Laminated battery and electric device

Abstract

The utility model discloses a laminated battery and an electric device, and belongs to the technical field of batteries. The laminated battery comprises a laminated battery cell main body. The laminated cell main body comprises a plurality of electrode plates with different polarities, the electrode plates with different polarities are alternately laminated, and a diaphragm is arranged between any two adjacent electrode plates with different polarities. Wherein at least part of the electrode pole piece comprises a current collector with a polygonal structure and an electrode active material layer coated on part of the surface of the current collector. At least two adjacent edge parts of the current collector are respectively provided with a first uncoated part and a second uncoated part which have preset sizes and are not coated, and the first uncoated part and the second uncoated part of the same current collector are directly connected. By welding the second uncoated parts of the plurality of electrode plates with the same polarity to form the electrode tabs and connecting the electrode tabs to the pole columns and welding the first uncoated parts of the plurality of electrode plates with the same polarity to form the diversion parts, electron transmission channels among the electrode plates can be increased, the current density distribution uniformity degree can be improved, the battery polarization can be reduced, and the battery performance can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a stacked battery and an electrical device. Background Technology

[0002] Lithium-ion batteries, as energy storage and conversion devices, are characterized by high energy density, long cycle life, and lightweight design. Their applications are diverse, ranging from new energy vehicles and consumer electronics to energy storage systems and military applications. In the new energy vehicle market, the power battery plays a crucial role, serving as a core component, analogous to the engine in a traditional gasoline vehicle. It stores and provides electrical energy, directly impacting the vehicle's range, lifespan, and acceleration performance. Therefore, the performance of the power battery determines the economic viability, reliability, and market competitiveness of electric vehicles.

[0003] However, existing power batteries are prone to polarization during operation, which can affect battery performance. Therefore, reducing battery polarization to improve power battery performance is an urgent problem to be solved. Utility Model Content

[0004] In view of the above-mentioned shortcomings, this application provides a stacked battery and an electrical device to improve the problem of poor battery performance caused by battery polarization in related technologies.

[0005] This application is implemented as follows:

[0006] In a first aspect, an example of this application provides a stacked battery, including a stacked cell body. The stacked cell body includes multiple electrode sheets of different polarities, which are alternately stacked, and a separator is disposed between any two adjacent electrode sheets of different polarities. At least a portion of the electrode sheets includes a polygonal current collector and an electrode active material layer coated on the surface of the current collector portion. At least two adjacent sides of the current collector each have a first uncoated portion and a second uncoated portion of a predetermined size, and the first and second uncoated portions of the same current collector are directly connected. The first uncoated portions of multiple electrode sheets of the same polarity are welded to form a current-conducting portion. The second uncoated portions of multiple electrode sheets of the same polarity are welded to form an electrode tab and connected to an electrode post.

[0007] During the operation of a stacked battery, electrons can be transported to the electrode active material within the coated area through the second uncoated portion directly connected to the terminal post, and similarly through the first uncoated portion directly connected to the second uncoated portion. This increases the electron transport channels, expands the current flow area, and improves the uniformity of the current density distribution in the electrode active material layer, reducing battery polarization. Furthermore, since the first and second uncoated portions are located on adjacent sides of the polygonal current collector, electrons can be transported to the electrode active material layer from different directions. This results in a more uniform current density distribution on both the terminal post side and the terminal post side of the electrode, further mitigating internal battery polarization and improving battery performance.

[0008] In conjunction with the first aspect, in an optional embodiment, the lengths of the first uncoated portion and the second uncoated portion are respectively consistent with the side lengths of the two sides corresponding to the current collector.

[0009] In the above implementation process, the lengths of the first uncoated portion and the second uncoated portion are consistent with the length of the current collector edge, which can further increase the current conduction area in different directions, further improve the uniformity of current density distribution at the electrode active material layer, further alleviate battery polarization, and improve battery performance.

[0010] In conjunction with the first aspect, in one optional embodiment, the current collector has a quadrilateral structure. The first uncoated portions of the electrode sheets of different polarities are located on opposite sides of the stacked cell body, and the first uncoated portions of the electrode sheets of the same polarity are located on the same side of the stacked cell body. The second uncoated portions of the electrode sheets of different polarities are located on the other opposite sides of the stacked cell body, and the second uncoated portions of the electrode sheets of the same polarity are located on the same side of the stacked cell body.

[0011] In the above implementation process, the first uncoated portions of the electrode sheets of different polarities are located on opposite sides of the stacked cell body, and the first uncoated portions of the electrode sheets of the same polarity are located on the same side of the stacked cell body. This facilitates the welding of the first uncoated portions of the electrode sheets of the same polarity to form a current-conducting portion, reducing the probability of short circuits caused by contact between the two current-conducting portions of different polarities. Similarly, the second uncoated portions of the electrode sheets of different polarities are located on the other opposite sides of the stacked cell body, and the second uncoated portions of the electrode sheets of the same polarity are located on the same side of the stacked cell body. This facilitates the welding of the second uncoated portions of the electrode sheets of the same polarity to form electrode tabs, allowing electrode tabs of different polarities to be led out from both sides of the cell structure, further improving the safety and other performance characteristics of the stacked battery.

[0012] In conjunction with the first aspect, in one alternative embodiment, the width of the second uncoated portion is greater than the width of the first uncoated portion.

[0013] In the above implementation process, the second uncoated portion has a suitable width, which facilitates welding the second uncoated portion at the same polarity electrode sheet to form an electrode tab, and facilitates the connection of the electrode tab to the terminal post. The first uncoated portion has a suitable width, which can alleviate battery polarization while relatively increasing the proportion of electrode active material at the electrode sheet, thereby increasing the specific capacity of the battery.

[0014] In conjunction with the first aspect, in one optional embodiment, the length of the first uncoated portion is 0.100–500 mm, and the width is 5–20 mm. The length of the second uncoated portion is 50–300 mm, and the width is 5–30 mm.

[0015] In conjunction with the first aspect, in one alternative embodiment, the surface of the flow guide is covered with an insulating layer.

[0016] In the above implementation process, covering the surface of the flow guide with an insulating layer can reduce the probability of the battery short circuit and further improve the battery safety.

[0017] In conjunction with the first aspect, in one alternative embodiment, the side of the current-conducting portion away from the electrode active material layer is bent toward the large surface of the stacked cell body.

[0018] In the above implementation process, bending the end of the current guide away from the electrode active material layer toward the large surface of the stacked cell body can reduce the volume occupancy rate of the stacked battery.

[0019] In conjunction with the first aspect, in an optional embodiment, the stacked battery further includes a housing, within which the stacked cell body is disposed. The housing has a top wall, a bottom wall, and a side wall connecting the top wall and the bottom wall. The side wall has a groove structure, and a current-guiding portion is disposed within the groove structure.

[0020] In the above implementation process, the main body of the stacked cell is placed inside the casing. The casing can protect the main body of the stacked cell, reduce the influence of external substances such as water vapor on the electrode material, and fix the stacked cell structure, thereby improving the stability of the stacked battery.

[0021] Furthermore, since a groove structure is provided on the side wall of the casing, when the stacked cell body is placed inside the casing, the current guide can be inserted into the groove while the stacked cell body is located outside the groove. The steps formed on the groove wall can be used to position and fix the stacked cell body, thereby improving the stability of the stacked battery.

[0022] In conjunction with the first aspect, in one alternative embodiment, the shell material is an aluminum-plastic film, and the groove structure, together with the side of the internal flow guide away from the electrode active material layer, is bent toward the large surface of the stacked cell body.

[0023] In the above implementation process, after the aluminum-plastic film shell is used to encapsulate the main body of the stacked cell, the groove structure on the side and the internal guide part can be bent so that the side of the guide part away from the electrode active material layer faces the large surface of the stacked cell body, thereby reducing the lateral width of the stacked battery.

[0024] In a second aspect, an example of this application provides an electrical device comprising a plurality of stacked batteries as provided in the first aspect.

[0025] In the above implementation process, the power-consuming device includes multiple stacked batteries provided in the first aspect. The stacked batteries have a high current-passing area and a relatively uniform current density distribution at the electrodes, which can alleviate the polarization phenomenon of the battery, reduce the internal resistance of the battery, and improve the battery's charge and discharge efficiency, capacity retention rate, cycle life, rate performance and safety performance, so as to better meet the power consumption needs of the power-consuming device. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0027] Figure 1 A planar schematic diagram of the electrode sheet for comparison.

[0028] Figure 2 This is a partial structural schematic diagram of a stacked battery provided in an embodiment of this application;

[0029] Figure 3 This is a planar schematic diagram of the positive electrode sheet provided in the embodiments of this application;

[0030] Figure 4 A planar schematic diagram of the negative electrode sheet provided in an embodiment of this application;

[0031] Figure 5 A cross-sectional schematic diagram of the housing provided in an embodiment of this application.

[0032] Icons: 101 - Electrode sheet; 102 - Current collector foil area;

[0033] 1-Laminated battery; 10-Laminated cell body; 11-Positive electrode; 111-Positive current collector; 1111-First uncoated positive electrode portion; 1112-Second uncoated positive electrode portion; 1113-First side; 1114-Second side; 112-Positive active material layer; 12-Negative electrode; 121-Negative current collector; 1211-First uncoated negative electrode portion; 1212-Second uncoated negative electrode portion; 1213-Fifth side; 1214-Sixth side; 122-Negative active material layer; 13-Separator; L1-First length; L2-First width; L3-Second length; L4-Second width; 20-Shell; 21-Shell top wall; 22-Shell bottom wall; 23-Shell side wall; 24-Groove structure. Detailed Implementation

[0034] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0036] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments of this application, the technical terms "middle", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "bottom", "inner" and other indications of the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0039] Lithium-ion batteries, as energy storage and conversion devices, are characterized by high energy density, long cycle life, and lightweight design. Their applications are extremely diverse, ranging from new energy vehicles and consumer electronics to energy storage systems and military applications.

[0040] In the new energy vehicle market, lithium-ion batteries play a crucial role, serving as the core component of new energy vehicles, much like the engine in traditional gasoline vehicles. They store and supply electrical energy, directly impacting the vehicle's range, lifespan, and acceleration performance. Specifically, the driving range of a new energy vehicle is determined by the energy density of the lithium-ion battery, its lifespan by its cycle life, and its charge / discharge capacity by its rate capability. Therefore, the performance of lithium-ion batteries determines the economy, reliability, and market competitiveness of new energy vehicles.

[0041] Without further breakthroughs in existing material systems, the performance of lithium-ion batteries is unlikely to be significantly improved. Therefore, how to enhance the performance of lithium-ion batteries through battery structure design is an urgent problem to be solved.

[0042] In existing lithium-ion batteries, such as Figure 1 As shown, the electrode sheet 101 is typically rectangular, and the top of the rectangular electrode sheet 101 has a current collector foil area 102 that is not coated with electrode active material. The current collector foil area 102 at the top is welded to an external electrode tab for connection to a battery terminal or current collector plate or other structure.

[0043] However, the inventors discovered that in existing lithium-ion batteries, welding an external tab to the current collector foil area 102 at the top of the electrode sheet 101 and connecting it to the battery terminals or current collector plate causes uneven current density distribution in the active material layer of the electrode sheet 101 between the side near the tab and the side far from the tab, resulting in battery polarization. That is, the current density distribution at the top and bottom of the electrode sheet 101 is uneven.

[0044] Uneven current density distribution can lead to overcharging or over-discharging in certain areas, accelerating the loss of active materials and electrolyte decomposition, thereby reducing battery capacity. Furthermore, areas with higher current density exhibit more intense electrochemical reactions, easily causing localized overheating and material degradation, resulting in a shortened battery life. Uneven current density distribution also exacerbates battery polarization, increasing internal resistance, which not only affects charge / discharge efficiency, leading to decreased energy utilization and reduced output power, but also causes severe heat generation at the tabs, impacting the battery's rate performance.

[0045] Therefore, this application further improves the battery, thereby improving battery polarization and performance to a certain extent. To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0046] Please see Figures 2 to 4 , Figure 2 This is a schematic diagram showing the stacking order of the electrode plates in the stacked battery 1. Figure 3 This is a planar schematic diagram of the positive electrode sheet provided in the embodiments of this application. Figure 4 This is a planar schematic diagram of the negative electrode sheet provided in an embodiment of this application. Please refer to... Figures 2 to 4 An example of this application provides a stacked battery 1, including a stacked cell body 10.

[0047] The laminated cell body 10 includes multiple electrode sheets of different polarities, which are alternately stacked and separated by a separator between any two adjacent electrode sheets of different polarities. At least some of the electrode sheets include a polygonal current collector and an electrode active material layer coated on the surface of the current collector. At least two adjacent sides of the current collector each have a first uncoated portion and a second uncoated portion of a predetermined size, which are directly connected. The first uncoated portions of multiple electrode sheets of the same polarity are welded together to form a current-conducting portion. The second uncoated portions of multiple electrode sheets of the same polarity are welded together to form electrode tabs, which are then connected to the electrode post.

[0048] "Electrode plates of different polarities" refers to the positive electrode plate 11 and the negative electrode plate 12.

[0049] "Electrode plates of different polarities are alternately stacked, and a diaphragm is provided between any two adjacent electrode plates of different polarities" refers to, for example... Figure 2 As shown, positive electrode 11 and negative electrode 12 are stacked alternately, and a separator 13 is provided between any two adjacent positive electrode 11 and negative electrode 12.

[0050] "The electrode sheet includes a polygonal current collector and an electrode active material layer coated on the surface of the current collector portion" refers to, for example... Figure 3 As shown, the positive electrode 11 includes a positive current collector 111 and a positive active material layer 112 coated on a portion of the surface of the positive current collector 111. Figure 4 As shown, the negative electrode 12 includes a negative current collector 121 and a negative active material layer 122 coated on a portion of the surface of the positive and negative current collectors 121.

[0051] In some possible embodiments, the positive current collector 111 and the negative current collector 121 may comprise metal foils. For example, aluminum foil may be used as the positive current collector 111. For example, copper foil may be used as the negative current collector 121.

[0052] In some embodiments, the positive electrode active material layer 112 may be formed by coating a positive electrode slurry containing the positive electrode active material onto the coating area of ​​the positive electrode current collector 111. The positive electrode active material may be a positive electrode active material known in the art for lithium-ion batteries. For example, the positive electrode active material may include lithium phosphate, lithium transition metal oxide, and their respective modified compounds.

[0053] In some embodiments, the negative electrode active material layer 122 may be formed by coating a positive electrode slurry containing the negative electrode active material onto the coating area of ​​the negative electrode current collector 121. The negative electrode active material may be a negative electrode active material known in the art for use in lithium-ion batteries. For example, the negative electrode active material may include artificial graphite, natural graphite, soft carbon, or hard carbon, etc.

[0054] "At least two adjacent sides of the current collector have a first uncoated portion and a second uncoated portion of a predetermined size, and the first uncoated portion and the second uncoated portion of the same current collector are directly connected" means, please refer to [further details needed]. Figure 3 In the positive electrode sheet 11, the positive electrode active material layer 112 is coated on a portion of the surface of the positive electrode current collector 111, and at least two adjacent sides of the positive electrode current collector 111 each have a first uncoated positive electrode portion 1111 and a second uncoated positive electrode portion 1112 of a predetermined size. The first uncoated positive electrode portion 1111 and the second uncoated positive electrode portion 1112 are directly connected and are not separated by the positive electrode active material. Please continue reading. Figure 4 In the negative electrode sheet 12, the negative electrode active material layer 122 is coated on a portion of the surface of the negative electrode current collector 121, and at least two adjacent sides of the negative electrode current collector 121 respectively have a first uncoated negative electrode portion 1211 and a second uncoated negative electrode portion 1212 of a predetermined size. The first uncoated negative electrode portion 1211 and the second uncoated negative electrode portion 1212 are directly connected and are not separated by the negative electrode active material.

[0055] In some embodiments, the positive current collector 111 and the negative current collector 121 can be quadrilateral in shape. The quadrilateral positive current collector 111 has uncoated areas of uncoated positive active material on each of its two adjacent sides, forming two uncoated positive electrode portions. Similarly, the quadrilateral negative current collector 121 has uncoated areas of uncoated negative active material on each of its two adjacent sides, forming two uncoated negative electrode portions.

[0056] For example, please continue reading Figure 3 The rectangular positive electrode current collector 111 has four sides. The first side 1113 and the second side 1114 are adjacent. The first side 1113 has a first uncoated positive electrode portion 1111 with a certain width and length, and the second side 1114 has a second uncoated positive electrode portion 1112 with a certain width and length. The third and fourth sides are coated with positive electrode active material.

[0057] For example, please continue reading Figure 4 The rectangular negative electrode current collector 121 has four sides. The fifth side 1213 and the sixth side 1214 are adjacent. The fifth side 1213 has a first uncoated negative electrode portion 1211 with a certain width and length, and the sixth side 1214 has a second uncoated negative electrode portion 1212 with a certain width and length. The seventh and eighth sides are coated with negative electrode active material.

[0058] Alternatively, in other embodiments, the current collector can be triangular, pentagonal, or hexagonal, etc. For example, two sides of a triangular current collector have uncoated portions, one of which is used to weld an electrode tab, and the other is used to weld a flow guide. For example, two or three adjacent sides of a pentagonal current collector have uncoated portions, one of which is used to weld an electrode tab, and the remaining uncoated portions are used to weld a flow guide. For example, three adjacent sides of a hexagon have uncoated portions, one of which is used to weld a positive electrode tab, and the remaining uncoated portions are used to weld a flow guide.

[0059] This application does not limit the specific width and length of each uncoated area. In some embodiments, please refer to [the relevant documentation]. Figure 3 The length of the first uncoated positive electrode portion 1111 is the same as the length of the first side 1113, and the length of the second uncoated positive electrode portion 1112 is the same as the length of the second side 1114. Please continue reading. Figure 4 The length of the first uncoated negative electrode portion 1211 is the same as the length of the fifth side 1213, and the length of the second uncoated negative electrode portion 1212 is the same as the length of the sixth side 1214.

[0060] Alternatively, in some other possible embodiments, the length of the first uncoated positive electrode portion 1111 is less than the length of the first side 1113, and the length of the second uncoated positive electrode portion 1112 is less than the length of the second side 1114 (not shown in the figure).

[0061] Alternatively, in some other possible embodiments, the length of the first uncoated negative electrode portion 1211 is less than the length of the fifth side 1213, and the length of the second uncoated negative electrode portion 1212 is less than the length of the sixth side 1214 (not shown in the figure).

[0062] In some embodiments, please continue reading Figure 3 The width of the second uncoated portion 1112 is greater than the width of the first uncoated portion 1111.

[0063] As an example, the length of the first side 1113 of the positive current collector 111 is 100–500 mm, and the length of the second side 1114 is 50–300 mm. Please refer to the following: Figure 3 The first uncoated positive electrode portion 1111 has a first length L1 and a first width L2. The first length L1 is the same as the length of the first side 1113, and the first width L2 is 10-20 mm. The second uncoated positive electrode portion 1112 has a second length L3 and a second width L4. The second length L3 is the same as the length of the second side 1114, and the second width L4 is 5-30 mm.

[0064] For example, the first length L1 of the first uncoated positive electrode portion 1111 is 222 mm, and the first width L2 is 10 mm. The second length L3 of the second uncoated positive electrode portion 1112 is 142 mm, and the second width L4 is 30 mm.

[0065] Similarly, as with the positive current collector 111, in some embodiments, please refer to [the relevant documentation]. Figure 4 The width of the second uncoated negative electrode portion 1212 in the negative electrode current collector 121 is greater than the width of the first uncoated negative electrode portion 1211.

[0066] The current collector has two surfaces opposite each other in its own thickness direction. In some possible embodiments, both surfaces of the current collector are coated with an electrode active material layer and a corresponding uncoated portion.

[0067] As an example, please continue reading Figure 2 ( Figure 2In this viewpoint, the positive electrode active material layer 112 on the back of the positive electrode current collector 111 is obscured. Both surfaces of the positive electrode current collector 111 are coated with the positive electrode active material layer 112, and a first uncoated positive electrode portion 1111 and a second uncoated positive electrode portion 1112 are provided at two adjacent edges of each surface. The projections of the positive electrode active material layer 112 on the two surfaces of the positive electrode current collector 111 along the thickness direction overlap, as do the projections of the first uncoated positive electrode portion 1111 and the second uncoated positive electrode portion 1112 on the two surfaces along the thickness direction.

[0068] As an example, please continue reading Figure 2 A negative electrode active material layer 122 is coated on both surfaces of the negative electrode current collector 121, and a first negative electrode uncoated portion 1211 and a second negative electrode uncoated portion 1212 are set at two adjacent edges of the two surfaces. The projections of the negative electrode active material layer 122, the negative electrode uncoated portion 1211 and the second negative electrode uncoated portion 1212 on the two surfaces along the thickness direction overlap one-to-one.

[0069] Furthermore, in some embodiments, in the stacked cell body 10, the outermost electrode electrode sheet is provided with an electrode active material layer and an uncoated portion only on one surface of the current collector.

[0070] Furthermore, in some embodiments, when stacking the positive electrode 11 and the negative electrode 12, the first uncoated positive portion 1111 of the plurality of positive electrode 11s can face one side of the stacked cell body 10, and the first uncoated negative portion 1211 of the plurality of negative electrode 12s can face the other side of the stacked cell body 10. That is, the first uncoated positive portion 1111 and the first uncoated negative portion 1211 are respectively located on opposite sides of the stacked cell body 10. Figure 2 As shown, multiple first positive electrode uncoated portions 1111 are located on the left side of the stacked cell body, and multiple first negative electrode uncoated portions 1211 are located on the right side of the stacked cell body.

[0071] Furthermore, in some embodiments, when stacking the positive electrode 11 and the negative electrode 12, the second uncoated positive portion 1112 of the plurality of positive electrode 11s can face one side of the stacked cell body 10, and the second uncoated negative portion 1212 of the plurality of negative electrode 12s can face the other side of the stacked cell body 10. That is, the second uncoated positive portion 1112 and the second uncoated negative portion 1212 are respectively located on opposite sides of the stacked cell body 10. Figure 2 As shown, multiple uncoated second positive electrode portions 1112 are located on the top side of the stacked cell body 10, and multiple uncoated second negative electrode portions 1212 are located on the bottom side of the stacked cell body 10.

[0072] After the electrode plates and the separator 13 are stacked, the first uncoated portions 1111 of each positive current collector 111 can be welded together to form a current guide portion.

[0073] Furthermore, in order to improve the safety of the stacked battery 1, an insulating layer (not shown in the figure) can be coated on the surface of the current-conducting part.

[0074] As an example, after welding is completed, the guide section can be cut and shaped. After cutting, insulating tape is pasted about 5mm away from the welded diaphragm 13.

[0075] Furthermore, after applying the insulating tape, the current-guiding portion can be bent so that the section of the current-guiding portion away from the electrode active material layer faces the larger surface of the stacked cell body 10. Bending the current-guiding portion reduces the lateral width of the casing when the stacked cell body 10 is installed into the casing, thereby reducing the volume occupancy of the stacked battery 1.

[0076] The large surface of the laminated cell body 10 refers to the side perpendicular to the thickness direction of the current collector.

[0077] In some embodiments, after the electrode plates and the separator 13 are stacked, the second uncoated portions 1112 at each of the positive current collectors 111 can be welded together and connected to the positive electrode post (not shown in the figure). The second uncoated portions 1212 at each of the negative current collectors 121 can be welded together and connected to the negative electrode post (not shown in the figure).

[0078] Furthermore, in some embodiments, the stacked battery 1 may also include a housing 20, in which the stacked cell body 10 is placed.

[0079] Furthermore, in some embodiments, please refer to Figure 5 The housing 20 has a top wall 21, a bottom wall 22, and a side wall 23 connecting the top wall 21 and the bottom wall 22. The side wall 23 is provided with a groove structure 24 for accommodating the flow guide. Because the side wall 23 is provided with a groove structure 24, the groove structure will form a step on the inner wall of the housing 20 receiving cavity. When the stacked cell body 10 is placed in the receiving cavity, the step on the inner wall will restrict the lateral movement of the stacked cell body 10, which can position and fix the stacked cell body 10, thereby improving the stability of the stacked battery 1.

[0080] Furthermore, in some possible embodiments, when the length of the first uncoated portion is less than the length of the corresponding side portion, the length of the groove structure 24 does not exceed 1.5 times the length of the flow guide portion. If the length of the groove structure 24 provided on the side wall of the housing is too long, the stacked cell body 10 is prone to lateral movement into the groove structure 24. For example, if the length of the first uncoated portion is 0.5 times the length of the corresponding side portion, and the length of the groove structure 24 is the same as the length of the side portion, the height of the step formed between the outer wall of the groove structure 24 and the bottom wall of the housing is low or even flush. Moreover, due to the flexibility of the flow guide portion, the stacked cell body 10 is prone to squeeze the flow guide portion and enter the groove structure 24, which may cause lateral sliding, thereby reducing the stability of the stacked battery 1.

[0081] Furthermore, in some embodiments, in order to extend the second uncoated portion out of the housing 20 and connect it to the pole post, corresponding openings or grooves can be provided at the top wall 21 and bottom wall 22 of the housing.

[0082] Furthermore, in some embodiments, the housing 20 may be a soft shell.

[0083] Furthermore, in some embodiments, the material of the soft-pack casing is aluminum-plastic film, and the stacked battery 1 is a soft-pack battery. After the stacked cell body 10 is encapsulated using the aluminum-plastic film casing 20, the side groove structure 24 and its internal current guiding part can be bent so that the side of the current guiding part away from the electrode active material layer faces the large surface of the stacked cell body, thereby reducing the lateral width of the stacked battery. When the stacked batteries are grouped and applied to electrical devices, the volume occupancy rate of the batteries can be reduced.

[0084] Furthermore, this application embodiment also provides an electrical device (not shown in the figure), the battery module including the stacked battery 1 provided in this application embodiment. As an example, in the electrical device, multiple stacked batteries 1 can be connected in series or in parallel.

[0085] As an example, an electrical device can be a mobile device, such as a mobile phone or a laptop.

[0086] As an example, the electrical device can be an electric vehicle, such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, etc.

[0087] The working principle of the stacked battery provided in this application embodiment is as follows:

[0088] During the operation of a stacked battery, some electrons at the electrode post can be directly transferred to the second uncoated portion of the current collector, and then from there to the positive electrode active material layer at the current collector. Simultaneously, since neither the first nor the second uncoated portion is coated with electrode active material, they have high conductivity, allowing other electrons to be transferred from the second uncoated portion of the current collector to the first uncoated portion, and then from the first uncoated portion to the positive electrode active material layer. By setting two uncoated portions with different orientations and welding the first uncoated portions of the same polarity to form a current-conducting portion, the electron transport channels between the electrodes can be increased, the current flow area can be increased, the uniformity of current density distribution can be improved, battery polarization can be alleviated, and thus battery performance can be improved.

[0089] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A stacked battery, characterized by, The battery includes a stacked cell body, which includes multiple electrode plates of different polarities. The electrode plates of different polarities are stacked alternately, and a separator is provided between any two adjacent electrode plates of different polarities. Wherein, at least a portion of the electrode sheet includes a polygonal current collector and an electrode active material layer coated on the surface of the current collector portion, and at least two adjacent sides of the current collector respectively have a first uncoated portion and a second uncoated portion of a predetermined size, and the first uncoated portion and the second uncoated portion of the same current collector are directly connected; The first uncoated portions of a plurality of electrode plates of the same polarity are welded together to form a current-conducting portion; the second uncoated portions of a plurality of electrode plates of the same polarity are welded together to form an electrode tab, which is then connected to the electrode post.

2. The stacked battery of claim 1, wherein The lengths of the first uncoated portion and the second uncoated portion are respectively consistent with the side lengths of the two sides corresponding to the current collector.

3. The stacked battery of claim 2, wherein, The current collector has a quadrilateral structure; the first uncoated portions of the electrode plates of different polarities are respectively located on opposite sides of the stacked cell body, and the first uncoated portions of the electrode plates of the same polarity are located on the same side of the stacked cell body; the second uncoated portions of the electrode plates of different polarities are respectively located on the other opposite sides of the stacked cell body, and the second uncoated portions of the electrode plates of the same polarity are located on the same side of the stacked cell body.

4. The stacked cell according to any one of claims 1 to 3, characterized by The width of the second uncoated portion is greater than the width of the first uncoated portion.

5. The stacked battery of claim 4, wherein, The length of the first uncoated portion is 100-500 mm and the width is 5-20 mm; the length of the second uncoated portion is 50-300 mm and the width is 5-30 mm.

6. The stacked battery of claim 1, wherein, The surface of the flow guide is covered with an insulating layer.

7. The stacked battery of claim 6, wherein, The side of the current-conducting section away from the electrode active material layer bends toward the large surface of the stacked cell body.

8. The stacked cell according to any one of claims 1 to 3, characterized by The stacked battery also includes a housing, and the stacked cell body is disposed inside the housing; the housing has a top wall, a bottom wall and a side wall connecting the top wall and the bottom wall, the side wall is provided with a groove structure, and the flow guide is disposed within the groove structure.

9. The stacked battery of claim 8, wherein, The shell is made of aluminum-plastic film, and the groove structure, together with the side of the internal flow guide that is away from the electrode active material layer, is bent toward the large surface of the stacked cell body.

10. An electrical device, characterized by Includes the stacked battery as described in any one of claims 1 to 9.

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