Bipolar current collector, bipolar electrode, unipolar current collector, unipolar electrode, battery and electric device

Abstract

In order to solve the problems that the process difficulty is high and the energy density is affected due to the fact that a composite current collector needs metal foil tab transfer welding, the bipolar current collector comprises a base film, a first conducting layer and a second conducting layer, the base film is provided with a first porous area and a second porous area, and the first conducting layer and the second conducting layer are arranged on the base film. The first conducting layer is located on the surface of one side of the base film, the first conducting layer at least partially covers the first porous area, the first conducting layer and the second porous area avoid each other, the second conducting layer is located on the surface of the other side of the base film, and the second conducting layer is located on the surface of the other side of the base film. And the second conductive layer at least partially covers the second porous area, and the second conductive layer avoids the first porous area. Meanwhile, the invention also discloses a bipolar electrode, a unipolar current collector, a unipolar electrode, a battery and an electric device. According to the bipolar current collector and the unipolar current collector provided by the invention, tabs can be directly cut and welded, so that the effects of reducing the internal resistance and simplifying the process are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery structures, and particularly relates to a bipolar current collector, a bipolar electrode, a unipolar current collector, a unipolar electrode, a battery, and an electrical device. Background Art

[0002] The current energy density of batteries has reached 300 Wh / kg. How to further improve the energy density of batteries and develop new energy storage devices has become the common focus of the academic and industrial circles. A typical battery structure consists of an anode, a cathode, an electrolyte, a separator, and a current collector. As one of the important components of a battery, the current collector plays a role in carrying the active material and collecting and conducting current. Commercial batteries all use metal materials as current collectors, including aluminum foil as the positive current collector and copper foil as the negative current collector, and the active material is coated on their surfaces to form positive and negative electrode sheets, which are then used for the assembly of the battery. Although metal current collectors have excellent electrical conductivity and good mechanical properties, their own density is relatively large, which cannot bring an increase in capacity, they do not have a flame retardant function, and there is a possibility of being corroded in the battery. A composite current collector is a new type of polymer-metal composite foil, presenting a "sandwich" structure. Compared with traditional current collectors, the composite current collector has the characteristics of low manufacturing cost (significantly lower than that of copper foil), high safety (the polymer is non-conductive and the conductive layer is thin), and good compatibility; in addition, the density of the substrate film is lower than that of common metal current collector materials, and the application of the composite current collector can also improve the energy density of the battery.

[0003] In the actual application process of the composite current collector, since the polymer-based film is non-conductive, additional metal copper foil or aluminum foil tabs need to be added to both sides of the conductive layer for welding and then led out, which increases the battery mass and the process difficulty and is not conducive to improving the energy density of the battery. Summary of the Invention

[0004] To overcome the problems of high process difficulty and influence on energy density caused by the need for metal foil tab welding in existing composite current collectors, the present invention provides a bipolar current collector, a bipolar electrode, a unipolar current collector, a unipolar electrode, a battery, and an electrical device.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0006] On the one hand, the present invention provides a bipolar current collector, comprising a base film, a first conductive layer and a second conductive layer. The base film is provided with a first porous region and a second porous region. The first porous region is provided with a plurality of first through holes penetrating the base film, and the second porous region is provided with a plurality of second through holes penetrating the base film. The first conductive layer is located on one side surface of the base film, and the first conductive layer at least partially covers the first porous region and at least partially fills the first through holes. The first conductive layer is spaced apart from the second porous region. The second conductive layer is located on the other side surface of the base film, and the second conductive layer at least partially covers the second porous region and at least partially fills the second through holes. The second conductive layer is spaced apart from the first porous region.

[0007] According to the bipolar current collector provided by the present invention, by separately arranging the first conductive layer and the second conductive layer on both sides of the base film, and simultaneously providing the first porous region and the second porous region on the base film, the first conductive layer covers the first porous region and avoids the second porous region, and the second conductive layer covers the second porous region and avoids the first porous region, so that the first conductive layer and the second conductive layer are insulated from each other and can be respectively used for coating the positive electrode active material layer and the negative electrode active material layer, and then a bipolar electrode sheet is obtained. Compared with the traditional unipolar current collector, this bipolar current collector can effectively shorten the lithium ion transmission distance between the positive and negative electrode active material layers and play a role in reducing the internal resistance. On the other hand, the first conductive layer is filled into the first porous region of the base film, and the second conductive layer is filled into the second porous region of the base film, so that the base film forms a composite high-strength structure and a double-sided conductive structure in the first porous region and the second porous region. Furthermore, the first porous region and the second porous region can meet the conductivity and structural strength required for tab welding in the subsequent battery structure, without additionally adding metal foil tab materials, reducing the battery weight, avoiding transfer welding in the process, and reducing the production difficulty and structural stability.

[0008] Optionally, the first porous region and the second porous region are respectively located at two end positions of the base film.

[0009] Optionally, the first porous region is a strip-shaped region extending along the inner edge of the end of the base film, or

[0010] The first porous region is a single or multiple tab regions spaced apart on the outer edge of the end of the base film. Optionally, the second porous region is a strip-shaped region extending along the inner edge of the end of the base film, or

[0011] The second porous region is a single or multiple tab regions spaced apart on the outer edge of the end of the base film.

[0012] Optionally, the first conductive layer and the second conductive layer are each independently selected from one or more of a metal material, a carbon material, and a conductive polymer. The metal material includes one or more of copper, aluminum, gold, silver, iron, nickel, and zinc. The carbon material includes one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. The conductive polymer includes one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene, and polystyrene sulfonate.

[0013] Optionally, the first conductive layer is selected from aluminum and its alloys, and the second conductive layer is selected from copper and its alloys.

[0014] Optionally, the first conductive layer includes a first thin region and a first thickened region. The first thickened region covers the first porous region. The thickness of the first thin region is 0.1 - 15 μm, and the thickness of the first thickened region is 105% - 120% of the thickness of the first thin region.

[0015] Optionally, the second conductive layer includes a second thin region and a second thickened region. The second thickened region covers the second porous region. The thickness of the second thin region is 0.1 - 15 μm, and the thickness of the second thickened region is 105% - 120% of the thickness of the second thin region.

[0016] Optionally, the aperture diameter of the first through-hole is 0.01 - 1 μm, the porosity of the first porous region is 5% - 95%, the aperture diameter of the second through-hole is 0.01 - 1 μm, and the porosity of the second porous region is 5% - 95%.

[0017] Optionally, the thickness of the base film is 0.2 - 30 μm.

[0018] Optionally, the base film includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, and polyethylene naphthalate.

[0019] Optionally, a first insulating transition region is formed between the first conductive layer and the second porous region, and the base film is exposed in the first insulating transition region. A second insulating transition region is formed between the second conductive layer and the first porous region, and the base film is exposed in the second insulating transition region.

[0020] Optionally, the width of the first insulating transition region is 10 - 1000 μm, and the width of the second insulating transition region is 10 - 1000 μm.

[0021] On the other hand, the present invention provides a bipolar electrode, comprising a positive electrode active material layer, a negative electrode active material layer, and the bipolar current collector as described above. The positive electrode active material layer covers the surface of the first conductive layer facing away from the base film, and the negative electrode active material layer covers the surface of the second conductive layer facing away from the base film.

[0022] Optionally, the positive electrode active material layer avoids the first porous region, and the negative electrode active material layer avoids the second porous region.

[0023] On the other hand, the present invention provides a unipolar current collector, comprising a base film and third conductive layers provided on both side surfaces of the base film. A third porous region is provided on the base film, and a plurality of third through holes penetrating the base film are formed in the third porous region. At least part of the third conductive layer covers the third porous region, and at least part of the third conductive layer fills the third through holes so that the third conductive layers on both side surfaces of the base film are electrically connected to each other.

[0024] According to the unipolar current collector provided by the present invention, third conductive layers are respectively provided on both sides of the base film, and a third porous region is provided, so that the third conductive layers are electrically connected to each other in the third porous region, forming a composite high-strength structure and a double-sided conductive structure. Furthermore, the third porous region can meet the conductivity and structural strength required for tab welding in the subsequent battery structure, without the need to additionally increase tab materials, reducing the battery weight. In terms of process, the transfer welding is avoided, reducing the production difficulty and improving the structural stability.

[0025] Optionally, the third porous region is located at the end position of the base film.

[0026] Optionally, the third porous region is a strip-shaped region extending along the inner edge of the end of the base film, or

[0027] the third porous region is a single or multiple tab regions spaced apart from each other on the outer edge of the end of the base film.

[0028] Optionally, the third conductive layer is selected from one or more of metal materials, carbon materials, and conductive polymers. The metal materials include one or more of copper, aluminum, gold, silver, iron, nickel, and zinc. The carbon materials include one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. The conductive polymers include one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene, and polystyrene sulfonate.

[0029] Optionally, the third conductive layer includes a third thin region and a third thickened region. The third thickened region covers the third porous region. The thickness of the third thin region is 0.1-15 μm, and the thickness of the third thickened region is 105%-120% of the thickness of the third thin region.

[0030] Optionally, the aperture of the third through-hole is 0.01-1 um, and the porosity of the third porous region is 5%-95%.

[0031] Optionally, the thickness of the base film is 0.2-30 um.

[0032] Optionally, the base film comprises one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, polyethylene naphthalate.

[0033] In another aspect, the present invention provides a unipolar electrode, comprising an active material layer and the unipolar current collector as described above, and the active material layer covers the surface of the third conductive layer facing away from the base film.

[0034] Optionally, the active material layer avoids the third porous region.

[0035] Optionally, the active material layer is a positive electrode material or a negative electrode material.

[0036] In another aspect, the present invention provides a battery, comprising the bipolar electrode as described above and / or the unipolar electrode as described above.

[0037] In another aspect, the present invention provides an electrical device, comprising the battery as described above. Description of the Drawings

[0038] Figure 1 is a schematic structural diagram of the bipolar current collector provided by the present invention;

[0039] Figure 2 is a schematic structural diagram of the bipolar electrode provided by the present invention;

[0040] Figure 3 is a schematic structural diagram of the unipolar current collector provided by the present invention;

[0041] Figure 4 is a schematic structural diagram of the unipolar electrode provided by the present invention.

[0042] The reference numerals in the accompanying drawings of the description are as follows:

[0043] 1. Base film; 11. First porous region; 12. Second porous region; 13. Third porous region; 2. First conductive layer; 21. First thin region; 22. First thickened region; 3. Second conductive layer; 31. Second thin region; 32. Second thickened region; 4. First insulating transition region; 5. Second insulating transition region; 6. Positive electrode active material layer; 7. Negative electrode active material layer; 8. Third conductive layer; 81. Third thin region; 82. Third thickened region; 9. Active material layer. Detailed Embodiments

[0044] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0046] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood according to specific situations.

[0047] See Figure 1 As shown, the present invention provides a bipolar current collector, including a base film 1, a first conductive layer 2 and a second conductive layer 3. A first porous region 11 and a second porous region 12 are provided on the base film 1. The first porous region 11 is provided with a plurality of first through holes penetrating the base film 1, and the second porous region 12 is provided with a plurality of second through holes penetrating the base film 1. The first conductive layer 2 is located on one side surface of the base film 1, and the first conductive layer 2 at least partially covers the first porous region 11. The first conductive layer 2 at least partially fills the first through holes, and the first conductive layer 2 is avoided from the second porous region 12. The second conductive layer 3 is located on the other side surface of the base film 1, and the second conductive layer 3 at least partially covers the second porous region 12. The second conductive layer 3 at least partially fills the second through holes, and the second conductive layer 3 is avoided from the first porous region 11.

[0048] By disposing the first conductive layer 2 and the second conductive layer 3 on both sides of the base film 1 respectively, and at the same time providing a first porous region 11 and a second porous region 12 on the base film 1, the first conductive layer 2 covers the first porous region 11 and avoids the second porous region 12, and the second conductive layer 3 covers the second porous region 12 and avoids the first porous region 11, so that the first conductive layer 2 and the second conductive layer 3 are insulated from each other and can be respectively used for coating the positive electrode active material layer 6 and the negative electrode active material layer 7, and then a bipolar pole piece is obtained. Compared with the traditional unipolar current collector, this bipolar current collector can effectively shorten the lithium ion transmission distance between the positive and negative electrode active material layers 7, playing the role of reducing internal resistance and increasing energy density; on the other hand, the first conductive layer 2 is filled into the first porous region 11 of the base film 1, and the second conductive layer 3 is filled into the second porous region 12 of the base film 1, so that the base film 1 forms a composite high-strength structure and a double-sided conductive structure in the first porous region 11 and the second porous region 12. Furthermore, the first porous region 11 and the second porous region 12 can meet the conductivity and structural strength required for tab welding in the subsequent battery structure, without adding extra tab materials, reducing the battery weight, avoiding transfer welding in the process, and reducing the production difficulty and structural stability.

[0049] In some embodiments, the first porous region 11 and the second porous region 12 are respectively located at two end positions of the base film 1.

[0050] It should be noted that in the description of the present invention, "end" does not specifically refer to the end of the base film 1 in a certain direction, and any edge position of the base film 1 can be considered as its end. For example, when the base film 1 is a rectangular sheet structure, the "end" can be the long side end or the short side end of the base film 1.

[0051] The first porous region 11 and the second porous region 12 are used to form the positive tab and the negative tab of the battery cell. By respectively disposing the first porous region 11 and the second porous region 12 at two end positions of the base film 1, it is convenient to cut and lead out the positive tab and the negative tab from both ends of the battery cell respectively, reducing the probability of short circuit between the positive and negative electrodes.

[0052] In other embodiments, the positions of the first porous region 11 and the second porous region 12 can be correspondingly set according to the way of stacking or winding the battery cell. For example, when the battery cell adopts the stacking method, the first porous region 11 and the second porous region 12 can be disposed at the short side ends of the base film 1; when the battery cell adopts the winding method, the first porous region 11 and the second porous region 12 can be disposed at the long side ends of the base film 1.

[0053] In other embodiments, the positions of the first porous region 11 and the second porous region 12 can also be adjusted correspondingly according to the positions where the tabs are required to be set. For example, the first porous region 11 and the second porous region 12 can also be arranged at intervals at the same end of the base film 1, or are respectively located at the long side end and the short side end of the base film 1.

[0054] In some embodiments, the first through hole and the second through hole are prepared by laser drilling.

[0055] In some embodiments, the first porous region 11 is a strip-shaped region extending along the inner edge of the end of the base film 1, or

[0056] the first porous region 11 is a tab region with one or more arranged at intervals on the outer edge of the end of the base film 1.

[0057] In some embodiments, the second porous region 12 is a strip-shaped region extending along the inner edge of the end of the base film 1, or

[0058] the second porous region 12 is a tab region with one or more arranged at intervals on the outer edge of the end of the base film 1.

[0059] The shapes of the first porous region 11 and the second porous region 12 can be set correspondingly according to the shape of the tab to be formed. This design can implement single-tab, multi-tab, and full-tab solutions, facilitating the subsequent arrangement of the electrode sheets in the battery cell and reducing the process complexity. When a full-tab needs to be formed, the first porous region 11 and the second porous region 12 are strip-shaped regions, which have the advantages of large tab contact area and low internal resistance. When a single tab needs to be formed, the first porous region 11 and the second porous region 12 can be cut into single tab regions, which have the advantage of flexible tab lead-out position. When multiple tabs need to be formed, the first porous region 11 and the second porous region 12 can be cut into multiple tab regions, which have the advantages of uniform current lead-out and reduced internal resistance.

[0060] In some embodiments, the widths of the first porous region 11 and the second porous region 12 are 10 - 1500 mm.

[0061] In some embodiments, the first conductive layer 2 and the second conductive layer 3 are each independently selected from one or more of metal materials, carbon materials, and conductive polymers. The metal materials include one or more of copper, aluminum, gold, silver, iron, nickel, and zinc. The carbon materials include one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. The conductive polymers include one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene, and polystyrene sulfonate.

[0062] In some embodiments, the first conductive layer 2 and the second conductive layer 3 are selected from metallic materials.

[0063] Compared with other conductive materials, using metallic materials as the first conductive layer 2 and the second conductive layer 3 is beneficial for subsequent welding operations. At the same time, metallic materials have relatively low resistance, and after welding, the interfacial contact impedance is small, which can effectively ensure the electrical connection effect, avoid the problem of tab heating, and improve the rate performance.

[0064] In some embodiments, the first conductive layer 2 is selected from aluminum and its alloys, and the second conductive layer 3 is selected from copper and its alloys.

[0065] In the bipolar current collector, the first conductive layer 2 is used for electron transport of the positive electrode active material layer 6, and the second conductive layer 3 is used for electron transport of the negative electrode active material layer 7; aluminum and its alloys have a relatively low potential and good electrical conductivity, which can effectively improve the electron conductivity. At the same time, the potential of the positive electrode active material layer 6 is relatively high, and aluminum and its alloys generate an oxide layer at high potential, which can avoid the corrosion problem of the first conductive layer 2; copper and its alloys have better electrical conductivity and thermal conductivity than aluminum. Therefore, as the second conductive layer 3, it is beneficial to improve the electron conductivity and heat dissipation performance.

[0066] In some embodiments, the first conductive layer 2 and the second conductive layer 3 are prepared on the base film 1 by one or a combination of physical vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating with water. The physical vapor deposition includes vacuum magnetron sputtering and / or evaporation.

[0067] Specifically, when the first conductive layer 2 is selected from aluminum and its alloys, aluminum and its alloys can be deposited on the base film 1 by evaporation.

[0068] When the second conductive layer 3 is selected from copper and its alloys, copper and its alloys can be directly deposited on the base film 1 by a one-step method of chemical deposition, vacuum magnetron sputtering, and vacuum evaporation, or by a two-step method of using vacuum magnetron sputtering as a primer and then electroplating with water on the base film 1, or by a three-step method of using vacuum magnetron sputtering as a primer, then evaporation, and then electroplating with water on the base film 1.

[0069] In some embodiments, the first conductive layer 2 includes a first thin region 21 and a first thickened region 22. The first thickened region 22 covers the first porous region 11. The thickness of the first thin region 21 is 0.1 - 15 μm, and the thickness of the first thickened region 22 is 105% - 120% of the thickness of the first thin region 21.

[0070] In a specific embodiment, the thickness of the first thin region 21 may be 0.1 um, 0.2 um, 0.3 um, 0.4 um, 0.5 um, 0.8 um, 1 um, 2 um, 3 um, 4 um, 5 um, 6 um, 7 um, 8 um, 9 um, 10 um, 11 um, 12 um, 13 um, 14 um, or 15 um. The thickness of the first thickened region 22 may be 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, 119%, or 120% of the thickness of the first thin region 21.

[0071] In some embodiments, the second conductive layer 3 includes a second thin region 31 and a second thickened region 32. The second thickened region 32 covers the second porous region 12. The thickness of the second thin region 31 is 0.1 - 15 um, and the thickness of the second thickened region 32 is 105% - 120% of the thickness of the second thin region 31.

[0072] In a specific embodiment, the thickness of the second thin region 31 may be 0.1 um, 0.2 um, 0.3 um, 0.4 um, 0.5 um, 0.8 um, 1 um, 2 um, 3 um, 4 um, 5 um, 6 um, 7 um, 8 um, 9 um, 10 um, 11 um, 12 um, 13 um, 14 um, or 15 um. The thickness of the second thickened region 32 may be 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, 119%, or 120% of the thickness of the second thin region 31.

[0073] The inventor found through a large number of experiments that when the thickness of the first thin region 21 is 0.1 - 15 um and the thickness of the second thin region 31 is 0.1 - 15 um, it is possible to reduce the impact on energy density while satisfying the electron flow, meeting the requirements of electron conduction of the positive electrode active material layer 6 and the negative electrode active material layer 7. However, under the same thickness conditions, the first conductive layer 2 and the second conductive layer 3 located in the first porous region 11 and the second porous region 12 cannot meet the requirements of welding and electrical conduction, and there are problems of large contact resistance and low peel strength. By thickening the first conductive layer 2 and the second conductive layer 3 in the first porous region 11 and the second porous region 12 respectively to form the first thickened region 22 and the second thickened region 32, this problem can be effectively solved, the contact resistance at the tab position can be effectively reduced, and at the same time, the welding yield of the tab can be improved.

[0074] In some embodiments, the aperture of the first through-hole is 0.01 - 1 um, the porosity of the first porous region 11 is 5% - 95%, the aperture of the second through-hole is 0.01 - 1 um, and the porosity of the second porous region 12 is 5% - 95%.

[0075] In a specific embodiment, the aperture of the first through-hole can be 0.01 um, 0.02 um, 0.05 um, 0.08 um, 0.1 um, 0.2 um, 0.3 um, 0.4 um, 0.5 um, 0.6 um, 0.7 um, 0.8 um, 0.9 um or 1 um, the porosity of the first porous region 11 can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 27%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 37%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 47%, 49%, 50%, 60%, 61%, 62%, 64%, 68%, 70%, 74%, 75%, 77%, 80%, 81%, 83%, 85%, 89% or 95%, the aperture of the second through-hole can be 0.01 um, 0.02 um, 0.05 um, 0.08 um, 0.1 um, 0.2 um, 0.3 um, 0.4 um, 0.5 um, 0.6 um, 0.7 um, 0.8 um, 0.9 um or 1 um, and the porosity of the second porous region 12 can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 27%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 37%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 47%, 49%, 50%, 60%, 61%, 62%, 64%, 68%, 70%, 74%, 75%, 77%, 80%, 81%, 83%, 85%, 89% or 95%.

[0076] In the description of the present invention, the term "porosity of the first porous region" refers to the percentage value of the total area of the first through-holes to the total area of the first porous region. The "porosity of the second porous region" and the "porosity of the third porous region" can be understood according to this definition.

[0077] The first through-hole and the second through-hole are respectively used for the electrical conduction of the first conductive layer 2 and the second conductive layer 3 on both sides of the base film 1. If the aperture of the first through-hole or the second through-hole is too small, it is difficult for the first conductive layer 2 or the second conductive layer 3 to enter the first through-hole or the second through-hole; if the aperture of the first through-hole or the second through-hole is too large, after the first conductive layer 2 or the second conductive layer 3 enters the first through-hole or the second through-hole, it is easy to flow out and diffuse from the other side of the base film 1, there is a certain risk of short circuit, and the first through-hole or the second through-hole cannot be completely filled. If the porosity of the first porous region 11 or the second porous region 12 is too low, it will result in a large resistance between the two surfaces of the base film 1, which is not conducive to the structural stability of the mutually welded tab and the reduction of the impedance at the tab position; if the porosity of the first porous region 11 or the second porous region 12 is too high, it will lead to a decrease in the composite structure strength of the first porous region 11 or the second porous region 12 and the first conductive layer 2 or the second conductive layer 3, which is also not conducive to the structural stability of the mutually welded tab.

[0078] In some embodiments, the thickness of the base film 1 is 0.2 - 30 um.

[0079] In a specific embodiment, the thickness of the base film 1 can be 0.5 um, 0.8 um, 1 um, 2 um, 3 um, 4 um, 5 um, 6 um, 7 um, 8 um, 9 um, 10 um, 11 um, 12 um, 13 um, 14 um, 15 um, 16 um, 17 um, 18 um, 19 um, 20 um, 21 um, 22 um, 23 um, 24 um, 25 um, 27 um, 29 um or 30 um.

[0080] In some embodiments, the base film 1 includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, polyethylene naphthalate.

[0081] Using the above polymers as the material of the base film 1, on the one hand, it has good affinity with the electrolyte, which is convenient for the infiltration and diffusion of the electrolyte and ensures the ion shuttle between the positive and negative electrodes; on the other hand, it has good electron isolation ability, which can avoid the direct contact between the first conductive layer 2 and the second conductive layer 3 and prevent the occurrence of internal short circuit.

[0082] In some embodiments, a first insulating transition region 4 is formed between the first conductive layer 2 and the second porous region 12, and the base film 1 is exposed in the first insulating transition region 4. A second insulating transition region 5 is formed between the second conductive layer 3 and the first porous region 11, and the base film 1 is exposed in the second insulating transition region 5.

[0083] The first insulating transition region 4 is used to isolate the first conductive layer 2 and the second porous region 12, and the second insulating transition region 5 is used to isolate the second conductive layer 3 and the first porous region 11, so as to avoid internal short circuits formed between the first conductive layer 2 and the second porous region 12 or between the second conductive layer 3 and the first porous region 11.

[0084] In some embodiments, the width of the first insulating transition region 4 is 10 - 1000 um, and the width of the second insulating transition region 5 is 10 - 1000 um.

[0085] When the widths of the first insulating transition region 4 and the second insulating transition region 5 are within the above ranges, they can play a good insulating role and also avoid excessive occupation of the area of the base film 1.

[0086] See Figure 2 As shown, another embodiment of the present invention provides a bipolar electrode, including a positive electrode active material layer 6, a negative electrode active material layer 7 and the bipolar current collector as described above. The positive electrode active material layer 6 covers the surface of the first conductive layer 2 facing away from the base film 1, and the negative electrode active material layer 7 covers the surface of the second conductive layer 3 facing away from the base film 1.

[0087] Due to the adoption of the bipolar current collector as described above, the bipolar electrode can realize the bipolar coating of the positive electrode active material layer 6 and the negative electrode active material layer 7 in the same electrode, effectively shortening the lithium ion transmission distance between the positive and negative electrode active material layers 7, playing a role in reducing the internal resistance and increasing the energy density. At the same time, the setting of the first porous region 11 and the second porous region 12 enables the base film 1 to form a double-sided conductive structure at this place, meeting the requirements of direct cutting of the tab and welding, avoiding the transfer welding, and simplifying the production process.

[0088] In some embodiments, the positive electrode active material layer 6 avoids the first porous region 11, and the negative electrode active material layer 7 avoids the second porous region 12.

[0089] The first porous region 11 is used to form a positive tab, and the second porous region 12 is used to form a negative tab. Through the avoidance setting of the positive electrode active material layer 6 and the negative electrode active material layer 7, it is beneficial to avoid the influence of the positive electrode active material layer 6 and the negative electrode active material layer 7 on the tab welding.

[0090] In some embodiments, the positive electrode active material layer 6 includes a positive electrode active material, and the positive electrode active material is selected from lithium nickel cobalt manganese oxide (N x M y C z, x + y + z = 1), lithium iron manganese phosphate (LiFe x Mn y PO 4 , x + y = 1), lithium iron phosphate, lithium manganate, lithium cobaltate, lithium nickelate, lithium-rich manganese-based, lithium nickel manganese oxide (LMNO), lithium vanadium phosphate oxide (Li 3 V 2 (PO 4 ) 3 , LiVOPO 4 ), or one or more of them.

[0091] In some embodiments, the negative electrode active material layer 7 includes a negative electrode material selected from one or more of carbon-based negative electrode materials, silicon-based negative electrode materials, metal oxides, tin-based negative electrode materials, and metallic lithium. Among them, carbon-based negative electrode materials include natural graphite, artificial graphite, hard carbon, soft carbon, and mesocarbon microbeads, etc. Silicon-based negative electrode materials include one or more of single-crystalline silicon, silicon carbide compounds, and silicon oxide compounds. Metal oxide negative electrode materials include lithium titanate. Tin-based negative electrode materials include one or more of elemental tin, tin-sulfur alloys, tin-phosphorus alloys, tin-iron alloys, and tin-cobalt alloys. Metallic lithium negative electrodes include metallic lithium foils or metallic lithium alloy foils. The metallic lithium alloy Li-M can be an alloy formed by metallic lithium and one or more of substances such as gold, indium, magnesium, zinc, chromium, nickel, molybdenum, tungsten, vanadium, titanium, niobium, zirconium, cobalt, manganese, aluminum, copper, boron, silver, tin, silicon, carbon, phosphorus, etc.

[0092] See Figure 3 As shown, the present invention provides a unipolar current collector, including a base film 1 and third conductive layers 8 disposed on both side surfaces of the base film 1. A third porous region 13 is provided on the base film 1. The third porous region 13 is provided with a plurality of third through holes penetrating the base film 1. The third conductive layer 8 at least partially covers the third porous region 13, and the third conductive layer 8 at least partially fills the third through holes, so that the third conductive layers 8 on both side surfaces of the base film 1 are electrically connected to each other.

[0093] The third conductive layers 8 are respectively disposed on both sides of the base film 1, and the third porous region 13 is provided, so that the third conductive layers 8 are electrically connected to each other in the third porous region 13, forming a composite high-strength structure and a double-sided conductive structure. Furthermore, the third porous region 13 can meet the electrical conductivity and structural strength required for tab welding in the subsequent battery structure, without the need to additionally increase tab materials, reducing the battery weight. In terms of process, the transfer welding is avoided, reducing the production difficulty and improving the structural stability.

[0094] In some embodiments, the third porous region 13 is located at the end position of the base film 1.

[0095] The third porous region 13 is used to form the positive or negative electrode tab of the battery cell. The third porous region 13 is disposed at the end position of the base film 1, facilitating the extraction of the electrode tab from the end of the battery cell and adapting to the battery structure setting.

[0096] In other embodiments, the position of the third porous region 13 can be correspondingly set according to the stacking or winding manner of the battery cell. For example, when the battery cell adopts the stacking manner, the third porous region 13 can be disposed at the short-side end of the base film 1; when the battery cell adopts the winding manner, the third porous region 13 can be disposed at the long-side end of the base film 1.

[0097] In some embodiments, the third through-holes are prepared by laser drilling.

[0098] In some embodiments, the third porous region 13 is a strip-shaped region extending along the inner edge of the end of the base film 1, or

[0099] the third porous region 13 is one or more electrode tab regions spaced apart from each other at the outer edge of the end of the base film 1.

[0100] The shape of the third porous region 13 can be correspondingly set according to the shape of the electrode tab to be formed. This design can implement single-electrode tab, multi-electrode tab, and full-electrode tab solutions, facilitating the subsequent arrangement of the electrode sheets in the battery cell and reducing the process complexity. When a full-electrode tab needs to be formed, the third porous region 13 is a strip-shaped region, which has the advantages of large electrode tab contact area and low internal resistance. When a single-electrode tab needs to be formed, the third porous region 13 can be made into a single electrode tab region by cutting, which has the advantage of flexible electrode tab extraction position. When multi-electrode tabs need to be formed, the third porous region 13 can be made into multiple electrode tab regions by cutting, which has the advantages of uniform current extraction and reduced internal resistance.

[0101] In some embodiments, the width of the third porous region 13 is 10 - 1500 mm.

[0102] In some embodiments, the third conductive layer 8 is selected from one or more of metal materials, carbon materials, and conductive polymers. The metal materials include one or more of copper, aluminum, gold, silver, iron, nickel, and zinc. The carbon materials include one or more of graphene, amorphous carbon, carbon nanotubes, and carbon fibers. The conductive polymers include one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene, and polystyrene sulfonate.

[0103] In some embodiments, the third conductive layer 8 is selected from metal materials.

[0104] Compared with other conductive materials, using a metal material as the third conductive layer 8 facilitates subsequent welding operations. At the same time, the metal material itself has a low resistance, and the interface contact impedance after welding is small, which can effectively ensure the electrical connection effect, avoid the problem of tab heating, and improve the rate performance.

[0105] In some embodiments, the material of the third conductive layer 8 can be selected according to its application scenario. Specifically, when the unipolar current collector is applied to the positive electrode, the third conductive layer 8 is selected from aluminum and its alloys. Aluminum and its alloys have a low potential and good electrical conductivity, which can effectively improve the electron conductivity. At the same time, the potential of the positive electrode active material layer 6 is relatively high, and the aluminum and its alloys generate an oxide layer at a high potential, which can avoid the corrosion problem of the third conductive layer 8; when the unipolar current collector is applied to the negative electrode, the third conductive layer 8 is selected from copper and its alloys. Copper and its alloys have better electrical conductivity and thermal conductivity than aluminum. Therefore, as the third conductive layer 8, it is beneficial to improve the electron conductivity and heat dissipation performance.

[0106] In some embodiments, the third conductive layer 8 is prepared on the base film 1 by using one or more of physical vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating in water. The physical vapor deposition includes vacuum magnetron sputtering and / or evaporation.

[0107] In some embodiments, the third conductive layer 8 includes a third thin region 81 and a third thickened region 82. The third thickened region 82 covers the third porous region 13. The thickness of the third thin region 81 is 0.1 - 15 μm, and the thickness of the third thickened region 82 is 105% - 120% of the thickness of the third thin region 81.

[0108] In a specific embodiment, the thickness of the third thin region 81 can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm. The thickness of the third thickened region 82 can be 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, 119%, or 120% of the thickness of the third thin region 81.

[0109] The inventor found through a large number of experiments that when the thickness of the third thin region 81 is 0.1 - 15 μm, it is possible to reduce the impact on the energy density while satisfying the electron flow, meeting the requirements of electron conduction in the positive electrode active material layer 6 and the negative electrode active material layer 7. However, under the same thickness condition, the third conductive layer 8 located in the third porous region 13 cannot meet the requirements of welding and electrical conduction, having problems of large contact resistance and low peel strength. By thickening the third conductive layer 8 in the third porous region 13 to form a third thickened region 82, this problem can be effectively solved, effectively reducing the contact resistance at the tab position and simultaneously improving the tab welding yield.

[0110] In some embodiments, the aperture of the third through - hole is 0.01 - 1 μm, and the porosity of the third porous region 13 is 5% - 95%.

[0111] In a specific embodiment, the aperture of the third through - hole can be 0.01 μm, 0.02 μm, 0.05 μm, 0.08 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm, and the porosity of the third porous region 13 can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 27%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 37%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 47%, 49%, 50%, 60%, 61%, 62%, 64%, 68%, 70%, 74%, 75%, 77%, 80%, 81%, 83%, 85%, 89%, or 95%.

[0112] The third through - hole is used for the electrical conduction of the third conductive layer 8 on both sides of the base film 1. If the aperture of the third through - hole is too small, it is difficult for the third conductive layer 8 to enter the third through - hole; if the aperture of the third through - hole is too large, the third conductive layer 8 is likely to flow out and diffuse from the other side of the base film 1 after entering the third through - hole, unable to completely fill the third through - hole, affecting the electrical conduction effect. If the porosity of the third porous region 13 is too low, it will result in a large resistance between the two surface sides of the base film 1, being unfavorable for the structural stability of forming tabs by mutual welding and the reduction of impedance at the tab position; if the porosity of the third porous region 13 is too high, it will lead to a decrease in the composite structure strength of the third porous region 13 and the third conductive layer 8, also being unfavorable for the structural stability of forming tabs by mutual welding.

[0113] In some embodiments, the thickness of the base film 1 is 0.2 - 30 um.

[0114] In a specific embodiment, the thickness of the base film 1 can be 0.5 um, 0.8 um, 1 um, 2 um, 3 um, 4 um, 5 um, 6 um, 7 um, 8 um, 9 um, 10 um, 11 um, 12 um, 13 um, 14 um, 15 um, 16 um, 17 um, 18 um, 19 um, 20 um, 21 um, 22 um, 23 um, 24 um, 25 um, 27 um, 29 um or 30 um.

[0115] In some embodiments, the base film 1 comprises one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, polyethylene naphthalate.

[0116] Using the above polymers as the material of the base film 1, on the one hand, it has good affinity with the electrolyte, facilitating the infiltration and diffusion of the electrolyte and ensuring the ion shuttle between the positive and negative electrodes; on the other hand, it has good electronic isolation ability, which can avoid the direct contact between the first conductive layer 2 and the second conductive layer 3 and prevent the occurrence of internal short circuit.

[0117] See Figure 4 As shown, the present invention provides a unipolar electrode, comprising an active material layer 9 and the unipolar current collector as described above, and the active material layer 9 covers the surface of the third conductive layer 8 facing away from the base film 1.

[0118] Due to the adoption of the unipolar current collector provided with the third porous region 13 as described above, the base film 1 forms a double-sided conductive structure in the third porous region 13, meeting the requirement of directly welding as a tab, reducing the contact resistance, avoiding the transfer welding, and simplifying the production process.

[0119] In some embodiments, the active material layer 9 avoids the third porous region 13.

[0120] The third porous region 13 is used to form a tab, and through the avoidance setting of the active material layer 9, it is beneficial to avoid the influence of the active material layer 9 on the tab welding.

[0121] In some embodiments, the active material layer 9 is a positive electrode material or a negative electrode material.

[0122] Another embodiment of the present invention provides a battery, comprising the bipolar electrode and / or the unipolar electrode as described above, and positive and negative tabs are led out from the bipolar electrode and / or the unipolar electrode.

[0123] In some embodiments, the battery is a laminated battery or a wound battery.

[0124] In some embodiments, the battery is a cylindrical battery or a prismatic battery.

[0125] When the battery is a cylindrical battery, the positive electrode tab and the negative electrode tab are respectively at both ends along the length direction of the cylindrical battery. The positive electrode tab and the negative electrode tab can be folded towards the center of the cylindrical battery simultaneously, folded towards the outside of the cylindrical battery simultaneously, or the positive electrode tab is folded towards the center of the cylindrical battery and the negative electrode tab is folded towards the outside of the cylindrical battery, or the positive electrode tab is folded towards the outside of the cylindrical battery and the negative electrode tab is folded towards the inside of the cylindrical battery.

[0126] When the battery is a prismatic battery (in laminated or wound form) and uses the single-polarity electrode as described above, the positive electrode tab and the negative electrode tab are on the same side or different sides of the battery.

[0127] When the battery is a prismatic battery (in laminated or wound form) and uses the bipolar electrode as described above, the positive electrode tab and the negative electrode tab are on different sides of the battery.

[0128] When the battery is a prismatic battery (in laminated or wound form) and uses both the single-polarity electrode and the bipolar electrode as described above simultaneously, the positive electrode tab and the negative electrode tab are on different sides of the battery.

[0129] In some embodiments, the battery is a pouch battery or a hard shell battery.

[0130] In one embodiment, the battery includes an electrolyte, a positive electrode sheet, and a negative electrode sheet. The electrolyte is located between the positive electrode sheet and the negative electrode sheet. Both the positive electrode sheet and the negative electrode sheet are selected from the single-polarity electrodes as described above. The difference is that the active material layer 9 of the positive electrode sheet is selected from positive electrode materials, and the active material layer 9 of the negative electrode sheet is selected from negative electrode materials.

[0131] In another embodiment, the battery includes an electrolyte and a plurality of bipolar electrodes as described above. The electrolyte is located between two adjacent bipolar electrodes and is used to separate the positive active material layer 6 and the negative active material layer 7 of two adjacent bipolar electrodes.

[0132] In another embodiment, the battery includes an electrolyte layer, a bipolar electrode as described above, and a single-polarity electrode as described above. The electrolyte layer is used to isolate the bipolar electrode and the single-polarity electrode, and the single-polarity electrode is a positive electrode sheet and / or a negative electrode sheet.

[0133] It should be noted that in the above different embodiments, in addition to including the bipolar electrodes and / or the unipolar electrodes as described above, the battery may also selectively include other types of positive electrode sheets and / or negative electrode sheets, such as positive electrode sheets using a metal current collector and negative electrode sheets using a metal current collector.

[0134] In the above different embodiments, the electrolyte layer is selected from one or more of a separator, a solid electrolyte, a semi-solid electrolyte, or a gel electrolyte. The separator includes one or more of polypropylene (PP) and polyethylene (PE); the solid electrolyte includes one or more of an oxide solid electrolyte, a sulfide solid electrolyte, a halogen solid electrolyte, a polymer solid electrolyte, and a composite solid electrolyte (inorganic filler + polymer matrix). The semi-solid electrolyte includes the solid electrolyte and an electrolyte solution, and the gel electrolyte includes a polymer matrix and an electrolyte solution, and the electrolyte solution and the polymer matrix form a gel state. And when the electrolyte layer is selected as a separator, the battery further includes an electrolyte solution, and at this time, the battery is a liquid electrolyte battery; when the electrolyte layer is selected as a solid electrolyte, the battery is a solid-state battery; when the electrolyte layer is selected as a semi-solid electrolyte, the battery is a semi-solid battery; when the electrolyte layer is selected as a gel electrolyte, the battery is a gel electrolyte battery.

[0135] The electrolyte solution includes a lithium salt, a solvent, and an additive; the solvent includes one or more of carbonates (ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (BL)), ethers (tetrahydrofuran (THF), 2-methyl-tetrahydrofuran (2-Me-THF), dimethoxydimethyl ether (DMM), 1,2-dimethoxyethane (DME)), nitriles (acetonitrile (AN), etc.); the lithium salt includes lithium hexafluorophosphate LiPF 6 、lithium perchlorate LiClO 4 、lithium tetrafluoroborate LiBF 4 、lithium hexafluoroarsenate LiAsF 6 、other organic lithium salts (such as lithium trifluoromethanesulfonate LiCF 3 SO, lithium bis(trifluoromethanesulfonyl)imide LiTFSI, lithium bis(fluorosulfonyl)imide LiFSI, lithium trifluoromethanesulfonyl-n-perfluorobutanesulfonylimide LiTNFSI, lithium fluorosulfonyl-n-perfluorobutanesulfonylimide LiFNFSI, lithium bis(oxalato)borate LiBOB, LiN(CF 3 SO 2 ) 2 、LiC(SO 2 CF 3 ) 3one or more of the above; the additives include one or more of film-forming additives, conductive additives, flame retardant additives, overcharge protection additives, additives for controlling the water and HF content in the electrolyte, general additives for improving low-temperature performance, or can be additives for improving the interface stability between the electrode sheet and the electrolyte, such as fluoroethylene carbonate FEC, etc.

[0136] Another embodiment of the present invention provides an electrical device including the battery as described above.

[0137] Due to the adoption of the battery as described above, the battery has a high energy density and a low impedance, can reduce the volume and weight of the electrical device, and alleviate the heat generation problem caused by the operation of the battery itself.

[0138] In some embodiments, the electrical device includes an electric vehicle, an electronic cigarette, an electronic vapor device, wireless headphones, a floor cleaning robot, a drone, a laptop computer, a pen input computer, a mobile computer, an e-book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a head-mounted stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, a power tool, a flash, a camera, a large household battery, and a lithium-ion capacitor, etc.

[0139] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bipolar current collector, characterized in that, it includes a base film, a first conductive layer and a second conductive layer. A first porous region and a second porous region are provided on the base film. A plurality of first through holes penetrating the base film are provided in the first porous region, and a plurality of second through holes penetrating the base film are provided in the second porous region. The first conductive layer is located on one side surface of the base film, and the first conductive layer at least partially covers the first porous region. The first conductive layer at least partially fills the first through holes, and the first conductive layer is spaced apart from the second porous region. The second conductive layer is located on the other side surface of the base film, and the second conductive layer at least partially covers the second porous region. The second conductive layer at least partially fills the second through holes, and the second conductive layer is spaced apart from the first porous region.

2. The bipolar current collector according to claim 1, characterized in that, the first porous region and the second porous region are respectively located at two end positions of the base film.

3. The bipolar current collector according to claim 2, characterized in that, the first porous region is a strip-shaped region extending along the inner edge of the end of the base film, or the first porous region is a tab region provided singly or in plurality at intervals on the outer edge of the end of the base film.

4. The bipolar current collector according to claim 2, characterized in that, the second porous region is a strip-shaped region extending along the inner edge of the end of the base film, or the second porous region is a tab region provided singly or in plurality at intervals on the outer edge of the end of the base film.

5. The bipolar current collector according to claim 1, characterized in that, the first conductive layer and the second conductive layer each independently include one or more of a metal material, a carbon material and a conductive polymer. The metal material includes one or more of copper, aluminum, gold, silver, iron, nickel and zinc. The carbon material includes one or more of graphene, amorphous carbon, carbon nanotubes and carbon fibers. The conductive polymer includes one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene and polystyrene sulfonate.

6. The bipolar current collector according to claim 5, characterized in that, the first conductive layer is selected from aluminum and its alloys, and the second conductive layer is selected from copper and its alloys.

7. The bipolar current collector according to claim 1, characterized in that, the first conductive layer includes a first thin region and a first thickened region. The first thickened region covers the first porous region. The thickness of the first thin region is 0.1-15 μm, and the thickness of the first thickened region is 105%-120% of the thickness of the first thin region.

8. The bipolar current collector according to claim 1, characterized in that, the second conductive layer includes a second thin region and a second thickened region. The second thickened region covers the second porous region. The thickness of the second thin region is 0.1-15 μm, and the thickness of the second thickened region is 105%-120% of the thickness of the second thin region.

9. The bipolar current collector according to claim 1, characterized in that, The aperture of the first through hole is 0.01 - 1 um, the porosity of the first porous region is 5% - 95%, the aperture of the second through hole is 0.01 - 1 um, and the porosity of the second porous region is 5% - 95%.

10. The bipolar current collector according to claim 1, wherein, the thickness of the base film is 0.2 - 30 um.

11. The bipolar current collector according to claim 1, wherein, the base film comprises one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, polyethylene naphthalate.

12. The bipolar current collector according to claim 1, wherein, a first insulating transition region is formed between the first conductive layer and the second porous region, the base film is exposed in the first insulating transition region, a second insulating transition region is formed between the second conductive layer and the first porous region, and the base film is exposed in the second insulating transition region.

13. The bipolar current collector according to claim 12, wherein, the width of the first insulating transition region is 10 - 1000 um, and the width of the second insulating transition region is 10 - 1000 um.

14. A bipolar electrode, wherein, it comprises a positive electrode active material layer, a negative electrode active material layer, and the bipolar current collector according to any one of claims 1 to 13. The positive electrode active material layer covers the surface of the first conductive layer facing away from the base film, and the negative electrode active material layer covers the surface of the second conductive layer facing away from the base film.

15. The bipolar electrode according to claim 1, wherein, the positive electrode active material layer avoids the first porous region, and the negative electrode active material layer avoids the second porous region.

16. A unipolar current collector, wherein, it comprises a base film and third conductive layers provided on both side surfaces of the base film. A third porous region is provided on the base film, and a plurality of third through holes penetrating the base film are formed in the third porous region. The third conductive layer at least partially covers the third porous region, and the third conductive layer at least partially fills the third through holes so that the third conductive layers on both side surfaces of the base film are electrically connected to each other.

17. The unipolar current collector according to claim 16, wherein, the third porous region is located at the end position of the base film.

18. The unipolar current collector according to claim 17, wherein, the third porous region is a strip-shaped region extending along the inner edge of the end of the base film, or the third porous region is a tab region formed by one or more spaced apart on the outer edge of the end of the base film.

19. The unipolar current collector according to claim 16, wherein, The third conductive layer is selected from one or more of metal materials, carbon materials and conductive polymers, the metal materials include one or more of copper, aluminum, gold, silver, iron, nickel and zinc, the carbon materials include one or more of graphene, amorphous carbon, carbon nanotubes and carbon fibers, and the conductive polymers include one or more of polyaniline, polythiophene, polyphenylene sulfide, polyacetylene and polystyrene sulfonate.

20. The unipolar current collector according to claim 16, It is characterized in that The third conductive layer includes a third thin area and a third thickened area, the third thickened area covers the third porous area, the thickness of the third thin area is 0.1-15um, and the thickness of the third thickened area is 105%-120% of the thickness of the third thin area.

21. The unipolar current collector according to claim 16, It is characterized in that The pore size of the third through hole is 0.01-1 um, and the porosity of the third porous region is 5%-95%.

22. The unipolar current collector according to claim 16, It is characterized in that The thickness of the base film is 0.2-30 um.

23. The unipolar current collector according to claim 16, It is characterized in that The base film includes one or more of polyethylene, polyethylene terephthalate, polyimide, polypropylene, polyethylene, polyamide, polyphenylene sulfide, and polyethylene naphthalate.

24. A monopolar electrode, It is characterized in that The invention comprises an active material layer and the unipolar current collector according to any one of claims 16 to 23, wherein the active material layer covers a surface of the third conductive layer away from the base film.

25. The monopolar electrode according to claim 24, It is characterized in that The active material layer avoids the third porous region.

26. The monopolar electrode according to claim 24, It is characterized in that The active material layer is a positive electrode material or a negative electrode material.

27. A battery, It is characterized in that It comprises the bipolar electrode as described in any one of claims 14 to 15 and / or the monopolar electrode as described in any one of claims 24 to 26.

28. An electrical device, It is characterized in that Comprising a battery as claimed in claim 27.

Images