Rolled and stacked battery cell

Abstract

The invention relates to the technical field of battery cells, in particular to a coiled battery cell which comprises an anode plate, two diaphragms, a plurality of cathode plates, an active substance and a current collector, the negative pole piece adopts a discontinuous sheet-shaped pole piece, each negative pole piece is disconnected and does not enter a winding corner of the battery cell, the positive pole adopts a continuous long pole piece, various structural designs can be provided to adapt to different welding requirements, and the diaphragm, the negative pole piece and the positive pole piece are combined into the battery cell in a winding manner. In the winding process, the cathode is wrapped by the anode in the clockwise or anticlockwise direction. The winding ending position can adopt a mode of wrapping the battery cell with a copper foil, wrapping the battery cell with a diaphragm or coating an active substance on a single surface, so that the problem of relatively high cost caused by high control requirement and low efficiency of the existing wound battery cell is solved, and the problem of lithium precipitation at the corner of the wound battery cell can be effectively solved due to the design that the cathode pole piece is not provided with a corner; the safety and service life of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery cells, and in particular to a wound battery cell. Background Art

[0002] With the continuous development of electronic devices, the requirements for battery performance are getting higher and higher. Lithium batteries have been widely used in daily life due to their high energy density and good safety.

[0003] At present, most commercial batteries are assembled by winding or stacking positive and negative electrodes and separators. The winding method has low manufacturing precision requirements and high efficiency, but low space utilization and inconsistent cycle expansion, especially at the corners of the winding, which is prone to lithium deposition, affecting the performance and life of the battery. The stacked battery cell has high space utilization, but has high manufacturing control requirements and low efficiency, resulting in high costs. Summary of the invention

[0004] The object of the present invention is to provide a wound battery cell, aiming to solve the problem that the existing wound battery cells have high control requirements and low efficiency resulting in high costs.

[0005] To achieve the above-mentioned purpose, the present invention provides a stacked battery cell, including an anode sheet, two separators, multiple cathode sheets, an active substance and a current collector; the multiple cathode sheets are composited with the two separators and are located between the two separators, the anode sheet is arranged on one side of the separator, the active substance is coated on the anode sheet, and the current collector is located on one side of the anode sheet.

[0006] Among them, the plurality of cathode sheets have a first pole ear, and the anode sheet has a second pole ear.

[0007] Wherein, the widths of the plurality of cathode sheets are the same.

[0008] Wherein, the widths of the plurality of cathode sheets are different.

[0009] There is no active substance at the welding point between the second pole ear and the anode sheet, and after welding, insulation protection is performed by insulating tape.

[0010] The anode sheet has a plurality of pole ears 2, and the plurality of pole ears 2 are exposed current collectors formed by laser or cutting.

[0011] Wherein, the active material is any one of graphite, silicon or a mixture of the two, lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide.

[0012] A wound battery cell of the present invention comprises an anode sheet, two separators, a plurality of cathode sheets, an active material and a current collector; firstly, the anode and cathode active materials are coated on the anode and cathode current collectors respectively, and the anode and cathode sheets are rolled and stripped to form anode and cathode sheets respectively. In particular, the cathode sheet needs to be cut into a sheet-like sheet by laser or hardware cutting. The plurality of cathode sheets are compounded with the two separators and are located between the two separators. Before winding, the anode sheet is arranged on one side of the separator. After winding, the anode wraps the cathode inside and is located on both sides of the cathode sheet. The cathode sheet adopts a non-continuous sheet-like sheet, and each cathode sheet is disconnected and does not enter the corner of the battery cell winding. Each cathode sheet exposes a piece of the current collector as a false ear for subsequent welding of the ear. The cathode electrode piece is located between the two layers of diaphragm, and the spacing between the cathode electrode pieces is unequal to adapt to the winding structure of the battery cell. The anode adopts a continuous long electrode piece, and can have a variety of structural designs to adapt to different welding requirements. The diaphragm, cathode electrode piece and anode electrode piece are combined into a battery cell by winding. During the winding process, the anode wraps the cathode in a clockwise or counterclockwise direction. The winding end can be made by copper foil coating the battery cell, diaphragm coating or single-sided coating of active material. The present invention adopts a winding method, which reduces the manufacturing precision requirements and improves the production efficiency. Since the anode wraps the cathode, the alignment requirements for each layer of cathode are relatively low, which reduces the manufacturing difficulty. Thereby solving the problem that the existing stacked battery cells have high control requirements and low efficiency, resulting in high costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic structural diagram of a rolled battery cell according to the first embodiment of the present invention.

[0015] Figure 2 It is a cross-sectional view of a stacked battery cell according to the first embodiment of the present invention.

[0016] Figure 3 It is a schematic structural diagram of a stacked battery cell according to the second embodiment of the present invention.

[0017] Figure 4 It is a cross-sectional view of a rolled battery cell according to the second embodiment of the present invention.

[0018] Figure 5 It is a schematic structural diagram of a stacked battery cell according to the third embodiment of the present invention.

[0019] Figure 6 It is a cross-sectional view of a stacked battery cell according to the third embodiment of the present invention.

[0020] Figure 7 The invention discloses a stacked battery cell display insulating tape according to the third embodiment of the present invention.

[0021] Figure 8 It is a schematic structural diagram of a stacked battery cell according to a fourth embodiment of the present invention.

[0022] Fig. 9 is a cross-sectional view of a rolled battery cell according to a fourth embodiment of the present invention.

[0023] In the figure: 1-anode sheet, 2-diaphragm, 3-cathode sheet, 4-active material, 5-current collector, 6-ear tab 1, 7-ear tab 2, 8-insulating tape. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] The first embodiment of the present application is:

[0026] See also Figure 1 to Figure 2 , the present invention provides a rolled battery cell, comprising an anode sheet 1, two separators 2, a plurality of cathode sheets 3, an active material 4 and a current collector 5;

[0027] The plurality of cathode sheets 3 are all compounded with the two separators 2 and are all located between the two separators 2 . The anode sheet 1 is arranged on one side of the separator 2 . The active material 4 is coated on the anode sheet 1 . The current collector 5 is located on one side of the anode sheet 1 .

[0028] The active material 4 is any one of magnesium oxide, aluminum oxide, silicon oxide and calcium oxide.

[0029] The plurality of cathode sheets 3 have a first pole tab 6 , and the anode sheet 1 has a second pole tab 7 .

[0030] The plurality of cathode sheets 3 have the same width.

[0031] In this embodiment, the cathode sheet 3 and the anode sheet 1 are both coated with the active material 4, the cathode adopts a sheet-shaped electrode sheet and each sheet has the same width, and each cathode sheet has a leaking current collector 5 as a false electrode ear; the anode is a continuous long electrode sheet, and there are multiple leaking current collectors 5 on one side of the electrode sheet as false electrode ears; the diaphragm 2 and the cathode electrode sheet are first compounded to obtain a continuous composite sheet; when winding, the composite sheet and the anode are rolled into a battery cell.

[0032] The second embodiment of the present application is:

[0033] See also Figure 3 to Figure 4 , the present invention provides a rolled battery cell, comprising an anode sheet 1, two separators 2, a plurality of cathode sheets 3, an active material 4 and a current collector 5;

[0034] The plurality of cathode sheets 3 are all compounded with the two separators 2 and are all located between the two separators 2 . The anode sheet 1 is arranged on one side of the separator 2 . The active material 4 is coated on the anode sheet 1 . The current collector 5 is located on one side of the anode sheet 1 .

[0035] The active material 4 is any one of graphite, silicon or a mixture of the two, lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide. Anode: graphite, silicon or a mixture of the two; cathode: lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, etc.; insulating material: any one of magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide;

[0036] The plurality of cathode sheets 3 have a first pole tab 6 , and the anode sheet 1 has a second pole tab 7 .

[0037] The plurality of cathode sheets 3 have different widths and form a composite sheet with the separator 2 .

[0038] In this embodiment, the cathode sheet 3 and the anode sheet 1 are both coated with the active material 4, the cathode adopts a sheet-shaped electrode sheet and the width of the sheets are not all the same, each cathode has a leaking current collector 5 as a false electrode ear; the anode is a continuous long electrode sheet, and there are multiple leaking current collectors 5 on one side of the electrode sheet as false electrodes; the diaphragm 2 and the cathode electrode sheet are first composited to obtain a continuous composite sheet; when winding, the composite sheet and the anode are rolled into a battery cell, and the innermost or outermost layer is required to be shorter than the other layers of the electrode sheets. The short inner sheet can make room for the diaphragm 2 in the winding, thereby improving the consistency of the battery cell thickness. The outer layer is shorter than the other electrode sheets to facilitate the anode electrode sheet at the end of the winding to completely cover the diaphragm 2.

[0039] The third embodiment of the present application is:

[0040] See also Figures 5 to 7 , the present invention provides a rolled battery cell, comprising an anode sheet 1, two separators 2, a plurality of cathode sheets 3, an active material 4 and a current collector 5;

[0041] The plurality of cathode sheets 3 are all compounded with the two separators 2 and are all located between the two separators 2 . The anode sheet 1 is arranged on one side of the separator 2 . The active material 4 is coated on the anode sheet 1 . The current collector 5 is located on one side of the anode sheet 1 .

[0042] The active material 4 is any one of graphite, silicon or a mixture of the two, lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide. Anode: graphite, silicon or a mixture of the two; cathode: lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, etc.; insulating material: any one of magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide;

[0043] The plurality of cathode sheets 3 have a first pole tab 6 , and the anode sheet 1 has a second pole tab 7 .

[0044] There is no active material 4 at the welding point between the electrode tab 2 7 and the anode sheet 1 , and the welding point is insulated and protected by insulating tape 8 .

[0045] In this embodiment, the cathode sheet 3 and the anode sheet 1 are both coated with the active material 4, the cathode adopts a sheet-shaped electrode sheet, and each cathode has a leaking current collector 5 as a false electrode ear; the anode is a continuous long electrode sheet, and a plurality of leaking current collectors 5 are provided on one side of the electrode sheet as false electrodes; the diaphragm 2 is firstly compounded with the cathode electrode sheet to obtain a continuous composite sheet; when winding, the composite sheet and the anode are rolled into a battery cell. In order to improve the safety of the battery, the diaphragm 2 is wound around the battery one more time to form an insulating layer between the battery cell and the encapsulated aluminum-plastic film or steel shell to prevent short circuit.

[0046] The fourth embodiment of the present application is:

[0047] See also Figures 8 to 9 , the present invention provides a rolled battery cell, comprising an anode sheet 1, two separators 2, a plurality of cathode sheets 3, an active material 4 and a current collector 5;

[0048] The plurality of cathode sheets 3 are all compounded with the two separators 2 and are all located between the two separators 2 . The anode sheet 1 is arranged on one side of the separator 2 . The active material 4 is coated on the anode sheet 1 . The current collector 5 is located on one side of the anode sheet 1 .

[0049] The active material 4 is any one of graphite, silicon or a mixture of the two, lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide. Anode: graphite, silicon or a mixture of the two; cathode: lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, etc.; insulating material: any one of magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide;

[0050] The plurality of cathode sheets 3 have a first pole tab 6 , and the anode sheet 1 has a second pole tab 7 .

[0051] The anode sheet 1 has a plurality of pole tabs 7 , and the plurality of pole tabs 7 are exposed current collectors formed by laser or cutting.

[0052] In this embodiment, the cathode sheet 3 and the anode sheet 1 are coated with the active material 4, and the exposed tabs are formed by cutting the current collector, i.e., the fake tabs. Subsequently, external tabs (aluminum tabs and nickel tabs) are welded on the fake tabs; the cathode uses a sheet-shaped tab and each tab has the same width, and each cathode has a leaking current collector 5 as a fake tab; the anode is a continuous long tab, and there is no fake tab on one side of the tab. The current collector 5 is emptied by scraping or laser cleaning on the active material 4 layer of the tab for welding the tab, and after the tab is welded, an insulating tape 8 is pasted on the tab for insulation protection; the diaphragm 2 is first composited with the cathode tab to obtain a continuous composite sheet; when winding, the composite sheet and the anode are rolled into a battery cell.

[0053] The present invention provides a wound battery cell with the following beneficial effects:

[0054] 1. The present invention provides a rolled battery cell that improves the space utilization and performance of the battery cell: by adopting the design of rolled battery cells, combining the cathode sheet and the separator and the continuous long anode sheet design, the present invention can improve the space utilization of the battery cell while maintaining a high manufacturing efficiency, thereby improving the energy density of the battery. In particular, in the second embodiment, by adopting a cathode sheet design of different widths, the spatial distribution inside the battery cell can be further optimized, the consistency of the battery cell thickness can be improved, and the overall performance and cycle stability of the battery can be improved.

[0055] 2. The present invention provides a wound battery cell that enhances the safety and cycle life of the battery: In the third embodiment, by removing the active material at the welding point of the anode tab and using insulating tape for insulation protection, the short circuit phenomenon that may occur during the charging and discharging process of the battery is effectively prevented, thereby enhancing the safety of the battery. At the same time, this design also helps to reduce the problem of battery performance degradation caused by poor tab welding or active material shedding, and prolongs the cycle life of the battery.

[0056] 3. A rolled battery cell provided by the present invention reduces manufacturing costs: Although the manufacture of rolled batteries has certain requirements for control accuracy, its manufacturing process is still relatively simple and efficient compared to laminated batteries. By optimizing the design of rolled batteries, the present invention can reduce manufacturing costs while ensuring battery performance. In particular, in the fourth embodiment, by scraping or laser cleaning the active material layer of the anode sheet to free up the current collector for welding the pole ear, additional pole ear processing steps are avoided, further reducing manufacturing costs.

[0057] 4. The rolled battery cell provided by the present invention improves the manufacturability and flexibility of the battery: The rolled battery cell design provided by the present invention has high manufacturability and can adapt to the needs of batteries of different sizes and capacities. By adjusting the number and size of cathode sheets, diaphragms and anode sheets, battery products that meet various application scenarios can be easily produced. In addition, the present invention also provides a variety of embodiments for selection, which can be flexibly combined and optimized according to specific needs to meet the customized needs of different customers.

[0058] The above disclosure is only a preferred embodiment of the rolled battery cell of the present invention, and it certainly cannot be used to limit the scope of the rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiment can be implemented, and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A wound battery cell, characterized in that: It includes an anode sheet, two separators, a plurality of cathode sheets, an active material and a current collector; The plurality of cathode sheets are all compounded with the two separators and are all located between the two separators. The anode sheet is arranged on one side of the separator. The active material is coated on the anode sheet. The current collector is located on one side of the anode sheet.

2. The wound battery cell according to claim 1, characterized in that: The plurality of cathode sheets have a first pole tab, and the anode sheet has a second pole tab.

3. The wound battery cell according to claim 2, characterized in that: The plurality of cathode sheets have the same width.

4. The wound battery cell according to claim 2, characterized in that: The widths of the plurality of cathode sheets are different.

5. The wound battery cell according to claim 2, characterized in that: The active material is not present at the welding point between the second pole ear and the anode sheet, and insulation protection is performed by insulating tape after welding.

6. The wound battery cell according to claim 2, characterized in that: The anode sheet has a plurality of pole ears 2, and the plurality of pole ears 2 are exposed current collectors formed by laser or cutting.

7. The wound battery cell according to claim 1, characterized in that: The active material is any one of graphite, silicon or a mixture of the two, lithium cobalt oxide, lithium iron phosphate, ternary material, lithium titanate, magnesium oxide, aluminum oxide, silicon oxide, and calcium oxide.

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