Current collector structure, pole piece and battery cell

Abstract

The utility model provides a current collector structure, a pole piece and a battery cell. The current collector structure comprises a first non-metal insulating layer, the first non-metal insulating layer is provided with a first side and a second side which are oppositely arranged in the thickness direction of the first non-metal insulating layer, the first side and / or the second side are / is provided with a metal layer, and the first non-metal insulating layer is further provided with a lithium ion channel communicated with the first side and the second side; and the central axis of the lithium ion channel is a curve or a broken line. The current collector structure provided by the technical scheme of the utility model can solve the problem that a current collector in the prior art is difficult to realize simultaneous improvement of energy density and charging capability.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, and in particular to a current collector structure, a pole piece and a battery core. Background Art

[0002] Electric vehicles have developed rapidly in recent years, and the electrification rate of vehicles continues to increase. However, extended-range and plug-in hybrid electric vehicles dominate the electric vehicle market, while the development of pure electric vehicles is limited. The main reason is people's concerns about the driving range and the convenience of recharging. In order to further develop electric vehicles, it is necessary to improve the performance of battery cells in terms of energy density and fast charging performance. At present, semi-solid and solid-state batteries are unable to be mass-produced due to technical reasons, and only traditional liquid lithium-ion batteries can be improved in performance. In order to increase the energy density of the battery, the coating surface density of the active material is generally increased. When the coating surface density is increased, the increase in lithium ion transmission paths will lead to a decrease in the fast charging capability of the battery cell. Therefore, the energy density and fast charging capability of the battery are mutually restricted, which limits the development of pure electric vehicles.

[0003] In the existing technology, the current collector generally uses copper foil as the negative electrode and aluminum foil as the positive electrode. In order to improve the energy density of the battery, the power battery industry has reduced the thickness of aluminum foil from 15um to 12um and copper foil from 8um to 4.5um. Due to technical difficulties and cost constraints, it is difficult to further reduce the thickness of copper foil and aluminum foil current collectors to reduce their mass share to increase the energy density of the battery cell. Increasing the energy density of the battery by increasing the density of the active material coating surface will increase the transmission path of lithium ions, thereby reducing the fast charging capability of the battery. From the above, it can be seen that the current collector of the existing technology is difficult to achieve while increasing the energy density of the battery and improving the charging capacity of the battery. Utility Model Content

[0004] The main purpose of the present invention is to provide a current collector structure, a pole piece and a battery core, which can solve the problem that the current collector of the prior art is difficult to achieve simultaneous improvement of energy density and charging capacity.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a current collector structure is provided, including: a first non-metallic insulating layer, along the thickness direction of the first non-metallic insulating layer, the first non-metallic insulating layer has a first side and a second side arranged opposite to each other, a metal layer is provided on the first side and / or the second side, the first non-metallic insulating layer also has a lithium ion channel connecting the first side and the second side, and the central axis of the lithium ion channel is a curve or a broken line.

[0006] Through the above-mentioned arrangement, lithium ions can reach the second side from the first side of the first non-metallic insulating layer, or reach the first side from the second side of the first non-metallic insulating layer, through the lithium ion channel, so that lithium ions can be quickly transmitted from one side of the current collector structure to the other side without bypassing obstacles or passing through more complicated paths. The transmission distance of lithium ions is reduced, thereby improving the charging and discharging capacity of the battery. In addition, compared with traditional copper foil and aluminum foil current collectors, the current collector structure of the present application can reduce the invalid mass proportion of copper foil and aluminum foil, thereby improving the energy density of the battery and achieving simultaneous improvement of the energy density and charging and discharging capacity of the lithium-ion battery.

[0007] Furthermore, the thickness of the first non-metallic insulating layer ranges from 2 μm to 16 μm, and the thickness of the metal layer ranges from 0.3 μm to 1 μm.

[0008] Through the above arrangement, both the mechanical strength and the electrical conductivity of the current collector structure can be ensured.

[0009] Furthermore, the first non-metallic insulating layer is a porous structure, and the porosity of the first non-metallic insulating layer ranges from 30% to 80%.

[0010] Through the above settings, it can be ensured that lithium ions have a good migration channel during the battery charging and discharging process, thereby improving the ion transmission rate and the electrochemical performance of the battery.

[0011] Furthermore, there are two first non-metallic insulating layers, wherein a metal layer is provided on the first side of one first non-metallic insulating layer and a metal layer is provided on the second side of the other first non-metallic insulating layer, and the sides of the two first non-metallic insulating layers not provided with the metal layer are connected.

[0012] Through the above-mentioned arrangement, during the production process, a metal layer can be formed on the first non-metallic insulating layer by combining one or more methods such as evaporation, magnetron sputtering, and water electroplating as needed, and then the sides of the two without the metal layer are connected, which can improve the production efficiency of the current collector structure.

[0013] Furthermore, there are two first non-metallic insulating layers, one of which is provided with a metal layer on the first side of the first non-metallic insulating layer, and the other is provided with a metal layer on the second side of the first non-metallic insulating layer. The current collector structure also includes a second non-metallic insulating layer. The sides of the two first non-metallic insulating layers that are not provided with a metal layer are respectively connected to the opposite sides of the second non-metallic insulating layer. When projected along the first direction, the first non-metallic insulating layer covers the second non-metallic insulating layer.

[0014] Through the above arrangement, it is possible to isolate the two metal layers from each other to achieve current convergence, while also preventing the two metal layers from being connected to each other to cause an internal short circuit.

[0015] Furthermore, the first non-metallic insulating layer and the corresponding metal layer have the same size. Along the second direction, one of the two first non-metallic insulating layers protrudes from the first end of the second non-metallic insulating layer, and the other of the two first non-metallic insulating layers protrudes from the second end of the second non-metallic insulating layer.

[0016] Through the above arrangement, welding with an external dummy tab can be achieved to realize circuit connectivity.

[0017] Furthermore, metal layers are provided on the first side and the second side of the first non-metallic insulating layer. One of the two metal layers is made of aluminum, and the other of the two metal layers is made of copper.

[0018] Through the above setting, one of the two metal layers is made of aluminum material, and the other of the two metal layers is made of copper material. Compared with the copper foil or aluminum foil current collector in the prior art, it can be used as a composite current collector, and the negative electrode material can be coated on the copper layer and the positive electrode material can be coated on the aluminum layer.

[0019] Furthermore, a metal layer is provided on the first side or the second side, and the ratio of the thickness of the metal layer to the thickness of the first non-metallic insulating layer is in the range of 0.06 to 0.15.

[0020] Through the above-mentioned setting, it can be ensured that the metal layer has sufficient electrical conductivity while ensuring the mechanical stability of the overall structure. At the same time, the thinner metal layer can reduce the use of materials, reduce costs, and reduce the weight of the battery, while the first non-metallic insulating layer is relatively thick, which can ensure good insulation performance and prevent short circuits.

[0021] According to another aspect of the present invention, a pole piece is provided, comprising: the current collector structure as described above, wherein the metal layer is coated with an active material.

[0022] According to another aspect of the present invention, a battery cell is provided, comprising: the pole piece as described above.

[0023] By applying the technical solution of the present invention, the first non-metallic insulating layer has a lithium ion channel, through which lithium ions can reach the second side from the first side of the first non-metallic insulating layer, or reach the first side from the second side of the first non-metallic insulating layer, so that lithium ions can be quickly transmitted from one side of the current collector structure to the other side without bypassing obstacles or passing through more complex paths. The transmission distance of lithium ions is reduced, thereby improving the charge and discharge capacity of the battery. At the same time, the current collector structure of the present application can reduce the invalid mass proportion of copper foil and aluminum foil compared to traditional copper foil and aluminum foil current collectors, thereby improving the energy density of the battery and achieving a simultaneous improvement in the energy density and charge and discharge capacity of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0025] In the picture:

[0026] Figure 1 A schematic structural diagram of a current collector structure according to an embodiment of the present invention is shown;

[0027] Figure 2 A schematic structural diagram of a current collector structure according to another embodiment of the present invention is shown;

[0028] Figure 3 A schematic structural diagram of a current collector structure according to another embodiment of the present invention is shown;

[0029] Figure 4 A schematic structural diagram of a battery cell according to an embodiment of the present invention is shown.

[0030] The above drawings include the following reference numerals:

[0031] 10. First non-metallic insulating layer; 20. Metal layer; 30. Second non-metallic insulating layer; 40. Separator; 50. Positive electrode active material; 60. Negative electrode active material; 70. Positive electrode electrical connection; 80. Negative electrode electrical connection; 90. Pole piece. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] See also Figures 1 to 3As shown, the utility model provides a current collector structure, which includes: a first non-metallic insulating layer 10, along the thickness direction of the first non-metallic insulating layer 10, the first non-metallic insulating layer 10 has a first side and a second side arranged opposite to each other, and a metal layer 20 is provided on the first side and / or the second side. The first non-metallic insulating layer 10 also has a lithium ion channel connecting the first side and the second side, and the central axis of the lithium ion channel is a curve or a broken line.

[0034] In this embodiment, the current collector structure includes a first non-metallic insulating layer 10 and a metal layer 20 disposed on the first and / or second sides of the first non-metallic insulating layer 10, which functions to conduct electrons and converge. When the metal layer 20 is disposed on the first and second sides of the first non-metallic insulating layer 10, the first non-metallic insulating layer 10 can disconnect the metal layers 20 on both sides, thereby achieving electron convergence and mutual insulation. The first non-metallic insulating layer 10 has a lithium ion channel through which lithium ions can pass from the first side of the first non-metallic insulating layer 10 to the second side, or from the second side of the first non-metallic insulating layer 10 to the first side. This allows lithium ions to be quickly transferred from one side of the current collector structure to the other without having to bypass obstacles or take a more complex path. This reduces the transmission distance of lithium ions, thereby improving the charge and discharge capacity of the battery. In other words, during the charge and discharge process of a battery cell having the current collector structure of the present application, lithium ions can either pass from the positive electrode through the separator 40 to the negative electrode of the adjacent electrode 90, as in a conventional battery cell, or directly pass through the lithium ion channel to the negative electrode material of the same electrode 90. At the same time, the provision of lithium-ion channels can also enable the first non-metallic insulating layer 10 to retain more electrolyte, thereby improving the battery's electrolyte retention capacity and battery cycle life. In addition, compared to traditional copper foil and aluminum foil current collectors, the current collector structure of the present application can reduce the ineffective mass proportion of copper foil and aluminum foil, thereby improving the battery's energy density and achieving a simultaneous improvement in the energy density and charge-discharge capacity of the lithium-ion battery.

[0035] It should be noted that the central axis of the lithium ion channel of the present application is a curve or a broken line, that is, the lithium ion channel of the present application is irregular. The first non-metallic insulating layer 10 is made of an organic polymer. By using a lighter organic polymer instead of the traditional copper foil and aluminum foil current collector, the energy density of the battery can be improved.

[0036] Specifically, the organic polymer is one or more of terephthalate, polyamide, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, poly(p-phenylene terephthalamide), polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl formal, polyvinyl butyral, polyurethane, polyurethane, polyacrylonitrile, polyvinyl acetate, polyoxymethylene, phenolic resin, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, polycarbonate, polysulfone, polyethersulfone or polyphenylene ether.

[0037] Preferably, the organic polymer is one of polypropylene, polyethylene and polyethylene terephthalate.

[0038] Specifically, the metal layer 20 is formed by combining one or more methods such as evaporation, magnetron sputtering, and water electroplating so that metal particles are attached to the surface of the organic polymer by physical adsorption or chemical bonding, thereby achieving conductivity.

[0039] In one embodiment, the metal layer 20 may be a copper layer or an aluminum layer.

[0040] In one embodiment of the present invention, the thickness of the first non-metallic insulating layer 10 is in the range of 2 μm to 16 μm, and the thickness of the metal layer 20 is in the range of 0.3 μm to 1 μm.

[0041] Through the above arrangement, both the mechanical strength and the electrical conductivity of the current collector structure can be ensured.

[0042] In one embodiment of the present invention, the first non-metallic insulating layer 10 is a porous structure, and the porosity of the first non-metallic insulating layer 10 is in the range of 30% to 80%.

[0043] In this embodiment, the first non-metallic insulating layer 10 has a porous structure similar to the prior art separator 40 (porous herein refers to multiple through-holes). The distribution of the multiple through-holes is staggered along the thickness direction of the first non-metallic insulating layer 10, forming the lithium ion channels of the present application. Lithium ions pass through the staggered through-holes from the first side of the first non-metallic insulating layer 10 to the second side, or from the second side of the first non-metallic insulating layer 10 to the first side. Specifically, the first non-metallic insulating layer 10 is made of an organic polymer by dry single-drawing, dry double-drawing, or wet drawing to form the porous structure. The porosity and tensile strength of the organic polymer are controlled by controlling process parameters. The porosity ranges from 30% to 80%. This configuration ensures that lithium ions have a good migration channel during the battery charging and discharging process, thereby improving the ion transmission rate and the electrochemical performance of the battery. The tensile strength is ≥50 MPa. The high tensile strength ensures that the first non-metallic insulating layer 10 has sufficient mechanical stability during battery assembly and long-term use, preventing internal short circuits or damage due to physical deformation.

[0044] Specifically, the diameter of the through hole is in the range of 1 nm to 60 nm, thereby ensuring smooth passage of lithium ions.

[0045] like Figure 2 As shown, in one embodiment of the present invention, there are two first non-metallic insulating layers 10, wherein a metal layer 20 is provided on a first side of one of the first non-metallic insulating layers 10, and a metal layer 20 is provided on a second side of the other first non-metallic insulating layer 10, and the two first non-metallic insulating layers 10 are connected on the sides where the metal layer 20 is not provided.

[0046] In this embodiment, there are two first non-metallic insulating layers 10, one of which has a metal layer 20 disposed on its first side, and the other of which has a metal layer 20 disposed on its second side. The metal layers 20 of both first non-metallic insulating layers 10 are copper layers or aluminum layers, or one of the two metal layers 20 is a copper layer and the other is an aluminum layer. When producing the current collector structure, the metal layers 20 can be formed on both first non-metallic insulating layers 10 simultaneously by a combination of one or more methods such as evaporation, magnetron sputtering, and water electroplating, and then the two sides without the metal layers 20 are connected, which can improve the production efficiency of the current collector structure.

[0047] It should be noted that the two first non-metallic insulating layers 10 on the sides where the metal layer 20 is not provided can be connected by chemical bonding or physical compounding.

[0048] Specifically, physical compounding refers to spraying or spot-coating PVDF polyvinylidene fluoride (PVDF), polyacrylic acid (PAA) and other adhesives on the side of the first non-metallic insulating layer 10 where the metal layer 20 is not provided, and then bonding the two first non-metallic insulating layers 10 to each other through the combined action of temperature and pressure; direct pressing can also be performed directly under the action of appropriate temperature and pressure.

[0049] In one embodiment of the present invention, there are two first non-metallic insulating layers 10, wherein a metal layer 20 is provided on the first side of one of the first non-metallic insulating layers 10, and a metal layer 20 is provided on the second side of the other first non-metallic insulating layer 10. The current collector structure also includes a second non-metallic insulating layer 30. The sides of the two first non-metallic insulating layers 10 where the metal layer 20 is not provided are respectively connected to the opposite sides of the second non-metallic insulating layer 30. When projected along the first direction, the first non-metallic insulating layer 10 covers the second non-metallic insulating layer 30.

[0050] In this embodiment, the second non-metallic insulating layer 30 is provided to isolate the two metal layers 20 from each other to achieve convergence, while also preventing the two metal layers 20 from being connected to each other to cause an internal short circuit.

[0051] Specifically, the second non-metallic insulating layer 30 is made of organic polymer.

[0052] In one embodiment of the present invention, one of the two first non-metallic insulating layers 10 is made of polyethylene terephthalate, and a metal layer 20 is provided on the first side of the first non-metallic insulating layer 10, and the metal layer 20 is made of aluminum material (the thickness of the first non-metallic insulating layer 10 is 2um to 16um, and the thickness of the aluminum layer is 0.6um to 1um); the other of the two first non-metallic insulating layers 10 is made of polypropylene, and a metal layer 20 is provided on the second side of the first non-metallic insulating layer 10, and the metal layer 20 is made of copper material (the thickness of the first non-metallic insulating layer 10 is 2um to 16um, and the thickness of the copper layer is 0.6um to 1um), and the second non-metallic insulating layer 30 is made of aramid, and one layer of the two first non-metallic insulating layers 10 that is not provided with the metal layer 20 is respectively connected to the opposite sides of the second non-metallic insulating layer 30.

[0053] In one embodiment of the present invention, the first non-metallic insulating layer 10 and the corresponding metal layer 20 have the same size. Along the second direction, one of the two first non-metallic insulating layers 10 protrudes from the first end of the second non-metallic insulating layer 30, and the other of the two first non-metallic insulating layers 10 protrudes from the second end of the second non-metallic insulating layer 30.

[0054] In this embodiment, the second direction refers to Figure 1The length of the first non-metallic insulating layer 10 extends in the direction of the length of the first non-metallic insulating layer 10. The portions of the two first non-metallic insulating layers 10 protruding from the second non-metallic insulating layer 30 are used for welding with the external dummy tabs to achieve circuit connectivity.

[0055] Specifically, it can be welded to the external dummy tab by ultrasonic roller welding or electric welding.

[0056] It should be noted that, when one of the two metal layers 20 is a copper layer and the other is an aluminum layer, the above arrangement can prevent perforation during the welding process from causing an internal short circuit between the two metal layers 20 .

[0057] Specifically, along the second direction, the length of the portions of the two first non-metallic insulating layers 10 protruding from the second non-metallic insulating layer 30 ranges from 3 mm to 30 mm.

[0058] Preferably, along the second direction, the length of the portions of the two first non-metallic insulating layers 10 protruding from the second non-metallic insulating layer 30 ranges from 5 mm to 8 mm.

[0059] In one embodiment of the present invention, metal layers 20 are provided on both the first side and the second side of the first non-metallic insulating layer 10 . One of the two metal layers 20 is made of aluminum, and the other of the two metal layers 20 is made of copper.

[0060] In this embodiment, one of the two metal layers 20 is made of aluminum material, and the other of the two metal layers 20 is made of copper material, that is, one is a copper layer and the other is an aluminum layer. Compared with the copper foil or aluminum foil current collector in the prior art, it can be used as a composite current collector, and the negative electrode material can be coated on the copper layer and the positive electrode material can be coated on the aluminum layer. During the battery charging and discharging process, lithium ions can pass through the lithium ion channel from the first side of the first non-metallic insulating layer 10 to the second side, or from the second side of the first non-metallic insulating layer 10 to the first side, thereby shortening the transmission path of lithium ions and thus achieving an improvement in the charging and discharging capacity.

[0061] In one embodiment of the present invention, metal layers 20 are provided on both the first side and the second side of the first non-metallic insulating layer 10 , and both metal layers 20 are made of copper or aluminum.

[0062] In one embodiment of the present invention, the two metal layers 20 are both made of positive electrode conductive metal material or negative electrode conductive metal material.

[0063] In one embodiment of the present invention, a metal layer 20 is provided on the first side or the second side, and the ratio of the thickness of the metal layer 20 to the thickness of the first non-metallic insulating layer 10 is in the range of 0.06 to 0.15.

[0064] Through the above-mentioned setting, it can be ensured that the metal layer 20 has sufficient electrical conductivity while ensuring the mechanical stability of the overall structure. At the same time, the thinner metal layer 20 can reduce the use of materials, reduce costs, and reduce the weight of the battery, while the first non-metallic insulating layer is relatively thick, which can ensure good insulation performance and prevent short circuits.

[0065] The present invention provides a pole piece 90 , which includes: the current collector structure as described above, and an active material coated on the metal layer 20 .

[0066] In this embodiment, the current collector structure of the pole piece 90 has all the technical solutions and all the technical effects of the above-mentioned current collector structure, which will not be described in detail here.

[0067] It should be noted that the active material refers to the positive electrode active material 50 or the negative electrode active material 60 .

[0068] like Figure 1 As shown, in one embodiment, a metal layer 20 is provided on both the first and second sides of the first non-metallic insulating layer 10, wherein one metal layer 20 is a copper layer and the other metal layer 20 is an aluminum layer. A negative electrode active material 60 is coated on the copper layer, and a positive electrode active material 50 is coated on the aluminum layer. The two sides of the first non-metallic insulating layer 10 not provided with the metal layer 20 and the second non-metallic insulating layer 30 are then thermally composited together to form a pole piece 90 coated with positive and negative electrode materials on both sides, which is then alternately placed with the separator 40 to form a new battery cell. In addition, because the first non-metallic insulating layer 10 and the second non-metallic insulating layer 30 made of a lower density organic polymer material are used in the middle of the pole piece 90 instead of the traditional copper foil and aluminum foil, the ineffective mass ratio of the battery can be reduced, thereby effectively improving the energy density of the battery.

[0069] It should be noted that a blank area of ​​3mm to 30mm is left between the coating area of ​​the positive electrode active material 50 and the edge of the current collector for ultrasonic welding of the aluminum layer and the external dummy pole ear; a blank area of ​​3mm to 30mm is left between the coating area of ​​the negative electrode active material 60 and the edge of the current collector for ultrasonic welding of the copper layer and the external dummy pole ear, thereby realizing circuit connectivity between the pole piece 90 and the pole ear of the battery cell.

[0070] The positive electrode active material 50 is coated on the aluminum layer and rolled to reach a compaction density (generally 2.2 g / cm for the iron-lithium system). 3 ~2.6g / cm 3 , ternary system is 3.0g / cm 3 ~3.7g / cm 3 ), the negative electrode active material is coated on the copper layer and rolled to reach a compaction density (1.4g / cm 3 ~1.7g / cm 3The aluminum layer coated with the positive electrode active material 50 is rolled and coiled, and the copper layer coated with the negative electrode active material 60 is rolled and coiled. Then, they are laminated together with the second non-metallic insulating layer 30 under the action of temperature and pressure through a roll-to-roll rolling device with a heating function. Finally, they are cut to the target size. Alternatively, the first non-metallic insulating layer 10 and the second non-metallic insulating layer 30 can be cut to the target size separately and then pressed together through a heated flat press.

[0071] Preferably, adhesives such as polyvinylidene fluoride (PVDF) or polyacrylic acid (PAA) are sprayed or spot-coated on both sides of the second non-metallic insulating layer 30 to improve the bonding strength between the first non-metallic insulating layer 10 and the second non-metallic insulating layer 30 .

[0072] Preferably, the negative electrode active material 60 coating region completely covers the positive electrode active material 50 coating region and extends beyond the positive electrode active material 50 coating region by 0.5 mm to 2 mm.

[0073] The utility model provides a battery core, which includes: the pole piece 90 as described above.

[0074] In this embodiment, the electrode piece 90 of the battery cell has all the technical solutions and all the technical effects of the above-mentioned electrode piece 90 , which will not be described in detail here.

[0075] like Figure 4 The figure shows a schematic diagram of the structure of an embodiment of the battery cell of the present application. There are three pole pieces 90. For the convenience of description, the three pole pieces 90 are named pole piece a, pole piece b, and pole piece c respectively. Pole piece a, pole piece b, and pole piece c are composed of two first non-metallic insulating layers 10 and a second non-metallic insulating layer 30. The first side of the two first non-metallic insulating layers 10 is provided with a metal layer 20, wherein one metal layer 20 is a copper layer and the other metal layer 20 is an aluminum layer. The negative electrode active material 60 is coated on the copper layer and the positive electrode active material 50 is coated on the aluminum layer. The sides of the two first non-metallic insulating layers 10 where the metal layer 20 is not provided are connected to the opposite sides of the second non-metallic insulating layer 30 respectively. Pole piece a, pole piece b, and pole piece c are arranged along Figure 4They are arranged in sequence in the horizontal direction, a diaphragm 40 is provided on the side of the electrode a facing away from the electrode b, a diaphragm 40 is provided on the side of the electrode c facing away from the electrode b, a diaphragm 40 is provided between each adjacent electrode 90, and the electrode 90 located at the head and tail ends are provided with a diaphragm 40, a diaphragm 40 is provided between the electrode a and the electrode b, a diaphragm 40 is provided between the electrode b and the electrode c to form a battery core, all the copper layers are ultrasonically spot welded or roller welded to form a negative electrode electrical connection 80, all the aluminum layers are ultrasonically spot welded or roller welded to form a positive electrode electrical connection 70, aluminum foil is welded together with the aluminum layer by roller welding to lead out the current, copper foil is welded together with the copper layer by roller welding to lead out the current, all the aluminum foils are connected in parallel and connected to the positive electrode column of the battery core by a connecting piece or direct welding to realize the connection of the external circuit, all the copper foils are connected in parallel and connected to the negative electrode column of the battery core by a connecting piece or direct welding to realize the connection of the external circuit.

[0076] It should be noted that the pole piece 90 located at the outermost layer of the battery cell is composed of a first non-metallic insulating layer and a second non-metallic insulating layer, wherein the first side and the second side of the first non-metallic insulating layer are both provided with metal layers, and one of the two metal layers is made of copper material (forming a copper layer), and the other of the two metal layers is made of aluminum material (forming an aluminum layer). In this way, it can be ensured that each aluminum layer of the battery cell has a corresponding copper layer corresponding to it.

[0077] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the first non-metallic insulating layer has a lithium ion channel, and lithium ions can reach the second side from the first side of the first non-metallic insulating layer through the lithium ion channel, or reach the first side from the second side of the first non-metallic insulating layer, so that lithium ions can be quickly transmitted from one side of the current collector structure to the other side without bypassing obstacles or passing through more complex paths. The transmission distance of lithium ions is reduced, thereby improving the charge and discharge capacity of the battery. At the same time, the current collector structure of the present application can reduce the invalid mass proportion of copper foil and aluminum foil compared with traditional copper foil and aluminum foil current collectors, thereby improving the energy density of the battery and achieving a simultaneous improvement in the energy density and charge and discharge capacity of the lithium-ion battery.

[0078] Obviously, the embodiments described above are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0079] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, tasks, devices, components and / or combinations thereof.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A current collector structure, characterized in that: include: A first non-metallic insulating layer (10) has a first side and a second side arranged opposite to each other along a thickness direction of the first non-metallic insulating layer (10), a metal layer (20) is provided on the first side and / or the second side, and the first non-metallic insulating layer (10) further has a lithium ion channel connecting the first side and the second side, and a central axis of the lithium ion channel is a curve or a broken line.

2. The current collector structure according to claim 1, characterized in that: The thickness of the first non-metallic insulating layer (10) ranges from 2 μm to 16 μm, and the thickness of the metal layer (20) ranges from 0.3 μm to 1 μm.

3. The current collector structure according to claim 1, characterized in that: The first non-metallic insulating layer (10) has a porous structure, and the porosity of the first non-metallic insulating layer (10) ranges from 30% to 80%.

4. The current collector structure according to any one of claims 1 to 3, characterized in that: There are two first non-metallic insulating layers (10), wherein the first side of one of the first non-metallic insulating layers (10) is provided with the metal layer (20), and the second side of the other first non-metallic insulating layer (10) is provided with the metal layer (20), and the two first non-metallic insulating layers (10) are connected at the sides where the metal layer (20) is not provided.

5. The current collector structure according to any one of claims 1 to 3, characterized in that: There are two first non-metallic insulating layers (10), one of which is provided with the metal layer (20) on the first side, and the other is provided with the metal layer (20) on the second side. The current collector structure further comprises a second non-metallic insulating layer (30), and the sides of the two first non-metallic insulating layers (10) not provided with the metal layer (20) are respectively connected to opposite sides of the second non-metallic insulating layer (30). When projected along a first direction, the first non-metallic insulating layer (10) covers the second non-metallic insulating layer (30).

6. The current collector structure according to claim 5, characterized in that: The first non-metallic insulating layer (10) and the metal layer (20) corresponding thereto have the same size; along the second direction, one of the two first non-metallic insulating layers (10) protrudes from the first end of the second non-metallic insulating layer (30), and the other of the two first non-metallic insulating layers (10) protrudes from the second end of the second non-metallic insulating layer (30).

7. The current collector structure according to any one of claims 1 to 3, characterized in that: The first side and the second side of the first non-metallic insulating layer (10) are both provided with the metal layer (20), one of the two metal layers (20) is made of aluminum material, and the other of the two metal layers (20) is made of copper material.

8. The current collector structure according to claim 1, characterized in that: The metal layer (20) is provided on the first side or the second side, and the ratio of the thickness of the metal layer (20) to the thickness of the first non-metallic insulating layer (10) is in the range of 0.06 to 0.

15.

9. A pole piece, characterized in that: include: The current collector structure according to any one of claims 1 to 8, wherein the metal layer (20) is coated with an active material.

10. A battery cell, characterized in that: include: A pole piece (90) as claimed in claim 9.

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