Bipolar battery

Abstract

The embodiment of the utility model relates to a bipolar battery. The bipolar battery comprises a plurality of battery units which are connected in series, each battery unit comprises two current collectors, and a negative plate, a diaphragm and a positive plate which are arranged between the two current collectors and are sequentially stacked; the negative plate abuts against one of the current collectors, and the positive plate abuts against the other current collector; and two adjacent battery units share one of the current collectors. The utility model also provides a preparation method of the bipolar battery. According to the structure, boosting can be achieved in a multi-stage series connection mode through the internal pole pieces. According to the invention, the free setting of the voltage can be realized only by increasing the number of stacked layers according to the voltage requirement, the series connection efficiency is greatly improved, the internal resistance of the battery is effectively reduced, and the performance and consistency of the product are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a bipolar battery. Background Technology

[0002] With the development of technology, power batteries have received increasing attention as an energy device and have been widely used in mobile phones, electric vehicles, power tools, home energy storage and other fields.

[0003] Currently, common lithium-ion battery structures include cylindrical, prismatic, and pouch cells. Cylindrical batteries are generally assembled in a single-string wound configuration; prismatic and pouch cells are typically composed of single-string wound cells or multi-parallel stacked cells. Both internal single-string and multi-parallel stacked cell structures suffer from low individual cell voltages. In practical applications, these low-voltage cells need to be connected in series to form battery modules to increase the output voltage and meet certain load voltage requirements. Connecting cells in series requires external soldering and a management system for module control, which is cumbersome and costly, making it difficult to meet the needs of practical applications. Utility Model Content

[0004] Based on this, the present invention provides a bipolar battery, which aims to solve the problems of low voltage of existing single cells, cumbersome series connection operation, need for management system for module control, and high cost.

[0005] To achieve the above objectives, the present invention proposes the following technical solution: a bipolar battery comprising multiple battery cells connected in series; each battery cell includes two current collectors, and a negative electrode, a separator, and a positive electrode disposed between the two current collectors and stacked sequentially; the negative electrode is in contact with one of the current collectors, and the positive electrode is in contact with the other current collector; two adjacent battery cells share one of the current collectors.

[0006] In a preferred embodiment, the thickness of the positive electrode sheet is 0.05 mm to 10.0 mm.

[0007] In a preferred embodiment, the thickness of the negative electrode sheet is 0.05 mm to 10.0 mm.

[0008] In a preferred embodiment, each battery cell is an isolated and sealed unit; adjacent battery cells are isolated and sealed by a shared current collector. Each battery cell forms a sealed unit, effectively preventing electrolyte cross-contamination.

[0009] In a preferred embodiment, the battery cell is a cylindrical battery cell or a square battery cell; when the battery cell is a cylindrical battery cell, the current collector, the negative electrode, the separator, and the positive electrode are all circular.

[0010] In a preferred embodiment, the two current collectors have the same radius; the radius of the current collector is larger than the radius of the diaphragm; the radius of the diaphragm is larger than the radius of the negative electrode; and the radius of the negative electrode is larger than the radius of the positive electrode.

[0011] In a preferred embodiment, the current collector is one of a stainless steel current collector, a titanium alloy current collector, or a nickel sheet current collector.

[0012] In a preferred embodiment, the positive electrode sheet is prepared from the following components by mass percentage: 80%–98% positive electrode active material powder, 1%–10% first binder powder, and 0.5%–10% first conductive agent powder;

[0013] The positive electrode active material powder is one or a mixture of at least two of lithium iron phosphate, ternary lithium compounds, lithium manganese oxide, sodium iron phosphate, sodium vanadium phosphate, sodium cobalt oxide, lithium ferrite, or lithium nickel oxide.

[0014] The ternary lithium compound is one of lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminum oxide;

[0015] The first adhesive powder is one or a mixture of at least two of PTFE, PVDF, PEO or short fibers;

[0016] The first conductive agent powder is one or a mixture of at least two of the following: conductive carbon black, carbon nanotubes, graphene, or conductive graphite.

[0017] In a preferred embodiment, the positive electrode sheet is prepared by the following method: 80%–98% of positive electrode active material powder, 1%–10% of first binder powder and 0.5%–10% of first conductive agent powder are mixed evenly and dispersed in an environment with a dew point temperature ≤ -30°C to obtain a mixed powder; the mixed powder is rolled and then die-cut to obtain a positive electrode sheet with a thickness of 0.05 mm–10.0 mm.

[0018] In a preferred embodiment, the dispersion temperature is 50℃~180℃, and the dispersion linear velocity is 10m / s~30m / s.

[0019] The temperature of the roller pressing is 80℃~200℃; the pressure of the roller pressing is 10T~500T.

[0020] In a preferred embodiment, the negative electrode sheet is prepared from the following components by mass percentage: 80%–98% negative electrode active material powder, 1%–10% second binder powder, and 0.5%–10% second conductive agent powder;

[0021] The negative electrode active material powder is one or a mixture of at least two of graphite, lithium titanate, or silicon negative electrode.

[0022] The graphite is hard carbon or soft carbon;

[0023] The second binder powder is one or a mixture of at least two of PTFE, PVDF, PEO or short fibers;

[0024] The second conductive agent powder is one or a mixture of at least two of the following: conductive carbon black, carbon nanotubes, graphene, or conductive graphite.

[0025] In a preferred embodiment, the negative electrode sheet is prepared by the following method: 80%–98% of negative electrode active material powder, 1%–10% of second binder powder and 0.5%–10% of second conductive agent powder are mixed evenly and dispersed in an environment with a dew point temperature ≤ -30°C to obtain a mixed powder; the mixed powder is rolled and then die-cut to obtain a negative electrode sheet with a thickness of 0.05 mm–10.0 mm.

[0026] In a preferred embodiment, the dispersion temperature is 50℃~180℃, and the dispersion linear velocity is 10m / s~30m / s; this is beneficial for the fiberization of the second binder powder and can also uniformly disperse the powders.

[0027] The temperature of the roller pressing is 80℃~200℃; the pressure of the roller pressing is 10T~500T.

[0028] In a preferred embodiment, the bipolar battery is a lithium-ion battery, a sodium-ion battery, or a zinc-ion battery.

[0029] On the other hand, embodiments of this application also provide a method for preparing the bipolar battery, including the following steps: in an environment with a dew point temperature ≤ -30°C, two current collectors, a negative electrode, a separator, and a positive electrode are stacked sequentially in the order of current collector, negative electrode, separator, positive electrode, and current collector to obtain a battery cell; multiple battery cells are connected in series to obtain a bipolar battery.

[0030] The beneficial effects achieved by this utility model are:

[0031] (1) This application changes the existing battery internal parallel or single-string structure, and obtains positive and negative electrode sheets by dry electrode preparation method. By optimizing the assembly method, the two adjacent battery cells are isolated and completely sealed by only one current collector. Thus, the single cell can be boosted by multi-level series through internal electrode sheets, which can effectively solve the problem of low voltage of single cell.

[0032] (2) Compared to traditional batteries, the bipolar battery of this application can remove solvents (NMP, deionized water, etc.), thickeners (CMC, etc.), copper foil, aluminum foil, and other raw materials at the raw material stage, greatly reducing solvent recycling and avoiding environmental pollution, while effectively reducing cell costs. Regarding voltage, the bipolar battery of this application can achieve free voltage setting simply by increasing the number of stacked layers according to voltage requirements; simultaneously, because it does not require external adapters like those used in traditional single-cell batteries, it can greatly improve series efficiency, effectively reduce battery internal resistance, and improve product performance and consistency. Regarding capacity, the bipolar battery of this application uses a dry electrode fabrication method, increasing the electrode thickness from the micrometer level of traditional batteries to the millimeter level of this application, thus ensuring higher energy density.

[0033] (3) Compared with the traditional battery manufacturing process, the bipolar battery of this application can eliminate the need for equipment such as coating machine, ultrasonic welding machine, laser welding machine, coating machine, casing machine, baking, etc., which can effectively reduce equipment investment; in terms of process flow, coating, ultrasonic welding, laser welding, coating, baking, assembly, etc. can be eliminated, which can effectively shorten the delivery cycle and effectively improve the production efficiency of the battery. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the overall structure of a bipolar battery according to an embodiment of the present invention;

[0036] Figure 2 for Figure 1 A schematic diagram of the exploded structure of a bipolar battery;

[0037] Figure 3 for Figure 1 A cross-sectional schematic diagram of a bipolar battery.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, top, bottom, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0043] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0044] In existing technologies, some high-voltage single-cell batteries are constructed using lateral series connection, which requires additional materials to form different sealed cavities, and in principle, it is still a traditional series connection method for single-cell batteries. Existing battery structures using a pouch design and connecting tabs to achieve lateral series connection inside the battery still require internal connecting tabs, and have a large footprint, long sealing dimensions, high limitations in series connection, and high cost. Traditional battery structures using wet-coated electrodes have high limitations in compaction density and energy density, making it impossible to achieve the required higher energy density and hindering mass production. Therefore, this application provides a bipolar battery and its fabrication method to solve the above-mentioned technical problems.

[0045] Specifically, on the one hand, such as Figures 1 to 3 As shown, the present invention proposes the following technical solution: a bipolar battery, comprising a plurality of battery cells 10 connected in series; each battery cell 10 includes two current collectors 11, and a negative electrode 12, a separator 13 and a positive electrode 14 disposed between the two current collectors 11 and stacked sequentially; the negative electrode 12 abuts against one of the current collectors 11, and the positive electrode 14 abuts against the other current collector 11; two adjacent battery cells 10 share one of the current collectors 11.

[0046] like Figures 2 to 3 As shown, in this embodiment, there are two battery cells 10 connected in series. It is understood that in other embodiments, depending on the actual needs of use, the number of battery cells 10 connected in series may also be 3, 4, 10, 15 or even more.

[0047] In a preferred embodiment, the thickness of the positive electrode 14 is 0.05 mm to 10.0 mm (it can be 0.05 mm, 0.1 mm, 3.0 mm, 6.0 mm, or 10.0 mm, depending on the actual application requirements). By controlling the thickness of the positive electrode in this application, the electrode thickness of traditional batteries at the micrometer level can be increased to the electrode thickness at the millimeter level, which can ensure that the battery structure has a higher energy density.

[0048] The thickness of the negative electrode 12 is 0.05 mm to 10.0 mm (it can be 0.05 mm, 0.1 mm, 3.0 mm, 6.0 mm, or 10.0 mm, depending on the actual application requirements). By controlling the thickness of the negative electrode in this application, the electrode thickness of traditional batteries at the micron level can be increased to the electrode thickness at the millimeter level, which can ensure that the battery structure has a higher energy density.

[0049] In a preferred embodiment, each battery cell 10 is an isolated and sealed unit; adjacent battery cells are isolated and sealed through a shared current collector. Each battery cell forms a sealed unit, effectively preventing electrolyte cross-contamination. Using a shared current collector to isolate and seal adjacent battery cells effectively simplifies the battery structure, increases its energy density, simplifies the manufacturing process, shortens the manufacturing time, and ensures the battery's sealing performance.

[0050] In a preferred embodiment, the battery cell 10 is a cylindrical battery cell or a square battery cell; when the battery cell 10 is a cylindrical battery cell, the two current collectors 11, the negative electrode 12, the separator 13, and the positive electrode 14 are all circular. Figures 1 to 3 As shown, taking a cylindrical battery cell as an example, when two current collectors 11, the negative electrode 12, the separator 13, and the positive electrode 14 are stacked to form a battery cell, the centers of the two current collectors 11, the negative electrode 12, the separator 13, and the positive electrode 14 are on the same vertical line, which is perpendicular to the center. It is understood that in other embodiments, the battery cell 10 may also be a square battery cell.

[0051] In a preferred embodiment, the two current collectors 11 have the same radius; the radius of the current collector 11 is larger than the radius of the diaphragm 13; the radius of the diaphragm 13 is larger than the radius of the negative electrode 12; and the radius of the negative electrode 12 is larger than the radius of the positive electrode 14.

[0052] In a preferred embodiment, the current collector 11 is one of a stainless steel current collector, a titanium alloy current collector, or a nickel sheet current collector.

[0053] In a preferred embodiment, the positive electrode 14 is prepared from the following components by mass percentage: 80% to 98% (which may be 80%, 82%, 85%, 90%, or 98% depending on the actual use requirements) of positive electrode active material powder, 1% to 10% (which may be 1%, 3%, 5%, 8%, or 10% depending on the actual use requirements) of first binder powder, and 0.5% to 10% (which may be 0.5%, 3%, 5%, 8%, or 10% depending on the actual use requirements) of first conductive agent powder;

[0054] The positive electrode active material powder is one or a mixture of at least two of lithium iron phosphate, ternary lithium compounds, lithium manganese oxide, sodium iron phosphate, sodium vanadium phosphate, sodium cobalt oxide, lithium ferrite, or lithium nickel oxide.

[0055] The ternary lithium compound is one of lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminum oxide;

[0056] The first adhesive powder is one or a mixture of at least two of PTFE, PVDF, PEO or short fibers;

[0057] The first conductive agent powder is one or a mixture of at least two of the following: conductive carbon black, carbon nanotubes, graphene, or conductive graphite.

[0058] The moisture content of the positive electrode active material powder, the first binder powder, and the first conductive agent powder is all less than 400 ppm. This effectively softens the first binder powder, allowing it to better perform its bonding function and promoting the release of internal stress in the electrode during rolling, thereby improving the mechanical strength and stability of the electrode. If the moisture content of each powder is too high, it will affect the bonding effect of the binder, reducing the mechanical strength and stability of the electrode; if the moisture content of each powder is too low, it will also affect the bonding effect of the binder and the release of internal stress in the electrode. The specific composition of each raw material powder of the positive electrode can be selected according to the above range, all of which can achieve the solution of this application.

[0059] In a preferred embodiment, the positive electrode 14 is prepared by the following method: 80%–98% of positive electrode active material powder, 1%–10% of first binder powder and 0.5%–10% of first conductive agent powder are mixed evenly and dispersed in an environment with a dew point temperature ≤ -30°C to obtain a mixed powder; the mixed powder is rolled and then die-cut to obtain a positive electrode, the thickness of which is 0.05 mm–10.0 mm.

[0060] In a preferred embodiment, the dispersion temperature is 50℃~180℃ (which can be 50℃, 80℃, 90℃, 150℃, or 180℃ depending on the actual needs of use), and the dispersion linear velocity is 10m / s~30m / s (which can be 10m / s, 15m / s, 20m / s, 23m / s, 26m / s, or 30m / s, etc. depending on the actual needs of use); this is beneficial for the fiberization of the first binder powder and can also uniformly disperse the powders.

[0061] The rolling temperature is 80℃~200℃ (depending on actual needs, it can be 80℃, 100℃, 120℃, 150℃, or 200℃); the rolling pressure is 10T~500T (depending on actual needs, it can be 10T, 50T, 200T, 350T, or 500T, etc.). Rolling is generally performed using a roller press, tablet press, or extruder. Controlling the rolling temperature at 80℃~200℃ can effectively soften the first binder powder, allowing it to better exert its bonding effect, and can also promote the release of internal stress in the electrode during the rolling process, improving the mechanical strength and stability of the electrode.

[0062] In a preferred embodiment, the negative electrode sheet 12 is prepared from the following components by mass percentage: 80% to 98% (which may be 80%, 82%, 85%, 90%, or 98% depending on the actual use requirements) of negative electrode active material powder, 1% to 10% (which may be 1%, 3%, 5%, 8%, or 10% depending on the actual use requirements) of second binder powder, and 0.5% to 10% (which may be 0.5%, 3%, 5%, 8%, or 10% depending on the actual use requirements) of second conductive agent powder;

[0063] The negative electrode active material powder is one or a mixture of at least two of graphite, lithium titanate, or silicon negative electrode.

[0064] The graphite is hard carbon or soft carbon;

[0065] The second binder powder is one or a mixture of at least two of PTFE, PVDF, PEO or short fibers;

[0066] The second conductive agent powder is one or a mixture of at least two of the following: conductive carbon black, carbon nanotubes, graphene, or conductive graphite.

[0067] The moisture content of the negative electrode active powder, the second binder powder, and the second conductive agent powder is all less than 400 ppm. This effectively softens the second binder powder, allowing it to better perform its bonding function and promoting the release of internal stress in the electrode during rolling, thereby improving the mechanical strength and stability of the electrode. If the moisture content of each powder is too high, it will affect the bonding effect of the binder, reducing the mechanical strength and stability of the electrode; if the moisture content of each powder is too low, it will also affect the bonding effect of the binder and the release of internal stress in the electrode. The specific composition of each raw material powder of the negative electrode can be selected according to the above range, all of which can achieve the solution of this application.

[0068] In a preferred embodiment, the negative electrode 12 is prepared by the following method: 80%–98% of negative electrode active material powder, 1%–10% of second binder powder and 0.5%–10% of second conductive agent powder are mixed evenly and dispersed in an environment with a dew point temperature ≤ -30°C to obtain a mixed powder; the mixed powder is rolled and then die-cut to obtain a negative electrode, the thickness of which is 0.05 mm–10.0 mm.

[0069] This application changes the existing internal parallel or single-string structure of batteries, and prepares positive and negative electrode sheets through a dry electrode preparation method. By optimizing the assembly method, two adjacent battery cells are isolated and completely sealed by only one current collector. This allows the single cell to be boosted through multi-stage series connection of internal electrode sheets, which can effectively solve the problem of low voltage of single cells.

[0070] In a preferred embodiment, the dispersion temperature is 50℃~180℃ (which can be 50℃, 80℃, 90℃, 150℃, or 180℃ depending on the actual needs of use), and the dispersion linear velocity is 10m / s~30m / s (which can be 10m / s, 15m / s, 20m / s, 23m / s, 26m / s, or 30m / s, etc. depending on the actual needs of use); this is beneficial for the fiberization of the second binder powder and can also uniformly disperse the powders.

[0071] The temperature of the roller pressing is 80℃~200℃ (it can be 80℃, 100℃, 120℃, 150℃, or 200℃ depending on the actual use requirements); the pressure of the roller pressing is 10T~500T (it can be 10T, 50T, 200T, 350T, or 500T, etc. depending on the actual use requirements).

[0072] Roll pressing is generally carried out using a roller press, tablet press, or extruder. Controlling the temperature of the roller pressing process between 80℃ and 200℃ can effectively soften the second binder powder, allowing it to better exert its bonding effect. It can also promote the release of internal stress in the electrode during the rolling process, thereby improving the mechanical strength and stability of the electrode.

[0073] In a preferred embodiment, the bipolar battery is a lithium-ion battery, a sodium-ion battery, or a zinc-ion battery.

[0074] The bipolar battery of this application can remove solvents (NMP, deionized water, etc.), thickeners (CMC, etc.), copper foil, aluminum foil, and other raw materials at the raw material stage, greatly reducing solvent recycling and avoiding environmental pollution, while effectively reducing cell costs. Regarding voltage, the bipolar battery of this application can achieve free voltage setting simply by increasing the number of stacked layers according to voltage requirements; simultaneously, because it does not require external adapters like those used in traditional single-cell batteries, it can greatly improve series efficiency, effectively reduce battery internal resistance, and improve product performance and consistency. Regarding capacity, the bipolar battery of this application uses a dry electrode fabrication method, increasing the electrode thickness from the micrometer level of traditional batteries to the millimeter level of this application, thus ensuring higher energy density.

[0075] On the other hand, embodiments of this application also provide a method for preparing the bipolar battery, including the following steps: in an environment with a dew point temperature ≤ -30°C, two current collectors, a negative electrode, a separator, and a positive electrode are stacked sequentially in the order of current collector, negative electrode, separator, positive electrode, and current collector to obtain a battery cell; multiple battery cells are connected in series to obtain a bipolar battery.

[0076] In this way, the bipolar battery is assembled in series with current collector (total negative electrode), negative electrode sheet, separator, positive electrode sheet, current collector, negative electrode sheet, separator, positive electrode sheet, current collector, negative electrode sheet... separator, positive electrode sheet, current collector (total positive electrode), forming a stacked assembly. Adjacent battery cells are isolated and completely sealed only by a current collector, which can effectively ensure that electrolyte cross-contamination does not occur between battery cells.

[0077] Because the workshop environment controls the dew point temperature, the bipolar batteries produced can be directly injected with electrolyte, followed by electrolyte immersion activation for 2-10 hours. After activation, the batteries undergo initial charging and formation activation using a high-voltage testing cabinet. Since the formation process generates gas, leading to electrolyte loss, electrolyte replenishment is necessary to ensure sufficient electrolyte levels. After replenishment, the batteries are sealed and helium tested, followed by a first aging process to further immerse the activated cell electrodes. High-voltage capacity testing is then performed to screen out batteries that meet capacity standards. A second aging process is then conducted, and the K-value is calculated using the voltage drop before and after aging: (voltage after aging - voltage before aging) / aging time. Batteries with higher self-discharge are then selected. Finally, the batteries are inspected and shipped according to customer requirements.

[0078] The dew point temperature of this application is ≤-30℃. By controlling the dew point temperature, the ambient humidity can be less than 400ppm, which is consistent with the moisture content of the raw materials of the positive electrode and the negative electrode. This can better soften the binder powder, allowing it to better perform its bonding function, and can promote the release of internal stress in the electrode during the rolling process, thereby improving the mechanical strength and stability of the electrode and meeting the needs of the operation process of this application.

[0079] The bipolar battery of this application can eliminate the need for equipment such as coating machine, ultrasonic welding machine, laser welding machine, coating machine, casing machine, and baking machine on the equipment side, which can effectively reduce equipment investment; in terms of process flow, it can eliminate processes such as coating, ultrasonic welding, laser welding, coating, baking, and assembly, which can effectively shorten the delivery cycle and effectively improve the production efficiency of the battery.

[0080] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0081] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0082] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A bipolar battery, characterized in that, The battery includes multiple battery cells connected in series; each battery cell includes two current collectors, and a negative electrode, a separator, and a positive electrode are disposed between the two current collectors and stacked in sequence; the negative electrode is in contact with one of the current collectors, and the positive electrode is in contact with the other current collector; two adjacent battery cells share one of the current collectors.

2. The bipolar battery according to claim 1, characterized in that, The thickness of the positive electrode sheet is 0.05 mm to 10.0 mm.

3. The bipolar battery according to claim 1, characterized in that, The thickness of the negative electrode sheet is 0.05 mm to 10.0 mm.

4. The bipolar battery according to claim 1, characterized in that, Each of the battery cells is an isolated and sealed unit; adjacent battery cells are isolated and sealed by a shared current collector.

5. The bipolar battery according to claim 1, characterized in that, The battery unit is a cylindrical battery unit or a square battery unit.

6. The bipolar battery according to claim 5, characterized in that, When the battery cell is a cylindrical battery cell, the two current collectors, the negative electrode, the separator, and the positive electrode are all circular.

7. The bipolar battery according to claim 6, characterized in that, The two current collectors have the same radius; the radius of the current collector is larger than the radius of the separator; the radius of the separator is larger than the radius of the negative electrode; the radius of the negative electrode is larger than the radius of the positive electrode.

8. The bipolar battery according to claim 1, characterized in that, The current collector is one of stainless steel current collector, titanium alloy current collector, or nickel sheet current collector.

9. The bipolar battery according to claim 1, characterized in that, The bipolar battery is a lithium-ion battery, a sodium-ion battery, or a zinc-ion battery.

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