Battery cell, battery pack, and electronic device

Abstract

The utility model provides a kind of battery monomer, battery pack and electronic equipment, battery monomer includes: shell, the one end of shell forms opening;End cover, fixedly connected in shell at opening, to with shell define accommodating space;Electrode module, is contained in accommodating space, and the circumferential side surface of electrode module is set between the inner wall of shell and circumferential side exhaust gap;Wherein, end cover is equipped with explosion-proof valve, and end cover has by explosion-proof valve surrounds explosion-proof valve area, and exhaust area between explosion-proof valve area and shell along the radial direction of end cover, end cover has at least two support structures, at least two support structures are located exhaust area and are spaced apart in the circumferential direction of end cover, and end side exhaust gap is formed between support structure, and end side exhaust gap is communicated with circumferential side exhaust gap.The above technical scheme can at least avoid that electrode module is blocked in end cover side, ensure that end cover side is successfully exhausted, reduce the risk of battery explosion.

Description

Technical Field

[0001] This utility model relates to a battery cell, a battery pack, and an electronic device. Background Technology

[0002] In the field of new energy power batteries, a single battery cell generally includes electrode components and a casing. The electrode component consists of a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. These positive and negative electrodes and the separator are stacked and wound to form the electrode component, which is then encapsulated within the casing. Currently, there are high requirements for the safety of single battery cells. If a single battery cell can ensure that the explosion-proof valve opens normally while the casing remains intact during a runaway event, the safety factor of the overall battery pack will be greatly increased. The end cap of the casing, as one of the key mechanical components of the single battery cell, has a significant impact on safety due to its design.

[0003] However, conventional end cap designs rarely consider the impact of the end cap on the venting of runaway battery cells, which can easily lead to excessive internal pressure and heat accumulation in the battery cells, resulting in battery explosion. Utility Model Content

[0004] In view of the problems existing in the related technologies, the purpose of this utility model is to provide a battery cell, battery pack and electronic device that can avoid the electrode components being blocked on the end cover side, ensure smooth venting on the end cover side, reduce heat accumulation and reduce the risk of battery explosion.

[0005] To achieve the above objectives, this utility model provides a battery cell comprising: a housing with an opening at one end; an end cap fixedly connected to the housing at the opening to define an accommodating space; an electrode module housed within the accommodating space and located axially along the end cap inside the end cap, with a circumferential venting gap between the peripheral side of the electrode module and the inner wall of the housing; wherein the end cap is provided with an explosion-proof valve, and the end cap has an explosion-proof valve area surrounded by the explosion-proof valve, and a venting area along the radial direction of the end cap between the explosion-proof valve area and the housing; the end cap has at least two support structures protruding toward the electrode module, the at least two support structures being located in the venting area and spaced apart circumferentially from the end cap, forming an end-side venting gap between the support structures, and the end-side venting gap communicating with the circumferential venting gap.

[0006] In some embodiments, the support structure has an annular peripheral sidewall connecting the top wall of the end cap, wherein in a cross section defined by the axial and radial directions, the peripheral sidewall is formed on a first side and a second side disposed radially opposite to each other, wherein the first side is close to the explosion-proof valve and extends obliquely toward the explosion-proof valve in the direction from the electrode module to the end cap, and the second side extends obliquely toward the inner wall of the housing.

[0007] In some embodiments, the support structure further includes a bottom wall connecting the peripheral sidewalls, the bottom wall including a bottom surface extending perpendicularly to the axial direction, and the peripheral sidewalls of the support structure, the bottom wall of the support structure, and the top wall of the end cap are all connected and transitioned by rounded corners.

[0008] In some embodiments, in a cross section perpendicular to the axial direction, the peripheral sidewalls of the support structure are formed on a first side and a second side arranged radially opposite to each other, and on a third side and a fourth side connecting the first side and the second side and arranged circumferentially opposite to each other. The first side is closer to the explosion-proof valve in the radial direction than the second side. The length of the first side is less than the length of the second side, and the third and fourth sides are streamlined.

[0009] In some embodiments, the support structure has a first circumferential sidewall and a second circumferential sidewall disposed opposite each other in the circumferential direction, the first circumferential sidewall and the second circumferential sidewall being smoothly joined end to end, and the first circumferential sidewall and the second circumferential sidewall extending radially. In some embodiments, the support structure further has a third circumferential sidewall near the explosion-proof valve and a fourth circumferential sidewall away from the explosion-proof valve in the radial direction of the end cap, the width of the third circumferential sidewall along the circumferential direction being smaller than the width of the fourth circumferential sidewall along the circumferential direction.

[0010] In some embodiments, the projection of the support structure along the axial direction is teardrop-shaped, wherein, in a cross-section perpendicular to the axial direction, the first and second peripheral sidewalls of the support structure form a fifth and a sixth side, respectively, and both the fifth and sixth sides are streamlined. The fourth peripheral sidewall of the support structure forms a first arc edge, and the third peripheral sidewall forms a second arc edge, wherein the radius of the first arc edge is larger than the radius of the second arc edge.

[0011] In some embodiments, the axial height of the support structure is greater than the wall thickness of the end cap, and the height of the support structure is greater than or equal to the maximum axial thickness of the end cap. The height of the support structure is the axial distance from the bottom surface of the support structure facing the electrode module to the outer surface of the end cap.

[0012] In some embodiments, the support structure has a radial center point, wherein the center point is distributed along the circumferential path of the end cap, and at least two support structures cover 10% to 80% of the circumferential path of the end cap, or 50% of the circumferential path.

[0013] In some embodiments, a support region is formed between the venting area and the peripheral side surface of the electrode module in the radial direction of the end cap, wherein a support structure is located in the support region; in the radial direction, there is a gap between the support structure and the peripheral side surface of the electrode module; in the radial direction, the distance between the support structure and the housing is less than the distance between the support structure and the explosion-proof valve.

[0014] In some embodiments, at least two support structures are symmetrically distributed in the circumferential direction; the side of the support structure facing away from the electrode module is grooved. In some embodiments, the support structure is integrally stamped from an end cap.

[0015] In some embodiments, the electrode module includes an electrode assembly and a manifold connected to the electrode assembly, the manifold being located between the electrode assembly and the end cap, wherein at least a portion of the axial projection of the support structure toward the bottom surface of the electrode module overlaps with the manifold.

[0016] In some embodiments, the support structure is closer to the housing than the explosion-proof valve in the radial direction from the center of the end cap toward the housing.

[0017] Embodiments of this application also provide a battery pack including the aforementioned battery cells.

[0018] Embodiments of this application also provide an electronic device, which includes a battery pack comprising the aforementioned battery cells.

[0019] The technical solution of this application, by setting a support structure in the venting area of ​​the end cap, can support the electrode module and the end cap. After the explosion-proof valve is opened, it can be used to abut the electrode assembly and vent through the venting gap formed between the support structures. This ensures that the electrode module does not block the venting path on the end cap side during battery runaway, guaranteeing initial venting space on the end cap side during the initial runaway process. This facilitates the smooth opening of the explosion-proof valve in the early stages of battery runaway. It ensures continuous and normal venting and heat dissipation on the end cap side, reduces heat accumulation, and lowers the risk of electrode posts flying out or exploding in the later stages of runaway. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A perspective view of a battery cell according to some embodiments is shown.

[0022] Figure 2 A schematic cross-sectional view of a vertical section of a battery cell according to an embodiment of this application is shown.

[0023] Figure 3A It shows Figure 2 A magnified view of a single battery cell on the end cap side.

[0024] Figure 3B It shows Figure 3A A cross-sectional schematic diagram of the end cap.

[0025] Figure 3C It shows Figure 3A A plan view of the end cap.

[0026] Figure 3D It shows Figures 3A to 3C A schematic diagram of the cross-section of the supporting structure in a section perpendicular to the axial direction.

[0027] Figure 4 A schematic diagram of the end cap side structure without a support structure is shown in the comparative embodiment.

[0028] Figure 5A A plan view of the end cap of another embodiment is shown.

[0029] Figure 5B It shows Figure 5A A schematic diagram of the cross-section of the supporting structure in a section perpendicular to the axial direction.

[0030] Figure 6 A schematic diagram is shown when the electronic device according to an embodiment of this application is a vehicle. Detailed Implementation

[0031] To better understand the spirit of the embodiments of this application, the following description is based on some preferred embodiments of this application.

[0032] Embodiments of this application will be described in detail below. Throughout this specification, identical or similar components and components having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative and diagrammatic in nature and are intended to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0033] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate minor variations. When used in conjunction with an event or situation, these terms may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately.

[0034] In this specification, unless otherwise specified or limited, relative terms such as “central,” “longitudinal,” “lateral,” “front,” “rear,” “right,” “left,” “inner,” “outer,” “lower,” “higher,” “horizontal,” “vertical,” “above,” “below,” “above,” “below,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the directions described in the discussion or depicted in the accompanying drawings. These relative terms are used for descriptive convenience only and do not require that this application be constructed or operated in a particular orientation.

[0035] For ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.

[0036] Currently, some electronic equipment manufacturers (such as electric vehicle manufacturers) have high requirements for the safety of individual battery cells. If a battery cell can ensure that the explosion-proof valve opens normally while the integrity of the casing remains intact during a runaway event, the safety factor of the overall battery pack will be greatly increased. As one of the key mechanical components of the battery cell, the design of the end cap of the casing has a significant impact on safety.

[0037] However, conventional end cap designs rarely consider the impact of the end cap on the venting of runaway battery cells, which can easily lead to excessive internal pressure and heat accumulation in the battery cells, causing the terminals to fly out or explode, ultimately resulting in heat spread within the battery pack.

[0038] Figure 1 A perspective view of a battery cell 100 according to some embodiments is shown. Figure 2 A schematic cross-sectional view of a vertical section of a battery cell 100 according to an embodiment of this application is shown.

[0039] Combination Figures 1 to 2 As shown in this embodiment, the battery cell 100 is illustrated as a cylindrical battery for example. However, this application is not limited to cylindrical batteries; it can also be other battery types such as prismatic batteries with rigid casings and explosion-proof valves. In some embodiments, the battery cell 100 can be a 4680 cylindrical battery (46mm in diameter, 80mm in height), a 4695 cylindrical battery (46mm in diameter, 95mm in height), or a 46120 cylindrical battery (46mm in diameter, 120mm in height). Here, the diameter refers to the outer diameter of the casing.

[0040] The battery cell 100 includes a housing, which comprises a casing 200 and an end cap 220. The casing 200 may specifically include an end wall 111 and a side wall 109 surrounding the end wall 111. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 111 and the side wall 109 can be achieved in various ways, such as integral stamping, integral casting, or separate welding. The side wall 109 may be cylindrical or follow any other closed-loop contour that matches the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 109 is cylindrical and surrounds the outer edge of the end wall 111. An opening 205 is formed at the end of the side wall 109 opposite to the end wall 111, and the end cap 220 covers the opening 205. The end cap 220 is fixedly connected to the end of the side wall 109 at the opening 205. The end cap 220 and the side wall 109 can be welded together, for example by laser welding, or mechanically connected by other methods. The connection between the end cap 220 and the side wall 109 needs to achieve both a fixed and sealed connection. The housing 200 and the end cap 220 together define a receiving space for accommodating the electrode module 500, which is located axially inside the end cap 220. The electrode module 500 may include an electrode assembly 120 and a first current collector 201 and a second current collector 202 connected to the electrode assembly 120. The receiving space can also accommodate electrolyte and other necessary battery components. The direction from the end cap 220 to the end wall 111 is the height direction D1 of the battery cell 100. The height direction D1 may be parallel to the axial direction of the electrode module 500.

[0041] The terminal 160 may pass through and be insulated from the end wall 111. In some embodiments, the terminal 160 may be made of a conductive metallic material. For example, the material of the terminal 160 may be aluminum (Al). In some embodiments, the terminal 160 is the positive terminal of the battery cell 100. Electrical insulation between the terminal 160 and the end wall 111 of the housing 200 can be achieved in various ways. For example, insulation can be achieved by placing an insulating gasket assembly between the terminal 160 and the end wall 111.

[0042] Specifically, the outer diameter of the housing 200 can be determined based on the specific dimensions of the electrode assembly 120. For example, the outer diameter of the housing 200 can be 18mm, 21mm, 46mm, etc. The housing 200 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The end cap 220 can be made of steel, such as stainless steel or nickel-plated steel, or aluminum alloy or a composite material of steel and aluminum, or other materials that meet the battery energy density requirements while also possessing strength, reliability, and sealing properties. Furthermore, the material can be adjusted to best suit the needs of lightweight battery design. To prevent the housing 200 from rusting during long-term use, a rust-preventive material, such as metallic nickel, can be plated onto the surfaces of both the housing 200 and the end cap 220.

[0043] The electrode assembly 120 can be mainly formed by winding a positive electrode sheet and a negative electrode sheet, with a separator provided between the positive and negative electrode sheets. The wound electrode assembly 120 can have a central through hole 120c, and the electrode assembly 120 and the central through hole 120c can have a common central axis Lx. The positive electrode sheet can include a positive current collector and a positive active material, with the positive active material coated on the surface of the positive current collector; the positive current collector can include a coated area coated with the active material and an uncoated area without the active material, and the uncoated area can be used to form the positive electrode tab of the electrode assembly 120 after winding. The negative electrode sheet includes a negative current collector and a negative active material, with the negative active material coated on the surface of the negative current collector; the negative current collector includes a coated area coated with the active material and an uncoated area without the active material, and the uncoated area can be used to form the negative electrode tab of the electrode assembly 120 after winding. Taking a lithium-ion battery cell as an example, the positive electrode current collector can be made of aluminum, and the positive electrode active material layer includes positive electrode active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes negative electrode active material, which can be carbon or silicon, etc. The separator material can be, for example, PP (polypropylene) or PE (polyethylene). To protect and insulate the electrode assembly 120, an insulating film can be wrapped around the electrode assembly 120. The insulating film can be synthesized from PP, PE, PET (polyethylene terephthalate), PVC (polyvinyl chloride), or other polymer materials.

[0044] Electrode assembly 120 may include a tab facing opening 205, such as a negative tab. A first current collector 201 is disposed between end cap 220 and electrode assembly 120. The negative tab of electrode assembly 120 may be welded to the first current collector 201 to connect to the sidewall 109 of housing 200 via the first current collector 201. In some embodiments, the first current collector 201 is a negative current collector. End cap 220 may be welded to the end of sidewall 109. Electrode assembly 120 may also include another tab facing end wall 111, such as a positive tab. The positive tab of electrode assembly 120 may be connected to post 160 via a second current collector 202. In some embodiments, the second current collector 202 is a positive current collector. In some embodiments, the axial directions of the first collector disk 201, the second collector disk 202, and the electrode assembly 120 may coincide and may be referred to as the axial direction of the electrode module 500, which may extend along the central axis Lx.

[0045] Figure 3A It shows Figure 2 A partial enlarged view of the battery cell 100 on the end cap side. Figure 3B It shows Figure 3A A cross-sectional schematic diagram of the end cap. Figure 3C It shows Figure 3A A plan view of the bottom side of the end cap. (Combined with...) Figures 3A to 3C As shown, an explosion-proof valve 225 is provided on the end cap 220. The end cap 220 has a top wall 2201 facing the electrode assembly 120 and a bottom surface 2202 facing away from the electrode assembly 120. The bottom surface 2202 can also be referred to as the outer surface of the end cap 220. In some embodiments, the explosion-proof valve 225 is an annular notch along the circumferential direction D3 of the end cap 220 on the top wall 2201 of the end cap 220, and the end cap 220 is thinner at the notch. In some other embodiments, other suitable structures can be used to form the explosion-proof valve. The end cap 220 has an explosion-proof valve region A1 surrounded by the explosion-proof valve 225 and an exhaust region A2, which is located radially D2 of the end cap 220 between the explosion-proof valve region A1 and the side wall 109 of the housing 200.

[0046] Gases are generated during the use of individual battery cells. The main source of gas generation on the end cap side is the interfacial reaction between the electrolyte and the negative electrode material. If these gases cannot be released in time, they may cause an increase in internal battery pressure, leading to safety issues such as battery swelling, deformation, or even thermal runaway.

[0047] like Figure 3AAs shown, a peripheral venting gap 262 is provided between the peripheral side surface of the electrode module 500 extending in direction D1 and the inner wall of the housing 200. Specifically, the peripheral venting gap 262 is provided between the peripheral side surface 120s of the electrode assembly 120 extending in direction D1 and the inner wall of the sidewall 109. The venting path of the electrode assembly 120 includes a central hole path P1 via the central through hole 120c and an outer path P2 via the space between the electrode assembly 120 and the sidewall 109. The outer path P2 is formed by the peripheral venting gap 262. The central hole path P1 and the outer path P2 are used to discharge the gas generated during the use of the battery cell. Since the size of the explosion-proof valve area A1 is a small area relative to the end cap 220, the gas outside the electrode assembly 120 needs to be discharged through the outer path P2 via the gap between the end cap 220 and the top side of the electrode module 500. The exhaust directions of both the central hole path P1 and the outer path P2 are towards the end cap 220, and the gas can be directed between the gas-guided electrode module 500 and the end cap 220.

[0048] Excessive gas accumulation that cannot be released in time can cause a dramatic increase in internal battery pressure, potentially leading to an explosion and fire. When the internal pressure reaches a certain level, the explosion-proof valve 225 on the end cap must be opened to release pressure and prevent an explosion. The opening pressure of the explosion-proof valve 225 can be controlled by adjusting the residual thickness at the valve, thereby releasing gas pressure through the explosion-proof valve area A1. It should be understood that in embodiments using other suitable structures to form the explosion-proof valve, the valve can also be opened by controlling its opening pressure.

[0049] When too much gas accumulates inside the battery, the internal pressure reaches the opening pressure of the explosion-proof valve, causing the valve to open. At the same time, the internal gas will be rapidly discharged towards the negative electrode side through the outer path P2 and the central hole path P1. However, during the exhaust process, due to the excessive internal pressure, the electrode module 500 will often directly press against the end cover towards the negative electrode side. This will block the gap between the electrode module 500 and the end cover 220, leading to a sharp increase in the internal pressure of the battery. This could cause the battery to explode and catch fire, or the positive electrode post 160 to detach from the casing 200 and fly out.

[0050] According to an embodiment of this application, the end cap 220 has at least two support structures 300 protruding toward the electrode assembly 120. A liquid injection hole 223 may be provided at the center of the end cap 220. In this embodiment, four support structures 300 are shown as an example. The support structures 300 are located in the venting region A2 and are spaced apart and evenly arranged on the circumferential direction D3 of the end cap 220. The area between the support structures 300 along the circumferential direction D3 forms an end-side venting gap 264 (see...). Figure 3CThe end-side exhaust gap 264 extends radially D2 and communicates with the peripheral exhaust gap 262, extending to the explosion-proof valve region A1. An exhaust gas flow 550 for battery gas generation can be formed via the peripheral exhaust gap 262 and the end-side exhaust gap 264. The exhaust gas flow 550 exits from the peripheral exhaust gap 262 through the end-side exhaust gap 264 from the explosion-proof valve region A1. The support structure 300 can be used to abut against the electrode module 500 after the electrode module 500 has shifted towards the negative electrode side after the explosion-proof valve 225 is opened, preventing further displacement of the electrode module 500 and thus preventing the exhaust path from being blocked.

[0051] See Figure 4 The function of the support structure 300 is illustrated in the comparative embodiment. Figure 4 A schematic diagram of the end cap side structure without a support structure in a comparative embodiment is shown. See also Figure 4 As shown, the outer path P42 of the electrode module 400 (including the electrode assembly 412 and the first collector 401) is used for venting. After the venting reaches the end cover 420 along the outer path P42, it extends further along the space between the end cover 420 and the electrode assembly 412 to the explosion-proof valve area A41. When the explosion-proof valve 425 is opened, the electrode module 400 is prone to directly pressing against the end cover 420 due to the internal pressure of the casing, causing a blockage in area A43, which is called the blockage area A43. Specifically in the field of cylindrical battery technology, the blockage area A43 is an annular area. When this blockage area A43 is blocked, it will cause poor venting, which can easily lead to excessive internal pressure and heat accumulation in the battery. The consequences may include: the electrode post flying out, the outer ring of the end cover 420 flying out directly, or cracks in the casing. It may even lead to increased thermal runaway inside the battery, overheating, or even fire and explosion, ultimately causing heat propagation within the battery cell and causing a safety accident. Therefore, this application requires optimization of the design of the end cap 420 and its associated features.

[0052] See also Figures 3A to 3CAs shown in the embodiment of this application, a support structure 300 is provided in the venting area A2 of the end cap 220. The support structure 300 can support the electrode module 500 and the end cap 220. After the explosion-proof valve 225 is opened, it can be used to abut against the electrode module 500. An end-side venting gap is formed between the support structures 300 to ensure that the gas passing through the end side of the electrode module 500 can be smoothly discharged. Furthermore, since the support structures 300 are spaced apart on the circumferential D3 of the end cap 220, they will not affect the outer path P2 of the electrode assembly 120. Thus, the electrode assembly 120 will not be blocked on the end cap side during battery runaway, ensuring the initial venting space on the end cap side during the initial runaway process, which facilitates the smooth opening of the explosion-proof valve in the early stage of battery runaway. This ensures that the venting and heat dissipation on the end cap side continue to be normal, reduces heat accumulation, reduces the risk of the electrode post flying out or exploding in the later stages of runaway, and reduces the risk of heat spread at the battery pack level.

[0053] In some embodiments, the plurality of support structures 300 may be symmetrically distributed relative to the center of the end cap 220. In this embodiment, the plurality of support structures 300 may be evenly distributed at equal intervals along the circumferential direction D3. This symmetrically distributed support structure 300 can provide stable support for the end cap 220.

[0054] At least a portion of the projection of the bottom surface of the support structure 300 toward the electrode module 500 along direction D1 can overlap with the first manifold 201. In this way, the support structure 300 can abut against the first manifold 201 after the explosion-proof valve 225 is opened, providing support between the first manifold 201 and the end cap 220, thus ensuring smooth exhaust from the end cap side. Furthermore, the abutment of the support structure 300 against the first manifold 201 strengthens the stable support effect of the outer periphery of the first manifold 201, facilitating the smooth folding of the central area of ​​the first manifold 201, thereby effectively avoiding the explosion-proof valve area A1.

[0055] Specifically, the support structure 300 may have a peripheral sidewall 250 of the top wall 2201 of the connecting end cap 220. See also Figure 3B In the cross-section defined by the axial and radial directions D2 of the end cap 220, a peripheral sidewall 250 forms a first sidewall Si and a second sidewall So that are radially opposite each other on D2. The first sidewall Si is closer to the explosion-proof valve 225 than the second sidewall So. In the direction from the electrode assembly 120 toward the end cap 220 (i.e., the opposite direction of direction D1), the first sidewall Si extends obliquely toward the explosion-proof valve 225, and the second sidewall So extends obliquely toward the inner wall of the sidewall 109. This oblique arrangement of the first sidewall Si facilitates the discharge of electrode assembly 120 debris along the exhaust region A2 outside the explosion-proof valve. This enhances the gas guiding efficiency and further facilitates debris discharge.

[0056] The support structure 300 also includes a bottom wall Sb connected to the peripheral sidewall 250. In some embodiments, the bottom wall Sb may include a bottom surface facing the electrode assembly 120, which may extend perpendicular to the axial direction of the end cap 220 (i.e., perpendicular to direction D1). Configuring the bottom wall Sb of the support structure 300 to have a planar bottom surface can enhance the stability and strength of the support structure 300's supporting function.

[0057] exist Figure 3B In the cross-sectional view, the peripheral sidewall 250 of the support structure 300 and the top wall 2201 of the end cap 220 are connected by a rounded corner. The cross-sectional shape of the support structure 300 is similar to a rounded trapezoid. Along the radial direction D2, the distance between the support structure 300 and the sidewall 109 of the housing 200 is less than the distance between the support structure 300 and the explosion-proof valve 225.

[0058] The top view shape of the support structure 300 can be a rounded trapezoid. Figure 3D As shown Figures 3A to 3C A schematic diagram of the cross-section of the supporting structure 300 in the section perpendicular to direction D1. (Combined with...) Figure 3C and Figure 3D As shown, the peripheral sidewall 250 of the support structure 300 is in Figure 3D A first side L1 and a second side L2 are formed opposite each other in the radial direction D2, and a third side L3 and a fourth side L4 are formed opposite each other in the circumferential direction D3. The third side L3 connects one end of the first side L1 and one end of the second side L2, and the fourth side L4 connects the other end of the first side L1 and the other end of the second side L2. The first side L1, the second side L2, the third side L3, and the fourth side L4 can be connected by rounded corners. In the radial direction D2, the first side L1 is closer to the explosion-proof valve 225 than the second side L2. The length of the first side L1 is less than the length of the second side L2. In this embodiment where the length of the first side L1 is less than the length of the second side L2, the length of the end of the support structure 300 in the radial direction D2 that is closer to the explosion-proof valve 225 (corresponding to the first side L1) is less than the length of the end that is farther away from the explosion-proof valve 225 (corresponding to the second side L2). In some embodiments, the third side L3 and the fourth side L4 may be streamlined, that is, the sidewalls of the peripheral sidewalls 250 of the support structure 300 that are opposite each other in the circumferential direction D3 are streamlined sidewalls.

[0059] See Figures 3A to 3CAs shown, a support region A4 is formed between the exhaust region A2 and the peripheral side surface 120s of the electrode assembly 120. The support structure 300 is projected axially into this support region A4. Thus, in the radial direction D2 of the end cap 220, there can be a gap Ga between the support structure 300 and the peripheral side surface 120s of the electrode assembly 120, and the support structure 300 is not positioned above the peripheral exhaust gap 262. This allows the support structure 300 to abut against and support the electrode assembly while preserving exhaust space and path to further avoid blockage, facilitate debris discharge, and prevent impact on the explosion-proof effect.

[0060] In some embodiments, the gap Ga between the support structure 300 and the peripheral side 120s of the electrode assembly 120 is ≥0.5mm. The upper limit of Ga can be adaptively adjusted based on the overall height of the battery cell, and is not specifically limited here. In some embodiments, considering processing feasibility, there is a gap between the support structure 300 and the explosion-proof valve 225 on the radial direction D2 of the end cap 220. The gap between the support structure 300 and the explosion-proof valve 225 is ≥0.5mm to avoid the support structure 300 affecting the explosion-proof function of the explosion-proof valve 225. In embodiments where the battery cell is a 46-series cylindrical battery, the preferred size range of the gap between the support structure 300 and the explosion-proof valve 225 is ≥2mm. Specifically, the starting position of the support structure 300 is smaller than the outer diameter of the electrode assembly 120, and the ending position is larger than the outer diameter of the explosion-proof valve 225. In this way, while meeting the support strength requirements, the coverage area is minimized, the radial size range is controlled, and the assembly of the end cap is not interfered with.

[0061] Furthermore, the support structure 300 may have a center point Co in the radial direction D2. In some embodiments, in the circumferential direction D3 passing through the center point Co of the support structure 300, multiple support structures 300 cover 10% to 80% of the circumferential path of the end cap 220 extending along the circumferential direction D3. It should be understood that coverage means that the projection of the support structure 300 along the direction D1 overlaps with the circumferential path. This allows the support structure 300 to provide good overall support for the electrode module 500, avoiding support failure, and at the same time, it can ensure the area of ​​the exhaust gap as much as possible, ensuring better exhaust effect. That is, if it is less than this value range, it may not provide effective support; if it is greater than this value range, it may affect pressure relief. In some embodiments, the support structure 300 covers 50% of the circumferential range of the end cap 220, which can well balance the support effect and ensure the pressure relief effect.

[0062] In some embodiments, the support structure 300 is configured such that the side facing away from the electrode assembly 120 is grooved, i.e., forming an opening. This structure of the support structure 300 has the advantages of simple manufacturing process, cost saving, and increased strength. In some embodiments, the support structure 300 is integrally stamped from the end cap 220. This forming method facilitates the manufacturing process and ensures the overall stability, weight, and strength of the end cap 220, offering advantages of simple manufacturing process, cost saving, and increased strength. In other embodiments, other separate fixing methods can also be used, such as welding or riveting, to attach the support structure 300 to the end cap 220, as long as the overall stability, weight, and strength of the end cap 220 can be controlled.

[0063] The support structure 300 has a height h in the direction from the end cap 220 to the electrode assembly 120 (i.e., direction D1). The height h of the support structure 300 is the distance along direction D1 from the bottom surface 2202 of the end cap 220 to the bottom surface of the support structure 300 facing the electrode assembly 120. The height h is greater than the wall thickness of the end cap 220, and the height h of the support structure 300 can be less than or equal to the maximum thickness T of the end cap 220. The maximum thickness T refers to the maximum distance along direction D1 from the top wall 2201 to the bottom surface 2202 of the end cap 220. By controlling the height h of the support structure 300, the overall thickness of the end cap 220 side can be avoided without increasing the internal dimensions and space occupied by the battery, while simultaneously achieving the support function. In other embodiments, the height h can also be greater than the maximum thickness T of the end cap 220. Although this would increase the overall thickness of the end cap 220, indirectly increasing the height of the battery cell, it would also increase the venting capacity on the end side. Therefore, this design can also solve the technical problem of this application.

[0064] Figure 5A A plan view of the bottom side of the end cap 220 according to another embodiment is shown. Figure 5A Several aspects of the illustrated embodiments are related to the above references. Figures 3A to 3C The descriptions are similar; the following mainly describes... Figure 5A The differences between the illustrated embodiments are as follows.

[0065] See Figure 5AAs shown, multiple support structures 300 are evenly distributed along the circumferential direction D3 of the end cap 220. In this embodiment, three support structures 300 are shown as an example. Along the circumferential direction D3 of the end cap 220, each support structure 300 has a first circumferential sidewall Sa and a second circumferential sidewall Sc disposed opposite to each other, with the first circumferential sidewall Sa and the second circumferential sidewall Sc smoothly connected end-to-end. For example, in this embodiment, the first circumferential sidewall Sa and the second circumferential sidewall Sc can be smoothly connected by an arc-shaped circumferential sidewall. The first circumferential sidewall Sa and the second circumferential sidewall Sc extend radially D2 and can be streamlined to form a streamlined air-guiding structure. The streamlined first circumferential sidewall Sa and the second circumferential sidewall Sc can add a streamlined air-guiding path to the exhaust path, optimizing the exhaust path and improving the pressure relief efficiency while ensuring pressure relief space. Furthermore, the support structure 300 can extend longitudinally along the radial direction D2. This can also improve the overall strength of the end cap 220 and enhance the overall strength and stability of the battery.

[0066] In this embodiment, the support structure 300 has a third circumferential sidewall Se near the explosion-proof valve 225 and a fourth circumferential sidewall Sg away from the explosion-proof valve 225 in the radial direction D2. The width of the third circumferential sidewall Se along the circumferential direction D3 of the end cap 220 is smaller than the width of the fourth circumferential sidewall Sg along the circumferential direction D3. The smaller width of the third circumferential sidewall Se near the explosion-proof valve 225 can optimize the gas guiding effect in the structure and improve the guiding efficiency in the radial direction.

[0067] In other embodiments, the support structure 300 may have the characteristics of a first circumferential sidewall Sa and a second circumferential sidewall Sc, but the specific shapes of the third circumferential sidewall Se and the fourth circumferential sidewall Sg are not limited. It can be understood that the first circumferential sidewall Sa and the second circumferential sidewall Sc extend towards the center, thereby achieving airflow guidance in the radial direction and optimizing the gas guidance path. The smaller width of the third circumferential sidewall Se can better guide the airflow towards the center and concentrate it, further optimizing other guidance paths. The curved surface of the fourth circumferential sidewall Sg can improve the streamlined airflow guidance effect.

[0068] In this embodiment, the support structure 300 is teardrop-shaped. Specifically, Figure 5B As shown Figure 5A A schematic diagram of the cross-section of the supporting structure 300 in the section perpendicular to direction D1. (Combined with...) Figure 5A and Figure 5BAs shown, the first circumferential sidewall Sa and the second circumferential sidewall Sc of the support structure 300 form the fifth side L5 and the sixth side L6, respectively. The fifth side L5 and the sixth side L6 can be arranged opposite each other along the circumferential direction D3. Both the fifth side L5 and the sixth side L6 are streamlined, that is, the first circumferential sidewall Sa and the second circumferential sidewall Sc are streamlined. The fourth circumferential sidewall Sg of the support structure 300 forms an arc edge L7, and the third circumferential sidewall Se also forms an arc edge L8. The radius of the arc edge L7 is larger than the radius of the arc edge L8. In this way, a teardrop-shaped support structure 300 is formed. The streamlined first circumferential sidewall Sa and the second circumferential sidewall Sc, as well as the smooth transition between the third circumferential sidewall Se and the fourth circumferential sidewall Sg, form a streamlined guiding surface. The debris of the electrode assembly can be discharged outside the explosion-proof valve 225 along the guide, which is conducive to venting and depressurization, can enhance the gas guiding efficiency, facilitate the discharge of debris, and reduce the risk of the electrode column flying out or exploding in the later stages of runaway.

[0069] See Figure 6 This utility model provides an electronic device 1000. For ease of explanation, the following embodiments use a vehicle as an example. A battery pack 1002 is installed inside the vehicle. The battery pack 1002 can be located at the bottom, head, or rear of the vehicle body 1001. The battery pack 1002 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The battery pack 1002 can include multiple battery cells, such as the battery cell 100 as described above. By providing a support structure 300 on the end cap 220 of the battery cell 100, the support structure 300 can be used to abut against the electrode assembly 120 after the explosion-proof valve 225 is opened. This ensures that the electrode assembly 120 will not block the end cap side during battery runaway, guaranteeing that the explosion-proof valve can open smoothly, ensuring continuous and normal exhaust and heat dissipation on the end cap side, reducing heat accumulation, and lowering the risk of heat spread within the battery pack 1002.

[0070] The working part of the electronic device 1000 is electrically connected to the battery pack 1002 to obtain electrical power. 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 is located at the bottom of the vehicle body 1001, providing electrical power for the vehicle's operation or the operation of its internal electrical components. However, in some 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 power from the battery pack 1002 and perform corresponding functions, 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.

[0071] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery cell, characterized in that, include: A housing, wherein one end of the housing is formed with an opening; An end cap is fixedly connected to the housing at the opening to define an accommodating space with the housing; An electrode module is housed within the receiving space and located on the inner side of the end cap along the axial direction of the electrode module. A circumferential venting gap is provided between the peripheral side surface of the electrode module and the inner wall of the housing. The end cap is provided with an explosion-proof valve, and the end cap has an explosion-proof valve area surrounded by the explosion-proof valve, and an exhaust area along the radial direction of the end cap between the explosion-proof valve area and the housing. The end cap has at least two support structures protruding toward the electrode module. The at least two support structures are located in the exhaust area and are spaced apart in the circumferential direction of the end cap. An end-side exhaust gap is formed between the support structures. The end-side exhaust gap extends radially to the explosion-proof valve area and communicates with the circumferential exhaust gap.

2. The battery cell according to claim 1, characterized in that, The support structure has an annular peripheral sidewall connecting to the top wall of the end cap, and in a cross-section defined by the axial and radial directions, the peripheral sidewall forms a first side and a second side disposed opposite each other in the radial direction. The first side is close to the explosion-proof valve, and in the direction from the electrode module to the end cap, the first side extends obliquely toward the explosion-proof valve, and the second side extends obliquely toward the inner wall of the housing.

3. The battery cell according to claim 2, characterized in that, The support structure further includes a bottom wall connecting the peripheral sidewalls, the bottom wall including a bottom surface extending perpendicular to the axial direction. The peripheral sidewall of the support structure, the bottom wall of the support structure, and the top wall of the end cap are all connected and transitioned by rounded corners.

4. The battery cell according to claim 2, characterized in that, In a cross-section perpendicular to the axial direction, the peripheral sidewalls of the support structure are formed by a first side and a second side that are radially opposite to each other, and a third side and a fourth side that connect the first side and the second side and are circumferentially opposite to each other. The first side is closer to the explosion-proof valve radially than the second side. The length of the first side is less than the length of the second side, and the third and fourth sides are streamlined.

5. The battery cell according to claim 1, characterized in that, The support structure has an annular circumferential sidewall connecting to the top wall of the end cap. The circumferential sidewall of the support structure has a first circumferential sidewall and a second circumferential sidewall disposed opposite each other in the circumferential direction. The first circumferential sidewall and the second circumferential sidewall are smoothly joined end-to-end and extend radially. The support structure also has a third circumferential sidewall close to the explosion-proof valve and a fourth circumferential sidewall away from the explosion-proof valve in the radial direction, wherein the width of the third circumferential sidewall along the circumferential direction is smaller than the width of the fourth circumferential sidewall along the circumferential direction.

6. The battery cell according to claim 5, characterized in that, The projection of the support structure along the axial direction is teardrop-shaped. In a cross-section perpendicular to the axial direction, the first and second peripheral sidewalls of the support structure form a fifth and a sixth side, respectively, both of which are streamlined. The fourth peripheral sidewall of the support structure forms a first arc edge, and the third peripheral sidewall forms a second arc edge, wherein the radius of the first arc edge is greater than the radius of the second arc edge.

7. The battery cell according to claim 1, characterized in that, The height of the support structure along the axial direction is greater than the wall thickness of the end cap, and the height of the support structure is greater than or equal to the maximum thickness of the end cap along the axial direction. The height of the support structure is the distance along the axial direction from the bottom surface of the support structure facing the electrode module to the outer surface of the end cap.

8. The battery cell according to claim 1, characterized in that, The support structure has a center point in the radial direction. The center point is distributed on the circumferential path of the end cap, and the at least two support structures cover 10% to 80% of the circumferential path, or 50% of the circumferential path.

9. The battery cell according to claim 1, characterized in that, A support region is formed between the exhaust region and the peripheral side surface of the electrode module, wherein the support structure is located in the support region; In the radial direction, there is a gap between the support structure and the peripheral side surface of the electrode module; In the radial direction, the distance between the support structure and the housing is less than the distance between the support structure and the explosion-proof valve.

10. The battery cell according to claim 1, characterized in that, The at least two supporting structures are symmetrically distributed in the circumferential direction; The side of the support structure facing away from the electrode module is grooved, and the support structure is integrally stamped from the end cap.

11. The battery cell according to claim 1, characterized in that, The electrode module includes an electrode assembly and a current collector connected to the electrode assembly. The current collector is located between the electrode assembly and the end cap, wherein at least a portion of the projection of the support structure along the axial direction overlaps with the current collector.

12. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1 to 11.

13. An electronic device comprising a battery pack, characterized in that, The battery pack includes the battery cells described in any one of claims 1 to 11.

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