Battery cell, battery, battery pack, and electric device

Abstract

This application provides a battery cell, a battery, a battery pack, and an electrical device, relating to the field of battery pack technology. The battery cell includes a cell body, a first tab, and a second tab. The first tab and the second tab are spaced apart along a first direction and disposed on the same side of the cell body. The distance between the first tab and the cold plate is set to be less than the distance between the second tab and the cold plate, and the two tabs satisfy T... 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1 ≥ 30mm, ensuring the width of the two tabs is within a reasonable range. The battery cell provided according to the embodiments of this application can reduce the temperature difference between the first and second tabs during fast charging, ensuring fast charging capability and improving performance.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery, battery pack and power-consuming device. Background Technology

[0002] Currently, battery packs are widely used in new energy vehicles and other electrical devices. Among them, the battery cell is the smallest unit in the battery pack, which is used to store and provide electrical energy.

[0003] Battery cells typically have positive and negative tabs. Because the current flowing through the tabs is larger during fast charging, the heat generation will increase significantly.

[0004] However, existing battery cells exhibit a significant temperature difference between the positive and negative terminals during fast charging, which affects fast charging capability. Utility Model Content

[0005] Based on this, this application provides a battery cell, a battery, a battery pack, and an electrical device to solve the problem of a large temperature difference between the positive and negative terminals of existing battery cells during fast charging.

[0006] In a first aspect, this application provides a battery cell, including a battery cell body, a first electrode tab and a second electrode tab, wherein the first electrode tab and the second electrode tab are spaced apart along a first direction and disposed on the same side end of the battery cell body.

[0007] The distance between the first electrode tab and the cold plate is less than the distance between the second electrode tab and the cold plate, and satisfies the following relationship:

[0008] T 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm;

[0009] In the formula: T 预1 The first preset temperature change ratio between the first electrode and the second electrode; T 预2The first electrode and the second electrode have a second preset temperature change ratio; ρ1 is the resistivity of the first electrode (Ω•m); ρ2 is the resistivity of the second electrode (Ω•m); L1 is the length of the first electrode (mm); L2 is the length of the second electrode (mm); n1 is the number of layers of the first electrode; n2 is the number of layers of the second electrode; δ1 is the thickness of the first electrode (mm); δ2 is the thickness of the second electrode (mm); C1 is the specific heat capacity of the first electrode (J / (kg•K); C2 is the specific heat capacity of the second electrode (J / (kg•K); M1 is the mass of the first electrode (kg); M2 is the mass of the second electrode (kg); λ1 is the heat transfer coefficient of the first electrode (W / (m•K); λ2 is the heat transfer coefficient of the second electrode (W / (m•K); A1 is the average heat transfer area from the first electrode to the cold plate (mm²). 2 A2 represents the average heat transfer area from the second electrode tab to the cold plate, in mm. 2 X1 is the distance from the first tab to the cold plate, in mm; X2 is the distance from the second tab to the cold plate, in mm; D1 is the width of the first tab, in mm; D2 is the width of the second tab, in mm; H is the width of the cell body, in mm.

[0010] In one possible implementation, the following relation is also satisfied:

[0011] 3mm≤W;

[0012] In the formula: W is the distance between the first electrode and the second electrode along the first direction, in mm.

[0013] In one possible implementation, the battery cell body has a first end and a second end, which are arranged along a second direction that intersects with the first direction.

[0014] In one possible implementation, the first end is provided with a first electrode and a second electrode;

[0015] Alternatively, the second end may have a first electrode and a second electrode.

[0016] In one possible implementation, both the first end and the second end are provided with a first electrode tab and a second electrode tab.

[0017] In one possible implementation, the first tab on the first end is the positive tab, and the first tab on the second end is the negative tab;

[0018] Alternatively, the first tab on the first end is the negative tab, and the first tab on the second end is the positive tab.

[0019] In one possible implementation, the first tab on the first end corresponds to the first tab on the second end;

[0020] And / or, the second tab on the first end corresponds to the second tab on the second end.

[0021] Secondly, this application also provides a battery, including a casing and any of the battery cells provided in the first aspect, wherein the battery cells are disposed within the casing.

[0022] Thirdly, this application also provides a battery pack including a cold plate and at least one battery provided in the first aspect, the battery being in contact with the cold plate.

[0023] Fourthly, this application also provides an electrical device, including the battery provided in the second aspect or the battery pack provided in the third aspect.

[0024] The battery cell, battery, battery pack, and electrical device provided in this application include a battery cell body, a first tab, and a second tab. The first tab and the second tab are spaced apart along a first direction on the same side of the battery cell body. The distance between the first tab and the cold plate is set to be less than the distance between the second tab and the cold plate, and the two tabs satisfy T... 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range. Therefore, the battery cell provided in this application can reduce the temperature difference between the first and second tabs during fast charging, ensuring fast charging capability and improving performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a partial schematic diagram showing the arrangement of the battery cells and cold plate in an embodiment of this application;

[0027] Figure 2 for Figure 1 A top view of the structure of a battery cell;

[0028] Figure 3 This is a first schematic diagram illustrating the arrangement relationship between the battery cell and the cold plate in an embodiment of this application.

[0029] Figure 4 This is a second schematic diagram showing the arrangement relationship between the battery cell and the cold plate provided in an embodiment of this application;

[0030] Figure 5 This is a third schematic diagram showing the arrangement relationship between the battery cell and the cold plate in an embodiment of this application.

[0031] Figure 6 for Figure 5 A schematic diagram of some current collectors in the battery cell, where (a) represents the positive current collector and (b) represents the negative current collector;

[0032] Figure 7 This is a fourth schematic diagram showing the arrangement of the battery cell and cold plate in an embodiment of this application.

[0033] Figure label:

[0034] 10: Cold-rolled plate;

[0035] 100: Battery cell body;

[0036] 101: First end;

[0037] 102: Second end;

[0038] 200: First pole ear;

[0039] 300: Second pole ear. Detailed Implementation

[0040] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of methods and apparatus consistent with some aspects of this application as detailed in the appended claims.

[0041] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] As mentioned in the background section, in existing battery cell structures, when the positive and negative tabs are on the same side of the cell, the sizes of the positive and negative tabs are usually designed to be equal. This does not take into account the influence of many factors such as tab material, size, and heat dissipation, resulting in inconsistent temperatures between the positive and negative tabs. The temperature difference between the two is large, which affects the fast charging capability.

[0043] In addition, for the structure of the battery cell with a single positive tab and a single negative tab at each end, the current inside can only flow in one direction. When the fast charging requirement is high, the large current flowing into the battery cell will cause the core to heat up severely, which will also seriously affect the fast charging capability.

[0044] To address the aforementioned problems in the prior art, this application provides a battery cell, a battery, a battery pack, and an electrical device. The battery cell provided in this application includes a cell body, a first tab, and a second tab. The first and second tabs are spaced apart along a first direction and positioned on the same side of the cell body. The distance between the first tab and the cold plate is set to be less than the distance between the second tab and the cold plate, and the two tabs satisfy T... 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range, which can reduce the temperature difference between the first and second tabs during fast charging, ensure fast charging capability, and improve performance.

[0045] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0046] Firstly, referring to Figures 1-7 As shown, this application embodiment provides a battery cell, including a battery cell body 100, a first tab 200 and a second tab 300, the first tab 200 and the second tab 300 being disposed at a distance along a first direction on the same side of the battery cell body 100.

[0047] The distance between the first electrode tab 200 and the cold plate 10 is less than the distance between the second electrode tab 300 and the cold plate 10, and satisfies the following relationship:

[0048] T 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 , X1 / H<1 / 2, X2-X1≥30mm.

[0049] In the formula: T 预1 The first preset temperature change ratio between the first electrode 200 and the second electrode 300; T 预2 The first electrode 200 and the second electrode 300 are defined as the second preset temperature change ratio; ρ1 is the resistivity of the first electrode 200 (Ω·m); ρ2 is the resistivity of the second electrode 300 (Ω·m); L1 is the length of the first electrode 200 (mm); L2 is the length of the second electrode (mm); n1 is the number of layers of the first electrode 200; n2 is the number of layers of the second electrode 300; δ1 is the thickness of the first electrode 200 (mm); δ2 is the thickness of the second electrode 300 (mm). C1 is the specific heat capacity of the first tab 200, in J / (kg•K); C2 is the specific heat capacity of the second tab 300, in J / (kg•K); M1 is the mass of the first tab 200, in kg; M2 is the mass of the second tab 300, in kg; λ1 is the heat transfer coefficient of the first tab 200, in W / (m•K); λ2 is the heat transfer coefficient of the second tab 300, in W / (m•K); A1 is the average heat transfer area from the first tab 200 to the cold plate 10, in mm. 2 A2 represents the average heat transfer area from the second electrode tab 300 to the cold plate, in mm. 2 X1 is the distance from the first tab 200 to the cold plate 10, in mm; X2 is the distance from the second tab 300 to the cold plate, in mm; D1 is the width of the first tab 200, in mm; D2 is the width of the second tab 300, in mm; H is the width of the cell body, in mm.

[0050] In this embodiment, the battery cell body 100 is generally a rectangular parallelepiped-shaped sheet or plate structure. The battery cell body 100 has a length, width, and thickness, and its height is between the length and thickness. The length of the battery cell body 100 is as follows: Figure 1 As shown in the Y direction, the width of the cell body 100 is as follows: Figure 1 As shown in the X-direction, the thickness of the cell body 100 is along... Figure 2 As shown in the Z direction.

[0051] It should be noted that the cell body 100 refers to the internal energy storage unit of the cell, which may include positive and negative electrodes, separators, electrolytes, etc., but does not include external components such as the casing and protection circuits.

[0052] In this embodiment, the first tab 200 and the second tab 300 are connected at intervals along a first direction to the same end of the cell body 100 so that they can be led out through the terminal posts respectively. The first tab 210 and the second tab 300 are located at one end of the length direction of the cell body 100, that is, the first direction is as follows: Figure 1 As shown in the X-axis direction. One of the first tab 200 and the second tab 300 is a positive tab, and the other is a negative tab. Alternatively, both ends of the battery cell body 100 are provided with a first tab 200 and a second tab 300, and the first tab 200 and the second tab 300 on the same current collector are both positive tabs or negative tabs.

[0053] In this embodiment, the cold plate 10 is used for thermal management of the battery cells, and it can be a rectangular, square, or other plate-shaped structure. Multiple battery cells can be arranged side by side along the thickness direction of the battery cell body 100, and one side surface of the battery cell body 100 is used to approach or contact the cold plate 10.

[0054] There are many parameters that affect the temperature of the electrode tab, such as electrode tab current, electrode tab resistivity, electrode tab length, number of electrode tab layers, electrode tab thickness, energizing time, electrode tab specific heat capacity, electrode tab mass, electrode tab heat transfer coefficient, average heat transfer area from electrode tab to cold plate 10, and distance from electrode tab to cold plate 10.

[0055] Specifically, the distance between the first electrode tab 200 and the cold plate 10 is less than the distance between the second electrode tab 300 and the cold plate 10. That is, the first electrode tab 200 is closer to the cold plate 10, and the second electrode tab 300 is further away from the cold plate 10. This distance can be calculated by dividing the sum of the minimum distance from the nearest edge of the electrode tab to the cold plate 10 and the maximum distance from the farthest edge of the electrode tab to the cold plate 10 by 2, and then performing the following calculation:

[0056] I. According to the heat generation formula Q of the electrode 产 =I 2 Rt=I 2 (ρL / s)t=I 2 The heat generated by the two electrodes is obtained from (ρL / nδD)t:

[0057] Q 1产 =I 2 (ρ1L1 / n1δ1D1)t;

[0058] Q 2产 =I 2 (ρ2L2 / n2δ2D2)t.

[0059] In the formula: Q 产1 The heat generated by the first electrode 200 is expressed in J; Q 产2 ρ1 is the heat generated by the second tab 300, in J; I is the current of the first tab 200 and the second tab 300, in A; ρ1 is the resistivity of the first tab 200, in Ω•m; ρ2 is the resistivity of the second tab 300, in Ω•m; L1 is the length of the first tab 200, in mm; L2 is the length of the second tab 300, in mm; n1 is the number of layers of the first tab 200; n2 is the number of layers of the second tab 300; δ1 is the thickness of the first tab 200, in mm; δ2 is the thickness of the second tab 300, in mm; D1 is the width of the first tab 200, in mm; D2 is the width of the second tab 300, in mm; t is the energizing time of the first tab 200 and the second tab 300, in s.

[0060] II. According to the heat dissipation formula Q 散 =λA(△T / X)The heat dissipation of the two electrodes is:

[0061] Q 1散 =λ1A1(△T1 / X1)

[0062] Q 2散 =λ2A2(△T2 / X2)

[0063] In the formula: Q1 is the heat dissipation of the first tab 200, in J; Q2 is the heat dissipation of the second tab 300, in J; λ1 is the heat transfer coefficient of the first tab 200, in W / (m•K); λ2 is the heat transfer coefficient of the second tab 300, in W / (m•K); A1 is the average heat transfer area from the first tab 200 to the cold plate 10, in mm. 2 A2 represents the average heat transfer area from the second electrode tab 300 to the cold plate 10, in mm. 2 ; △T1 is the temperature change of the first electrode 200, in K; △T2 is the temperature change of the second electrode 300, in K; X1 is the distance from the first electrode 200 to the cold plate 10, in mm; X2 is the distance from the second electrode 300 to the cold plate 10, in mm.

[0064] III. According to the temperature change formula Q 产 -Q 散=CM△T, Derivation:

[0065] I 2 (ρL / nδ)t-λA (△T / X)=CM△T;

[0066] That is △T=I 2 (ρL / nδD)t / (CM+λA / X).

[0067] The temperature changes on the two tabs are as follows:

[0068] △T1=I 2 (ρ1L1 / n1δ1D1)t / (C1M1+λ1A1 / X1);

[0069] △T2=I 2 (ρ2L2 / n2δ2D2)t / (C2M2+λ2A2 / X2).

[0070] In the formula: C1 is the specific heat capacity of the first electrode 200, in J / (kg•K); C2 is the specific heat capacity of the second electrode 300, in J / (kg•K); M1 is the mass of the first electrode 200, in kg; M2 is the mass of the second electrode 300, in kg.

[0071] As can be seen from the above formula, after clarifying the design requirements for the distance X between the tab and the cold plate 10, and given that other temperature-affecting parameters are not easily changed, the temperature difference between the two tabs can be easily kept within the ideal range by changing the width D of the two tabs. Since the resistance of the tab is inversely proportional to its cross-section, in tabs of approximately the same thickness, the smaller the width D, the smaller the cross-section, and the greater the resistance. When the same current flows through and the energizing time is equal, more heat is generated. Therefore, the first tab 200 needs to be close to the cold plate 10.

[0072] Continuing the calculation, let the temperature change of the first electrode 200 be denoted as ΔT1, and the temperature change of the second electrode 300 be denoted as ΔT2. The ratio of their temperature changes is denoted as ΔT1 / ΔT2. The ratio of the temperature changes of the two electrodes is T. 预1 ≤△T1 / △T2≤T 预2 We get: Among them, T 预1 The first preset temperature change ratio between the first electrode 200 and the second electrode 300; T 预2 The second preset temperature change ratio is between the first electrode 200 and the second electrode 300.

[0073] T 预1 ≤[I 2 (ρ1L1 / n1δ1D1)t / (C1M1+λ1A1 / X1)] / [I 2 (ρ2L2 / n2δ2D2)t / (C2M2+λ2A2 / X2)]≤T预2 ;

[0074] Where I and t are the same, they can be omitted. Then:

[0075] T 预1 ≤[(ρ1L1 / n1δ1D1) / (C1M1+λ1A1 / X1)] / [(ρ2L2 / n2δ2D2) / (C2M2+λ2A2 / X2)]≤T 预2 ;

[0076] Through transformation, the following relation is obtained:

[0077] T 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)].

[0078] Moreover, 0 <T 预1 <T 预2 X1 < H / 2, X2 - X1 ≥ 30mm. Furthermore, the following relationships are also satisfied: 15mm ≤ X1, X2 < H, 70mm ≤ H ≤ 200mm. 3mm ≤ W. Where: W is the distance between the first tab 200 and the second tab 300 along the first direction, in mm. D1 + W + D2 < H, where H is the width of the cell body 100.

[0079] Example 1

[0080] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2, and H, the values ​​of X1=18mm and X2=50.5mm are first determined. Then, based on the relationship between D1, D2, W, and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D1=20.5mm and D2=34.6mm are obtained, and D2 / D1=1.68 is determined.

[0081] Example 2

[0082] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2, and H, the values ​​of X1=34mm and X2=66.5mm are first determined. Then, based on the relationship between D1, D2, W, and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D1=25.8mm and D2=32mm are obtained, and D2 / D1=1.24 is determined.

[0083] Example 3

[0084] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2 and H, the values ​​of X1=23.5mm and X2=55mm are first determined. Then, based on the relationship between D1, D2, W and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D2 / D1=1.14 is determined.

[0085] Example 4

[0086] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2 and H, the values ​​of X1=23.5mm and X2=55mm are first determined. Then, based on the relationship between D1, D2, W and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D2 / D1=1.92 is determined.

[0087] Comparative Example 1

[0088] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2, and H, the values ​​of X1=34mm and X2=66.5mm are first determined. Then, based on the relationship between D1, D2, W, and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D1=8.7mm and D2=31.8mm are obtained, and D2 / D1=3.6 is determined.

[0089] Comparative Example 2

[0090] In this embodiment, H=90mm and W=8mm are selected. Based on the relationship between X1, X2 and H, the values ​​of X1=18mm and X2=50.5mm are determined first. Then, based on the relationship between D1, D2, W and H, 0.57≤D2 / D1≤2.26 is selected. Combined with the actual design conditions, D2 / D1=0.3 is determined.

[0091] The temperature changes of the first tab 200 and the second tab 300 of the battery cells in the above embodiments and comparative examples were measured under energized conditions, and the temperature change ratio between the two was calculated. The results are shown in Table 1.

[0092] Table 1

[0093]

[0094] According to the cell design requirements, it is necessary to meet T... 预1 ≤△T1 / △T2≤T 预2 Take T 预1 =0.5, T 预2=2. In Examples 1 to 4 and Comparative Examples 1 to 2, the distance X2-X1 between the first tab 200 and the second tab 300 is greater than 30mm. In Examples 1 to 4, the temperature change ratio ΔT1 / ΔT2 between the first tab 200 and the second tab 300 is within the range of [0.5, 2], ensuring the temperature difference between the two tabs meets the design requirements, thus enabling the battery cell to achieve good fast charging capability. However, in Comparative Examples 1 to 2, the temperature change ratio ΔT1 / ΔT2 between the first tab 200 and the second tab 300 is not within the range of [0.5, 2], resulting in a larger temperature difference between the two tabs, failing to meet the design requirements, and thus further limiting the fast charging capability of the battery cell.

[0095] This demonstrates that by determining D1 and D2 based on the design requirements of the temperature change ratio on the two tabs and the above formula, the width of the two tabs can be limited to a reasonable range, which can prevent the tabs from overheating, thus ensuring the fast charging capability of the battery cell and providing a reliable basis for the tab width design.

[0096] Therefore, the battery cell provided in this embodiment includes a battery cell body 100, a first tab 200, and a second tab 300. The first tab 200 and the second tab 300 are spaced apart along a first direction at the same end of the battery cell body 100. The distance between the first tab 200 and the cold plate 10 is set to be smaller than the distance between the second tab 300 and the cold plate 10, and the two tabs satisfy T... 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range, which can reduce the temperature difference between the first tab 200 and the second tab 300 during fast charging, ensuring fast charging capability and improving performance.

[0097] In some embodiments, the battery cell body 100 has a first end 101 and a second end 102, the first end 101 and the second end 102 are arranged along a second direction, the second direction intersecting or perpendicular to the first direction.

[0098] Specifically, such as Figure 3 As shown, the first end 101 and the second end 102 are arranged at intervals along the second direction, such as along... Figure 3 As shown in the Y-axis direction. That is, the first end 101 and the second end 102 are located at the two ends of the cell length direction, respectively.

[0099] Furthermore, in this embodiment, the first end 101 is provided with a first electrode tab 200 and a second electrode tab 300.

[0100] Alternatively, the second end 102 may be provided with a first tab 200 and a second tab 300.

[0101] For example, such as Figure 3 As shown, a first electrode tab 200 and a second electrode tab 300 are provided on the first end 101, while no first electrode tab 200 and second electrode tab 300 are provided on the second end 102. Of course, as... Figure 4 As shown, it is also possible to provide only the first tab 200 and the second tab 300 on the second end 102, while not providing the first tab 200 and the second tab 300 on the first end 101. This can be determined according to actual needs, and no excessive restrictions are imposed in this embodiment.

[0102] Furthermore, in this embodiment, both the first end 101 and the second end 102 are provided with a first electrode tab 200 and a second electrode tab 300.

[0103] That is, such as Figure 5 , Figure 7 As shown, a first tab 200 and a second tab 300 are provided on both the first end 101 and the second end 102. In this way, by providing first tabs 200 and second tabs 300 on both the first end 101 and the second end 102, the current path inside the battery cell is increased, and the direction of some current flow is changed from the original unidirectional flow to bidirectional or multidirectional flow, such as... Figure 5 or Figure 7 As indicated by the arrow, the current path is shorter, thus improving fast charging capability.

[0104] The specific positions of the two tabs on the first end 101 and the second end 102 can be determined according to actual needs, and are not specifically limited in this embodiment.

[0105] In some embodiments, the first tab 200a on the first end 101 is a positive tab, and the first tab 200b on the second end 102 is a negative tab.

[0106] Alternatively, the first electrode tab 200a on the first end 101 is the negative electrode tab, and the first electrode tab 200b on the second end 102 is the positive electrode tab.

[0107] That is, the positive and negative tabs on the first end 101 and the second end 102 are arranged alternately. This arrangement facilitates the flow of current within the cell, shortening its flow path. In one example, such as... Figure 5 As shown, the first tab 200a on the first end 101 is the positive tab, and the first tab 200b on the second end 102 is the negative tab. For example... Figure 6 As shown in (a), the same positive current collector has a first tab 200a and a third tab 300b, and both are positive electrodes. For example... Figure 6 As shown in (b), the same negative current collector has a first tab 200b and a third tab 300a, and both are negative electrodes.

[0108] In another example, such as Figure 7 As shown, the first tab 200a on the first end 101 is the negative tab, and the first tab 200b on the second end 102 is the positive tab. This also facilitates the flow of current within the cell, making its flow path shorter.

[0109] Furthermore, in this embodiment, the first tab 200a on the first end 101 corresponds to the first tab 200b on the second end 102.

[0110] And / or, the second tab 300a on the first end 101 corresponds to the second tab 300b on the second end 102.

[0111] In this way, such as Figure 5 or Figure 7 As shown, the path between the first tab 200a on the first end 101 and the first tab 200b on the second end 102 can be further shortened, as can the straight-line distance between the second tab 300a on the first end 101 and the second tab 300b on the second end 102. The path is shorter, the charge and discharge cycle capability is stronger, and the layout is more reasonable.

[0112] Secondly, embodiments of this application also provide a battery, including a casing and a battery cell provided in any of the above embodiments, wherein the battery cell is disposed within the casing. That is, the battery cell is encapsulated into a single battery cell by the casing.

[0113] The structure of the battery cell has been described in detail in the above embodiments, and will not be repeated here.

[0114] The battery provided in this application embodiment, by configuring the battery cell, includes a battery cell body 100, a first electrode 200, and a second electrode 300. The first electrode 200 and the second electrode 300 are spaced apart along a first direction at the same end of the battery cell body 100. The distance between the first electrode 200 and the cold plate 10 is set to be smaller than the distance between the second electrode 300 and the cold plate 10, and the two electrodes satisfy T... 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range, which can reduce the temperature difference between the first tab 200 and the second tab 300 during fast charging, ensuring fast charging capability and improving performance.

[0115] Thirdly, embodiments of this application also provide a battery pack, including at least one battery provided in any of the above embodiments, the battery being in contact with the cold plate 10.

[0116] Specifically, multiple batteries can be combined into a battery module, with the cold plate 10 integrated on a tray. The multiple battery modules contact the cold plate 10 and can be packaged into a battery pack using the tray and cover. Of course, components such as a power distribution box and cooling pipes can also be installed inside the battery pack.

[0117] The battery pack provided in this application embodiment, by configuring the battery, includes a cell, the cell including a cell body 100, a first tab 200 and a second tab 300, by arranging the first tab 200 and the second tab 300 at intervals along a first direction on the same side of the cell body 100, setting the distance between the first tab 200 and the cold plate 10 to be smaller than the distance between the second tab 300 and the cold plate 10, and making the two tabs satisfy T 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range, which can reduce the temperature difference between the first tab 200 and the second tab 300 during fast charging, ensuring fast charging capability and improving performance.

[0118] Fourthly, embodiments of this application also provide an electrical device, including the battery provided in any of the above embodiments or the battery pack provided in any of the above embodiments.

[0119] The electrical device provided in this application embodiment, by configuring the aforementioned battery pack or battery, wherein the battery pack includes a battery, the battery includes a cell, the cell includes a cell body 100, a first tab 200 and a second tab 300, by arranging the first tab 200 and the second tab 300 at intervals along a first direction on the same side of the cell body 100, setting the distance between the first tab 200 and the cold plate 10 to be smaller than the distance between the second tab 300 and the cold plate 10, and ensuring that the two tabs satisfy T 预1[ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)], 0 <T 预1 <T 预2 X2-X1≥30mm ensures that the width of the two tabs is within a reasonable range, which can reduce the temperature difference between the first tab 200 and the second tab 300 during fast charging, ensuring fast charging capability and improving performance.

[0120] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0121] It should be understood that this application is not limited to the precise structures described above and shown in the appendix, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A battery cell, characterized in that, It includes a battery cell body (100), a first electrode (200) and a second electrode (300), wherein the first electrode (200) and the second electrode (300) are disposed at the same end of the battery cell body (100) at a distance along a first direction; The distance between the first electrode tab (200) and the cold plate (10) is less than the distance between the second electrode tab (300) and the cold plate (10), and satisfies the following relationship: T 预1 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)]≤D2 / D1≤T 预2 [ρ2L2n1δ1(C1M1+λ1A1 / X1)] / [ρ1L1n2δ2(C2M2+λ2A2 / X2)],0<T 预1 <T 预2 , X2-X1≥30mm; In the formula: T 预1 The first preset temperature change ratio between the first electrode (200) and the second electrode (300); T 预2 ρ1 is the resistivity of the first electrode (200) and the second electrode (300) in Ω·m; ρ2 is the resistivity of the second electrode (300) in Ω·m; L1 is the length of the first electrode (200) in mm; L2 is the length of the second electrode (300) in mm; n1 is the number of layers of the first electrode (200); n2 is the number of layers of the second electrode (300); δ1 is the thickness of the first electrode (200) in mm; δ2 is the thickness of the second electrode (300). The units are mm; C1 is the specific heat capacity of the first tab (200), in J / (kg•K); C2 is the specific heat capacity of the second tab (300), in J / (kg•K); M1 is the mass of the first tab (200), in kg; M2 is the mass of the second tab (300), in kg; λ1 is the heat transfer coefficient of the first tab (200), in W / (m•K); λ2 is the heat transfer coefficient of the second tab (300), in W / (m•K); A1 is the average heat transfer area from the first tab (200) to the cold plate (10), in mm. 2 A2 represents the average heat transfer area from the second electrode tab (300) to the cold plate (10), in mm. 2 X1 is the distance from the first tab (200) to the cold plate (10), in mm; X2 is the distance from the second tab (300) to the cold plate (10), in mm; D1 is the width of the first tab (200), in mm; D2 is the width of the second tab (300), in mm; H is the width of the battery cell body (100), in mm.

2. The battery cell according to claim 1, characterized in that, It also satisfies the following relationship: 3mm≤W; In the formula: W is the distance between the first electrode tab (200) and the second electrode tab (300) along the first direction, in mm.

3. The battery cell according to claim 1 or 2, characterized in that, The battery cell body (100) has a first end (101) and a second end (102), the first end (101) and the second end (102) are arranged along a second direction, which intersects with the first direction.

4. The battery cell according to claim 3, characterized in that, The first end (101) is provided with a first electrode tab (200) and a second electrode tab (300); Alternatively, the second end (102) may be provided with the first tab (200) and the second tab (300).

5. The battery cell according to claim 3, characterized in that, Both the first end (101) and the second end (102) are provided with the first electrode tab (200) and the second electrode tab (300).

6. The battery cell according to claim 5, characterized in that, The first electrode tab (200) on the first end (101) is a positive electrode tab, and the first electrode tab (200) on the second end (102) is a negative electrode tab; Alternatively, the first tab (200) on the first end (101) is a negative tab, and the first tab (200) on the second end (102) is a positive tab.

7. The electric cell of claim 6, wherein, The first tab (200) on the first end (101) corresponds to the first tab (200) on the second end (102); And / or, the second tab (300) on the first end (101) corresponds to the second tab (300) on the second end (102).

8. A battery, characterized in that, It includes a housing and a battery cell as described in any one of claims 1 to 7, wherein the battery cell is disposed within the housing.

9. A battery pack, characterized in that, It includes a cold plate (10) and at least one battery as claimed in claim 8, the battery being in contact with the cold plate (10).

10. An electrical appliance, characterized in that, It includes the battery as described in claim 8 or the battery pack as described in claim 9.

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