Battery monomer, battery pack and electric equipment

Abstract

The invention discloses a battery monomer, a battery pack and electric equipment. The battery monomer comprises a shell, an electrode assembly, a gas guide part and an anti-explosion valve, the shell is provided with a containing cavity, the electrode assembly is arranged in the containing cavity, the shell comprises a first wall, the anti-explosion valve is arranged on the first wall, the gas guide part is arranged in the containing cavity, and the gas guide part is arranged between the electrode assembly and the first wall; the battery monomer has a first direction and a second direction which are perpendicular to each other, the air guide piece comprises a first section, a second section and an air guide part which are connected, the first section corresponds to the anti-explosion valve, the second section is arranged on at least one side of the first section along the second direction, the air guide part is arranged on at least one side of the second section along the first direction, and the air guide part protrudes out of the second section along the first direction; the gas guide part is used for guiding gas generated by the electrode assembly to the anti-explosion valve. Therefore, the gas guide part can play a role in guiding the gas, and the gas generated in the accommodating cavity can be quickly guided to the anti-explosion valve, so that the gas can be conveniently discharged.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a battery cell, a battery pack, and an electrical device. Background Technology

[0002] During battery operation, the reaction between the battery cells and electrolyte produces gas. To prevent gas from accumulating inside the battery and causing an explosion, some batteries are equipped with an explosion-proof valve. When the internal gas pressure of the battery becomes too high, the explosion-proof valve opens, allowing the gas inside the battery to escape to the outside.

[0003] To prevent the explosion-proof valve from entering the passenger compartment and causing injury to passengers, the explosion-proof valve is usually located at the bottom of the battery, and a venting structure is installed between the explosion-proof valve and the battery casing to guide the gas inside the battery to the explosion-proof valve. However, due to the incompatibility between the venting structure and the explosion-proof valve in related technologies, gas tends to accumulate inside the casing and cannot be quickly guided to the explosion-proof valve, resulting in delayed pressure relief or failure. Summary of the Invention

[0004] This application aims to provide a battery cell, battery pack, and electrical equipment that can solve the problem of delayed or failed pressure relief caused by mismatch between the gas guiding structure and the explosion-proof valve in the prior art.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a battery cell, comprising: a housing, an electrode assembly, a gas guide, and an explosion-proof valve; the housing has a receiving cavity, the electrode assembly is disposed in the receiving cavity, the housing includes a first wall, the explosion-proof valve is disposed in the first wall, the gas guide is disposed in the receiving cavity, and the gas guide is disposed between the electrode assembly and the first wall; the battery cell has a first direction and a second direction perpendicular to each other, the gas guide includes a first segment, a second segment, and a gas guide portion connected together, the first segment corresponds to the explosion-proof valve, the second segment is disposed on at least one side of the first segment along the second direction, the gas guide portion is disposed on at least one side of the second segment along the first direction, and the gas guide portion protrudes from the second segment along the first direction, the gas guide portion being used to guide the gas generated by the electrode assembly to the explosion-proof valve.

[0006] Optionally, the air guide has a first end and a second end disposed opposite to each other along the second direction; the first end is disposed on the side of the second end close to the first segment, and from the second end to the first end, the air guide extends obliquely in a direction away from the second segment.

[0007] Optionally, from the second end to the first end, the width of the air guide gradually increases along the first direction.

[0008] Optionally, the width of the air guide portion along the first direction first increases and then decreases.

[0009] Optionally, the battery cell further has a third direction that is perpendicular to both the first direction and the second direction; the orthographic projection of the air guide portion on a plane perpendicular to the third direction is a first profile line, and the angle between the portion of the first profile line corresponding to the first end and the second direction is greater than the angle between the portion of the first profile line corresponding to the second end and the second direction.

[0010] Optionally, the first contour line is an arc; from the second end to the first end, the angle between the tangent of the arc and the second direction first decreases and then increases.

[0011] Optionally, the battery cell also has a third direction that is perpendicular to both the first direction and the second direction; the air guide portion protrudes along the third direction toward the first wall and abuts against the first wall; a gap exists between the second section and the first wall to form an air guide groove.

[0012] Optionally, the air guide portion is provided in multiple ways; the multiple air guide portions are provided on both sides of the second segment along the first direction, and the multiple air guide portions located on the same side of the second segment are spaced apart along the second direction.

[0013] Optionally, the air guide has a first axis extending along the first direction, and the air guide is arranged axially symmetrically along the first axis.

[0014] Optionally, the air guide has a second axis extending along the second direction, and the air guide is arranged axially symmetrically along the second axis.

[0015] Optionally, the electrode assembly includes an electrode core and an insulating film, the insulating film covering the outer surface of the electrode core, the gas guide having a first positioning hole at at least one end along the second direction, and the insulating film having a second positioning hole on the side facing the gas guide, the first positioning hole and the second positioning hole being positioned and engaged.

[0016] Optionally, the width of the first segment along the first direction is smaller than the width of the explosion-proof valve along the first direction.

[0017] Optionally, the maximum width of the air guide along the first direction is greater than the width of the explosion-proof valve along the first direction.

[0018] Optionally, the length of the air guide along the second direction is L, the maximum width of the air guide along the first direction is W, and the surface area of ​​the first wall facing the receiving cavity is S, satisfying: 0.32≤(L*W) / S≤0.81.

[0019] Optionally, the battery cell further has a third direction that is perpendicular to both the first direction and the second direction, and the thickness of the air guide portion along the third direction is greater than or equal to the thickness of the second segment along the third direction.

[0020] Secondly, embodiments of this application propose a battery pack including the single battery cells described in the above embodiments.

[0021] Thirdly, embodiments of this application propose an electrical device including a single battery cell as described in the above embodiments; or a battery pack as described in the above embodiments.

[0022] In this embodiment, a first section is provided corresponding to the explosion-proof valve, a second section is provided on at least one side of the first section along a second direction, and a gas guide is provided on at least one side of the second section along a first direction and protrudes from the second section. Thus, the gas guide provided in the gas guide can guide the gas, quickly directing the gas generated by the electrode assembly within the containment cavity to the explosion-proof valve, allowing the gas to be discharged from the explosion-proof valve. This effectively avoids localized gas accumulation within the housing, thereby improving the pressure relief response speed and reliability.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a battery cell according to an embodiment of this application; Figure 2 This is a bottom view of a battery cell according to an embodiment of this application; Figure 3 This is a schematic diagram of the housing according to an embodiment of this application; Figure 4 This is a top view of a first type of air guide according to an embodiment of this application; Figure 5 This is a side view of a first type of air guide according to an embodiment of this application; Figure 6 This is a schematic diagram of a second type of air guide according to an embodiment of this application; Figure 7 This is a side view of a second type of air guide according to an embodiment of this application.

[0025] Figure label: 1. Shell; 11. Receiving cavity; 12. First wall; 2. Electrode assembly; 21. Electrode core; 22. Insulating film; 23. Second positioning hole; 3. Air guide component; 31. First section; 32. Second section; 33. Air guide part; 331. First end; 332. Second end; 333. First tangent; 334. Second tangent; 34. Air guide groove; 35. First positioning hole; 36. First axis; 37. Second axis; 4. Explosion-proof valve; X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0026] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0028] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In existing technology, a battery includes an electrode assembly, a housing, and a venting structure. The housing has a receiving cavity, the electrode assembly is disposed within the receiving cavity, and the venting structure is disposed between the electrode assembly and the housing. To prevent the explosion-proof valve from entering the passenger compartment and causing injury to passengers, the explosion-proof valve is usually located at the bottom of the battery, and a venting structure is provided between the explosion-proof valve and the battery housing to guide the gas from the electrode assembly to the explosion-proof valve.

[0031] However, the gas guiding structure in related technologies is mostly a regular guide plate with multiple through holes to connect the electrode assembly and the explosion-proof valve. Generally speaking, the size of the guide plate is the same as or slightly smaller than the size of the bottom of the battery casing, which makes it easy for the guide plate to block the explosion-proof valve. The electrode assembly can only connect to the explosion-proof valve through the through holes. When the battery experiences thermal runaway, the gas tends to accumulate in the casing and cannot be quickly guided to the explosion-proof valve, resulting in delayed pressure relief or failure and slow gas exhaust speed.

[0032] The battery cell, battery pack, and electrical equipment provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0033] like Figures 1 to 4 As shown in the embodiment of this application, a battery cell is proposed, including: a housing 1, an electrode assembly 2, a gas guide 3, and an explosion-proof valve 4; the housing 1 has a receiving cavity 11, the electrode assembly 2 is disposed in the receiving cavity 11, the housing 1 includes a first wall 12, the explosion-proof valve 4 is disposed in the first wall 12, the gas guide 3 is disposed in the receiving cavity 11, and the gas guide 3 is disposed between the electrode assembly 2 and the first wall 12; the battery cell has a first direction X and a second direction Y that are perpendicular to each other, the gas guide 3 includes a first segment 31, a second segment 32, and a gas guide portion 33 connected together, the first segment 31 corresponds to the explosion-proof valve 4, the second segment 32 is disposed on at least one side of the first segment 31 along the second direction Y, the gas guide portion 33 is disposed on at least one side of the second segment 32 along the first direction X, and the gas guide portion 33 protrudes from the second segment 32 along the first direction X, the gas guide portion 33 is used to guide the gas generated by the electrode assembly 2 to the explosion-proof valve 4.

[0034] In this embodiment, a first segment 31 is positioned corresponding to the explosion-proof valve 4, a second segment 32 is located on at least one side of the first segment 31 along the second direction Y, and a gas guide 33 is located on at least one side of the second segment 32 along the first direction X and protrudes from the second segment 32 along the first direction X. Thus, the gas guide 33 in the gas guide 3 can guide the gas, quickly directing the gas generated by the electrode assembly 2 within the receiving cavity 11 to the explosion-proof valve 4, allowing the gas to be discharged from the explosion-proof valve 4. This effectively prevents localized gas accumulation within the housing 1, thereby improving the pressure relief response speed and reliability.

[0035] Specifically, the first direction X is the width direction of the battery cell, the second direction Y is the length direction of the battery cell, and the third direction Z is the height direction of the battery cell. The correspondence between the first segment 31 and the explosion-proof valve 4 means that there is a certain misalignment between the first segment 31 and the explosion-proof valve 4. That is, the projection of the first segment 31 in the plane perpendicular to the third direction Z and the projection of the explosion-proof valve 4 in the plane perpendicular to the third direction Z do not completely overlap, so that the gas will not delay the opening of the explosion-proof valve 4 due to the obstruction of the first segment 31.

[0036] Furthermore, the explosion-proof valve 4 is provided with a weak point, which can be a serrated line or multiple spaced grooves. In this way, when gas flows through the explosion-proof valve 4, due to the increase in gas pressure, the explosion-proof valve 4 can be quickly opened through the weak point, thereby timely venting the gas.

[0037] It should be noted that the first wall 12 of the housing 1 can be a side wall of the housing 1 surrounding the battery cell, or it can be the bottom wall of the housing 1. This embodiment of the application does not impose any restrictions here.

[0038] Optionally, such as Figure 4 As shown, the air guide 33 has a first end 331 and a second end 332 disposed opposite to each other along the second direction Y; the first end 331 is disposed on the side of the second end 332 close to the first segment 31, and the air guide 33 extends obliquely away from the second end 332 to the first end 331.

[0039] Specifically, when the gas diffuses within the receiving cavity 11, the gas flow direction is divergent, and the inclined gas guide 33 can provide a guiding slope for the gas. Here, "inclined" refers to... Figure 4 The gas guide section 33 shown can be inclined upward relative to the edge of the second section 32 from the second end 332. When the battery cell experiences thermal runaway, the gas will flow from the second end 332 toward the first end 331, that is, the gas flows from both sides of the gas guide 3 along the second direction Y toward the middle (first section 31), thereby causing the gas to converge rapidly at the explosion-proof valve 4.

[0040] In this embodiment, the gas guide 33 extends obliquely from the second end 332 to the first end 331, moving away from the second section 32. This allows the gas in the regions on both sides of the gas guide 3 in the second direction Y to be guided to the region near the explosion-proof valve 4 via the inclined surface, thereby reducing energy loss and flow turbulence during gas flow and improving the gas delivery efficiency to the explosion-proof valve 4.

[0041] It should be noted that the air guide section 33 extends at an angle away from the second section 32, which can be like the hypotenuse of a right triangle, or it can be like... Figure 4 The inclination of the arc in the embodiment is not limited in this application.

[0042] Optionally, such as Figure 4 As shown, from the second end 332 to the first end 331, the width of the air guide 33 gradually increases along the first direction X.

[0043] In this embodiment, by setting the second end 332 to the first end 331, the width of the gas guide 33 gradually increases along the first direction X. This allows gas to flow from the second end 332 to the first end 331. Since the width of the gas guide 33 is greatest at the first end 331 near the explosion-proof valve 4, gas is difficult to flow from the first end 331 to the second end 332; that is, the gas guide 33 can guide gas forward to the first section 31 and, more importantly, suppress gas diffusion in the reverse direction, ensuring the effectiveness and stability of pressure convergence.

[0044] In some embodiments, the air guide 33 may be arranged in the form of a right-angled triangle, that is, the projection of the air guide 33 onto a plane perpendicular to the third direction Z is a triangle, one right-angled side of the triangle is connected to the second segment 32, the other right-angled side extends from the first end 331 in a direction away from the second segment 32, and the hypotenuse connects the two right-angled sides.

[0045] Optionally, such as Figure 4 As shown, from the second end 332 to the first end 331, the width of the air guide 33 along the first direction X first increases and then decreases.

[0046] In this embodiment, the width of the gas guide 33 along the first direction X is first increased and then decreased from the second end 332 to the first end 331. This facilitates the formation of the Venturi effect, achieving gas acceleration and efficient convergence.

[0047] Specifically, the design of the air guide section 33, with its width increasing and then decreasing along the first direction X, creates a flow channel similar to a "Venturi tube" between the air guide section 33 and the housing 1. When gas flows in from the second end 332, the cross-sectional area of ​​the flow channel first decreases, the flow velocity increases, and the pressure decreases, forming a pressure difference that promotes the gas to converge towards the explosion-proof valve 4; subsequently, the cross-sectional area of ​​the flow channel increases again to ensure that the gas has sufficient exhaust space.

[0048] It should be noted that the cross-sectional area of ​​the flow channel is negatively correlated with the cross-sectional area of ​​the air guide 33, that is, the larger the cross-sectional area of ​​the air guide 33, the smaller the cross-sectional area of ​​the flow channel.

[0049] Optionally, such as Figure 4 As shown, the battery cell also has a third direction Z that is perpendicular to both the first direction X and the second direction Y; the orthographic projection of the air guide 33 on the plane perpendicular to the third direction Z is the first contour line, and the angle between the part of the first contour line corresponding to the first end 331 and the second direction Y is greater than the angle between the part of the first contour line corresponding to the second end 332 and the second direction Y.

[0050] Specifically, such as Figure 4 As shown, the first contour line is an arc. The connection between the first end 331 and the second segment 32 of the first contour line is the first connection point. The tangent line of the first contour line at the first connection point is the first tangent line 333. The angle between the portion of the first contour line corresponding to the first end 331 and the second direction Y is the first angle a. The connection between the second end 332 and the second segment 32 of the first contour line is the second connection point. The tangent line of the first contour line at the second connection point is the second tangent line 334. The angle between the portion of the first contour line corresponding to the second end 332 and the second direction Y is the second angle b. The second angle b is greater than the first angle a.

[0051] In this embodiment of the application, by setting the second angle b to be greater than the first angle a, the gas is difficult to flow from the second end 332 to the first end 331 because the second angle b is greater than the first angle a; that is, the gas guide 33 can guide the gas smoothly and efficiently in the forward direction, and can also suppress the gas diffusion in the reverse direction, thus ensuring the effectiveness and stability of pressure convergence.

[0052] In some embodiments, the first angle a can be set to an acute angle, and the second angle b can be set to an acute angle or an obtuse angle. This application does not impose any limitations on these embodiments.

[0053] Optionally, such as Figure 4 As shown, the first contour line is an arc; from the second end 332 to the first end 331, the angle between the tangent of the arc and the second direction Y first decreases and then increases.

[0054] In this embodiment, the angle between the tangent of the arc and the second direction Y is first reduced and then increased. This makes the gas guiding slope of the gas guiding section 33 a gradually curvature guiding surface, allowing the gas to adhere to the guiding surface and flow smoothly and rapidly. This maximizes the use of the energy of gas expansion to promote pressure relief, thereby improving pressure relief efficiency and response speed.

[0055] Optionally, such as Figure 1 and Figure 6As shown, the battery cell also has a third direction Z that is perpendicular to both the first direction X and the second direction Y. The air guide 33 protrudes along the third direction Z toward the direction close to the first wall 12 and abuts against the first wall 12. There is a gap between the second section 32 and the first wall 12 to form an air guide groove 34.

[0056] In this embodiment, a gas guide 33 is provided that protrudes along the third direction Z towards the first wall 12 and abuts against the first wall 12, and a gas guide groove 34 is formed between the second section 32 and the first wall 12. In this way, gas can be guided from the gas guide groove 34 to the first section 31, and then to the explosion-proof valve 4, thereby further preventing gas accumulation.

[0057] Optionally, such as Figure 6 As shown, there are multiple air guides 33; the multiple air guides 33 are respectively arranged on both sides of the second section 32 along the first direction X, and the multiple air guides 33 located on the same side of the second section 32 are spaced apart along the second direction Y.

[0058] In this embodiment, multiple air guide sections 33 are provided, which are distributed on both sides of the second segment 32 along the first direction X. Multiple air guide sections 33 located on the same side of the second segment 32 are spaced apart along the second direction Y. This allows the air guide member 3 to simultaneously collect and guide gas from both sides along the first direction X, thereby improving the range and efficiency of air guidance. Furthermore, by arranging multiple air guide sections 33 on the same side spaced apart along the second direction Y, multiple air guide sections 33 on the same side can simultaneously collect and guide gas, thereby improving the range and efficiency of air guidance.

[0059] It should be noted that the number of air guides 33 on each side may be the same or different; the spacing between multiple air guides 33 on the same side may be the same or different; this application embodiment does not limit this.

[0060] Optionally, such as Figure 4 As shown, the air guide 3 has a first axis 36 extending along the first direction X, and the air guide 3 is arranged axially symmetrically along the first axis 36.

[0061] In this embodiment, the air guide 3 is axially symmetrical along the first axis 36. This facilitates pressure equalization and symmetrical airflow guidance along the first direction X, thereby ensuring that the airflow gathered throughout the battery can act evenly and balancedly on the explosion-proof valve 4 from all directions.

[0062] Optionally, such as Figure 4 As shown, the air guide 3 has a second axis 37 extending along the second direction Y, and the air guide 3 is arranged axially symmetrically along the second axis 37.

[0063] In this embodiment, the air guide 3 is arranged to be axially symmetrical along the second axis 37. This facilitates the achievement of pressure balance and symmetrical distribution of the airflow along the second direction Y, thereby optimizing the pressure relief efficiency.

[0064] Specifically, the gas generated on the left and right sides of the electrode assembly 2 can be guided to the explosion-proof valve 4 in the center through symmetrical paths and channels, thereby eliminating problems such as gas bias to one side and uneven flow resistance caused by the asymmetry of the guide in the second direction Y. This allows the airflow on the left and right sides of the guide to flow into the first section 31 in a balanced and synchronous manner, thus ensuring the stability and uniformity of the pressure establishment at the inlet of the explosion-proof valve 4.

[0065] Optionally, such as Figure 1 and Figure 4 As shown, the electrode assembly 2 includes an electrode core 21 and an insulating film 22; the insulating film 22 covers the outer surface of the electrode core 21, and the gas guide 3 has a first positioning hole 35 at at least one end along the second direction Y, and the insulating film 22 has a second positioning hole 23 on the side facing the gas guide 3, and the first positioning hole 35 and the second positioning hole 23 are positioned and engaged.

[0066] Specifically, the second positioning hole 23 is located at the bottom of the insulating film 22, and the insulating film 22 is also provided with multiple liquid guiding holes for the flow of electrolyte. During the assembly of the battery cell, the second positioning hole 23 of the insulating film 22 is first aligned with the first positioning hole 35 on the gas guide 3 to achieve positioning of the two, and then the two are fused together by a hot-melt process. Finally, the insulating film 22 is wrapped around the outer surface of the electrode core 21.

[0067] In this embodiment, a first positioning hole 35 is provided at one end of the gas guide 3 along the second direction Y, and a second positioning hole 23 is provided on the side of the insulating film 22 facing the gas guide 3. The first positioning hole 35 and the second positioning hole 23 are positioned and fitted together. Thus, during the assembly of the electrode assembly 2 and the gas guide 3, the placement and fixing of the gas guide 3 can be quickly completed by aligning the first positioning hole 35 and the second positioning hole 23, simplifying the operation, reducing alignment time, and improving production efficiency. At the same time, this error-proof design effectively avoids misalignment, rotation, and other errors that may occur during manual assembly, thereby improving the product assembly yield.

[0068] It should be noted that the first positioning hole 35 and the second positioning hole 23 can be round holes or elliptical holes, and this application embodiment does not limit them.

[0069] Optionally, such as Figure 4 As shown, the width of the first segment 31 along the first direction X is smaller than the width of the explosion-proof valve 4 along the first direction X.

[0070] In this embodiment, the width of the first segment 31 along the first direction X is set to be smaller than the width of the explosion-proof valve 4 along the first direction X. This avoids the first segment 31 being too large and covering the explosion-proof valve 4, thereby preventing airflow from blocking the flow through the explosion-proof valve 4.

[0071] Optionally, such as Figure 4 As shown, the maximum width of the air guide 3 along the first direction X is greater than the width of the explosion-proof valve 4 along the first direction X.

[0072] It should be noted that the maximum width of the air guide 3 along the first direction X is as follows: Figure 4 The distance W in the figure is shown.

[0073] In this embodiment, the maximum width of the gas guide 3 along the first direction X is set to be greater than the width of the explosion-proof valve 4 along the first direction X. This allows the gas guide width of the gas guide 33 along the first direction X to exceed the width of the explosion-proof valve 4 along the first direction X, thereby capturing a larger range of gas.

[0074] Optionally, such as Figure 4 As shown, the length of the air guide 3 along the second direction Y is L, the maximum width of the air guide 3 along the first direction X is W, and the surface area of ​​the first wall 12 facing the receiving cavity 11 is S, satisfying: 0.32≤(L*W) / S≤0.81.

[0075] In this embodiment, by setting the relationship between the length L of the gas guide 3, the maximum width W of the gas guide 3, and the surface area S of the first wall 12, it is ensured that the proportion of the surface area of ​​the gas guide 3 that generates gas collection to the surface area S of the first wall 12 is within a suitable range; where L*W represents the surface area of ​​the gas guide 3 that generates gas collection. In this way, it is ensured that the gas guide 3 has a sufficiently large effective current collection area to fully cover the gas generation area, while avoiding the gas guide 3 from excessively occupying the internal space of the battery cell, leaving space for the expansion of the electrode assembly 2, electrolyte wetting, and necessary assembly tolerances, and ensuring the energy density of the battery cell.

[0076] For example, the value of (L*W) / S can be set to any value among 0.32, 0.4, 0.5, 0.6, 0.7, and 0.81, or any range of two values.

[0077] Optionally, such as Figure 7 As shown, the battery cell also has a third direction Z that is perpendicular to both the first direction X and the second direction Y. The thickness of the air guide 33 along the third direction Z is greater than or equal to the thickness of the second segment 32 along the third direction Z.

[0078] Specifically, such as Figure 7 As shown, the thickness of the air guide section 33 along the third direction Z is H1, and the thickness of the second section 32 along the third direction Z is H2.

[0079] In this embodiment, the thickness H1 of the air guide 33 along the third direction Z is set to be greater than or equal to the thickness H2 of the second segment 32 along the third direction Z. This ensures the overall mechanical strength and deformation resistance of the air guide 3, while the thickness difference allows airflow to pass between the air guide 33 and the second segment 32, thereby improving exhaust efficiency.

[0080] Optionally, such as Figure 5 As shown, the thickness H1 of the air guide 33 along the third direction Z satisfies 0.3mm≤H1≤5mm.

[0081] In this embodiment, the thickness H1 of the gas guide 33 along the third direction Z is set to be within the range of 0.3mm-5mm. This ensures the structural rigidity and mechanical strength of the gas guide 33 while avoiding excessive occupation of the internal space of the battery cell by the gas guide 33, leaving room for the expansion of the electrode assembly 2, electrolyte wetting, and necessary assembly tolerances, thus ensuring the energy density of the battery cell.

[0082] For example, H1 can be set to any value among 0.3mm, 1mm, 2mm, 3mm, 4mm, 5mm, or any range of two values.

[0083] Preferably, such as Figure 7 As shown, the thickness H2 of the second segment 32 along the third direction Z satisfies: 0.1≤H2 / H1≤0.9.

[0084] In this embodiment of the application, by setting the value of H2 / H1 between 0.1 and 0.9, it can ensure that the second segment 32 has a certain structural rigidity and strength, can stably support the gas guide 33 and resist the load caused by gas pressure and the expansion of the electrode assembly 2, and prevent structural instability. At the same time, it can also achieve material thinning optimization, reduce the overall weight of the gas guide 3, and save material costs.

[0085] For example, the value of H2 / H1 can be set to any value among 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9, or any range of two values.

[0086] In some embodiments, taking a square lithium iron phosphate battery with a thickness of 30mm, a width of 300mm, and a height of 115mm as an example, the explosion-proof valve 4 is located at the bottom of the casing 1. Different length and width dimensions of the air guide 3 are used in the battery cell for testing, and a pressure gauge is installed inside the battery cell to detect the internal pressure. The exhaust bracket used in the experiment is made of polypropylene. A heating test is performed on the battery. The test conditions are: the battery cell is fully charged and then placed in a constant temperature chamber. The temperature chamber is continuously heated to 200℃ at a rate of 5℃ / min, and then maintained at 200℃ until the battery experiences thermal runaway. The maximum internal pressure of the battery cell is observed. The test results are shown in Table 1. Table 1

[0087] It should be noted that the battery cell in Comparative Example 1 does not have a gas guide 3; the gas guide 3 in Examples 1 to 6 adopts the method described in this application. Figure 4 The air guide 3 shown is flush with the second section 32, with no height difference. Furthermore, apart from the parameters listed in Table 1, all other parameters of the air guide 3 are the same.

[0088] As shown in Table 1, the experimental data in Comparative Example 1, lacking the venting component 3, resulted in a maximum internal pressure of 1.56 MPa in the battery cell when heated to 200°C. This high internal pressure posed a significant risk of explosion. In Examples 2-5, the inclusion of the venting component 3 in the battery cell improved venting efficiency, resulting in a maximum internal pressure between 0.79 MPa and 1.03 MPa. This more reasonable maximum internal pressure reduced the risk of explosion.

[0089] Furthermore, a comparison between Embodiment 1 and Embodiment 2 shows that although both Embodiment 1 and Embodiment 2 include a gas guide 3, the value of (L*W) / S in Embodiment 1 is 0.97, which is greater than 0.81. This results in the gas guide 3 covering most of the surface area of ​​the first wall, thus covering the explosion-proof valve 4. As a result, the gas guide 3 cannot be discharged from the explosion-proof valve 4, leading to a maximum internal pressure of 1.53 MPa for the battery cell, which is much greater than the maximum internal pressure of 1.03 MPa for the battery cell in Embodiment 2. This results in a higher risk of explosion.

[0090] Furthermore, a comparison between Examples 5 and 6 shows that the value of (L*W) / S in Example 20 is 0.16, which is less than 0.32. This indicates that the size of the gas guide 3 is relatively small, making it unable to effectively exhaust the gas inside the individual battery cells. Consequently, the maximum internal pressure of the battery cell reaches 1.35 MPa, which is significantly higher than the maximum internal pressure of 0.79 MPa in Example 5, resulting in a higher risk of explosion. Therefore, based on Examples 2 to 5, setting the value of (L*W) / S between 0.32 and 0.81 is more reasonable.

[0091] Optionally, embodiments of this application propose a battery pack including the single battery cells described in the above embodiments.

[0092] In this embodiment, a first segment 31 is positioned corresponding to the explosion-proof valve 4, a second segment 32 is positioned on at least one side of the first segment 31 along the second direction Y, and a gas guide 33 is positioned on at least one side of the second segment 32 along the first direction X and protrudes from the second segment 32. Thus, the gas guide 33 in the gas guide 3 can guide the gas, quickly directing the gas generated by the electrode assembly 2 within the receiving cavity 11 to the explosion-proof valve 4, allowing the gas to be discharged from the explosion-proof valve 4. This effectively prevents localized gas accumulation within the housing 1, thereby improving the pressure relief response speed and reliability.

[0093] Optionally, embodiments of this application provide an electrical device including a single battery cell from the above embodiments; or a battery pack from the above embodiments.

[0094] In this embodiment, a first segment 31 is positioned corresponding to the explosion-proof valve 4, a second segment 32 is positioned on at least one side of the first segment 31 along the second direction Y, and a gas guide 33 is positioned on at least one side of the second segment 32 along the first direction X and protrudes from the second segment 32. Thus, the gas guide 33 in the gas guide 3 can guide the gas, quickly directing the gas generated by the electrode assembly 2 within the receiving cavity 11 to the explosion-proof valve 4, allowing the gas to be discharged from the explosion-proof valve 4. This effectively prevents localized gas accumulation within the housing 1, thereby improving the pressure relief response speed and reliability.

[0095] In some embodiments, electrical devices may include laptops, pen-based computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini CDs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, electric bicycles, bicycles, ships, spacecraft, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium-ion capacitors, etc.

[0096] Specifically, 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, etc.

[0097] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0098] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: Housing (1), electrode assembly (2), gas guide (3) and explosion-proof valve (4); The housing (1) has a receiving cavity (11), the electrode assembly (2) is disposed in the receiving cavity (11), the housing (1) includes a first wall (12), the explosion-proof valve (4) is disposed in the first wall (12), the air guide (3) is disposed in the receiving cavity (11), and the air guide (3) is disposed between the electrode assembly (2) and the first wall (12); The battery cell has a first direction (X) and a second direction (Y) that are perpendicular to each other. The gas guide (3) includes a first section (31), a second section (32) and a gas guide (33) connected together. The first section (31) corresponds to the explosion-proof valve (4). The second section (32) is located on at least one side of the first section (31) along the second direction (Y). The gas guide (33) is located on at least one side of the second section (32) along the first direction (X), and the gas guide (33) protrudes from the second section (32) along the first direction (X). The gas guide (33) is used to guide the gas generated by the electrode assembly (2) to the explosion-proof valve (4).

2. The battery cell according to claim 1, characterized in that, The air guide (33) has a first end (331) and a second end (332) disposed opposite to each other along the second direction (Y); The first end (331) is located on the side of the second end (332) near the first segment (31), and the air guide (33) extends obliquely away from the second end (332) to the first end (331).

3. The battery cell according to claim 2, characterized in that, From the second end (332) to the first end (331), the width of the air guide (33) gradually increases along the first direction (X); And / or, the width of the air guide (33) along the first direction (X) first increases and then decreases.

4. The battery cell according to claim 2, characterized in that, The battery cell also has a third direction (Z) that is perpendicular to both the first direction (X) and the second direction (Y). The orthographic projection of the air guide (33) on a plane perpendicular to the third direction (Z) is a first profile line. The angle between the portion of the first profile line corresponding to the first end (331) and the second direction (Y) is greater than the angle between the portion of the first profile line corresponding to the second end (332) and the second direction (Y).

5. The battery cell according to claim 4, characterized in that, The first contour line is an arc; from the second end (332) to the first end (331), the angle between the tangent of the arc and the second direction (Y) first decreases and then increases.

6. The battery cell according to claim 1, characterized in that, The battery cell also has a third direction (Z) that is perpendicular to the first direction (X) and the second direction (Y). The air guide (33) protrudes along the third direction (Z) toward the first wall (12) and abuts against the first wall (12). There is a gap between the second section (32) and the first wall (12) to form an air guide groove (34).

7. The battery cell according to claim 1, characterized in that, The air guide section (33) is provided with multiple parts; Multiple air guides (33) are disposed on both sides of the second section (32) along the first direction (X), and multiple air guides (33) located on the same side of the second section (32) are spaced apart along the second direction (Y).

8. The battery cell according to claim 7, characterized in that, The air guide (3) has a first axis (36) extending along the first direction (X), and the air guide (3) is symmetrically arranged along the first axis (36). And / or, the air guide (3) has a second axis (37) extending along the second direction (Y), and the air guide (3) is axially symmetrical along the second axis (37).

9. The battery cell according to claim 1, characterized in that, The electrode assembly (2) includes an electrode core (21) and an insulating film (22). The insulating film (22) covers the outer surface of the pole core (21). The air guide (3) has a first positioning hole (35) at at least one end along the second direction (Y). The insulating film (22) has a second positioning hole (23) on the side facing the air guide (3). The first positioning hole (35) and the second positioning hole (23) are positioned and engaged.

10. The battery cell according to any one of claims 1-9, characterized in that, The width of the first segment (31) along the first direction (X) is smaller than the width of the explosion-proof valve (4) along the first direction (X).

11. The battery cell according to any one of claims 1-9, characterized in that, The maximum width of the air guide (3) along the first direction (X) is greater than the width of the explosion-proof valve (4) along the first direction (X).

12. The battery cell according to any one of claims 1-9, characterized in that, The length of the air guide (3) along the second direction (Y) is L, the maximum width of the air guide (3) along the first direction (X) is W, and the surface area of ​​the first wall (12) facing the receiving cavity (11) is S, satisfying: 0.32≤(L*W) / S≤0.

81.

13. The battery cell according to claim 12, characterized in that, The battery cell also has a third direction (Z) that is perpendicular to both the first direction (X) and the second direction (Y), and the thickness of the air guide (33) along the third direction (Z) is greater than or equal to the thickness of the second segment (32) along the third direction (Z).

14. A battery pack, characterized in that, Includes the single-cell battery as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes the single cell battery as described in any one of claims 1-13; or the battery pack as described in claim 14.

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