A composite battery

Abstract

The application belongs to the technical field of lithium ion batteries, and relates to a composite battery, which comprises a shell and a battery core arranged in the shell. The battery core comprises a winding type battery core and a laminated type battery core connected in parallel. The laminated type battery core comprises a plurality of first bipolar sheets stacked and a first diaphragm arranged between two adjacent layers of the first bipolar sheets. The winding type battery core comprises a winding core in a multi-layer structure with an internal hollow formed by winding a second bipolar sheet and a second diaphragm stacked on one side surface of the second bipolar sheet. The composite battery of the application only needs to control the alignment of the entire sheet during lamination. Only one kind of sheet is used during lamination, the process flow is simplified, and the lamination speed is significantly improved. The metal burrs can be eliminated during cutting. The composite battery is light in weight. The winding core is formed by winding only one kind of bipolar sheet and one layer of diaphragm, the process flow is simplified, and the energy density is high.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology and relates to a composite battery. Background Technology

[0002] Lithium-ion batteries possess advantages such as large capacity, high operating voltage, strong charge retention, and high safety, and are widely used in consumer electronics and electric vehicles. With the development of new energy vehicles, people are placing higher demands on their driving range. Therefore, improving the energy density of lithium-ion batteries is a major development direction. Reducing the weight of the current collector, as one way to improve energy density, does not introduce safety risks and can also reduce battery production costs, thus having broader application prospects.

[0003] Currently, the mainstream lithium-ion battery uses aluminum foil as the positive electrode current collector and copper foil as the negative electrode current collector. When the thickness of the metal foil decreases to a certain extent, its mechanical strength decreases, and the processing difficulty increases significantly. To ensure mechanical strength while reducing thickness, some patents propose reducing the current collector thickness by plating copper or aluminum onto a plastic film.

[0004] While this method reduces the thickness, the plastic film can negatively impact welding during assembly and may cause a short circuit in the battery. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a composite battery, which addresses the problem that existing plastic films can have an adverse effect on welding during the assembly process and may cause short circuits in the battery.

[0006] To address the aforementioned technical problems, the present invention provides a composite battery. The composite battery includes a casing and battery cells disposed within the casing, wherein the battery cells include wound battery cells and stacked battery cells connected in parallel.

[0007] The stacked battery cell includes multiple stacked first bipolar plates and a first separator disposed between two adjacent layers of the first bipolar plates;

[0008] The wound cell includes a core, which is a hollow, multi-layered structure formed by winding a second bipolar electrode and a second diaphragm superimposed on one side surface of the second bipolar electrode.

[0009] Optionally, the first bipolar electrode includes a first plastic film, a first negative metal plating layer, a first positive metal plating layer, a first negative active material, a first positive active material, a first negative electrode tab, and a first positive electrode tab. The first negative metal plating layer covers the upper surface of the first plastic film and encloses a first side edge of the first plastic film. The first positive metal plating layer covers the lower surface of the first plastic film and encloses a second side edge of the first plastic film. The first negative active material is coated on the upper surface of the first negative metal plating layer and the first positive active material is coated on the lower surface of the first positive metal plating layer. The first negative metal plating layer, the first plastic film, and the first positive metal plating layer are stacked to form a bipolar current collector. The first negative metal plating layer is insulated from the first positive metal plating layer. The first negative electrode tab is connected to the first side edge of the first negative metal plating layer, and the first positive electrode tab is connected to the second side edge of the first positive metal plating layer. The first negative electrode tab and the first positive electrode tab are disposed opposite to each other.

[0010] Optionally, the upper surface of the first side of the first plastic film is provided with a first stepped surface, and the first negative electrode metal coating covers the first stepped surface;

[0011] The lower surface of the second side of the first plastic film is provided with a second stepped surface, and the first positive electrode metal coating covers the second stepped surface.

[0012] Optionally, the upper surface of the first separator is covered with the first positive electrode active material of the upper layer of the first bipolar electrode, and the lower surface of the first separator is covered with the first negative electrode active material of the lower layer of the first bipolar electrode.

[0013] Optionally, the wound cell further includes a second negative electrode tab and a second positive electrode tab. The second bipolar electrode includes a second plastic film, a second negative metal plating layer, a second positive metal plating layer, a second negative active material, and a second positive active material. The second negative metal plating layer covers one side surface of the second plastic film and encloses the first end of the second plastic film. The second positive metal plating layer covers the other side surface of the second plastic film and encloses the first end of the second plastic film. The second negative active material is coated on the side surface of the second negative metal plating layer opposite to the second plastic film, and the second positive active material is coated on the side surface of the second positive metal plating layer opposite to the second plastic film. The second negative metal plating layer, the second plastic film, and the second positive metal plating layer are stacked and wound into a bipolar current collector. The second negative metal plating layer is insulated from the second positive metal plating layer. The second negative electrode tab is connected to the first end of the second negative metal plating layer, and the second positive electrode tab is connected to the first end of the second positive metal plating layer. The second negative electrode tab and the second positive electrode tab are located outside the wound core.

[0014] Optionally, a first stepped surface is provided on one side surface of the second plastic film, and the second negative electrode metal coating covers the first stepped surface;

[0015] The other side surface of the second plastic film is provided with a second stepped surface, and the second positive electrode metal coating covers the second stepped surface.

[0016] Optionally, the second diaphragm is attached to the second positive electrode active material or the second negative electrode active material.

[0017] Optionally, the first negative electrode metal plating layer is a copper plating layer, and the first positive electrode metal plating layer is an aluminum plating layer; the first negative electrode tab is a copper foil, and the first positive electrode tab is an aluminum foil.

[0018] The second negative electrode metal plating is a copper plating, and the second positive electrode metal plating is an aluminum plating; the second negative electrode tab is a copper foil, and the second positive electrode tab is an aluminum foil.

[0019] Optionally, the thickness of the first plastic film is 1-50 micrometers;

[0020] The thickness of the second plastic film is 1-50 micrometers.

[0021] Optionally, the thickness of the first negative electrode metal coating is 0.5-1 micrometer, and the thickness of the first positive electrode metal coating is 0.5-1 micrometer;

[0022] The thickness of the second negative electrode metal coating is 0.5-1 micrometer, and the thickness of the second positive electrode metal coating is 0.5-1 micrometer.

[0023] The composite battery provided in this invention includes a casing and battery cells disposed within the casing. The battery cells include wound cells and stacked cells connected in parallel. The stacked cell includes multiple stacked first bipolar plates and a first separator disposed between adjacent layers of the first bipolar plates. The wound cell includes a core, which is a hollow, multi-layered structure formed by winding a second bipolar plate and a second separator superimposed on one side surface of the second bipolar plate. The composite battery of this application only requires controlling the alignment of the entire electrode sheet during stacking; it uses only one type of electrode sheet during stacking, simplifying the process and significantly improving the stacking speed; it eliminates metal burrs during cutting; it is lightweight; and the core only requires one type of bipolar plate and one layer of separator for winding, simplifying the process and achieving high energy density. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a composite battery provided in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the first bipolar electrode of a composite battery provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of a stacked cell for a composite battery according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the second bipolar electrode of a composite battery provided in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the second bipolar electrode and separator of the composite battery provided in the first embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the second bipolar electrode and separator of the composite battery provided in the second embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of a wound cell for a composite battery according to an embodiment of the present invention.

[0031] The reference numerals in the accompanying drawings are as follows:

[0032] 1. Shell;

[0033] 10. First bipolar electrode; 11. First negative electrode tab; 12. First negative electrode metal plating; 13. First separator; 14. First negative electrode active material; 15. First plastic film; 16. First positive electrode tab; 17. First positive electrode active material; 18. First positive electrode metal plating;

[0034] 20. Second bipolar electrode; 21. Second negative electrode tab; 22. Second negative electrode metal coating; 23. Second separator; 24. Second negative electrode active material; 25. Second plastic film; 26. Second positive electrode tab; 27. Second positive electrode active material; 28. Second positive electrode metal coating. Detailed Implementation

[0035] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the 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 merely illustrative and are not intended to limit the invention.

[0036] like Figures 1 to 2 As shown, the composite battery provided in this embodiment of the invention includes a housing 1 and battery cells disposed within the housing 1. The battery cells include wound battery cells and stacked battery cells connected in parallel.

[0037] The stacked battery cell includes multiple stacked first bipolar plates 10 and a first separator 13 disposed between two adjacent layers of the first bipolar plates 10.

[0038] The wound cell includes a core, which is a hollow, multi-layered structure formed by winding a second bipolar electrode 20 and a second diaphragm 23 superimposed on one side surface of the second bipolar electrode 20.

[0039] In one embodiment, the first bipolar electrode 10 includes a first plastic film 15, a first negative electrode metal plating layer 12, a first positive electrode metal plating layer 18, a first negative electrode active material 14, a first positive electrode active material 17, a first negative electrode tab 11, and a first positive electrode tab 16. The first negative electrode metal plating layer 12 covers the upper surface of the first plastic film 15 and encloses the first side edge of the first plastic film 15. The first positive electrode metal plating layer 18 covers the lower surface of the first plastic film 15 and encloses the second side edge of the first plastic film 15. The first negative electrode active material 14 is coated on the first negative electrode active material 16. The first negative electrode metal plating layer 12 is placed on the upper surface, and the first positive electrode active material 17 is coated on the lower surface of the first positive electrode metal plating layer 18. The first negative electrode metal plating layer 12, the first plastic film 15, and the first positive electrode metal plating layer 18 are stacked to form a bipolar current collector. The first negative electrode metal plating layer 12 is insulated from the first positive electrode metal plating layer 18. The first negative electrode tab 11 is connected to the first side edge of the first negative electrode metal plating layer 12, and the first positive electrode tab 16 is connected to the second side edge of the first positive electrode metal plating layer 18. The first negative electrode tab 11 and the first positive electrode tab 16 are disposed opposite to each other.

[0040] In one embodiment, the upper surface of the first side of the first plastic film 15 is provided with a first stepped surface, and the first negative electrode metal plating layer 12 covers the first stepped surface.

[0041] The lower surface of the second side of the first plastic film 15 is provided with a second stepped surface, and the first positive electrode metal plating layer 18 covers the second stepped surface.

[0042] In one embodiment, the upper surface of the first diaphragm 13 is covered with the first positive electrode active material 17 of the upper layer of the first bipolar electrode 10, and the lower surface of the first diaphragm 13 is covered with the first negative electrode active material 14 of the lower layer of the first bipolar electrode 10.

[0043] In one embodiment, the wound battery cell further includes a second negative electrode tab 21 and a second positive electrode tab 26. The second bipolar electrode 20 includes a second plastic film 25, a second negative electrode metal plating layer 22, a second positive electrode metal plating layer 28, a second negative electrode active material 24, and a second positive electrode active material 27. The second negative electrode metal plating layer 22 covers one side surface of the second plastic film 25 and encloses the first end of the second plastic film. The second positive electrode metal plating layer 28 covers the other side surface of the second plastic film 25 and encloses the first end of the second plastic film 25. The second negative electrode active material 24 is coated on the second negative electrode metal plating layer 22. On the side of the second positive electrode active material 27 facing away from the second plastic film 25, the second positive electrode metal plating layer 28 is coated on the side of the second positive electrode metal plating layer 28 facing away from the second plastic film 25; the second negative electrode metal plating layer 22, the second plastic film 25 and the second positive electrode metal plating layer 28 are stacked and wound into a bipolar current collector, the second negative electrode metal plating layer 22 is insulated from the second positive electrode metal plating layer 28; the second negative electrode tab 21 is connected to the first end of the second negative electrode metal plating layer 22, the second positive electrode tab 26 is connected to the first end of the second positive electrode metal plating layer 28, and the second negative electrode tab 21 and the second positive electrode tab 26 are located outside the core.

[0044] In one embodiment, a first stepped surface is provided on one side surface of the second plastic film 25, and the second negative electrode metal plating layer 22 covers the first stepped surface.

[0045] The other side surface of the second plastic film 25 is provided with a second stepped surface, and the second positive electrode metal coating 28 covers the second stepped surface.

[0046] In one embodiment, the second membrane 23 is attached to the second positive electrode active material 27 or the second negative electrode active material 24.

[0047] In one embodiment, the first negative electrode metal plating layer 12 is a copper plating layer, and the first positive electrode metal plating layer 18 is an aluminum plating layer; the first negative electrode tab 11 is a copper foil, and the first positive electrode tab 16 is an aluminum foil.

[0048] The second negative electrode metal plating layer 22 is a copper plating layer, and the second positive electrode metal plating layer 28 is an aluminum plating layer; the second negative electrode tab 21 is a copper foil, and the second positive electrode tab 26 is an aluminum foil.

[0049] In one embodiment, the thickness of the first plastic film 15 is 1-50 micrometers.

[0050] The thickness of the second plastic film 25 is 1-50 micrometers.

[0051] In one embodiment, the thickness of the first negative electrode metal coating 12 is 0.5-1 micrometer, and the thickness of the first positive electrode metal coating 18 is 0.5-1 micrometer.

[0052] The thickness of the second negative electrode metal coating 22 is 0.5-1 micrometer, and the thickness of the second positive electrode metal coating 28 is 0.5-1 micrometer.

[0053] Optionally, the first negative electrode tab 11 and the second negative electrode tab 21 are not limited to copper, but may also be other metals or alloy elements. The first positive electrode tab 16 and the second positive electrode tab 26 are not limited to aluminum, but may also be other metals or alloy elements.

[0054] In one embodiment, the first plastic film 15 and the second plastic film 25 are PET films.

[0055] Optionally, the materials of the first plastic film 15 and the second plastic film 25 include, but are not limited to, PET, OPP, PI, CPP, PVC, etc.

[0056] In one embodiment, the first negative electrode metal coating 12 is deposited onto the upper surface of the first plastic film 15 by vapor deposition. The first positive electrode metal coating 18 is deposited onto the lower surface of the first plastic film 15 by vapor deposition.

[0057] In one embodiment, the second negative electrode metal coating 22 is deposited onto one side of the second plastic film 25 by vapor deposition. The second positive electrode metal coating 8 is deposited onto the other side of the second plastic film 25 by vapor deposition.

[0058] According to an embodiment of the present invention, the stacked battery cell includes a plurality of stacked first bipolar plates and a first separator disposed between two adjacent layers of the first bipolar plates; the wound battery cell includes a core, the core being a hollow, multi-layered structure formed by winding a second bipolar plate and a second separator superimposed on one side surface of the second bipolar plate. The composite battery of this application only requires controlling the alignment of the entire electrode sheet during stacking; only one type of electrode sheet is used during stacking, simplifying the process and significantly improving the stacking speed; metal burrs can be eliminated during cutting; it is lightweight; the core only requires one type of bipolar plate and one layer of separator for winding, simplifying the process and achieving high energy density.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hybrid battery, characterized by comprising: It includes a housing and battery cells disposed within the housing, wherein the battery cells include wound battery cells and laminated battery cells connected in parallel; The stacked battery cell includes multiple stacked first bipolar plates and a first separator disposed between two adjacent layers of the first bipolar plates; The wound cell includes a core, which is a hollow multi-layer structure formed by winding a second bipolar electrode and a second diaphragm superimposed on one side surface of the second bipolar electrode. The first bipolar electrode includes a first plastic film, a first negative metal plating layer, a first positive metal plating layer, a first negative active material, a first positive active material, a first negative electrode tab, and a first positive electrode tab. The first negative metal plating layer covers the upper surface of the first plastic film and encloses a first side edge of the first plastic film. The first positive metal plating layer covers the lower surface of the first plastic film and encloses a second side edge of the first plastic film. The first negative active material is coated on the upper surface of the first negative metal plating layer and the first positive active material is coated on the lower surface of the first positive metal plating layer. The first negative metal plating layer, the first plastic film, and the first positive metal plating layer are stacked to form a bipolar current collector. The first negative metal plating layer is insulated from the first positive metal plating layer. The first negative electrode tab is connected to the first side edge of the first negative metal plating layer, and the first positive electrode tab is connected to the second side edge of the first positive metal plating layer. The first negative electrode tab and the first positive electrode tab are disposed opposite to each other. The upper surface of the first side of the first plastic film is provided with a first stepped surface near the edge of the first negative electrode tab, and the first negative electrode metal plating layer covers the first stepped surface. A second stepped surface is provided on the lower surface of the second side of the first plastic film near the edge of the first positive electrode tab, and the first positive electrode metal coating covers the second stepped surface.

2. The hybrid battery of claim 1, wherein, The upper surface of the first separator is covered with the first positive electrode active material of the upper layer of the first bipolar electrode, and the lower surface of the first separator is covered with the first negative electrode active material of the lower layer of the first bipolar electrode.

3. The hybrid battery of claim 1, wherein, The wound battery cell further includes a second negative electrode tab and a second positive electrode tab. The second bipolar electrode includes a second plastic film, a second negative metal plating layer, a second positive metal plating layer, a second negative active material, and a second positive active material. The second negative metal plating layer covers one side surface of the second plastic film and encloses the first end of the second plastic film. The second positive metal plating layer covers the other side surface of the second plastic film and encloses the first end of the second plastic film. The second negative active material is coated on the side surface of the second negative metal plating layer opposite to the second plastic film, and the second positive active material is coated on the side surface of the second positive metal plating layer opposite to the second plastic film. The second negative metal plating layer, the second plastic film, and the second positive metal plating layer are stacked and wound into a bipolar current collector. The second negative metal plating layer is insulated from the second positive metal plating layer. The second negative electrode tab is connected to the first end of the second negative metal plating layer, and the second positive electrode tab is connected to the first end of the second positive metal plating layer. The second negative electrode tab and the second positive electrode tab are located outside the wound core.

4. The hybrid battery of claim 3, wherein, The second plastic film has a first stepped surface on one side surface, and the second negative electrode metal coating covers the first stepped surface; The other side surface of the second plastic film is provided with a second stepped surface, and the second positive electrode metal coating covers the second stepped surface.

5. The hybrid battery of claim 3, wherein, The second diaphragm is attached to the second positive electrode active material or the second negative electrode active material.

6. The hybrid battery of claim 3, wherein, The first negative electrode metal plating layer is a copper plating layer, and the first positive electrode metal plating layer is an aluminum plating layer; the first negative electrode tab is a copper foil sheet, and the first positive electrode tab is an aluminum foil sheet; The second negative electrode metal plating is a copper plating, and the second positive electrode metal plating is an aluminum plating; the second negative electrode tab is a copper foil, and the second positive electrode tab is an aluminum foil.

7. The hybrid battery of claim 3, wherein, The thickness of the first plastic film is 1-50 micrometers; The thickness of the second plastic film is 1-50 micrometers.

8. The hybrid battery of claim 3, wherein, The thickness of the first negative electrode metal coating is 0.5-1 micrometer, and the thickness of the first positive electrode metal coating is 0.5-1 micrometer; The thickness of the second negative electrode metal coating is 0.5-1 micrometer, and the thickness of the second positive electrode metal coating is 0.5-1 micrometer.

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