Battery cell

Abstract

The invention discloses a battery cell. The battery cell comprises an electrode assembly; the shell defines a containing space, the electrode assembly is arranged in the containing space, the shell comprises a first wall arranged on one side of the containing space, the first wall is provided with a pressure relief structure, and the pressure relief structure is used for releasing the pressure in the battery monomer when the internal pressure or temperature of the battery monomer reaches a threshold value; the supporting structure is arranged between the electrode assembly and the first wall, the supporting structure is used for forming a gap communicated with the pressure relief structure between the first wall and the electrode assembly, the supporting structure comprises first supporting parts, the first supporting parts are located at the two ends of the first wall in the length direction of the first wall, and the maximum size of the first supporting parts in the width direction of the first wall is W1, the maximum size of the pressure relief structure is W2, and the maximum size of the electrode assembly is W3. According to the technical scheme, at least the exhaust effect can be improved, the electrode assembly is prevented from blocking the pressure relief structure, and directional pressure relief is effectively achieved.

Description

Technical Field

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

[0002] In recent years, battery cells have continued to develop towards larger capacities. In the development of battery technology, besides improving the performance of individual cells, safety is also a crucial issue. If the safety of a battery cell cannot be guaranteed, then that cell cannot be used. Therefore, how to enhance the safety of battery cells is a pressing technical problem that needs to be solved in battery technology. Summary of the Invention

[0003] To address the above issues, this application proposes a battery cell that can at least improve the venting effect, prevent the electrode assembly from clogging the pressure relief structure, and effectively achieve directional pressure relief.

[0004] According to one aspect of this application, a battery cell is provided, comprising: an electrode assembly; a housing defining an accommodating space, the electrode assembly being disposed within the accommodating space, the housing including a first wall disposed on one side of the accommodating space, the first wall having a pressure relief structure for releasing internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold; and a support structure disposed between the electrode assembly and the first wall, the support structure forming a gap between the first wall and the electrode assembly communicating with the pressure relief structure, the support structure including first support portions located at both ends of the first wall along its length direction, and along the width direction of the first wall, the maximum dimension of the first support portion is W1, the maximum dimension of the pressure relief structure is W2, and the maximum dimension of the electrode assembly is W3, wherein...

[0005] In some embodiments, the support structure further includes a second support portion disposed around the pressure relief structure.

[0006] In some embodiments, the maximum dimension of the second support portion along the width direction is W4, wherein W1 < W4.

[0007] In some embodiments, the support structure includes a pressure relief channel; the pressure relief channel extends through the first support portion along its length. In some embodiments, the pressure relief channel extends through the second support portion along its length.

[0008] In some embodiments, the support structure is integrally formed with the first wall. In some embodiments, the support structure is welded to the first wall. In some embodiments, an insulating member is provided between the first wall and the electrode assembly along the thickness direction of the first wall. The insulating member includes a protrusion protruding toward the electrode assembly, and a groove is formed on the side of the insulating member facing the first wall corresponding to the protrusion, in which the support structure is accommodated.

[0009] In some embodiments, along the thickness direction of the first wall, the maximum dimension of the first support portion is H1, and the maximum dimension of the second support portion is H2, wherein H1 < H2.

[0010] In some embodiments, along the length direction, the maximum dimension of the first support portion is L1, and the maximum dimension of the second support portion is L2, wherein L1 > L2.

[0011] In some embodiments, the housing further includes an outer shell having an opening, and a first wall for covering the opening; the electrode assembly includes tabs extending toward the first wall; the minimum distance between the support structure and the tabs along the length direction is D1, wherein D1 ≥ 20 mm; or the minimum dimension of the tabs along the length direction is L3, wherein D1 / L3 ≥ 1 / 4.

[0012] In some embodiments, along the length direction, the minimum distance between the first support and the electrode tab is D2, and the minimum distance between the second support and the electrode tab is D3, wherein D2 < D3.

[0013] In some embodiments, along the length direction, the minimum distance between the first support and the second support is D4, and the maximum dimension of the first wall is L5, wherein...

[0014] In some embodiments, the pressure relief structure is an explosion-proof valve, which includes an explosion-proof hole extending along the thickness direction of the first wall and an explosion-proof disc installed in the explosion-proof hole. The explosion-proof disc opens to release the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold.

[0015] The above-mentioned technical solution of this application provides a support structure at the end of the first wall along the length direction and restricts the size of the support structure along the width direction. The support structure can provide partial support for the electrode assembly, so that part or all of the electrode assembly can be misaligned, tilted or twisted in the casing when the battery cell thermally runs away. This increases the space of the electrode assembly facing the pressure relief structure and improves the venting effect. At the same time, due to the size restriction of the support structure along the width direction X, the space for deformation of the electrode assembly is limited. Therefore, it can prevent the electrode assembly from blocking the pressure relief structure, effectively achieve directional pressure relief and improve the safety of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1A A three-dimensional schematic diagram of a battery cell according to an embodiment of this application is shown.

[0018] Figure 1B and Figure 1C The diagram shows a side view of the electrode assembly and the first wall of a battery cell according to an embodiment of this application on different sides.

[0019] Figure 2A and Figure 2B A schematic diagram of the first wall on different sides according to an embodiment of this application is shown.

[0020] Figure 2C A front view of the first wall according to an embodiment of this application is shown.

[0021] Figure 2D It shows along Figure 2C The first wall section view is taken by line AA.

[0022] Figure 3A An exploded view of the first wall and insulation of a battery cell according to an embodiment of this application is shown.

[0023] Figure 3B It shows Figure 3A A schematic diagram of the first wall, insulating components, and poles after assembly.

[0024] Figure 4 An exploded view of the first wall and insulation of a battery cell according to another embodiment of this application is shown.

[0025] Figure 5 The diagram shows a structural schematic of an electronic device provided in some embodiments of this application when it is a vehicle. Detailed Implementation

[0026] 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. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] The following disclosure provides numerous different embodiments or instances for implementing various features of the provided subject matter. Specific examples of elements and arrangements will be described below to simplify this application. These are merely examples and are not intended to limit the application. For example, in the following description, forming a first component above or on a second component may include embodiments where the first and second components are in direct contact, or embodiments where an additional component is formed between the first and second components such that the first and second components are not in direct contact. Furthermore, references to numbers and / or letters may be repeated in various instances throughout this application. Such repetition is for brevity and clarity only and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0028] Furthermore, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] When a battery cell experiences thermal runaway, a large amount of gas is generated internally. This gas can cause the electrode assembly to be lifted and move within the cell. If the electrode assembly moves towards the pressure relief structure and blocks it, the waste gas cannot be discharged smoothly, preventing directional pressure relief. Ultimately, this leads to the casing breaking and cracking under the high temperature and pressure conditions inside, resulting in non-directional pressure relief and posing a significant safety hazard. Therefore, existing battery cells suffer from the problem of electrode assemblies easily clogging the explosion-proof valve during thermal runaway, hindering directional pressure relief, and the pressure relief efficiency needs improvement. Especially for large-capacity battery cells, the temperature rise rate, gas production scale, and gas production rate are all at a high level during thermal runaway. Therefore, how to effectively achieve directional pressure relief for thermal runaway in large-capacity battery cells is one of the most pressing problems to be solved in the industry.

[0030] An embodiment of this application provides a battery cell. Figure 1A A perspective view of a battery cell according to an embodiment of this application is shown. The battery cell 100 may include a housing 200 for accommodating electrode assemblies, the housing 200 including a first wall 300. Figure 1B and Figure 1C The diagram shows a side view of the electrode assembly and the first wall of a battery cell according to an embodiment of this application on different sides.

[0031] See Figures 1A to 1C As shown, the battery cell 100 may include a housing 200 defining a receiving space, within which an electrode assembly 120 is disposed. In some embodiments, a plurality of electrode assemblies 120 are stacked in the housing 200 along direction X. Direction X may be the width direction of the battery cell 100.

[0032] The housing 200 may include a first wall 300 disposed on one side of the receiving space of the housing 200. Direction X may also be the width direction of the first wall 300, hereinafter referred to as the width direction X. Specifically, in this embodiment, the housing 200 includes a shell 202 with an opening. The first wall 300 is used to cover the opening to define, together with the shell 202, a receiving space for the electrode assembly 120. The first wall 300 is disposed at one end of the shell 202 along direction Z. Direction Z may be the height direction of the battery cell 100 and also the thickness direction of the first wall 300, hereinafter referred to as the thickness direction Z.

[0033] Electrode assembly 120 can be a wound body formed by winding a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. In other embodiments, electrode assembly 120 can also be a stacked body formed by sequentially stacking a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. The positive electrode sheet may include a positive current collector and a positive active material layer, the positive active material layer being coated on a portion of the surface of the positive current collector. Uncoated areas of the positive current collector not covered by the positive active material layer can be used to form positive electrode tabs. The negative electrode sheet may include a negative current collector and a negative active material layer, the negative active material layer being coated on a portion of the surface of the negative current collector. Uncoated areas of the negative current collector not covered by the negative active material layer can be used to form negative electrode tabs. In some embodiments, such as in a lithium-ion battery, the material of the positive current collector can be aluminum. The positive active material of the positive active material layer can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. For high-nickel ternary lithium batteries, the positive electrode active material can be a ternary material composed of nickel, cobalt, and manganese (or aluminum). The negative electrode current collector material can be copper. The negative electrode active material layer can be carbon or silicon, etc.

[0034] A positive electrode, a negative electrode, and a separator can be wound or stacked to form an electrode assembly 120, which is then sealed within a housing 200 to form a battery cell 100. The electrode assembly 120 includes tabs 125 extending toward the first wall 300. Tabs 125 can include positive and negative tabs of opposite polarity. The positive tab is formed by stacking multiple layers of positive electrode tabs, and the negative tab is formed by stacking multiple layers of negative electrode tabs. The positive and negative tabs are spaced apart along direction Y. Direction Y can be the length direction of the battery cell 100 and the first wall 300, and is hereinafter referred to as the length direction Y.

[0035] Two pole posts 260 are disposed on the first wall 300. The two pole posts 260 are spaced apart along the length direction Y. The two pole posts 260 can be negative pole posts and positive pole posts with opposite polarities. The pole posts 260 can pass through the first wall 300 and can be insulated from the first wall 300. The pole posts 260 pass through the first wall 300 to be electrically connected to the corresponding tabs 125 respectively.

[0036] Figure 2A and Figure 2B These are isometric views of the first wall 300 on different sides according to embodiments of this application; Figure 2C This is a front view of the first wall 300 according to an embodiment of this application; Figure 2D It is along Figure 2C The first wall 300 is a cross-sectional view taken by line AA. The outer surface 3001 of the first wall 300 is the surface of the first wall 300 facing away from the electrode assembly 120, and the inner surface 3002 of the first wall 300 is the surface of the first wall 300 facing the electrode assembly 120.

[0037] Combination Figures 1A to 2D As shown, the first wall 300 is provided with a pressure relief structure 320. The pressure relief structure 320 is used to release the internal pressure of the battery cell 100 when the internal pressure or temperature reaches a threshold. The pressure relief structure 320 may be located between the two terminals 260. The pressure relief structure 320 is located above the gap between the two tabs 125. In the length direction Y, each tab 125 is located on one side of the pressure relief structure 320.

[0038] A support structure 400 is disposed between the electrode assembly 120 and the first wall 300. The support structure 400 can be fixedly connected to the inner surface 3002 of the first wall 300. The support structure 400 forms a gap between the first wall 300 and the electrode assembly 120 that communicates with the pressure relief structure 320. This gap can be part of the exhaust channel of the battery cell 100. Specifically, the exhaust channel includes a space inside the battery cell 100 that communicates with the pressure relief structure 320 and allows for the flow of effluent. When the battery cell experiences thermal runaway, gas can pass through the exhaust channel to the pressure relief structure 320 and activate the pressure relief structure 320 to reduce the internal pressure of the battery cell and prevent it from exploding. When the battery cell experiences thermal runaway, the support structure 400 can support the electrode assembly and the first wall 300, ensuring unobstructed exhaust channels and smooth pressure relief. The support structure 400 can be made of a material with a high melting point or that is not easily softened by heat at high temperatures. For example, in some embodiments, the material of the support structure 400 can be ceramic, phenolic resin, aluminum, or steel. In other embodiments, the melting point or softening temperature of the support structure 400 is not lower than 200°C, and can also be not lower than 250°C or 300°C. In still other embodiments, the melting point of the support structure 400 can be not lower than the melting point of the first wall 300, further ensuring the reliability of the support structure 400 when the battery cell experiences thermal runaway.

[0039] The support structure 400 includes a first support portion 410 located at the end of the first wall 300 along the length direction Y. The end refers to the region near both ends of the first wall 300 along the length direction Y. For example, along the length direction Y, the edge of the first support portion 410 may be flush with the edge of the first wall 300; or, along the length direction Y, the edge of the first support portion 410 may have a small distance relative to the edge of the first wall 300, which may not exceed 1 / 4, for example, 1 / 10, 1 / 5, etc., of the maximum dimension of the first wall 300 along the length direction Y. In other embodiments, along the length direction Y, the pole post 260 is closer to the pressure relief structure 320 than the first support portion 410; for example, the pole post 260 is located between the first support portion 410 and the pressure relief structure 320. Along the width direction X, the maximum dimension of the first support portion 410 is W1 (see...). Figure 1B and Figure 2C The maximum dimension of the pressure relief structure 320 is W2 (see...). Figure 2C The maximum size of electrode assembly 120 is W3 (see...). Figure 1B In some embodiments, W1, W2, and W3 satisfy: Where W1, W2, and W3 are in the same unit, for example, millimeters (mm). That is, along the width direction X, the maximum dimension W1 of the first support portion 410 is limited to being greater than or equal to half of the maximum dimension W2 of the pressure relief structure 320, and less than the maximum dimension W3 of the electrode assembly 120. It should be noted that in other embodiments, when measuring and comparing height, width, length, thickness, or distance, the same unit is used uniformly, for example, mm is used as the unit of measurement.

[0040] The above technical solution provides a support structure 400 at the opposite ends of the first wall 300 along the length direction Y, and restricts the size of the support structure 400 along the width direction X. The support structure 400 can provide partial support for the electrode assembly 120. By setting W1 < W3, the support structure 400 provides incomplete support for the electrode assembly 120 in the width direction X. This allows part or all of the electrode assembly 120 to be misaligned, tilted, or twisted within the housing during thermal runaway. For example, the electrode assembly 120 can be misaligned, tilted, or twisted relative to the plane perpendicular to the width direction X, thereby increasing the space of the electrode assembly 120 toward the pressure relief structure 320 and improving the exhaust effect. For example, the electrode assembly 120 may include multiple wound bodies or stacked bodies. For instance, the electrode assembly 120 may include four wound bodies arranged along the width direction X. The two wound bodies located at the two ends of the width direction X are not fully supported by the support structure 400. Therefore, the entirety or part of these two wound bodies can be misaligned with the other two wound bodies in the thickness direction Z with the other two wound bodies in the middle. This increases the space in the misaligned portion, facilitating the passage of discharged materials and improving the pressure relief effect. Simultaneously, due to the dimensional limitations of the support structure 400 along the width direction X, it satisfies… The space for the electrode assembly 120 to undergo the aforementioned deformation is limited, and the size of the support structure 400 is not too small. Therefore, the electrode assembly 120 can be prevented from blocking the pressure relief structure 320, which can effectively achieve directional pressure relief and improve the safety of the battery cell.

[0041] In addition, in some embodiments, the support structure 400 may also include a second support portion 420, which is disposed around the pressure relief structure 320. The periphery refers to the area on the first wall 300 surrounding the pressure relief structure 320. For example, it may extend outward from the outer contour of the pressure relief structure 320 on the first wall 300 to within 1 / 5 of the maximum dimension of the first wall 300 along the length direction Y. For example, it may extend to 1 / 8 or 1 / 10 of the maximum dimension. In some embodiments, the extension distance may be selected within the above range and shall not exceed 30 mm. When the second support portion 420 is separately disposed from the first wall 300, the projection of the second support portion 420 along the thickness direction Z on the first wall 300 may be located around the pressure relief structure 320. In other embodiments, the second support portion 420 is disposed on one or both sides of the periphery of the pressure relief structure 320 along the length direction of the first wall 300. Multiple second support portions 420 can be spaced apart or continuously arranged around the pressure relief structure 320. That is, the second support portions 420 can be rectangular or annular structures surrounding the pressure relief structure 320, enclosing it within their inner sides; alternatively, multiple second support portions 420 can not completely surround the pressure relief structure 320, with adjacent second support portions 420 spaced apart. By providing the second support portions 420, when a battery cell experiences thermal runaway, support can be provided for the portion of the electrode assembly 120 near the pressure relief structure 320, preventing the electrode assembly 120 near the pressure relief structure 320 from tilting or twisting excessively in a free state and blocking the exhaust channels near the pressure relief structure 320. Furthermore, by providing the second support portions 420, the spacing between adjacent support structures 400 in the length direction Y can be smaller, providing more support points when the electrode assembly 120 moves towards the first wall 300, and the spacing between these support points is also smaller. When the second support 420 is positioned on one or both sides of the first wall 300 along the length Y direction around the pressure relief structure 320, the pressure relief structure 320 and the second support 420 can be arranged along the length Y direction of the first wall 300. Because the space on the first wall 300 is limited, the dimension of the first wall 300 along the length direction Y is larger than the dimension along the width direction X. Therefore, compared with arranging them along the width direction X of the first wall 300, arranging them along the length direction Y is more conducive to forming a larger pressure relief structure 320 and the second support portion 420 on the first wall 300. This is beneficial for providing better support and a larger pressure relief area, thereby improving the safety of the battery cell. Furthermore, in these embodiments, the distance between the second support portion 420 and the first support portion 410 is smaller than when the second support portion 420 and the pressure relief structure 320 are arranged along the width direction X. This allows each part of the electrode assembly 120 to obtain a better support effect in the length direction Y, reducing the probability that the electrode assembly 120 near the pressure relief structure 320 will arch or even tear and block the pressure relief structure 320, further improving the safety of the battery cell.

[0042] The support structure 400 can be disposed between the electrode assembly 120 and the first wall 300 in any suitable manner. In some embodiments, the support structure 400 is fixedly connected to the first wall 300. The support structure 400 protrudes from the first wall 300 toward the electrode assembly 120. Figures 1B to 2D In the illustrated embodiment, the support structure 400 and the first wall 300 are integrally formed. The support structure 400 can be integrally formed by stamping the first wall 300, and a groove can be formed on the side of the support structure 400 facing away from the electrode assembly 120. The reliability of the support structure 400 is related to the stability of the emission path during thermal runaway of the battery cell. If the fixing method of the support structure 400 itself is unreliable, it is very likely that after being subjected to movement / impact or compression by the electrode assembly 120, the support structure 400 will be displaced and cannot be maintained in the preset position, thus failing to provide a sufficiently reliable support effect. By integrally forming the support structure 400 with the first wall 300, the support structure 400 can be made part of the first wall 300. Since the first wall 300 is usually fixedly connected to other parts of the housing 200 (such as the outer shell 202), the position of the first wall 300 in the battery cell is fixed. As the support structure 400 is part of the first wall 300, the position of the support structure 400 is also fixed, thus the support structure 400 can provide reliable support and ensure the stability of the emission path.

[0043] In other embodiments, the support structure 400 can be welded to the first wall 300, meaning the support structure 400 and the first wall 300 can be manufactured separately, reducing processing difficulty. Compared to snap-fit, adhesive, or non-fixed connections, welding the support structure 400 to the first wall 300 provides a more reliable connection with higher structural strength and provides reliable support, ensuring the stability of the emission path.

[0044] Along the width direction X, the maximum dimension of the second support 420 is W4 (see... Figure 2C The second support portion 420 refers to an integral support structure located on one side of the pressure relief structure 320 along the length direction Y. In some embodiments, the second support portion 420 includes a pressure relief channel 425 extending along the length direction Y. The dimension of the pressure relief channel 425 along the height direction Z is approximately the same as that of the second support portion along the height direction Z. That is, the pressure relief channel 425 divides the second support portion 420 into several parts, and W4 should be the maximum dimension of these several parts along the width direction X. For example, refer to... Figure 2B and Figure 2C The second support portion 420 along the length direction Y includes a pressure relief channel 425 extending along the length direction Y. The pressure relief channel 425 divides the second support portion 420 into two parts along the width direction X. At this time, W4 is Figure 2CWithin the dashed box, the maximum dimension of the second support portion 420 as a whole in the width direction X.

[0045] In some embodiments, the maximum dimension W1 of the first support portion 410 is smaller than the maximum dimension W4 of the second support portion 420, i.e., W1 < W4. When a battery cell experiences thermal runaway, some of the emissions need to flow from the positions near both ends of the first wall 300 along the length direction Y inside the housing 200 to the pressure relief structure 320. In other words, a large amount of emissions inside the housing 200 will move from the side of the electrode assembly 120 away from the first wall 300 along the thickness direction Z towards the first wall 300. There is a gap between the two ends of the first wall 300 along the length direction Y of the electrode assembly 120 and the inner surface of the housing 200. Therefore, the emissions can converge to the two ends of the first wall 300 along the length direction Y through this gap. Thus, a large amount of emissions will flow through the position of the first support portion 410 and continue to converge towards the pressure relief structure 320. By setting W1 < W4, the electrode assembly 120 can undergo greater misalignment, tilting, or torsion near the first support portion 410. Since the first support portion 410 is close to both ends of the first wall 300 along its length, this greater deformation (misalignment, tilting, or torsion) helps ensure that some of the emissions from both ends of the first wall 300 along its length can pass through this area more efficiently and continue flowing to the pressure relief structure 320, thus improving pressure relief efficiency. Simultaneously, by setting W1 < W4, the support of the second support portion 420 can be more sufficient, thereby better constraining the electrode assembly 120 near the pressure relief structure 320. This prevents the electrode assembly 120 from partially or completely blocking the emission path near the pressure relief structure 320 during deformation, improving the safety of the battery cell.

[0046] In some embodiments, the second support portion 420 may be provided with a pressure relief channel 425 extending through the second support portion 420 along the length direction Y (see Figure 2B and Figure 2C Through the pressure relief channel 425, the venting channel within the battery cell 100 can penetrate the second support portion 420, allowing some emissions to pass through the location of the second support portion 420 without bypassing it. Compared to bypassing the second support portion 420, passing through the support structure 400 via the pressure relief channel 425 results in a shorter flow path for the emissions, which helps maintain unobstructed emission passages and improves pressure relief efficiency.

[0047] Along the thickness direction Z of the first wall 300, the maximum dimension of the first support portion 410 is H1, and the maximum dimension of the second support portion 420 is H2 (see...). Figure 2DH1 and H2 can both be measured relative to the inner surface 3002 of the first wall 300, that is, the maximum height of the first support portion 410 and the second support portion 420 protruding relative to the inner surface 3002. When the first support portion 410 or the second support portion 420 is not fixedly connected to the first wall 300, H1 and H2 can be their maximum dimensions in the thickness direction Z. In some embodiments, H1 < H2. When the battery cell 100 experiences thermal runaway, the internal pressure increases, and the first wall 300 deforms and bulges towards the side away from the receiving space. Since the edge portion of the first wall 300 (the edge along the length direction Y or the width direction X) is connected to the rest of the housing 200, it is partially constrained during deformation, resulting in a smaller degree of deformation. The portion of the first wall 300 away from the edge is less constrained, and the degree of deformation during thermal runaway is greater. Since the pressure relief structure 320 is located in the central region of the first wall 300 away from the edge, the degree of deformation here is greater than that at both ends of the first wall 300 along the length Y direction. By setting H1 < H2, it can be ensured that the second support part 420 with a larger maximum size H2 can still provide reliable support when thermal runaway occurs and the first wall 300 is deformed. In other words, when different degrees of deformation occur at various locations of the first wall 300, H1 < H2 can still provide a uniform and sufficient support effect on the surface of the electrode assembly 120 facing the first wall 300, keeping the discharge path unobstructed and improving the safety of the battery cell.

[0048] Along the length direction Y, the maximum dimension of the first support portion 410 is L1, and the maximum dimension of the second support portion 420 is L2 (see...). Figure 2D In some embodiments, L1 > L2; in other embodiments, L1 > L2 and L2 / L1 > 1 / 2. During thermal runaway, emissions from the battery cells need to converge near the pressure relief structure 320 and be discharged in a directed manner. Therefore, ensuring sufficient space for the discharge pathway near the pressure relief structure 320 is of higher priority. By setting L1 > L2, it means that when the support dimensions of the support structure 400 along the length Y direction to the electrode assembly 120 are relatively fixed, the support dimensions of different parts of the support structure 400 can be controlled by adjusting the relationship between L1 and L2. The first support portion 410, with larger dimensions L1 at both ends, can provide reliable support for the electrode assembly 120 with its larger support dimensions, while the second support portion 420 near the pressure relief structure 320, while maintaining a certain support effect, maximizes the space around the pressure relief structure 320, further ensuring unobstructed discharge pathways.

[0049] Along the length direction Y, the minimum distance between the support structure 400 and the tab 125 is D1 (see... Figure 1CD1 is the smaller of D2 and D3. Wherein, D2 is the minimum distance between the first support 410 and the tab 125, and D3 is the minimum distance between the second support 420 and the tab 125. It should be understood that in... Figure 1C In this embodiment, the minimum distance D1 is D2, but in other embodiments, the minimum distance D1 can be D3. It should be noted that the tabs 125 in the battery cell include positive and negative tabs of different polarities. Therefore, in some embodiments, the tabs 125 extending from the electrode assembly 120 to the first wall 300 can be tabs of the same polarity, for example, all positive or negative tabs; or they can include tabs of different polarities. When the tabs 125 extending from the electrode assembly 120 to the first wall 300 include both positive and negative tabs, D1 is the minimum distance among multiple spacings between the support structure 400 and the positive or negative tab along the length direction Y.

[0050] In some embodiments, D1 satisfies: D1≥20mm, to ensure a certain size gap is reserved between the support structure 400 and the tab 125. For example, D1 can be 21mm, 25mm, or 30mm. Alternatively, in other embodiments, D1 satisfies: D1 / L3≥1 / 4. For example, the value of D1 / L3 can be 1 / 3, 1 / 2, or 2 / 3, etc., where L3 represents the minimum size of the tab 125 along the length direction Y. This also ensures a certain size gap is reserved between the support structure 400 and the tab 125. The tab 125 can include positive and negative tabs with different polarities. In this case, L3 is the minimum size along the length direction Y among these tabs with different polarities. The tab 125 can also include tabs of the same polarity but different sizes. In this case, L3 is the minimum size along the length direction Y among these tabs. By setting the minimum distance D1 between the support structure 400 and the tab 125, a certain gap can be maintained between them. This prevents the distance between the support structure 400 and the tab 125 from being too close, which could lead to blockage of the emission passages or impede the flow of emissions near the support structure 400 and the tab 125, thus improving the safety of the battery cell. Furthermore, setting the minimum distance D1 also prevents interference between the tab 125 and the support structure 400 during the manufacturing and assembly of the battery cell. This prevents the tab 125 from being squeezed due to interference, causing wrinkles or cracks, and reduces the risk of tab insertion.

[0051] Furthermore, in some embodiments, D2 < D3. This increases the distance between the tab 125 and the second support 420, thereby increasing the space near the pressure relief structure 320. When a battery cell experiences thermal runaway, a large amount of emissions are generated on the side of the electrode assembly 120 facing the first wall 300. Setting D2 < D3 can shorten the flow distance of most of these emissions, improving pressure relief efficiency. Increasing the space near the pressure relief structure 320 also reduces the probability of blockage near the pressure relief structure 320, further improving the safety of the battery cell.

[0052] Along the length direction Y, the minimum distance between the first support portion 410 and the second support portion 420 is D4 (see... Figure 2D The first wall 300 has a dimension of L5 (see...). Figure 2D In some embodiments, D4 and L5 satisfy: The size range of D4 is defined. By defining this size range of D4, the distance between the first support portion 410 and the second support portion 420 in the length direction Y will not be too small and cause them to cluster together. This avoids the local support structure 400 being too densely distributed, which would cause obstruction of the flow of emissions. It also avoids uneven distribution, which would cause the support structure 400 to fail to provide sufficient and reliable support in the entire length direction Y. At the same time, when the battery cell experiences thermal runaway, the electrode assembly 120 will not lack support and deform upwards due to the large distance between the first support portion 410 and the second support portion 420, thus ensuring that the emission path is unobstructed.

[0053] In some embodiments, an insulating element 500 may be provided between the support structure 400 and the electrode assembly 120 along the thickness direction Z. Figure 3A An exploded view of the first wall 300 and the insulating component 500 of the battery cell is shown. Figure 3B This is an isometric view of the assembled first wall 300, insulating component 500, and pole post 260. See also... Figure 3A and Figure 3B and combined Figure 1B and Figure 1C The insulating member 500 is located on one side of the inner surface of the first wall 300. The insulating member 500 can extend longitudinally in the length direction Y to insulate and isolate the electrode assembly 120 from the first wall 300.

[0054] The insulating member 500 may include a protrusion 501 protruding toward the electrode assembly 120. A groove 502 is formed on the side of the insulating member 500 facing the first wall 300 corresponding to the protrusion 501. The shape of the groove 502 can be adapted to the support structure 400, and the support structure 400 is accommodated in the corresponding groove 502. Providing the insulating member 500 between the first wall 300 and the electrode assembly 120 improves the insulation performance of the battery cell. The protrusion 501 on the insulating member 500 allows space between the other parts of the insulating member 500 and the protrusion 501, which can be used to accommodate the tab 125 and connecting pieces for connecting the terminal post 260 to the tab 125. Simultaneously, the protrusion 501 also provides support for the electrode assembly 120, making the position of the electrode assembly 120 within the battery cell more stable and helping to resist vibration or impact. The support structure 400 is accommodated in the groove 502 defined by the protrusion 501, which can restrict the support structure 400 in the groove 502, which helps to keep the position of the support structure 400 stable. At the same time, it eliminates the need to fix the support structure 400 to the first wall 300, which helps to reduce the processing difficulty and cost and improve the production efficiency of the battery cell.

[0055] In some embodiments, an insulating structure may be provided between the support structure 400 and the electrode assembly 120 along the thickness direction Z. For example, an insulating patch, polyimide sheet, etc. may be fixedly provided on the surface of the support structure 400 facing the electrode assembly 120. The insulating structure may be bonded or thermally fused to the support structure 400. Alternatively, an insulating coating may be formed on at least the surface of the support structure 400 facing the electrode assembly 120. The insulating coating may be further configured as an insulating coating with high temperature resistance.

[0056] In some embodiments, the pressure relief structure 320 is an explosion-proof valve, which includes an explosion-proof hole 322 extending along the thickness direction Z of the first wall 300, and an explosion-proof plate 324 installed in the explosion-proof hole 322. When the internal pressure or temperature of the battery cell reaches a threshold, the explosion-proof plate 324 can open to release the internal pressure of the battery cell. In other embodiments, the pressure relief structure 320 may also employ other structures capable of directional pressure relief.

[0057] Figure 4 An exploded view of the first wall 300 and the insulating member 500 of a battery cell according to another embodiment of this application is shown. Figure 4 The embodiments shown are comparable to the above references in several respects. Figures 1A to 3B The embodiments shown are the same as or similar to those described below; the following mainly describes... Figure 4 The differences between the illustrated embodiments are as follows. See also: Figure 4 and combined Figure 1B and Figure 1CAs shown, the first support portion 410 and the second support portion 420 are separate structures from the first wall 300. In some such embodiments, the first support portion 410 and the second support portion 420 can be welded to the first wall 300; in other embodiments, the first support portion 410 and the second support portion 420 can be accommodated in the grooves 502 at both ends and the middle of the insulating member 500 along the length Y direction.

[0058] The second support portion 420 may be provided with a pressure relief channel 425 extending through the second support portion 420 along the length direction Y. Through the pressure relief channel 425, the exhaust channel within the battery cell 100 can extend through the second support portion 420. In some embodiments not shown, the first support portion 410 may also be provided with a pressure relief channel extending through the first support portion 410 along the length direction Y. The support structure 400 includes a pressure relief channel, allowing some emissions to pass through the location of the support structure 400 without bypassing it. Compared to bypassing the support structure 400, passing through the support structure 400 via the pressure relief channel results in a shorter flow path for the emissions, which helps maintain unobstructed emission pathways and improves pressure relief efficiency.

[0059] In some embodiments, the pressure relief channel 425 is a pressure relief hole extending through the second support portion 420 along the length direction Y. The outline of the pressure relief hole can be circular, rectangular, or elliptical, etc. In other embodiments, the pressure relief channel 425 is a pressure relief groove extending through the second support portion 420 along the length direction Y. This pressure relief groove can be formed by a portion of the second support portion 420 recessed along the thickness direction Z or the width direction X. In other embodiments, the second support portion 420 is stretched and integrally formed from the first wall 300. Along the thickness direction Z, the second support portion 420 protrudes towards the electrode assembly 120, and has different protrusion heights at some locations. The surface of the second support portion 420 facing the electrode assembly 120 is also staggered in the thickness direction Z to correspond to different protrusion heights, thereby forming the pressure relief channel 425. Similarly, the first support portion 410 can also form a pressure relief channel 425 using the above method to shorten the flow path of some emissions. In some embodiments, both the first support portion 410 and the second support portion 420 can form pressure relief channels 425 to achieve a better pressure relief effect. In addition, refer to Figure 4 When the support structure 400 is independently molded, it can also be provided with recessed grooves or through holes along the thickness direction to reduce the weight of the support structure 400 and improve the mass energy density of the entire battery cell. For example, a rectangular through hole can be formed on the first support part 410 along the thickness direction Z.

[0060] Embodiments of this application also provide an electronic device including the above-described battery cell. Figure 5This is a structural diagram of an electronic device provided in some embodiments of this application when it is a vehicle. For ease of explanation, the following embodiments use a vehicle as an example for the electronic device 1000. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, but are not limited thereto. The working part is the vehicle body 1001, and the battery pack 1002, composed of the aforementioned battery cells, is disposed at the bottom of the vehicle body 1001, providing electrical power support for the vehicle's movement or the operation of electrical components within the vehicle. The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power support. In other embodiments, the electronic device 1000 can also be a mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; the working part can obtain electrical energy from the battery pack 1002 and perform corresponding work, such as a fan blade rotation unit or a vacuum cleaner suction unit. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the aforementioned electronic device 1000.

[0061] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A housing defining an accommodating space, wherein the electrode assembly is disposed within the accommodating space, the housing including a first wall disposed on one side of the accommodating space, the first wall having a pressure relief structure for releasing the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold. A support structure is disposed between the electrode assembly and the first wall. The support structure forms a gap between the first wall and the electrode assembly that communicates with the pressure relief structure. The support structure includes a first support portion located at both ends of the first wall along its length. Along the width direction of the first wall, the maximum dimension of the first support portion is W1, the maximum dimension of the pressure relief structure is W2, and the maximum dimension of the electrode assembly is W3, wherein...

2. The battery cell according to claim 1, characterized in that, The support structure further includes a second support portion, which is disposed on the periphery of the pressure relief structure.

3. The battery cell according to claim 2, characterized in that, Along the width direction, the maximum dimension of the second support portion is W4, where W1 < W4.

4. The battery cell according to claim 2, characterized in that, The support structure includes a pressure relief channel; Along the length direction, the pressure relief channel extends through the first support portion; and / or Along the length direction, the pressure relief channel extends through the second support portion.

5. The battery cell according to claim 2, characterized in that, The supporting structure is integrally formed with the first wall; or The supporting structure is welded to the first wall; or Along the thickness direction of the first wall, an insulating member is provided between the first wall and the electrode assembly. The insulating member includes a protrusion protruding toward the electrode assembly, and a groove is formed on the side of the insulating member facing the first wall corresponding to the protrusion. The support structure is accommodated in the groove.

6. The battery cell according to claim 2, characterized in that, Along the thickness direction of the first wall, the maximum dimension of the first support portion is H1, and the maximum dimension of the second support portion is H2, wherein H1 < H2.

7. The battery cell according to claim 2, characterized in that, Along the length direction, the maximum dimension of the first support portion is L1, and the maximum dimension of the second support portion is L2, wherein L1 > L2.

8. The battery cell according to claim 2, characterized in that, The housing also includes an outer shell, the outer shell having an opening, and the first wall being used to cover the opening; The electrode assembly includes tabs extending toward the first wall; Along the length direction, the minimum distance between the support structure and the electrode tab is D1, where D1 ≥ 20 mm; or Along the length direction, the minimum dimension of the electrode tab is L3, where D1 / L3 ≥ 1 / 4.

9. The battery cell according to claim 8, characterized in that, Along the length direction, the minimum distance between the first support and the electrode tab is D2, and the minimum distance between the second support and the electrode tab is D3, wherein D2 < D3.

10. The battery cell according to claim 2, characterized in that, Along the length direction, the minimum distance between the first support and the second support is D4, and the maximum dimension of the first wall is L5, wherein...

11. The battery cell according to any one of claims 1-10, characterized in that, The pressure relief structure is an explosion-proof valve, which includes an explosion-proof hole extending along the thickness direction of the first wall and an explosion-proof plate installed in the explosion-proof hole. The explosion-proof plate opens to release the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches the threshold.

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