electrode 12 and explosion-proof valve 13, liquid injection hole 14 and electrode assembly (not shown in drawing) being arranged in shell, electrode assembly is electrically connected with electrode on shell 10.Wherein, the shape of shell 10 is matched with the shape of electrode assembly, and the material of shell 10 is for example aluminum shell, steel shell or flexible shell etc., and the accommodating cavity is formed in shell 10, for accommodating electrode assembly.Specifically, after placing electrode assembly in shell 10, shell is sealed using top cover, and first electrode 11, second electrode 12, explosion-proof valve 13 and liquid injection hole 14 etc. are arranged on top cover, electrolyte is injected through liquid injection hole 14, and then liquid injection hole 14 is sealed.Wherein, the polarity of first electrode 11 and second electrode 12 is opposite, and first electrode 11 and second electrode 12 are respectively positive or negative, and the utility model does not limit the specific polarity category corresponding to first electrode 11 and second electrode 12.First electrode 11 is electrically connected with the same polarity tab on electrode assembly, and second electrode 12 is electrically connected with the same polarity tab on electrode assembly.In the embodiment, the position of first electrode 11 and second electrode 12 is not limited, can be located at the same end of shell, also can be located at both ends of shell, and is set according to the position of tab on electrode assembly or design requirement.

[0043] Please refer to Figure 1As shown in the utility model one embodiment, when the first electrode 11 and the second electrode 12 are arranged at one end of the shell, the explosion-proof valve 13 and the liquid injection hole 14 are arranged between the first electrode 11 and the second electrode 12, the explosion-proof valve 13 is arranged at the intermediate position of the first electrode 11 and the second electrode 12 for example, and has a preset distance between the first electrode 11 and the second electrode 12 respectively, the liquid injection hole 14 is arranged between the explosion-proof valve 13 and the first electrode 11, or arranged between the explosion-proof valve 13 and the second electrode 12, that is, the explosion-proof valve 13, the liquid injection hole 14, the first electrode 11 and the second electrode 12 are arranged at intervals. The explosion-proof valve 13 can open the air permeability function when the battery cell works normally, so that the airflow inside and outside the battery cell can circulate, and the particulate matter cannot circulate. When the battery cell occurs thermal runaway, the pressure difference inside and outside the battery cell reaches the explosion-proof preset value, the explosion-proof valve opens, and the gas and solid can be discharged from the inside of the battery cell to the outside of the battery cell through the explosion-proof valve, thereby improving the safety performance of the battery cell.

[0044] Please refer to Figure 2 As shown in the utility model one embodiment, the electrode assembly includes a current collector assembly, and the current collector assembly includes a composite current collector which is stacked in sequence, and the composite current collector includes a polymer base material and a conductive metal layer arranged on both sides of the polymer base material. The composite current collector includes a penetration region and a tab region outside the penetration region, and the conductive metal layer in the tab region is coated with an active layer. In this embodiment, according to the different types of conductive metal layer and active layer on the composite current collector, the composite current collector coated with different polarity active layers is defined as a positive tab 100 and a negative tab 200, and a separator 300 is arranged between the positive tab 100 and the negative tab 200 in the electrode assembly to prevent the positive tab 100 and the negative tab 200 from contacting to cause safety problems. The electrolyte (not shown in the figure) is filled between the positive tab 100, the negative tab 200 and the separator 300, and between the electrode assembly and the shell, which plays a role in conducting ions between the positive and negative tabs. The electrolyte is selected from any suitable electrolyte of a lithium ion battery. The stacking mode of the composite current collector is not specifically limited in this application, and is selected according to the production requirements.

[0045] Please refer to Figure 2 As shown in the utility model one embodiment, the separator 300 is, for example, a polyethylene film (Polyethylene, PE), a polypropylene film (Polypropylene, PP), a glass fiber film, a polyethylene film or a composite film, etc. In this embodiment, the thickness of the separator 300 is, for example, 1-15 μm.

[0046] Please refer to Figures 3-4As shown, in one embodiment of this utility model, the positive electrode 100 includes a positive current collector 110 and positive active layers 120 disposed on both sides of the positive current collector 110. The positive current collector 110 includes a first polymer substrate 111 and a first conductive metal layer 112. The first conductive metal layer 112 is disposed on both sides of the first polymer substrate 111. The first polymer substrate 111 includes polymer layers such as polypropylene (PP), polyethylene terephthalate (PET), or polyimide (PI). The first conductive metal layer 112 is, for example, an aluminum layer. This application does not limit the thickness of the first polymer substrate 111 and the first conductive metal layer 112, and they can be selected according to manufacturing requirements. The area coated with the positive active layer 120 is defined as the positive electrode region 101, and the area of ​​the positive current collector 110 without the positive active layer 120 is defined as the positive electrode penetration region 102.

[0047] Please see Figures 3-4 As shown, in one embodiment of this utility model, the positive electrode active layer 120 on the positive electrode current collector 110 has a uniform thickness at different positions in all directions. The positive electrode active layer 120 includes a positive electrode active material, a binder, and a conductive agent. The positive electrode active material is, for example, one or more of ternary positive electrode materials, lithium manganese oxide, lithium iron phosphate, or lithium titanate. The binder is, for example, selected from any one or more of polyvinylidene fluoride (PVDF), polyamide (PA), polyacrylonitrile (PAN), polyacrylate (polyacrylate), polymethyl methacrylate (PMMA), ethylene-propylene-diene terpolymer (EPDM), polyhexanefluoropropylene (Polyhexafluoropropylene), or polymerized styrene-butadiene rubber (SBR). The conductive agent is, for example, selected from any one or more of conductive carbon black, acetylene black, carbon nanotubes, and graphene. This invention does not limit the thickness of the positive electrode active layer 120; the specific thickness can be selected based on the battery design requirements.

[0048] Please see Figure 5As shown, in one embodiment of this utility model, the negative electrode sheet 200 includes a negative electrode current collector 210 and a negative electrode active layer 220 disposed on both sides of the negative electrode current collector 210. The negative electrode current collector 210 includes a second polymer substrate 211 and a second conductive metal layer 212. The second conductive metal layer 212 is disposed on both sides of the second polymer substrate 211, and the second polymer substrate 211 includes a non-polar polymer layer such as polypropylene, polyethylene terephthalate, or polyimide. The second conductive metal layer 212 is, for example, a copper layer. This application does not limit the thickness of the second polymer substrate 211 and the second conductive metal layer 212, and they can be selected according to the manufacturing requirements. The area coated with the negative electrode active layer 220 is defined as the negative electrode sheet region 201, and the area of ​​the negative electrode current collector 210 without the negative electrode active layer 220 is defined as the negative electrode penetration region 202.

[0049] Please see Figure 5 As shown, in one embodiment of this invention, the thickness of the negative electrode active layer 220 on the negative electrode current collector 210 is uniform at different positions in all directions. The negative electrode active layer 220 includes a negative electrode active material, a binder, a thickener, and a conductive agent. The negative electrode active material is selected from, for example, any one or a combination of at least two of the following: soft carbon, hard carbon, artificial graphite, natural graphite, silicon, silicon oxide compounds, silicon carbide compounds, or lithium titanate. The binder is selected from, for example, any one or more of the following: polyvinylidene fluoride, polyamide, polypropylene, polyacrylate, polyethylene ether, polymethyl methacrylate, polyhexafluoropropylene, or styrene-butadiene rubber. The conductive agent is selected from, for example, any one or more of the following: conductive carbon black, acetylene black, carbon nanotubes, and graphene. The thickener is selected from, for example, sodium carboxymethyl cellulose. This invention does not limit the thickness of the negative electrode coating; the specific thickness is selected according to the battery requirements. By setting the thickness of the active material layer to be uniform, the consistency of charging and discharging of the secondary battery can be improved.

[0050] Please see Figure 2 , Figures 6-11 As shown, in one embodiment of this utility model, in the electrode assembly, the positive electrode 100 includes a positive electrode region 101 and a positive electrode insertion region 102, and the negative electrode 200 includes a negative electrode region 201 and a negative electrode insertion region 202. A diaphragm 300 is provided between the positive electrode region 101 of the positive electrode 100 and the negative electrode region 201 of the negative electrode 200 to prevent the electrode regions of the positive electrode 100 and the negative electrode 200 from contacting and causing a short circuit. The connected composite current collector is an insertion region of the same polarity, that is, the positive electrode insertion regions 102 of multiple positive electrode 100 are connected together. After insertion, the multiple positive electrode 100s are electrically connected and serve as positive electrode tabs. The negative electrode insertion regions 202 of multiple negative electrode 200s are connected together. After insertion, the multiple negative electrode 200s are electrically connected and serve as negative electrode tabs. In this embodiment, the positive electrode interpenetration region 102 and the negative electrode interpenetration region 202 can beFigures 7-11 Any one or more combinations of the first interpenetration region 130 or the second interpenetration region 140 shown, and any two adjacent composite current collectors are respectively provided with any one of the first interpenetration region 130 or the second interpenetration region 140, that is, in a plurality of stacked positive electrode sheets 100 or negative electrode sheets 200, the first interpenetration region 130 or the second interpenetration region 140 is staggered. In this embodiment, the length direction is parallel to the direction of the interpenetration region and the electrode sheet region boundary, and the width direction is perpendicular to the boundary. In particular, as shown in Figure 6 The first interpenetration region 130 shown is preferably present at the beginning and end of the plurality of positive electrode sheets 100 or the plurality of negative electrode sheets 200 in the stacking direction.

[0051] Please refer to Figure 6 and Figure 7 In an embodiment of the present application, the first interpenetration region 130 is provided at one end of the positive electrode sheet region 101 or the negative electrode sheet region 201 (101 / 201), the size of the first interpenetration region 130 in the length direction is defined as length L, and the size of the first interpenetration region 130 in the width direction is defined as D. Along the length direction of the first interpenetration region 130, the first interpenetration region 130 is divided into at least two movable end pieces from the same side of the first interpenetration region 130, that is, at least including the first movable end piece 131 and the second movable end piece 132, and for example, along the length direction, the first interpenetration region 130 is divided into the first movable end piece 131, the second movable end piece 132 and the third movable end piece 133 arranged in turn. Among them, the lengths of the plurality of movable end pieces of the first interpenetration region 130 are equal, for example, the length of the movable end piece is L1, and the length L1 of the movable end piece of the first interpenetration region 130 is less than the length L of the first interpenetration region 130. That is, from the same side of the first interpenetration region 130, part of the first movable end piece 131 and the second movable end piece 132, part of the second movable end piece 132 and the third movable end piece 133 are discontinuously arranged, and on the other side of the first interpenetration region 130, the first interpenetration region 130 is continuously arranged, wherein any one side surface of the first interpenetration region 130 is defined as the first surface (A), and the other side surface is defined as the second surface (B, not shown in the figure), that is, the first surface (A) and the second surface (B) are respectively opposite surfaces of the first interpenetration region 130.

[0052] Please refer to Figure 8 and Figure 9As shown in the embodiment of the present application, the second insertion area 140 is arranged at one side of the partial positive pole piece area 101 or the partial negative pole piece area 201, wherein the size of the second insertion area 140 along the length direction is defined as length l, and the size of the first insertion area 130 along the width direction is defined as d. In the embodiment of the present application, along the length direction of the second insertion area 140, the second insertion area 140 is divided into at least two movable end pieces from the same side of the second insertion area 140, and for example, along the length direction, the second insertion area 140 is divided into the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 arranged in sequence. Wherein the length l1 of the movable end piece of the second insertion area 140 is less than the length l of the second insertion area 140. That is, the movable end pieces are discontinuously arranged from the same side of the second insertion area 140, and the second insertion area 140 is continuously arranged at the other side of the second insertion area 140. Wherein the side of the second insertion area 140 away from the first surface is defined as the front face (+), and the other side surface is defined as the back face (-, not shown in the figure), that is, the front face (+) and the back face (-) are opposite two surfaces of the second insertion area 140.

[0053] As shown in the embodiment of the present application, the second insertion area 140 is arranged at one side of the partial positive pole piece area 101 or the partial negative pole piece area 201, wherein the size of the second insertion area 140 along the length direction is defined as length l, and the size of the first insertion area 130 along the width direction is defined as d. In the embodiment of the present application, along the length direction of the second insertion area 140, the second insertion area 140 is divided into at least two movable end pieces from the same side of the second insertion area 140, and for example, along the length direction, the second insertion area 140 is divided into the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 arranged in sequence. Wherein the length l1 of the movable end piece of the second insertion area 140 is less than the length l of the second insertion area 140. That is, the movable end pieces are discontinuously arranged from the same side of the second insertion area 140, and the second insertion area 140 is continuously arranged at the other side of the second insertion area 140. Wherein the side of the second insertion area 140 away from the first surface is defined as the front face (+), and the other side surface is defined as the back face (-, not shown in the figure), that is, the front face (+) and the back face (-) are opposite two surfaces of the second insertion area 140. Figures 6-10 As shown in the embodiment of the present application, the second insertion area 140 is arranged at one side of the partial positive pole piece area 101 or the partial negative pole piece area 201, wherein the size of the second insertion area 140 along the length direction is defined as length l, and the size of the first insertion area 130 along the width direction is defined as d. In the embodiment of the present application, along the length direction of the second insertion area 140, the second insertion area 140 is divided into at least two movable end pieces from the same side of the second insertion area 140, and for example, along the length direction, the second insertion area 140 is divided into the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 arranged in sequence. Wherein the length l1 of the movable end piece of the second insertion area 140 is less than the length l of the second insertion area 140. That is, the movable end pieces are discontinuously arranged from the same side of the second insertion area 140, and the second insertion area 140 is continuously arranged at the other side of the second insertion area 140. Wherein the side of the second insertion area 140 away from the first surface is defined as the front face (+), and the other side surface is defined as the back face (-, not shown in the figure), that is, the front face (+) and the back face (-) are opposite two surfaces of the second insertion area 140.

[0054] As shown in the embodiment of the present application, the second insertion area 140 is arranged at one side of the partial positive pole piece area 101 or the partial negative pole piece area 201, wherein the size of the second insertion area 140 along the length direction is defined as length l, and the size of the first insertion area 130 along the width direction is defined as d. In the embodiment of the present application, along the length direction of the second insertion area 140, the second insertion area 140 is divided into at least two movable end pieces from the same side of the second insertion area 140, and for example, along the length direction, the second insertion area 140 is divided into the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 arranged in sequence. Wherein the length l1 of the movable end piece of the second insertion area 140 is less than the length l of the second insertion area 140. That is, the movable end pieces are discontinuously arranged from the same side of the second insertion area 140, and the second insertion area 140 is continuously arranged at the other side of the second insertion area 140. Wherein the side of the second insertion area 140 away from the first surface is defined as the front face (+), and the other side surface is defined as the back face (-, not shown in the figure), that is, the front face (+) and the back face (-) are opposite two surfaces of the second insertion area 140. Figures 6-10As shown, in one embodiment of this utility model, the lengths of the first interpenetrating region 130 and the second interpenetrating region 140 are, for example, equal. The length L1 of the movable end piece of the first interpenetrating region 130 is, for example, equal to half the length L of the first interpenetrating region 130, and the length l1 of the movable end piece of the second interpenetrating region 140 is, for example, equal to half the length l of the second interpenetrating region 140. In the stacked composite current collector, the movable end of the movable end piece of the second interpenetrating region 140 is arranged opposite to the movable end piece of the movable end piece of the first interpenetrating region 130. After adjacent first interpenetrating regions 130 and second interpenetrating regions 140 interpenetrate, the first interpenetrating region 130 and the second interpenetrating region 140 coincide along the length direction. That is, the orthographic projection of the first interpenetrating region 130 onto the second interpenetrating region 140 coincides with the second interpenetrating region 140. In other words, the interpenetrating process does not increase the range of the interpenetrating region in the length direction.

[0055] Please see Figure 9 and Figure 10 As shown, in one embodiment of this utility model, at least one movable end piece in the second interlacing region 140 has a length of zero. For example, the length of the fourth movable end piece 141 or the length of the fourth movable end piece 141 and the fifth movable end piece 142 is zero; this application does not impose specific limitations. By setting the length of some movable end pieces in the second interlacing region 140 to zero, the movable end pieces of adjacent first interlacing regions 130 are easier to interlaced in the stacked composite current collector, thus improving efficiency.

[0056] Please see Figure 6 , Figure 7 and Figure 11 As shown, in another embodiment of this utility model, the second interpenetrating region 140 is configured as a continuous whole, that is, the second interpenetrating region 140 is not divided. In this case, along the length direction, the first interpenetrating region 130 is divided into at least two movable end pieces, the length of which is less than the length of the first interpenetrating region 130, and the length of the movable end piece of the first interpenetrating region 130 is greater than or equal to the length of the second interpenetrating region 140. That is, in the stacked composite current collector, after the movable end piece of the first interpenetrating region 130 interpenetrates the adjacent second interpenetrating region 140, that is, the orthographic projection of the second interpenetrating region 140 onto the first interpenetrating region 130 is within the range of the first interpenetrating region 130, that is, the interpenetrating process does not cause an increase in the range of the interpenetrating region in the length direction.

[0057] Please see Figures 6-10As shown in the utility model one embodiment, the width of the first insertion area 130 and the width of the second insertion area 140 are equal, for example, and the application does not limit the width of the first movable end piece 131, the second movable end piece 132 and the third movable end piece 133, for example, the width of the first movable end piece 131, the second movable end piece 132 and the third movable end piece 133 are equal, for example, each is one third of the width of the first insertion area 130. The application also does not limit the width of the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143, for example, the width of the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 are equal, for example, each is one third of the width of the second insertion area 140. In other embodiments, at least one movable end piece of the second insertion area 140 and the movable end piece of the first insertion area 130 are equal in width to ensure that the insertion process does not increase the range of the insertion area in the width direction in the laminated composite fluid.

[0058] Please refer to Figure 7 、 Figure 9 and Figure 12 As shown in the utility model one embodiment, for example, taking the laminated stack as an example, the connection mode of any adjacent composite current collector is described. The length of the first insertion area 130 and the length of the second insertion area 140 are equal, the length of the first movable end piece 131 and the second movable end piece 132 is equal, for example, the sum of the length of the first movable end piece 131 and the fourth movable end piece 141 is equal to the length of the first insertion area 130, the length of the fifth movable end piece 142 is zero, for example, the width of the first movable end piece 131 and the fourth movable end piece 141 is equal, and the width of the second movable end piece 132 and the fifth movable end piece 142 is equal. In this embodiment, for example, the second insertion area 140, the first insertion area 130 and the second insertion area 140 are staggered, and after stacking, the movable end of the movable end piece of the second insertion area 140 is arranged opposite to the movable end of the movable end piece of the first insertion area 130. Before the movable end piece is inserted, any adjacent first insertion area 130 and second insertion area 140, the first surface (A) of the first insertion area 130 and the reverse (-) of the second insertion area 140 are in contact or the second surface (B) of the first insertion area 130 and the front (+) of the second insertion area 140 are in contact, that is, any adjacent first insertion area 130 and second insertion area 140 have only one surface in contact, the two contact conductive metal layers constitute the first electrically conductive path, and the two non-contact conductive metal layers constitute the second electrically conductive path. Due to the presence of the polymer matrix, the second electrically conductive path is not electrically connected at this time.

[0059] Please refer to Figure 7 、 Figure 9 and Figure 12As shown, in the embodiment of the present application, the second insertion area 140 is arranged in the position of the first sheet in the multi-layer sheet, and the composite sheet pair insertion process is described by arranging the second insertion area 140, the first insertion area 130 and the second insertion area 140. The first movable end sheet 131 of the first insertion area 130 is inserted into the fourth movable end sheet 141 of the second insertion area 140 of the sheet before the first insertion area 130, the second surface (B) of the first insertion area 130 and the front face (+) of the second insertion area 140 are abutted, and the electrical communication of the second electrical conduction path of the first sheet composite current collector and the second sheet composite current collector is realized. The second movable end sheet 132 of the same first insertion area 130 is inserted into the second insertion area 140 through the position of the fifth movable end sheet 142 of the second insertion area 140 of the sheet after the first insertion area 130, the first surface (A) of the first insertion area 130 and the back face (-) of the second insertion area 140 of the sheet after the first insertion area 130 are abutted, and the electrical communication of the second electrical conduction path of the second sheet composite current collector and the third sheet composite current collector is realized. The first surface (A) and the second surface (B) of the third movable end sheet 133 are respectively abutted with the back face (-) and the front face (+) of the sixth movable end sheet 143 of the two sheets before and after, and the electrical communication of the first electrical conduction path is realized. That is, when the multi-sheet composite current collector is inserted, the movable end sheet of at least one first insertion area 130 makes the two conductive metal layers constituting the first electrical conduction path abutted, and the electrical communication of the first electrical conduction path is realized. The movable end sheet of at least one first insertion area 130 is inserted into the adjacent second insertion area 140, and the two non-contact conductive metal layers constituting the second electrical conduction path are abutted, and the electrical communication of the second electrical conduction path is realized.

[0060] Please refer to Figures 6-13As shown, in an embodiment of the present application, when the first insertion area 130 is located at the first or last position of the laminated composite current collector, the first insertion area 130 only needs one movable end piece to insert the adjacent second insertion area 140, therefore, the first insertion area 130 is divided into two movable end pieces for example, and the abutting of the two conductive metal layers constituting the first electrical conduction path is realized, and the abutting of the two non-contact conductive metal layers constituting the second electrical conduction path is realized through insertion, thereby realizing the electrical connection of the first electrical conduction path and the second electrical conduction path. When the first insertion area 130 is located at the middle position of the laminated composite current collector, the first insertion area 130 is divided into three movable end pieces for example, at least one movable end piece is needed to make the two conductive metal layers constituting the first electrical conduction path abut, realizing the electrical connection of the first electrical conduction path, and two movable end pieces are needed to insert the adjacent different second insertion area 140, so that the two non-contact conductive metal layers constituting the second electrical conduction path abut, realizing the electrical connection of the second electrical conduction path, therefore, the first insertion area 130 is divided into three movable end pieces for example. The electrical connection of the second electrical conduction path is realized through insertion, and each composite current collector does not need to be connected by switching welding, and the tab can be formed under the premise of ensuring the double-sided conduction of all insertion areas, without increasing the thickness of the tab. Compared with the switching welding process, the thickness of the tab area is lower, the overall size of the laminated core is smaller, and the damage to the tab and the heating problem of the welding point position caused by the switching welding process are avoided, thereby improving the safety and cycle performance of the battery.

[0061] Please refer to Figure 14 As shown, in another embodiment of the present application, the length and width of the first insertion area 130 are equal to the length and width of the second insertion area 140 respectively, the lengths of the first movable end piece 131, the second movable end piece 132 and the third movable end piece 133 are equal for example, and the lengths of the fourth movable end piece 141, the fifth movable end piece 142 and the sixth movable end piece 143 are equal for example. The sum of the lengths of the first movable end piece 131 and the fourth movable end piece 141 is greater than or equal to the length of the first insertion area 130, and the first insertion area 130 and the second insertion area 140 are coincided along the length direction, the width of the first movable end piece 131 is equal to the width of the fourth movable end piece 141, and the width of the second movable end piece 132 is equal to the width of the fifth movable end piece 142. The first movable end piece 131 of the first insertion area 130 is inserted into the fourth movable end piece 141 of the second insertion area 140 located in front of the first insertion area 130, the second movable end piece 132 of the same first insertion area 130 is inserted into the fifth movable end piece 142 of the second insertion area 140 located behind the first insertion area 130, and the third movable end piece 133 abuts against the two adjacent sixth movable end pieces 143, thereby realizing the electrical connection of the first electrical conduction path and the electrical connection of the second electrical conduction path.

[0062] Please refer toFigure 15 As shown in the utility model another embodiment, the length and width of the first insertion area 130 and the length and width of the second insertion area 140 are equal, the first insertion area 130 includes the first movable end piece 131, the second movable end piece 132 and the third movable end piece 133 with equal length, and the length of the first movable end piece 131 is greater than the length of the second insertion area 140. The first movable end piece 131 and the second movable end piece 132 of the same first insertion area 130 are inserted into the adjacent second insertion area 140 respectively, so as to realize the electrical connection of the first electrical path and the electrical connection of the second electrical path. At this time, the orthographic projection of the second insertion area 140 on the first insertion area 130 is within the range of the first insertion area 130.

[0063] Hereinafter, the utility model will be explained more specifically by referring to the embodiments, which should not be understood as limiting. In the range consistent with the main idea of the utility model, appropriate modifications can be made, which all fall within the technical scope of the utility model.

[0064] Example 1

[0065] The electrode assembly is formed by the laminated lamination method, and according to the design method of the insertion area, a copper sheet is welded to the outermost sheet at one end of the electrode assembly, and the thickness of the whole tab formed after insertion and the resistance of the two surfaces of any sheet are measured.

[0066] Example 2

[0067] The electrode assembly is formed by the laminated lamination method, and according to the design method of the tab insertion, a copper sheet is welded to the outermost sheet at both ends of the electrode assembly, and the resistance of the whole tab formed after insertion and the resistance of the two surfaces of any sheet are measured.

[0068] Comparative Example 1

[0069] The electrode assembly is formed by the laminated lamination method, and according to the method of single sheet switching welding, the resistance of the two surfaces of any sheet and the thickness of the whole tab after lamination are measured.

[0070] Please refer to Figure 16As shown by the test results of the tab overall thickness and the tab resistance of Examples 1-2 and Comparative Example 1, the tab overall thickness of Examples 1 and 2 is smaller, and the double-sided welding of the conductive metal layer can further reduce the tab resistance relative to the single-sided welding of the conductive metal layer. In Comparative Example 1, the tab overall thickness is larger, and the tab resistance is sharply increased relative to Examples 1-2, because the two sides of the entire tab have been connected after the insertion area is inserted and the copper pad is welded in the examples, and the resistance tested is the resistance of the entire tab, so the tab resistance is smaller. Therefore, the secondary battery provided by the application can reduce the thickness of the single-piece composite current collector tab, reduce the overall thickness of the battery, reduce the internal resistance of the battery, and thus improve the safety and cycle performance of the battery.

[0071] In summary, the utility model provides a kind of current collector assembly, secondary battery and electronic equipment, by adopting composite current collector, the stability of current collector, low permeability, strong adaptability and adjustability can be improved, the safety and cycle life of secondary battery are improved.And without every piece of composite current collector is connected, can guarantee that all insertion areas are double-sidedly connected under the premise of forming tab, without increasing the thickness of tab.Compared with the switching process, the thickness of tab area is lower, the overall size of the laminated core is smaller, and the damage of switching process to tab and the heating problem of welding point position are avoided, to improve the safety and cycle performance of battery.

[0072] The above description is only the preferred embodiment of the application and the explanation of the applied technical principles, and those skilled in the art should understand that the utility model range involved in the application is not limited to the technical solutions formed by the specific combination of the above technical features, and also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the utility model concept, for example, the technical solutions formed by replacing the above features with the technical features disclosed in the application (but not limited to) having similar functions.

[0073] In addition to the technical features described in the specification, the remaining technical features are known to those skilled in the art, and to highlight the innovative features of the utility model, the remaining technical features will not be described here.

Claims

1. A current collector assembly comprising a composite current collector stacked in sequence, characterized in that, The composite current collector comprises a polymer substrate and a conductive metal layer arranged on both sides of the polymer substrate, wherein in any two adjacent composite current collectors, two contacting conductive metal layers form a first electrical conduction path, and two non-contacting conductive metal layers form a second electrical conduction path. Any two adjacent composite current collectors are provided with any one of a first interpenetration region or a second interpenetration region, the first interpenetration region on the composite current collector is divided into at least two movable end pieces, wherein at least one movable end piece makes the two conductive metal layers forming the first electrical conduction path abut to realize electrical connection of the first electrical conduction path, and at least one movable end piece interpenetrates the adjacent second interpenetration region to make the two non-contacting conductive metal layers forming the second electrical conduction path abut to realize electrical connection of the second electrical conduction path.

2. The current collector assembly of claim 1, wherein, The composite current collector is further provided with a pole piece region in a region outside the first interpenetration region or the second interpenetration region, and a surface of the conductive metal layer in the pole piece region is coated with an active layer.

3. The current collector assembly of claim 2, wherein, In a length direction parallel to a boundary between the interpenetration region and the pole piece region, the movable end piece of the first interpenetration region is divided along the length direction, the length of the movable end piece of the first interpenetration region is less than the length of the first interpenetration region, and the length of the movable end piece of the first interpenetration region is greater than or equal to the length of the second interpenetration region.

4. The current collector assembly of claim 2, wherein, In a length direction parallel to a boundary between the interpenetration region and the pole piece region, the movable end piece of the first interpenetration region is divided along the length direction, the second interpenetration region on the composite current collector is divided into at least two movable end pieces along the length direction, and the movable end of the movable end piece of the second interpenetration region is arranged opposite to the movable end of the movable end piece of the first interpenetration region.

5. The current collector assembly of claim 4, wherein, The lengths of the first interpenetration region and the second interpenetration region are equal and coincide in the length direction, the length of the movable end piece of the first interpenetration region is less than the length of the first interpenetration region, the length of the movable end piece of the second interpenetration region is less than the length of the second interpenetration region, and the sum of the length of the movable end piece of the first interpenetration region and the length of the movable end piece of the second interpenetration region is greater than or equal to the length of the first interpenetration region.

6. The current collector assembly of claim 4, wherein, The lengths of the first interpenetration region and the second interpenetration region are equal and coincide in the length direction, the length of the movable end piece of the first interpenetration region is equal to half of the length of the first interpenetration region, and the length of the movable end piece of the second interpenetration region is equal to half of the length of the second interpenetration region.

7. The current collector assembly of claim 4, wherein, The length of at least one movable end piece of the second interpenetration region is zero.

8. The current collector assembly of claim 4, wherein, The width of at least one movable end piece of the second interpenetration region is equal to the width of the movable end piece of the first interpenetration region.

9. A secondary battery characterized by comprising: The application provides a current collector assembly comprising the current collector as claimed in any one of claims 1-8.

10. An electronic device, comprising: The application provides a secondary battery comprising the current collector as claimed in claim 9.

Images