Single cell and battery pack

Abstract

The application provides a single battery and a battery pack, and relates to the technical field of batteries. In the prior art, the positive and negative tabs are arranged on the same side of the winding core. In the application, the first tab group and the second tab group are arranged on the adjacent two sides of the electrode assembly. On the one hand, the horizontal transmission distance of the current on the pole piece is shortened, the internal resistance is reduced, the current distribution is more uniform, and the heat production is more dispersed. On the other hand, the heat generated by the first tab group and the second tab group can be respectively conducted to the shell assembly from two different directions, the heat dissipation efficiency and the fast charging performance of the single battery are improved, local overheating is effectively avoided, and the internal temperature rise of the single battery is reduced, so that the large current and fast charging capacity are significantly enhanced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a single cell and a battery pack. Background Technology

[0002] Currently, in lithium-ion battery technology, improving battery energy density and fast charging capability are two important development directions. Improving energy density can not only significantly enhance the performance and application range of lithium batteries, but also reduce watt-hour costs and enhance market competitiveness. Meanwhile, improving fast charging capability can improve the efficiency of human production and life.

[0003] However, as the energy density and fast charging capability of lithium batteries increase, the current density passing through the tabs of a single battery cell during charging increases, resulting in high heat generation at the tabs and difficulty in heat dissipation, ultimately affecting the battery's fast charging performance and cycle life. Summary of the Invention

[0004] The purpose of this application is to provide a single battery cell and a battery pack that can improve the heat dissipation efficiency and fast charging performance of the single battery cell.

[0005] The embodiments of this application can be implemented as follows: In a first aspect, this application provides a single cell battery including an electrode assembly. The electrode assembly has a first direction, a second direction, and a third direction that are perpendicular to each other. The electrode assembly includes a plurality of first electrodes, a plurality of spacers, and a plurality of second electrodes. The plurality of first electrodes, the plurality of spacers, and the plurality of second electrodes are stacked along the third direction. The electrode assembly has a first tab group at at least one end in the first direction, and the electrode assembly has a second tab group at at least one end in the second direction; The housing assembly has an electrode assembly disposed within it. The housing assembly has a first electrode post at one end in the first direction and a second electrode post at one end in the second direction. The first electrode tab group is connected to the first electrode post, and the second electrode tab group is connected to the second electrode post.

[0006] In an optional embodiment, the electrode assembly is provided with two first electrode tabs, which are located at opposite ends of the electrode assembly along the first direction.

[0007] In an optional embodiment, the electrode assembly is provided with two second electrode tabs, which are located at opposite ends of the electrode assembly along the second direction.

[0008] In an optional embodiment, the single battery cell further includes a first connector located on one side of the electrode assembly along the third direction, the first connector being connected to two first tabs at both ends along the first direction, and the first connector being electrically connected to the first electrode post.

[0009] In an optional embodiment, the first connector has a first bent section at one end facing the first pole post, the first bent section bends toward the first pole post, and the first pole post is connected to the first bent section; And / or, the first connector includes a first electrical connection area and a first insulating area, the connection position of the first connector with the first tab assembly and the first pole post is the first electrical connection area, the area of ​​the first connector facing the electrode assembly and the housing assembly is the first insulating area, the first insulating area includes a first conductive layer and a first insulating layer, the first conductive layer is electrically connected to the first electrical connection area, and the first insulating layer is disposed on the surface of the first conductive layer.

[0010] In an optional embodiment, the single cell further includes a second connector located on the other side of the electrode assembly along the third direction, with two second tabs connected to each end of the second connector along the second direction, and the second connector electrically connected to the second electrode post.

[0011] In an optional embodiment, the second connector has a second bent section at one end facing the second pole post, the second bent section bends toward the second pole post, and the second connector is connected to the second pole post; And / or, the second connector includes a second electrical connection area and a second insulating area, the connection position of the second connector with the second tab assembly and the second pole post is the second electrical connection area, the area of ​​the second connector facing the electrode assembly and the housing assembly is the second insulating area, the second insulating area includes a second conductive layer and a second insulating layer, the second conductive layer is electrically connected to the second electrical connection area, and the second insulating layer is disposed on the surface of the second conductive layer.

[0012] In an optional embodiment, the first electrode includes a first body and a first tab region, wherein the first body is provided with the first tab region at one end or opposite ends in the first direction; and at least one side of the opposite sides in the third direction is coated with a first electrode material layer. And / or, the second electrode includes a second body and a second tab region, wherein the second body is provided with the second tab region at one end or opposite ends in the second direction; and at least one side of the opposite sides in the third direction is coated with a second electrode material layer.

[0013] In an optional embodiment, the housing assembly includes a first top cover, a second top cover, and a housing. The housing has a first opening at one end in the first direction, the first top cover is located at the first opening and connected to the housing, and the first pole post is disposed on the first top cover. The housing has a second opening at one end in the second direction, the second top cover is located at the second opening and connected to the housing, and the second pole post is disposed on the second top cover.

[0014] In an optional embodiment, the first electrode group includes at least two first electrode portions, and the at least two first electrode portions are spaced apart along the second direction; And / or, the second electrode group includes at least two second electrode portions, which are spaced apart along the first direction.

[0015] In an optional embodiment, the first connector includes a first connecting segment and a second connecting segment, the first connecting segment being connected to the second connecting segment, and the melting point of the first connecting segment being higher than the melting point of the second connecting segment; Of the two first electrode tab groups, the one facing the first electrode post is the first electrode tab group A, and the one away from the first electrode post is the first electrode tab group B. The first connecting segment is connected to the first electrode tab group A, and the second connecting segment is connected to the first electrode tab group B.

[0016] In an optional embodiment, the surface of the second connecting segment is provided with an inorganic porous layer.

[0017] In an optional embodiment, the pores of the inorganic porous layer include oxides and / or sulfides, wherein the oxides include at least one of calcium oxide, titanium dioxide, aluminum oxide, and magnesium peroxide, and the sulfides include at least one of zinc sulfide, magnesium sulfide, and lithium sulfide.

[0018] In an optional embodiment, the housing assembly includes a housing and an explosion-proof valve. The housing has a first sidewall facing the first tab group B, and the explosion-proof valve is located on the first sidewall. The orthographic projection of the explosion-proof valve in the first direction at least partially overlaps with the orthographic projection of the second connecting segment in the first direction.

[0019] In an optional embodiment, the second connecting section is provided with a weak area, and the orthographic projection of the weak area in the first direction at least partially overlaps with the orthographic projection of the explosion-proof valve in the first direction; The weak area is marked, or the thickness of the weak area is less than the thickness of the non-weak area of ​​the second connecting segment.

[0020] Secondly, this application provides a battery pack including any of the single-cell batteries described in the foregoing embodiments.

[0021] The beneficial effects of the single-cell battery and battery pack provided in this application embodiment include: Compared to existing technologies that place the positive and negative tabs on the same side of the core, this application places the first tab group and the second tab group on two adjacent sides of the electrode assembly. On the one hand, this shortens the lateral transmission distance of the current on the electrode sheet, reducing internal resistance, making the current distribution more uniform, and dispersing heat generation more effectively. On the other hand, the heat generated by the first tab group and the second tab group can be conducted outward to the housing assembly from two different directions, improving the heat dissipation efficiency and fast charging performance of the individual battery, effectively avoiding local overheating and reducing the internal temperature rise of the individual battery, thereby significantly enhancing the high current and fast charging capabilities. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a first schematic diagram of the electrode assembly provided in this embodiment; Figure 2 This is a schematic diagram showing the connection between the second electrode assembly and the second connector provided in this embodiment; Figure 3 This is a schematic diagram showing the connection between one of the second electrode groups and the second connector provided in this embodiment; Figure 4 A schematic diagram showing the bending of the second connector provided in this embodiment; Figure 5 This is a schematic diagram showing the connection between one of the first electrode groups and the first connector provided in this embodiment; Figure 6 A schematic diagram showing the bending of the first connector provided in this embodiment; Figure 7 This is a first schematic diagram showing the connection between the two second electrode assemblies and the second top cover provided in this embodiment; Figure 8 This is a first schematic diagram showing the connection between the two first electrode assemblies and the first top cover provided in this embodiment; Figure 9 This is a schematic diagram of forming a bare battery cell by wrapping an insulating film around the counter electrode assembly, as provided in this embodiment. Figure 10This is a schematic diagram of a single battery cell from a first-view perspective provided in this embodiment; Figure 11 This is a second schematic diagram of the electrode assembly provided in this embodiment; Figure 12 Various schematic diagrams showing the connection between the first electrode and the insulating component provided in this embodiment; Figure 13 This embodiment provides various schematic diagrams showing the connection between the second electrode and the insulating component; Figure 14 This is a second-view schematic diagram of a single battery cell provided in this embodiment; Figure 15 This is a third-view schematic diagram of a single battery cell provided in this embodiment; Figure 16 This is a second schematic diagram showing the connection between the two first electrode assemblies and the first top cover provided in this embodiment; Figure 17 This is a second schematic diagram showing the connection between the two second electrode groups and the second top cover provided in this embodiment.

[0024] Icons: 010 - Single cell; X - First direction; Y - Second direction; Z - Third direction; 100 - Electrode assembly; 110 - First electrode tab group; 111 - First electrode tab portion; 112 - First electrode sheet; 1121 - First body; 1122 - First electrode tab region; 1123 - First electrode material layer; 110a - First electrode tab group A; 110b - First electrode tab group B; 120 - Second electrode lug assembly; 121 - Second electrode lug portion; 122 - Second electrode plate; 1221 - Second body; 1222 - Second electrode lug region; 1223 - Second electrode material layer; 130 - First connector; 131 - First bending section; 132 - First electrical connection area; 133 - First insulating area; 133a - First conductive layer; 133b - First insulating layer; 130a - First connecting section; 130b - Second connecting section; 130c - Weak area; 130d - Inorganic porous layer; 140 - Second connector; 141 - Second bend; 142 - Second electrical connection area; 143 - Second insulating area; 143a - Second conductive layer; 143b - Second insulating layer; 150 - Insulating film; 160 - Isolator; 200 - Housing assembly; 210 - First pole; 220 - Second pole; 230 - First top cover; 240 - Second top cover; 250 - Housing; 251 - First side wall; 260 - Explosion-proof valve. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this application, it should be noted that if the terms "upper", "lower", "inner", "outer", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0029] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0030] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0031] Currently, in lithium-ion battery technology, improving battery energy density and fast charging capability are two important development directions. Improving energy density can not only significantly enhance the performance and application range of lithium batteries, but also reduce watt-hour costs and enhance market competitiveness. Meanwhile, improving fast charging capability can improve the efficiency of human production and life.

[0032] However, as the energy density and fast charging capability of lithium batteries increase, the current density passing through the tabs of a single battery cell during charging increases, resulting in high heat generation at the tabs and difficulty in heat dissipation, ultimately affecting the battery's fast charging performance and cycle life.

[0033] Therefore, please refer to Figures 1-17The embodiments of this application propose a single battery cell 010 and a battery pack. The single battery cell 010 is applied in the battery pack, which can improve the fast charging capability of the single battery cell 010 and increase the heat dissipation area of ​​the single battery cell 010.

[0034] This application proposes a single cell 010, including an electrode assembly 100. The electrode assembly 100 has a first direction X, a second direction Y and a third direction Z that are perpendicular to each other. The electrode assembly 100 includes a plurality of first electrode plates 112, a plurality of spacers 160 and a plurality of second electrode plates 122. The plurality of first electrode plates 112, the plurality of spacers 160 and the plurality of second electrode plates 122 are stacked along the third direction Z. The electrode assembly 100 has a first tab group 110 at at least one end in the first direction X, and a second tab group 120 at at least one end in the second direction Y. The housing assembly 200 and the electrode assembly 100 are disposed inside the housing assembly 200. The housing assembly 200 has a first electrode post 210 at one end in the first direction X and a second electrode post 220 at one end in the second direction Y. The first electrode tab group 110 is connected to the first electrode post 210 and the second electrode tab group 120 is connected to the second electrode post 220.

[0035] Understandably, compared to the prior art where the positive and negative tabs are placed on the same side of the core, this application places the first tab group 110 and the second tab group 120 on two adjacent sides of the electrode assembly 100. On the one hand, this shortens the lateral transmission distance of the current on the electrode sheet, reducing internal resistance, making the current distribution more uniform, and dispersing heat generation more effectively. On the other hand, the heat generated by the first tab group 110 and the second tab group 120 can be conducted outward to the housing assembly 200 from two different directions, improving the heat dissipation efficiency and fast charging performance of the single battery 010, effectively avoiding local overheating and reducing the internal temperature rise of the single battery 010, thereby significantly enhancing the high current and fast charging capabilities.

[0036] Please refer to Figures 1-17 The specific structure of the single cell 010 proposed in this embodiment is described below: In this embodiment, the electrode assembly 100 has a first direction X, a second direction Y, and a third direction Z that are perpendicular to each other.

[0037] Wherein, the first direction X can be the length direction of the single cell 010, the second direction Y can be the width direction of the single cell 010, and the third direction Z can be the thickness direction of the single cell 010. Alternatively, the first direction X can be the width direction of the single cell 010, the second direction Y can be the length direction of the single cell 010, and the third direction Z can be the thickness direction of the single cell 010.

[0038] In this embodiment, the single cell 010 includes an electrode assembly 100, please refer to... Figure 1 The electrode assembly 100 has a first tab group 110 at at least one end in the first direction X, and a second tab group 120 at at least one end in the second direction Y.

[0039] In this embodiment, please refer to Figure 1 The electrode assembly 100 is provided with two first tab groups 110, which are located at opposite ends of the electrode assembly 100 along the first direction X.

[0040] Meanwhile, the electrode assembly 100 is provided with two second electrode tabs 120, which are located at opposite ends of the electrode assembly 100 along the second direction Y.

[0041] Understandably, tabs extend simultaneously from all four sides of the electrode assembly 100. Two first tab groups 110 of the same polarity are located at both ends of the electrode assembly 100 along the first direction X, and two second tab groups 120 of the same polarity are located at both ends of the electrode assembly 100 along the second direction Y. This increases the number of first tab groups 110 and second tab groups 120, reduces the current density of a single tab group, and makes the current density distribution of the single cell 010 more uniform. At the same time, the heat generated by the four tab groups can be transferred from the single cell 010 in four different directions, improving the overall heat dissipation efficiency, increasing the heat dissipation area, effectively avoiding local overheating and reducing the internal temperature rise of the single cell 010, thereby significantly enhancing the high current and fast charging capabilities. In addition, under high-rate charge and discharge conditions, it is beneficial to reduce side reactions such as electrolyte decomposition, active material shedding, and structural collapse, thereby improving the cycle life of the single cell 010.

[0042] It is worth mentioning that the aforementioned electrode assembly 100 is also highly compatible with existing lithium battery production equipment and can be used for large-scale industrial production.

[0043] In an optional embodiment, the electrode assembly 100 is provided with a first tab group 110 at one end in the first direction X, and the electrode assembly 100 is provided with a second tab group 120 at one end or opposite ends in the second direction Y.

[0044] In an optional embodiment, if the electrode assembly 100 is provided with a first tab group 110 at one end or opposite ends in the first direction X, then the electrode assembly 100 is provided with a second tab group 120 at one end in the second direction Y.

[0045] In this embodiment, the first electrode assembly 110 includes a first electrode portion 111, which is located at the middle of one end of the electrode assembly 100 in the first direction X.

[0046] Alternatively, please refer to Figure 11 The first electrode assembly 110 includes at least two first electrode portions 111, which are spaced apart along a second direction Y. The presence of multiple first electrode portions 111 increases the heat dissipation area of ​​the first electrode assembly 110.

[0047] In this embodiment, the second electrode assembly 120 includes a second electrode portion 121, which is located at the middle of one end of the electrode assembly 100 in the second direction Y.

[0048] Alternatively, please refer to Figure 11 The second electrode assembly 120 includes at least two second electrode portions 121, which are spaced apart along a first direction X. The presence of multiple second electrode portions 121 increases the heat dissipation area of ​​the second electrode assembly 120.

[0049] It is understandable that the tabs are the current conduction path. The first tab group 110 and the second tab group 120 can reduce the current density of a single tab by increasing the number of tabs, so that the current density distribution of the single cell 010 is more uniform, especially for high-capacity or wide-capacity cells. At the same time, this setting is beneficial to reducing side reactions such as electrolyte decomposition, active material shedding, and structural collapse under high-rate charge and discharge conditions, thereby improving the cycle life of the battery.

[0050] In this embodiment, the electrode assembly 100 includes a plurality of first electrode plates 112, a plurality of spacers 160, and a plurality of second electrode plates 122, which are stacked in a third direction Z. The electrode assembly 100 is formed by stacking or winding the plurality of first electrode plates 112, spacers 160, and second electrode plates 122 in a third direction Z.

[0051] In this embodiment, please refer to Figure 12 The first electrode 112 includes a first body 1121 and a first electrode tab region 1122. The first body 1121 is provided with the first electrode tab region 1122 at one end or at both opposite ends in the first direction X. The first body 1121 is coated with a first electrode material layer 1123 on at least one of the opposite sides in the third direction Z.

[0052] In this embodiment, please refer to Figure 13 The second electrode 122 includes a second body 1221 and a second tab region 1222. The second body 1221 is provided with the second tab region 1222 at one end or at both opposite ends in the second direction Y. The second electrode 122 is coated with a second electrode material layer 1223 on at least one of the opposite sides in the third direction Z.

[0053] Specifically, the number of first electrode tabs 111 and second electrode tabs 121 in the electrode assembly 100 determines the number and position of the first electrode plate 112 and the second electrode plate 122. Multiple stacked first electrode tabs 1122 form the first electrode tab 111, and multiple stacked second electrode tabs 1222 form the second electrode tab 121.

[0054] Alternatively, please refer to Figure 12 In the case of 'a', the first body 1121 of the first electrode 112 does not have an isolation element 160. Alternatively, please refer to... Figure 12 In the figures b and c, the first body 1121 of the first electrode 112 can have an isolation element 160 provided at one end in the Z direction. Alternatively, please refer to Figure 12 In the first pole piece 112, the first body 1121 can also have isolation members 160 at the two opposite ends of the third direction Z.

[0055] Alternatively, please refer to Figure 13 In the case of 'a', the second body 1221 of the second electrode 122 does not have an isolation element 160. Alternatively, please refer to... Figure 13 In the figures b and c, the second body 1221 of the second electrode 122 can have an isolation member 160 provided at one end facing Z. Alternatively, please refer to Figure 13 In the second pole piece 122, the second body 1221 can also be provided with isolation members 160 at the two opposite ends of the third direction Z.

[0056] Among them, the isolation component 160 is a diaphragm.

[0057] Specifically, when the first electrode 112 and the second electrode 122 are stacked, there are multiple ways to stack them, such as: Example 1, Figure 12 The first electrode 112 shown in a or b is... Figure 13 The second pole piece 122 shown in b or d is superimposed; Example 2. Figure 12 The first electrode 112 shown in c or d is... Figure 13 The second electrode 122 shown in a or c is superimposed.

[0058] It is worth mentioning that, provided that an isolation member 160 is provided between the first electrode 112 and the second electrode 122, the stacking method of the first electrode 112 and the second electrode 122 includes, but is not limited to, the forms listed above. Any feasible stacking method can be adopted according to actual needs, and this application does not limit it.

[0059] In this embodiment, please refer to Figures 5-8The single cell 010 also includes a first connector 130, which is located on one side of the electrode assembly 100 along the third direction Z. The two ends of the first connector 130 along the first direction X are respectively connected to two first tab groups 110, and the first connector 130 is electrically connected to the first pole post 210.

[0060] Specifically, please refer to Figure 8 The first connector 130 has a first bent section 131 at one end facing the first pole post 210. The first bent section 131 bends toward the first pole post 210, and the first pole post 210 is connected to the first bent section 131.

[0061] It is understood that the first connector 130 is used to electrically connect the two first tab groups 110 located at opposite ends of the electrode assembly 100 to the first pole post 210. The first connector 130 forms a parallel circuit between the two first tab groups 110, thereby halving the resistance and doubling the current carrying capacity.

[0062] Specifically, please refer to Figure 8 The first connector 130 includes a first electrical connection area 132 and a first insulation area 133. The connection position of the first connector 130 with the first tab assembly 110 and the first pole post 210 is the first electrical connection area 132, and the area of ​​the first connector 130 facing the electrode assembly 100 and the housing assembly 200 is the first insulation area 133.

[0063] Further, please refer to Figure 16 The first insulating region 133 includes a first conductive layer 133a and a first insulating layer 133b. The first conductive layer 133a is electrically connected to the first electrical connection region 132. The first insulating layer 133b is disposed on the surface of the first conductive layer 133a.

[0064] In this process, an insulating and highly thermally conductive material is coated on the surface of the first conductive layer 133a, thereby forming a first insulating layer 133b on the surface of the first conductive layer 133a. The first insulating layer 133b is beneficial for the insulation of the first connector 130 from the housing 250 and the electrode assembly 100, and also for heat dissipation.

[0065] It is understandable that the process of connecting the first connector 130 to the electrode assembly 100 and the first electrode post 210 is as follows: Please refer to... Figure 5 The first electrical connection area 132 at one end of the first connector 130 is soldered to the first electrode assembly 110; please refer to Figure 6 The other end of the first connector 130 is bent to form the first bent segment 131; please refer to Figure 7Simultaneously, the first electrical connection area 132 at the other end of the first connector 130 is welded to the first tab group 110 and the first electrode post 210. The first connector 130, including the first electrical connection area 132 and the first insulation area 133, not only enables the parallel connection of the two first tab groups 110 and the electrical connection with the first electrode post 210, but also ensures the insulation of the first connector 130 from the electrode assembly 100, preventing internal short circuits in the single cell 010.

[0066] In one embodiment, please refer to Figure 15 The first connector 130 includes a first connecting segment 130a and a second connecting segment 130b, which are connected to each other. The melting point of the first connecting segment 130a is higher than that of the second connecting segment 130b.

[0067] Specifically, of the two first electrode groups 110, the one facing the first pole post 210 is the first electrode group A 110a, and the one away from the first pole post 210 is the first electrode group B 110b. The first connecting section 130a connects to the first electrode group A 110a, and the second connecting section 130b connects to the first electrode group B 110b.

[0068] It is understandable that, since the second connecting segment 130b is located on the side away from the first electrode post 210, the heat at the first connecting segment 130a can be dissipated through the first electrode post 210, while the heat at the second connecting segment 130b is difficult to dissipate. That is, the heat dissipation conditions of the second connecting segment 130b are worse than those of the first connecting segment 130a. At the same time, the second connecting segment 130b is also more susceptible to the superimposed effects of heat conduction inside the single cell 010. Therefore, it can be concluded that the second connecting segment 130b is in the high-temperature melting zone.

[0069] Therefore, by designing the melting point of the first connecting segment 130a to be higher than that of the second connecting segment 130b, the second connecting segment 130b is more likely to melt and break. If the single cell 010 generates heat during abnormal fast charging, the second connecting segment 130b can be disconnected first, while the first connecting segment 130a remains electrically connected to the first tab A group 110a. This can reduce current transmission, hinder the fast charging process, and reduce the subsequent risks caused by the single cell 010 generating heat during abnormal fast charging.

[0070] Optionally, when the first tab group 110 is a negative tab group, the material of the first connecting section 130a can be copper, with a melting point of about 900℃~1050℃; at this time, the material of the second connecting section 130b can be a tin-bismuth alloy, with a melting point of about 138℃~160℃; or, the material of the second connecting section 130b can also be a tin-silver-copper alloy, with a melting point of about 217℃~220℃.

[0071] In one embodiment, please refer to Figure 15 The surface of the second connecting section 130b is provided with an inorganic porous layer 130d.

[0072] Optionally, the inorganic porous layer 130d can be a ceramic porous layer, such as an alumina porous layer or a boehmite porous layer. The inorganic porous layer 130d can be formed on the surface of the second connecting section 130b by coating.

[0073] It is understandable that by providing an inorganic porous layer 130d on the surface of the second connecting section 130b, the molten metal can be adsorbed by the inorganic porous layer 130d during the melting process of the second connecting section 130b, reducing the migration of the molten metal into the electrode and lowering the risk of causing an internal short circuit.

[0074] Furthermore, the inorganic porous layer 130d has multiple channels containing oxides and / or sulfides. The oxides include at least one of calcium oxide, titanium dioxide, aluminum oxide, and magnesium peroxide, and the sulfides include at least one of zinc sulfide, magnesium sulfide, and lithium sulfide.

[0075] Understandably, by placing oxides and / or sulfides within the pores of the inorganic porous layer 130d, when molten metal enters the pores, it reacts chemically with the oxides and / or sulfides, forming a coating layer (e.g., a metal sulfide layer and / or a metal oxide layer) on the surface of the molten metal and adhering to the pores. This enhances the adhesion of the molten metal to the inorganic porous layer 130d, preventing molten metal from falling into the electrolyte and reducing the risk of secondary short circuits caused by the molten metal, thereby improving the safety of the single-cell battery 010.

[0076] In one embodiment, please refer to Figure 14 and Figure 15 The housing assembly 200 includes a housing 250 and an explosion-proof valve 260. The housing 250 is provided with a first sidewall 251 facing the first tab group B 110b. The explosion-proof valve 260 is located on the first sidewall 251. The orthographic projection of the explosion-proof valve 260 in the first direction X at least partially overlaps with the orthographic projection of the second connecting section 130b in the first direction X.

[0077] Understandably, at least a portion of the second connecting section 130b faces the explosion-proof valve 260. When the second connecting section 130b melts and breaks, the fractured area facilitates the migration of gas inside the housing 250 to the explosion-proof valve 260, opening the valve for venting. Therefore, this arrangement improves the flow of gas inside the housing 250 at the explosion-proof valve 260, facilitating rapid pressure relief from the valve.

[0078] Further, please refer to Figure 15The second connecting section 130b is provided with a weak area 130c, and the orthographic projection of the weak area 130c in the first direction X at least partially overlaps with the orthographic projection of the explosion-proof valve 260 in the first direction X.

[0079] Optionally, the weak area 130c is provided with a notch, or the thickness of the weak area 130c is less than the thickness of the non-weak area of ​​the second connecting segment 130b.

[0080] It is understandable that the second connecting section 130b has a weak zone 130c facing the explosion-proof valve 260. This allows gas to accumulate inside the housing 250 at the explosion-proof valve 260, and when the explosion-proof valve 260 depressurizes, the airflow can generate a large pressure in the weak zone 130c of the second connecting section 130b, causing the weak zone 130c to break rapidly. This design facilitates the rapid opening and depressurization of the explosion-proof valve 260, reduces the electrochemical reaction inside the housing 250, and reduces heat generation inside the housing 250. Simultaneously, combined with the aforementioned inorganic porous layer 130d and other designs, it helps to jointly suppress the thermal runaway development of the single-cell battery 010.

[0081] In this embodiment, please refer to Figures 2-8 The single cell 010 also includes a second connector 140, which is located on the other side of the electrode assembly 100 along the third direction Z. The two ends of the second connector 140 along the second direction Y are respectively connected to two second tab groups 120, and the second connector 140 is electrically connected to the second pole post 220.

[0082] The first connector 130 and the second connector 140 are located on opposite sides of the electrode assembly 100 along the third direction Z, which makes reasonable use of the internal space of the housing 250, avoids interference between the first connector 130 and the second connector 140, and also meets the electrical connection requirements of the two tabs and the two poles. Specifically, the second connector 140 has a second bent section 141 at one end facing the second pole post 220, the second bent section 141 bends toward the second pole post 220, and the second connector 140 is connected to the second pole post 220.

[0083] Understandably, the second connector 140 is used to electrically connect the two second tab groups 120 located at opposite ends of the electrode assembly 100 to the second pole post 220. The second connector 140 forms a parallel circuit between the two second tab groups 120, thereby halving the resistance and doubling the current carrying capacity.

[0084] Specifically, the second connector 140 includes a second electrical connection region 142 and a second insulation region 143. The connection position between the second connector 140 and the second electrode assembly 120 and the second electrode post 220 is the second electrical connection region 142, and the area of ​​the second connector 140 facing the electrode assembly 100 and the housing assembly 200 is the second insulation region 143.

[0085] Further, please refer to Figure 17 The second insulating region 143 includes a second conductive layer 143a and a second insulating layer 143b. The second conductive layer 143a is electrically connected to the second electrical connection region 142, and the second insulating layer 143b is provided on the surface of the second conductive layer 143a. Specifically, an insulating and highly thermally conductive material is coated on the surface of the second conductive layer 143a, thereby forming the second insulating layer 143b on the surface of the second conductive layer 143a. The second insulating layer 143b facilitates insulation between the second connector 140 and the housing 250 and the electrode assembly 100, and also facilitates heat dissipation.

[0086] Understandably, please refer to Figures 2-3 The second electrical connection area 142 at one end of the second connector 140 is welded to the second electrode assembly 120; please refer to Figure 4 and Figure 8 The other end of the second connector 140 is bent to form the second bent segment 141; please refer to Figure 8 Simultaneously, the second electrical connection area 142 at the other end of the second connector 140 is welded to the second tab group 120 and the second electrode post 220. The second connector 140, including the second electrical connection area 142 and the second insulation area 143, can realize the parallel connection of the two second tab groups 120 and the electrical connection with the second electrode post 220, and can also ensure the insulation of the second connector 140 from the electrode assembly 100, avoiding internal short circuits in the single cell 010.

[0087] In this embodiment, please refer to Figures 8-9 The single cell 010 includes a housing assembly 200, an electrode assembly 100 disposed within the housing assembly 200, a first electrode post 210 provided at one end of the housing assembly 200 in the first direction X, a second electrode post 220 provided at one end of the housing assembly 200 in the second direction Y, a first tab assembly 110 connected to the first electrode post 210, and a second tab assembly 120 connected to the second electrode post 220.

[0088] In this embodiment, please refer to Figures 8-9 The housing assembly 200 includes a first top cover 230, a second top cover 240, and a housing 250. The housing 250 has a first opening at one end in the first direction X, the first top cover 230 is located at the first opening and connected to the housing 250, and a first pole post 210 is disposed on the first top cover 230. The housing 250 has a second opening at one end in the second direction Y, the second top cover 240 is located at the second opening and connected to the housing 250, and a second pole post 220 is disposed on the second top cover 240.

[0089] The housing 250 is provided with a first side wall 251, and an explosion-proof valve 260 is provided on the first side wall 251. The first side wall 251 and the first pole post 210 are located at opposite ends of the housing 250 along the first direction X.

[0090] Optionally, the first opening and the second opening can be connected, and the first top cover 230 and the second top cover 240 can be welded to the housing 250. The connection between the first opening and the second opening facilitates the insertion of the electrode assembly 100 into the housing and allows for direct welding of the first top cover 230 and the second top cover 240. Alternatively, the first opening and the second opening can be disconnected, in which case the first top cover 230 and the second top cover 240 can be welded to the housing 250 respectively.

[0091] Specifically, please refer to Figures 2-4 The second electrode tabs 120 at both ends of the electrode assembly 100 are welded together using the second connector 140; please refer to Figures 5-6 The first electrode tabs 110 at both ends of the electrode assembly 100 are welded together using the first connector 130; further, please refer to... Figures 7-8 The first connector 130 is welded to the first top cover 230; further, please refer to... Figure 9 After welding the second connector 140 and the second top cover 240, the electrode assembly 100, the first connector 130, the second connector 140, the first top cover 230, and the second top cover 240 are covered with an insulating film 150 to form a bare battery cell; please refer to Figure 10 Then, the bare battery cells are inserted into the casing through the first opening and the second opening; after the casing is completed, the first top cover 230 and the second top cover 240 are welded together, and subsequent liquid injection and other processes are carried out.

[0092] Optionally, if the first electrode 112 is a negative electrode, then the first tab group 110 is a negative tab group and the first pole post 210 is a negative pole post; correspondingly, if the second electrode 122 can be a positive electrode, then the second tab group 120 is a positive tab group and the second pole post 220 is a positive pole post.

[0093] Of course, in other embodiments, the first electrode 112 can be a positive electrode, then the first tab group 110 is a positive tab group and the first pole post 210 is a positive pole post; correspondingly, the second electrode 122 is a negative electrode, then the second tab group 120 is a negative tab group and the second pole post 220 is a negative pole post.

[0094] Furthermore, embodiments of this application also provide a battery pack, including the single cell 010 in the above embodiments.

[0095] In summary, the single-cell battery 010 and battery pack provided in this application, compared with the prior art in which the positive and negative tabs are set on the same side of the core, this application sets the first tab group 110 and the second tab group 120 on two adjacent sides of the electrode assembly 100, respectively. On the one hand, this shortens the lateral transmission distance of the current on the electrode sheet, thereby reducing the internal resistance, making the current distribution more uniform, and dispersing the heat generation more effectively. On the other hand, the heat generated by the first tab group 110 and the second tab group 120 can be conducted outward to the housing assembly 200 from two different directions, thereby improving the heat dissipation efficiency and fast charging performance of the single-cell battery 010, effectively avoiding local overheating and reducing the internal temperature rise of the single-cell battery 010, thus significantly enhancing the high current and fast charging capabilities.

[0096] Furthermore, two first tab groups 110 are provided at opposite ends of the electrode assembly 100, and two second tab groups 120 are provided at opposite ends of the electrode assembly 100, so that the current density distribution of the single cell 010 is uniform. At the same time, the heat generated by the four tab groups can be transferred from the single cell 010 in four different directions, which improves the overall heat dissipation efficiency, increases the heat dissipation area, effectively avoids local overheating and reduces the internal temperature rise of the single cell 010, thereby significantly enhancing the high current and fast charging capabilities. Meanwhile, under high rate charge and discharge conditions, it is beneficial to reduce side reactions such as electrolyte decomposition, active material shedding, and structural collapse, thereby improving the cycle life of the single cell 010.

[0097] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A single-cell battery, comprising an electrode assembly (100), characterized in that, The electrode assembly (100) has a first direction (X), a second direction (Y) and a third direction (Z) that are perpendicular to each other. The electrode assembly (100) includes a plurality of first electrodes (112), a plurality of spacers (160) and a plurality of second electrodes (122). The plurality of first electrodes (112), the plurality of spacers (160) and the plurality of second electrodes (122) are stacked along the third direction (Z). The electrode assembly (100) has a first tab group (110) at at least one end in the first direction (X), and the electrode assembly (100) has a second tab group (120) at at least one end in the second direction (Y). The housing assembly (200) has an electrode assembly (100) disposed within it. The housing assembly (200) has a first electrode post (210) at one end in the first direction (X) and a second electrode post (220) at one end in the second direction (Y). The first electrode tab group (110) is connected to the first electrode post (210), and the second electrode tab group (120) is connected to the second electrode post (220).

2. The single-cell battery according to claim 1, characterized in that, The electrode assembly (100) is provided with two first electrode tabs (110), which are located at opposite ends of the electrode assembly (100) along the first direction (X).

3. The single-cell battery according to claim 1, characterized in that, The electrode assembly (100) is provided with two second electrode tabs (120), which are located at opposite ends of the electrode assembly (100) along the second direction (Y).

4. The single-cell battery according to claim 2, characterized in that, The single cell (010) further includes a first connector (130), which is located on one side of the electrode assembly (100) along the third direction (Z). The first connector (130) is connected to two first tab groups (110) at both ends along the first direction (X), and the first connector (130) is electrically connected to the first electrode post (210).

5. The single-cell battery according to claim 4, characterized in that, The first connector (130) has a first bent section (131) at one end facing the first pole post (210), the first bent section (131) bends toward the first pole post (210), and the first pole post (210) is connected to the first bent section (131); And / or, the first connector (130) includes a first electrical connection area (132) and a first insulating area (133), the connection position of the first connector (130) with the first tab assembly (110) and the first pole post (210) is the first electrical connection area (132), the area of ​​the first connector (130) facing the electrode assembly (100) and the housing assembly (200) is the first insulating area (133), the first insulating area (133) includes a first conductive layer (133a) and a first insulating layer (133b), the first conductive layer (133a) is electrically connected to the first electrical connection area (132), and the first insulating layer (133b) is disposed on the surface of the first conductive layer (133a).

6. The single-cell battery according to claim 3, characterized in that, The single cell (010) further includes a second connector (140), which is located on the other side of the electrode assembly (100) along the third direction (Z). The two ends of the second connector (140) along the second direction (Y) are respectively connected to two second tab groups (120), and the second connector (140) is electrically connected to the second pole post (220).

7. The single-cell battery according to claim 6, characterized in that, The second connector (140) has a second bent section (141) at one end facing the second pole post (220), the second bent section (141) bends toward the second pole post (220), and the second connector (140) is connected to the second pole post (220); And / or, the second connector (140) includes a second electrical connection area (142) and a second insulating area (143), the connection position of the second connector (140) with the second tab assembly (120) and the second pole post (220) is the second electrical connection area (142), the area of ​​the second connector (140) facing the electrode assembly (100) and the housing assembly (200) is the second insulating area (143), the second insulating area (143) includes a second conductive layer (143a) and a second insulating layer (143b), the second conductive layer (143a) is electrically connected to the second electrical connection area (142), and the surface of the second conductive layer (143a) is provided with the second insulating layer (143b).

8. The single-cell battery according to claim 1, characterized in that, The first electrode (112) includes a first body (1121) and a first tab region (1122). The first body (1121) is provided with the first tab region (1122) at one end or opposite ends in the first direction (X). The first body (1121) is coated with a first electrode material layer (1123) on at least one of the opposite sides in the third direction (Z). And / or, the second electrode (122) includes a second body (1221) and a second tab region (1222), wherein the second body (1221) is provided with the second tab region (1222) at one end or opposite ends of the second direction (Y); and the second electrode (122) is coated with a second electrode material layer (1223) on at least one side of opposite sides of the third direction (Z).

9. The single-cell battery according to claim 1, characterized in that, The housing assembly (200) includes a first top cover (230), a second top cover (240), and a housing (250). The housing (250) has a first opening at one end in the first direction (X), the first top cover (230) is located at the first opening and connected to the housing (250), and a first pole post (210) is disposed on the first top cover (230). The housing (250) has a second opening at one end in the second direction (Y), the second top cover (240) is located at the second opening and connected to the housing (250), and a second pole post (220) is disposed on the second top cover (240).

10. The single-cell battery according to claim 1, characterized in that, The first electrode group (110) includes at least two first electrode portions (111), and the at least two first electrode portions (111) are spaced apart along the second direction (Y); And / or, the second electrode group (120) includes at least two second electrode portions (121), which are spaced apart along the first direction (X).

11. The single-cell battery according to claim 4, characterized in that, The first connector (130) includes a first connecting segment (130a) and a second connecting segment (130b), the first connecting segment (130a) and the second connecting segment (130b) are connected, and the melting point of the first connecting segment (130a) is higher than the melting point of the second connecting segment (130b); Of the two first electrode groups (110), the one facing the first pole post (210) is the first electrode group A (110a), and the one away from the first pole post (210) is the first electrode group B (110b). The first connecting segment (130a) is connected to the first electrode group A (110a), and the second connecting segment (130b) is connected to the first electrode group B (110b).

12. The single-cell battery according to claim 11, characterized in that, The surface of the second connecting section (130b) is provided with an inorganic porous layer (130d).

13. The single-cell battery according to claim 12, characterized in that, The inorganic porous layer (130d) contains oxides and / or sulfides within its pores. The oxides include at least one of calcium oxide, titanium dioxide, aluminum oxide, and magnesium peroxide, and the sulfides include at least one of zinc sulfide, magnesium sulfide, and lithium sulfide.

14. The single-cell battery according to claim 11, characterized in that, The housing assembly (200) includes a housing (250) and an explosion-proof valve (260). The housing (250) is provided with a first sidewall (251) facing the first tab group B (110b). The explosion-proof valve (260) is located on the first sidewall (251). The orthographic projection of the explosion-proof valve (260) in the first direction (X) at least partially overlaps with the orthographic projection of the second connecting section (130b) in the first direction (X).

15. The single-cell battery according to claim 14, characterized in that, The second connecting section (130b) is provided with a weak area (130c), the orthographic projection of the weak area (130c) in the first direction (X) at least partially overlaps with the orthographic projection of the explosion-proof valve (260) in the first direction (X); The weak area (130c) is provided with a notch, or the thickness of the weak area (130c) is less than the thickness of the non-weak area of ​​the second connecting segment (130b).

16. A battery pack, characterized in that, Includes the single cell battery (010) as described in any one of claims 1-15.

Images