Battery and power consuming device

Abstract

The application relates to the technical field of batteries, and particularly discloses a battery and a power utilization device. The battery comprises a shell, a current collecting disc, a battery cell assembly, a sealing nail and a sealing piece. The shell comprises a first end wall; the current collecting disc and the battery cell assembly are arranged in the shell; the first end wall is provided with a protruding portion facing the battery cell assembly; the protruding portion is provided with a first stepped portion and a liquid injection hole penetrating through the protruding portion; the first stepped portion is welded with the current collecting disc; the protruding portion is provided with a cavity on the back side and the cavity is communicated with the liquid injection hole; the sealing piece is welded with the first end wall to form a first welding line and covers the cavity; the sealing nail comprises a body portion and an extension portion; the extension portion seals the liquid injection hole; and the body portion is sealed between the sealing piece and the first stepped portion. In the application, the sealing nail realizes a double sealing mechanism by means of the extension portion and the body portion, so that the electrolyte is prevented from leaking into the cavity and the first welding line of the sealing piece and the first end wall is not affected.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and specifically proposes a battery and an electrical device. Background Technology

[0002] Existing batteries typically inject electrolyte into the cells by setting an injection hole that penetrates the inner wall of the casing. After injection, the injection hole is sealed by a metal seal. However, during use, there is often a risk of leakage at the weld points where the metal seal is welded to the casing, which can cause the inside and outside of the battery to connect, affecting the battery's safety and cycle life. Summary of the Invention

[0003] The purpose of this application is to at least solve the technical problem mentioned above, namely, that "electrolyte easily leaks and may corrode the weld marks between the seals and the housing." This purpose is achieved through the following technical solution: In a first aspect, this application proposes a battery comprising a casing, a current collector, a cell assembly, a sealing pin, and a sealing element. The casing includes a first end wall, and the current collector and the cell assembly are both disposed inside the casing. Along the height direction of the battery, the cell assembly is disposed above the first end wall. The cell assembly includes a cell body and a first electrode tab electrically led out from the cell body, the first electrode tab being electrically connected to the current collector. The first end wall has a protrusion facing the cell body, the protrusion having a first step and a liquid injection hole penetrating the first step, the first step being welded to the current collector. The side of the protrusion facing away from the cell body has a cavity, the cavity communicating with the liquid injection hole. The sealing pin includes a connected body portion and an extension portion, the extension portion extending into the liquid injection hole and interference-fitting the inner wall of the liquid injection hole. The body portion is located within the cavity. The sealing element is welded to the first end wall to form a first weld line, and together with the first step portion, seals the cavity, the sealing element abutting against the side of the body portion facing away from the cell body.

[0004] Secondly, this application also proposes an electrical device that includes the battery of the first aspect.

[0005] The technical solution proposed in this application has at least the following technical effects: In this application, a dual sealing mechanism is achieved using the extension and body of the sealing pin to prevent electrolyte leakage into the cavity, thereby ensuring that the first weld line between the seal and the first end wall of the housing is unaffected. Specifically, the extension of the sealing pin presses against the injection hole in an interference fit to provide an initial sealing effect; the body of the sealing pin abuts against the bottom wall of the cavity and the seal to achieve a secondary seal, further ensuring that electrolyte does not leak to the first weld line between the seal and the housing, causing corrosion. Attached Figure Description

[0006] To better integrate the content illustrated in the accompanying drawings with the description of the specific embodiments, a brief introduction to the drawings is provided below. It is understood that the accompanying drawings mentioned below are merely schematic illustrations of some embodiments of the relevant technical solutions and the technical solutions of this application. Without creative effort, those skilled in the art can create drawings illustrating other embodiments.

[0007] Specifically, the annotations for the accompanying drawings are as follows: Figure 1 This is a schematic diagram of the overall structure of the battery described in some embodiments of this application; Figure 2 This is a schematic diagram of the exploded structure of the battery described in some embodiments of this application; Figure 3 This is a first schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 4 This is a second schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 5 This is a third schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 6 This is a fourth schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 7 This is a fifth schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 8 This is a sixth schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application; Figure 9 This is a seventh schematic diagram of the peripheral structure of the first end wall as described in some embodiments of this application.

[0008] Specifically, the annotations for the figure marks in the instruction manual are as follows: 10. Housing; 101. First end wall; 1011. Injection hole; 1012. Protrusion; 1013. Cavity; 1014. First step; 1016. Second step; 1017. Flange; 1018. Channel; 1019. Side wall; 1020. Limiting groove; 1021. Second weld wire; 102. Second end wall; 103. Housing side wall; 20. Collector plate; 201. Through hole; 202. Flanged part; 203. Abutment part; 30. Cell assembly; 301. Cell body; 3011. Core hole; 302. First electrode ear; 303. Second electrode ear; 40. Sealing pin; 401. Body part; 402. Extension part; 50. Seal; 501. First weld wire; 60. Terminal post; Z, height direction. Detailed Implementation

[0009] To make the embodiments of this application clearer, they will be described below in conjunction with the accompanying drawings. It should be understood that the content mentioned below represents only some embodiments of this application, and not all embodiments are listed exhaustively. Therefore, other embodiments that can be obtained based on the following embodiments without any inventive effort fall within the protection scope of this application.

[0010] It should be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to impose strict limitations on the technical solutions unless the context clearly indicates otherwise. For example, the use of "a," "an," and "the" to modify a feature does not preclude the possibility that the feature may be plural in other embodiments.

[0011] It should be understood that the terms "comprising," "including," and "having" are open-ended, indicating the presence of the stated features but not excluding the possibility of other features in the embodiment. Similarly, the use of terms such as "first," "second," etc., to describe multiple features only indicates the distinction between one feature and another, and such terms do not imply order or sequence unless explicitly stated in the context.

[0012] It should be understood that, unless the context clearly indicates otherwise, the terms "setup," "connection," and "installation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a direct connection or an indirect connection via a medium. Those skilled in the art will understand the specific meaning of these terms in this document based on the specific circumstances.

[0013] In addition, for ease of description, the text will use terms of spatial relative relationship to describe the position of one feature relative to another feature, such as "inner", "outer", "end", "side", "upper", "middle", "lower", "high", "low", "axial", "circumferential", "radial", "horizontal", "vertical", "first direction", "second direction", etc. It can be understood that the spatial relative relationship between two features should include other specific situations besides those shown in the accompanying drawings of the specification.

[0014] The embodiments of this application are described below with reference to the accompanying drawings. It can be understood that the technical features involved in the different embodiments described below can be combined with each other as long as they do not conflict with each other.

[0015] First, let me further explain the background technology: Research has found that the main reason for the failure of the electrolyte injection hole 1011 is that when the electrolyte injection hole 1011 is located on the bottom wall of the battery casing 10, the electrolyte will flow into the space between the cell assembly 30 and the casing 10 due to gravity. In order to prevent the electrolyte from leaking from the electrolyte injection hole 1011, some batteries will be equipped with insulating sealing nails 40 to block the electrolyte injection hole 1011, and then welded metal sealing parts 50 to seal it. However, during the use of the battery, vibration will occur. Under the combined action of vibration and gravity, the insulating sealing nails 40 are easy to loosen or even fall off, resulting in electrolyte leakage, which in turn causes corrosion of the weld at the sealing parts 50, leading to sealing failure.

[0016] In the embodiments of this application, in the first aspect, combined with Figures 1 to 7 Key reference Figure 2 and Figure 3 A battery is proposed, comprising a housing 10, a current collector 20, a cell assembly 30, a sealing pin 40, and a sealing element 50. The housing 10 includes a first end wall 101, with the current collector 20 and the cell assembly 30 both disposed inside the housing 10 (the current collector 20 is located between the cell assembly 30 and the first end wall 101). Along the height direction Z of the battery, the cell assembly 30 is positioned above the first end wall 101. The cell assembly 30 includes a cell body 301 and a first electrode tab 302 electrically led out from the cell body 301, the first electrode tab 302 being electrically connected to the current collector 20. The first end wall 101 has a protrusion 1012 facing the cell body 301, the protrusion 1012 having a first stepped portion 1014 and a liquid injection hole 1011 penetrating the first stepped portion 1014. A stepped portion 1014 is welded to the current collector 20; the protrusion 1012 has a cavity 1013 on the side facing away from the cell body 301, and the cavity 1013 communicates with the injection hole 1011; the sealing pin 40 includes a connected body portion 401 and an extension portion 402, the extension portion 402 extends into the injection hole 1011 and is interference-fitted with the inner wall of the injection hole 1011; the body portion 401 is located inside the cavity 1013; the sealing member 50 is welded to the first end wall 101 to form a first weld line 501, and surrounds the sealing cavity 1013 with the first stepped portion 1014, and the sealing member 50 abuts against the side of the body portion 401 facing away from the cell body 301.

[0017] In this embodiment, refer to Figure 3A double sealing mechanism is achieved using the extension 402 and the body 401 of the sealing pin 40 to prevent electrolyte leakage into the cavity 1013, thereby ensuring that the first weld line 501 between the seal 50 and the first end wall 101 on the housing 10 is not affected. Specifically, the extension 402 of the sealing pin 40 blocks the injection hole 1011 in an interference fit to provide an initial sealing effect; the body 401 of the sealing pin 40 abuts against the bottom wall of the cavity 1013 and the seal 50 to achieve a secondary seal, further ensuring that electrolyte will not leak to the first weld line 501 between the seal 50 and the housing 10, causing corrosion to the first weld line 501.

[0018] Specifically, the protrusion 1012 can be formed by stamping the first end wall 101 using a stamping process; the injection hole 1011 can be formed by stamping the first step 1014 using a stamping process; and the welding method between the seal 50 and the housing 10 can be laser butt welding.

[0019] Optionally, the sealing pin 40 is an insulating elastic material component, such as silicone, fluororubber, soluble polytetrafluoroethylene, or polytetrafluoroethylene components, which can produce a certain elastic deformation to achieve an interference fit seal on the injection hole 1011 and at least part of the cavity 1013, thereby preventing the electrolyte from flowing to the first weld line 501 of the sealing component 50.

[0020] Optionally, the seal 50 is a metal part. Specifically, the material of the seal 50 can be the same as that of the housing 10, such as aluminum or stainless steel, because the welding effect between metals of the same polarity is better. More specifically, the seal 50 can be a sheet-like or plate-like structure, which not only facilitates welding connection with the first end wall 101 of the housing 10, serving as the final line of defense against electrolyte leakage, but also allows the metal seal 50 to cover the cavity 1013 and expose it. In cooperation with the housing 10, this ensures the strength of the overall battery structure (especially the structural strength at the injection hole 1011).

[0021] In addition, the seal 50 can protect the flexible sealing nail 40 from damage by external parts; and the seal 50 can provide extrusion force to the body part 401 of the sealing nail 40, thereby enabling the body part 401 to press against the bottom wall of the cavity 1013 and achieve sealing of the cavity 1013.

[0022] Furthermore, the sealing element 50 presses against the body portion 401 of the sealing nail 40, and the body portion 401 presses against the bottom of the cavity 1013 (that is, the back of the protrusion 1012), thereby pressing the weld between the protrusion 1012 and the collector plate 20, making the two fit more tightly and the welding effect better. In other words, it can improve the connection tightness, connection uniformity and conductivity of the welding interface between the housing 10 and the collector plate 20.

[0023] It should be noted that some batteries have the liquid injection hole 1011 and the terminal post 60 located on the same end face of the housing 10, and in order to coordinate the setting space of the two, the liquid injection hole 1011 is drilled in the middle of the terminal post 60. However, this design will reduce the current flow performance of the terminal post 60.

[0024] In this embodiment, refer to Figure 2 The injection hole 1011 and the electrode 60 can be disposed on two different end walls of the housing 10. For example, the injection hole 1011 is disposed on the first end wall 101 and the electrode 60 is disposed on the second end wall 102. The first end wall 101 and the second end wall 102 are located at opposite ends of the housing 10. This design can not only avoid interference between the electrode 60 and the injection hole 1011, but also ensure the flow performance of the electrode 60.

[0025] Specifically, refer to Figure 2 The two ends of the battery cell body 301 can be electrically led out as a first electrode tab 302 and a second electrode tab 303 respectively. The first electrode tab 302 is welded to the current collector 20, and the current collector 20 is welded to the protrusion 1012 on the first end wall 101 of the housing 10. The first end wall 101 leads the current through the housing side wall 103 of the housing 10 to the second end wall 102, and finally realizes the electric extraction of the first polarity current from the second end wall 102. In addition, the pole post 60 is provided on the second end wall 102 and is insulated from the second end wall 102. The second electrode tab 303 is directly connected to the pole post 60, or indirectly connected through an adapter, so as to realize the electric extraction of the second polarity current from the pole post 60.

[0026] Furthermore, in this embodiment, referring to Figure 3 The first end wall 101 of the housing 10 is provided with a protrusion 1012 facing the collector plate 20. The protrusion 1012 is welded to the collector plate 20. Compared with the entire surface of the first end wall 101 being welded to the collector plate 20, the welding area in this embodiment is reduced, which solves the problem of incomplete welding caused by the uneven thickness of the first end wall 101 and / or the collector plate 20, and improves the welding effect between the first end wall 101 of the housing 10 and the collector plate 20.

[0027] Optionally, refer to Figures 2 to 7 The collector plate 20 is also provided with an abutment portion 203 protruding toward the first end wall 101. The abutment portion 203 and the protrusion portion 1012 on the first end wall 101 are at least partially projected to coincide along the height direction Z of the battery. The abutment portion 203 on the collector plate 20 and the protrusion portion 1012 on the first end wall 101 are welded together, thereby further reducing the welding area, improving the uniformity of the contact surface between the two, and improving the welding effect.

[0028] It should be noted that the protrusion 1012 on the first end wall 101 and the abutment 203 on the collector plate 20 can be made by stamping.

[0029] Optionally, refer to Figure 1 and Figure 2 The battery is a cylindrical battery, which has advantages over square batteries such as strong resistance to mechanical impact, simple manufacturing process, and high consistency of individual cells. Specifically, the cell body 301 can be formed by winding the positive electrode, separator and negative electrode to form a core. The core does not require a pressure forming process and can be directly put into the cylindrical battery casing 10. It has good adaptability, high production efficiency, and high utilization rate of the internal space of the cylindrical casing 10.

[0030] Furthermore, referring to Figure 2 The core has a core hole 3011 in the middle, which corresponds to the injection hole 1011. This prevents the cell body 301 from blocking the electrolyte from flowing into the casing 10 from the injection hole 1011. It also promotes the electrolyte to fully wet the cell body 301 through the core hole 3011, thereby enhancing the battery performance.

[0031] As can be seen from the above, the battery in this application is a cylindrical battery with a high internal space utilization rate. There is less electrolyte between the cell assembly 30 and the casing 10, and most of the electrolyte can be injected into the cell assembly 30 through the combination of the injection hole 1011 and the core hole 3011.

[0032] Furthermore, referring to Figure 2 and Figure 3 First, the current collector 20 is welded to the first end wall 101. Then, the cell assembly 30 is placed inside the cylinder formed by the side wall 103 of the housing. The first electrode ear 302 in the cell assembly 30 is removed and welded to the current collector 20. Then, the first end wall 101 is welded to the side wall 103 of the housing. The second electrode ear 303 in the cell assembly 30 is removed and directly welded to the electrode post 60 on the second end wall 102 or indirectly connected through an adapter. Then, the second end wall 102 is welded to the side wall 103 of the housing. Electrolyte is injected into the housing 10 through the injection hole 1011 on the first end wall 101. After the injection is completed, the injection hole 1011 is sealed with a sealing pin 40. Subsequently, a battery formation reaction may be carried out first, and then the sealing pin 40 may be opened for a second injection. Finally, the sealing element 50 is welded to the first end wall 101 for final sealing, and the sealing pin 40 is squeezed to fully seal the injection hole 1011 and the cavity 1013.

[0033] It should be noted that, referring to Figure 2 and Figure 3In some battery designs, the upper end of the casing 10 is provided with a terminal post 60, and the lower end of the casing 10 is provided with an injection hole 1011. During battery use, the electrolyte is affected by gravity and may leak, flowing irregularly and seeping into the weld of the sealing component, corroding the weld mark 501, thus causing seal failure. Furthermore, to prevent electrolyte leakage from the injection hole 1011, some batteries are equipped with a sealing pin 40 to block the injection hole 1011. However, during battery use, vibration occurs, and under the combined action of vibration and gravity, the sealing pin 40 is prone to loosening, leading to electrolyte leakage, which in turn causes corrosion of the weld mark 501 at the sealing component 50, resulting in seal failure. Therefore, in this embodiment, the sealing component 50 is used to compress the body part 401 of the sealing pin 40, and the body part 401 is pressed tightly between the sealing component 50 and the bottom wall of the cavity 1013 to achieve a sufficient seal.

[0034] Optionally, refer to Figure 2 The first tab 302 and / or the second tab 303 are full tabs, which means that the entire current collector edge (or tail) of the cell body 301 is led out as tabs and flattened to achieve full-surface current conduction, thereby improving the battery's overcurrent capacity and production efficiency; in particular, the full tab setting is especially compatible with cylindrical batteries.

[0035] To enhance understanding of this application, some features of the battery are described below.

[0036] (1) Housing 10: Housing 10 is a component used to provide a receiving space to house the battery cell assembly 30 and other components and isolate them from the outside environment. Housing 10 generally includes a body with an opening at at least one end and a receiving cavity. The opening of housing 10 can be closed by a cover plate to seal and isolate the internal environment of the battery cell from the external environment. The materials of housing 10 include, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, aluminum-plastic film, etc.

[0037] (2) Cell Assembly 30: The cell body 301 in the cell assembly 30 is the component in the battery where electrochemical reactions occur, and is the smallest unit in the battery capable of electrochemical reactions such as charging / discharging. The cell assembly 30 is the basic unit in the battery, and typically includes a positive electrode, a negative electrode, and a separator. Lithium-ion cells mainly rely on the insertion and extraction of lithium ions between the positive and negative electrodes to operate. In cylindrical cells, the thin film structure of three layers of material is wound into a cylindrical electrode assembly, while in cuboid cells, the thin film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0038] (3) Tab: The tab is located on one side of the current collector in the positive / negative electrode plate and is formed separately / integrally with the current collector. That is, the tab is electrically connected to the current collector to conduct the current on the corresponding current collector. The tab is made of a metal material with good conductivity (such as copper, aluminum, copper or nickel).

[0039] (4) Terminal 60: Terminal 60 is used to electrically connect the cell assembly 30 located inside the housing 10 to external devices (adjacent batteries or other electrical equipment) located outside the housing 10. The battery can discharge to external devices through the electrical connection between the cell output terminal (tab) and the external device output terminal (terminal 60), and an external power source can also charge the battery through this path. Terminal 60 can be directly electrically connected to the tab or electrically connected to the tab through a metal adapter. Terminal 60 is made of metal materials including but not limited to copper, aluminum, aluminum alloy, and copper-aluminum alloy.

[0040] (5) Adapter: One end is used to electrically connect to the output terminal (tab) of the cell body 301, and the other end is used to electrically connect to the output terminal (terminal 60) of the battery, so that the tab and the terminal 60 form a current conduction. The adapter can be an aluminum adapter, a copper adapter, or an alloy (such as steel) adapter, or other conductive materials. The specific material of the adapter is selected according to the material of the battery terminal 60 and the tab. Generally, the material of the adapter must be the same as the material of the battery tab and the terminal 60 to ensure the welding quality.

[0041] (6) Current collector 20: It is a key structural component in lithium-ion batteries (especially cylindrical batteries), mainly used to collect current and connect the tabs to the casing 10 / terminal 60. It plays a dual role of electrical connection and structural support inside the battery. Among them, the negative current collector 20 is usually made of nickel-plated steel or copper, while the positive current collector 20 is mostly made of aluminum or aluminum alloy.

[0042] In some embodiments, combined with Figure 8 and Figure 9 The initial height of the cavity 1013 is H, the thickness of the seal 50 extending into the cavity 1013 is h, and the remaining height of the cavity 1013 after the seal 50 covers the cavity 1013 is Hh; the initial thickness of the body part 401 is d, the maximum compressibility coefficient of the body part 401 is ε, and the minimum thickness of the body part 401 after being compressed is (dd×ε), and the difference between (dd×ε) and (Hh) is 0 to 2.2 mm.

[0043] In this embodiment, for example, H can be from 0.3mm to 2.5mm. Specifically, H can be any one of 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, and 2.5mm, or a range between any two of these values. h can be from 0.3mm to 2mm. Specifically, h can be any one of 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, and 2mm, or a range between any two of these values. Hh can be 0.2mm-2.2mm, specifically, Hh can be any one of 0.2mm, 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.2mm or within any two of these values; d can be 2mm-4mm, specifically, d can be 2mm, 2.5mm, 3mm, 3.5mm, and 4mm; ε can be 0.4; (dd×ε) can be 1.2mm-2.4mm, specifically, it can be any one of 1.2mm, 1.5mm, 1.8mm, 2mm, 2.4mm or within any two of these values.

[0044] In this embodiment, the thickness of the body part 401 when compressed to its thinnest is dd×ε. After the sealing member 50 covers the cavity 1013, the remaining height inside the cavity 1013 is Hh. The difference between (dd×ε) and (Hh) is greater than 0. That is, when the body part 401 is compressed to its thinnest, its thickness is still greater than the remaining height of the cavity 1013 after the sealing member 50 is assembled. In other words, the body part 401 must be interference-fitted between the sealing member 50 and the bottom wall of the cavity 1013 to ensure that the body part 401 of the sealing nail 40 has sufficient reaction force, so that the protrusion 1012 and the manifold 20 fit tightly together, thereby improving the welding quality and sealing performance.

[0045] Furthermore, the difference between (dd×ε) and (Hh) is less than or equal to 2.2 mm, which can control the compression amount and avoid excessive interference, which may push up the seal 50, causing the weld line between the seal 50 and the shell 10 to crack, leading to the seal failure of the seal 50, communication between the inside and outside of the battery, and affecting the safety of battery use. At the same time, it avoids the large rebound force of the sealing nail 40 during the welding process, which may cause the welding position of the seal 50 and the first wall to deviate, resulting in a small weld size between the seal 50 and the shell 10 and the risk of incomplete welding. Thus, a balance is achieved between sealing performance and process feasibility.

[0046] It is important to note that when selecting and using the sealing pin 40 and the sealing element 50, excessive compression of the sealing pin 40 should be avoided as much as possible. This is to prevent the sealing pin 40 from being crushed and failing or from undergoing permanent deformation, which would result in a loss of its rebound sealing ability. This would lead to insufficient contact force between the sealing pin 40 and the first wall, resulting in a sealing gap during battery vibration, electrolyte leakage, and corrosion of the structural strength of the weld wire between the current collector 20 and the step surface. This would cause the weld wire to be corroded, affecting the current transmission of the battery.

[0047] Specifically, (dd×ε)-(Hh) can take any one of the following values: 0mm, 0.5mm, 1mm, 1.5mm, 1.8mm, 2mm, 2.2mm, or a range between any two of these values.

[0048] In some embodiments, combined with Figure 3 and Figure 4 The first end wall 101 also includes a second step portion 1016 and a side wall 1019, the second step portion 1016 and the side wall 1019 forming a limiting groove 1020, the second step portion 1016 being disposed away from the cell assembly 30 compared to the first step portion 1014, the sealing member 50 being at least partially located within the limiting groove 1020, and the sealing member 50 being welded to the limiting groove 1020.

[0049] In this embodiment, the first end wall 101 forms a limiting groove 1020 using the second step portion 1016 and the side wall 1019. The limiting groove 1020 limits the edge of the seal 50, preventing the seal 50 from deviating, ensuring accurate positioning and convenient installation. Moreover, the second step portion 1016 provides a welding connection base for the seal 50, ensuring a firm connection. In addition, the limiting groove 1020 is recessed, providing a receiving space for the seal 50 and preventing the seal 50 from protruding from the first end wall 101, thereby making the first end wall 101 relatively flat overall.

[0050] It should be noted that in some embodiments, the two ends of the seal 50 may be welded to the side wall 1019 or the second step portion 1016; of course, in other embodiments, the ends of the seal 50 may also be welded to both the side wall 1019 and the second step.

[0051] In some embodiments, refer to Figure 3 The side of the seal 50 facing away from the cell assembly 30 does not protrude from the side of the first end wall 101 facing away from the cell assembly 30.

[0052] In this embodiment, the limiting groove 1020 is recessed to provide a receiving space for the sealing member 50, so that the sealing member 50 does not protrude from the first end wall 101, achieving a relatively flat effect for the first end wall 101 as a whole; in addition, it can also ensure that the first weld line 501 between the sealing member 50 and the second step portion 1016 does not protrude from the first end wall 101, thereby further ensuring the flatness of the first end wall 101.

[0053] In some embodiments, combined with Figure 3 and Figure 4 The ratio a / b of the depth a of the limiting groove 1020 to the depth b of the cavity 1013 is 0.5-17.

[0054] It should be noted that the depth of cavity 1013 refers to the depth after the sealing member 50 is sealed. The depth of the limiting groove 1020 and the depth of cavity 1013 are both dimensions along the height direction Z of the battery.

[0055] In this embodiment, if a / b is too small, that is, the depth of the limiting groove 1020 is too small, while the thickness of the sealing member 50 remains unchanged, the sealing member 50 may protrude from the limiting groove 1020, thereby affecting the flatness of the first end wall 101 and causing the battery to vibrate easily during use. This makes it difficult to guarantee the welding strength of the first welding line 501 on the sealing member 50. In addition, this will also cause the first welding line 501 to protrude from the first end wall 101, and further lead to poor flatness of the bottom surface of the housing 10.

[0056] If a / b is too large, that is, the depth of the limiting groove 1020 is large, when the seal 50 is only welded to the side wall 1019, that is, the seal 50 with the same thickness does not contact the second step portion 1016, it is easy to cause insufficient resistance of the seal 50 to the sealing nail 40, the sealing effect of the body portion 401 of the sealing nail 40 to the cavity 1013 is poor, and the electrolyte is easy to leak into the cavity 1013 and affect the welding effect of the first welding line 501 and the second welding line 1021.

[0057] Optionally, a / b can take any one of the values ​​of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 and 17 or a range between any two of these values.

[0058] Optionally, the value of 'a' ranges from 1mm to 5mm. For example, 'a' can be any one of 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm, or fall within the range of any two of these values. The value of 'b' ranges from 0.3mm to 2mm. For example, 'b' can be any one of 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, and 2mm, or fall within the range of any two of these values.

[0059] In some embodiments, the center line of the body portion 401 coincides with the center line of the cavity 1013.

[0060] In this embodiment, the center line of the body part 401 coincides with the center line of the cavity 1013, which can ensure that the compressive force of the body part 401 is uniformly transmitted to the inner wall of the cavity 1013 along the axial direction. This ensures that the protrusion 1012 and the collector plate 20 are uniformly fitted through the transmission of force, and avoids local sealing failure caused by pressure bias.

[0061] Furthermore, aligning the centerline of the main body 401 with the centerline of the cavity 1013 can improve the symmetry of the structure, which is beneficial for automated assembly and reduces assembly defects caused by eccentricity.

[0062] It should be noted that the center lines of the main body 401 and the extension 402 of the sealing nail 40 coincide.

[0063] In some embodiments, refer to Figure 5 Before the sealing member 50 covers the cavity 1013, on the projection plane perpendicular to the height direction Z of the battery, the cross-sectional area of ​​the main body 401 is S1, and the cross-sectional area of ​​the cavity 1013 is S2, and S1≥S2 is satisfied.

[0064] In this embodiment, S1≥S2 means that the body part 401 can fill a large portion or completely cover the cavity 1013. Moreover, when S1>S2, the body part 401 can be higher than the cavity 1013, forming an interference fit. This allows the body part 401 to fully seal the cavity 1013 under the pressure of the seal 50 and the bottom wall of the cavity 1013, thereby isolating the electrolyte from contacting the solder mark 501 and fundamentally preventing corrosion.

[0065] Furthermore, the elastic force of the main body 401 is evenly distributed throughout the cavity 1013, making the force on the sealing element 50 and the inner wall of the cavity 1013 more uniform.

[0066] It should be noted that, as Figure 3 As shown, after the sealing element 50 seals the cavity 1013, the body part 401 can fill part of the remaining space of the cavity 1013; as Figure 4 As shown, after the sealing member 50 covers the cavity 1013, the body part 401 can also fill all the remaining space of the cavity 1013; the above are all preferred embodiments.

[0067] The sealing nail 40 body 401 fills the cavity 1013 in a large number of ways. This not only strengthens the seal and prevents electrolyte from leaking into the solder 501, but also applies pressure more evenly to the bottom wall of the cavity 1013, ensuring that the protrusion 1012 of the first bottom wall fits tightly with the abutment 203 of the collector 20, thus enhancing the connection and improving the conductivity.

[0068] However, since the sealing nail 40 body 401 fills the cavity 1013 in large quantities, it is necessary to pay attention to the large interference fit, which may easily push up the sealing element 50 or cause difficulties in welding and assembling the sealing element 50 with the first end wall 101.

[0069] In some embodiments, along the radial direction of the injection hole 1011, the shortest distance between the edge of the first weld line 501 and the injection hole 1011 is 3 mm to 12 mm.

[0070] In this embodiment, if the shortest distance is too small, the electrolyte at the injection hole 1011 will easily cause the first bonding wire 501 to be at greater risk of corrosion. If the shortest distance is too large, the current-carrying area of ​​the current collector 20 will be small, affecting the current transmission of the battery.

[0071] Therefore, the aforementioned shortest distance should be moderate, for example, it can be any one of 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, or 12mm, or fall within the range of any two of these values.

[0072] In some embodiments, refer to Figure 3 The first step portion 1014 is welded to the collector plate 20 to form a second weld line 1021, and the second weld line 1021 is set through the first step portion 1014.

[0073] In this embodiment, the second welding line 1021 starts welding from the side of the first step portion 1014 facing away from the cell assembly 30, and welds through the first step portion 1014, reducing its size on the side close to the cell assembly 30, so that the weld width gradually narrows, thereby reducing the risk of electrolyte corrosion.

[0074] In some embodiments, refer to Figure 3 The second welding line 1021 does not penetrate the side of the current collector 20 near the cell assembly 30.

[0075] In this embodiment, since the current collector 20 is closer to the cell assembly 30, that is, closer to the electrolyte, the second bonding wire 1021 is welded from the side of the first step portion 1014 to the side of the current collector 20 without welding through the current collector 20, thereby ensuring that the second bonding wire 1021 is not at risk of being corroded by the electrolyte.

[0076] It should be noted that laser penetration welding can be used to weld the manifold 20 and the first step 1014.

[0077] In some embodiments, refer to Figure 3 The collector plate 20 is provided with a through hole 201, and the through hole 201 and the liquid injection hole 1011 at least partially overlap in projection along the height direction Z of the battery.

[0078] In this embodiment, the collector plate 20 is provided with a through hole 201, which corresponds to the injection hole 1011 to avoid obstructing the injection process. It should be noted that in some embodiments, the cell body 301 can be formed by winding a positive electrode sheet, a separator and a negative electrode sheet to form a core. The core has a core hole 3011 in the middle. The core hole 3011, the injection hole 1011 and the through hole 201 on the collector plate 20 correspond to each other to ensure that the needle is accurately inserted during injection and to avoid injection deviation or damage to the cell.

[0079] In addition, the through hole 201 in the collector plate 20 can reduce the contact area between the collector plate 20 and the first end wall 101, improve the thickness uniformity of the contact surface between the collector plate 20 and the protrusion 1012 of the first end wall 101, and improve the welding effect.

[0080] In some embodiments, the injection hole 1011 protrudes in the direction of the cell assembly 30 to form an annular flange 1017, and a channel 1018 is formed inside the flange 1017 and communicates with the injection hole 1011; on the orthographic projection plane of the battery height direction Z, the orthographic projection of the flange 1017 is located within the orthographic projection range of the first step portion 1014.

[0081] In this embodiment, the above-mentioned arrangement ensures the welding area between the first step portion 1014 and the collector plate 20, while also ensuring that the liquid injection hole 1011 accurately injects the liquid into the cell body 301 after injection, avoiding liquid spillage during the injection process and corrosion of the welding wire.

[0082] In some embodiments, the collector 20 is provided with a through hole 201, and along the height direction Z of the battery, the flange 1017 is inserted into the through hole 201.

[0083] In this embodiment, the flange 1017 extends toward the cell body 301 and into the through hole 201, making the positioning more accurate and avoiding misalignment between the injection hole 1011 and the through hole 201 on the collector plate 20, which would affect the injection effect.

[0084] Furthermore, referring to Figure 3 The collector plate 20 is provided with a flange 202 around the edge of the through hole 201, and the flange 202 extends toward the cell body 301.

[0085] In this embodiment, the flange 202 is located on the outer side of the injection hole 1011 wall and cooperates with the injection hole 1011 to further improve the alignment accuracy between the injection hole 1011 and the through hole 201, improve component assembly efficiency, and ensure injection effect. Furthermore, the flange 202 can abut against or be spaced from the outer wall of the injection hole 1011 to limit or buffer vibrations of the injection hole 1011, preventing excessive outward deformation of the injection hole 1011 wall, and also serving to protect the injection hole 1011 wall.

[0086] Specifically, refer to Figure 3 The flange 202 is located at the edge of the abutment portion 203.

[0087] It should be understood that, referring to Figure 7 Alternatively, the collector plate 20 may not have the flange 202, which is also a viable implementation method.

[0088] Or, refer to Figure 3 The flanged portion 202 is clearance-fitted with the wall of the injection hole 1011. In this embodiment, the clearance fit between the flanged portion 202 and the wall of the injection hole 1011 serves as a vibration buffer for the injection hole 1011. Furthermore, this embodiment does not excessively limit the wall of the injection hole 1011, ensuring that the injection hole 1011 can have a certain amount of outward deformation, thus ensuring flexibility in its adaptation to the sealing nail 40 and the manifold.

[0089] It should be understood that, referring to Figure 6 Alternatively, the flanged part 202 can directly abut against the wall of the injection hole 1011, which is also a desirable implementation method.

[0090] In some embodiments, a winding hole 3011 is formed at the center of the cell body 301, and on the positive projection plane in the height direction Z of the battery, the projection of the flange 1017 and the projection of the winding hole 3011 at least partially coincide.

[0091] In this embodiment, the flange 1017 and the core hole 3011 at least partially overlap in projection, that is, the core hole 3011 can correspond to the injection hole 1011, thereby preventing the cell body 301 from blocking the electrolyte from flowing into the housing 10 from the injection hole 1011, and promoting the electrolyte to fully wet the cell body 301 through the core hole 3011, thereby enhancing the battery performance.

[0092] Furthermore, the centerlines of the injection hole 1011, the cavity 1013, and the sealing pin 40 coincide, resulting in a highly symmetrical structure. This ensures that injection, sealing, and force application are all along the same axis, avoiding problems such as uneven compression of the sealing pin 40 due to eccentricity, loosening under shear force, or poor injection. Moreover, this embodiment improves the uniformity of the contact force between the protrusion 1012 and the collector plate 20 through the uniform pressure of the body part 401, resulting in a tight connection between the protrusion 1012 and the collector plate 20 and improved conductivity. In addition, this embodiment also improves assembly consistency and increases production efficiency.

[0093] In some embodiments not shown in the figures, along the battery height direction Z, the flange 1017 is at least partially inserted into the core hole 3011.

[0094] In this embodiment, the electrolyte injection rate can be increased and the free electrolyte between the cell body 301 and the housing 10 can be reduced.

[0095] It should be noted that the core hole 3011 at least partially penetrates the axial direction of the battery cell, and preferably completely penetrates it.

[0096] In some embodiments, refer to Figure 3 Along the height direction Z of the battery, the extension 402 of the sealing pin 40 is at least partially inserted into the channel 1018 of the flange 1017.

[0097] In this embodiment, the extension 402 is at least partially inserted into the channel 1018, thereby achieving a better sealing effect.

[0098] In some embodiments, along the height direction Z of the battery, the extension 402 of the sealing pin 40 extends beyond the channel 1018 of the flange 1017, and the bottom end of the extension 402 is disposed between the end face of the cell body 301 and the bottom end of the flange 1017.

[0099] In this embodiment, the extension 402 protrudes from the bottom end of the flange 1017, which can further improve the sealing performance.

[0100] In some embodiments, the extension 402 protrudes from the bottom end of the flange 1017 in the height direction Z of the battery by 1mm-3mm.

[0101] In this embodiment, if the extension 402 protrudes too small from the bottom of the flange 1017, the sealing effect will be poor, and the electrolyte will easily flow into the cavity 1013 through the space between the sealing nail 40 and the inner wall of the flange 1017, corroding the solder wire; if the extension 402 protrudes too large, it will occupy the internal space of the housing 10 and affect the energy density inside the battery.

[0102] Optionally, the dimension of the bottom end of the protruding flange 1017 of the extension 402 can be any one of 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm or a range between any two of these values.

[0103] In some embodiments, refer to Figure 3 On the positive projection plane of the battery height direction Z, the projected area of ​​the extension 402 near the end of the cell assembly 30 is smaller than the projected area of ​​the extension 402 away from the cell assembly 30.

[0104] In this embodiment, the radial dimension of the extension 402 near the end of the cell assembly 30 is smaller, which makes it easier for the sealing pin 40 to pass through the injection hole 1011 and the channel 1018, thereby enabling better assembly. In addition, the extension 402 protrudes from the flange 1017, and the radial dimension of the extension 402 away from the end of the cell assembly 30 is larger, thereby enabling better sealing with the injection hole 1011 and improving the sealing effect.

[0105] In some embodiments, refer to Figure 1 and Figure 2 The battery is a cylindrical battery.

[0106] In some embodiments, refer to Figure 1 and Figure 2 The housing 10 also includes a second end wall 102, which is disposed opposite to the first end wall 101 along the height direction Z of the battery. The second end wall 102 is provided with a terminal post 60. The cell assembly 30 also includes a second electrode tab 303 electrically led out from the cell body 301, which is electrically connected to the terminal post 60.

[0107] In some embodiments, the first end wall 101 (bottom) is used for liquid injection without interference from the electrode post 60; the second end wall 102 (top) is provided with the electrode post 60 for current output, which completely avoids the "spatial conflict caused by the electrode post 60 and the liquid injection hole 1011 being arranged at the same end", and at the same time, the cooperation between the sealing pin 40 and the sealing element 50 is used to prevent the electrolyte from flowing to the solder mark 501 due to gravity.

[0108] It should be noted that some batteries have the liquid injection hole 1011 and the terminal post 60 located on the same end face of the housing 10, and in order to coordinate the setting space of the two, the liquid injection hole 1011 is drilled in the middle of the terminal post 60. However, this design will reduce the current flow performance of the terminal post 60.

[0109] In this embodiment, refer to Figure 2The injection hole 1011 and the electrode 60 can be disposed on two different end walls of the housing 10. For example, the injection hole 1011 is disposed on the first end wall 101 and the electrode 60 is disposed on the second end wall 102. The first end wall 101 and the second end wall 102 are located at opposite ends of the housing 10. This design can not only avoid interference between the electrode 60 and the injection hole 1011, but also ensure the flow performance of the electrode 60.

[0110] Specifically, refer to Figure 2 The two ends of the battery cell body 301 can be electrically led out as a first electrode tab 302 and a second electrode tab 303 respectively. The first electrode tab 302 is welded to the current collector 20, and the current collector 20 is welded to the protrusion 1012 on the first end wall 101 of the housing 10. The first end wall 101 leads the current through the housing side wall 103 to the second end wall 102, and finally realizes the electric extraction of the first polarity current from the second end wall 102. In addition, the pole post 60 is provided on the second end wall 102 and is insulated from the second end wall 102. The second electrode tab 303 is directly connected to the pole post 60, or indirectly connected through an adapter, so as to realize the electric extraction of the second polarity current from the pole post 60.

[0111] In addition, refer to Figure 1 and Figure 2 The battery is a cylindrical battery, which has advantages over square batteries such as strong resistance to mechanical impact, simple manufacturing process, and high consistency of individual cells. Specifically, the cell body 301 can be formed by winding the positive electrode, separator and negative electrode to form a core. The core does not require a pressure forming process and can be directly put into the cylindrical battery casing 10. It has good adaptability, high production efficiency, and high utilization rate of the internal space of the cylindrical casing 10.

[0112] Furthermore, referring to Figure 2 The core has a core hole 3011 in the middle, which corresponds to the injection hole 1011. This prevents the cell body 301 from blocking the electrolyte from flowing into the casing 10 from the injection hole 1011. It also promotes the electrolyte to fully wet the cell body 301 through the core hole 3011, thereby enhancing the battery performance.

[0113] Furthermore, referring to Figure 2 and Figure 3First, the current collector 20 is welded to the first end wall 101. Then, the cell assembly 30 is placed inside the cylinder formed by the side wall 103 of the housing. The first electrode ear 302 in the cell assembly 30 is removed and welded to the current collector 20. Then, the first end wall 101 is welded to the side wall 103 of the housing. The second electrode ear 303 in the cell assembly 30 is removed and directly welded to the electrode post 60 on the second end wall 102 or indirectly connected through an adapter. Then, the second end wall 102 is welded to the side wall 103 of the housing. Electrolyte is injected into the housing 10 through the injection hole 1011 on the first end wall 101. After the injection is completed, the injection hole 1011 is sealed with a sealing pin 40. Subsequently, a battery formation reaction may be carried out first, and then the sealing pin 40 may be opened for a second injection. Finally, the sealing element 50 is welded to the first end wall 101 for final sealing, and the sealing pin 40 is squeezed to fully seal the injection hole 1011 and the cavity 1013.

[0114] It should be noted that, referring to Figure 2 and Figure 3 In some battery designs, the upper end of the casing 10 is provided with a terminal post 60, and the lower end of the casing 10 is provided with an injection hole 1011. During battery use, the electrolyte is affected by gravity and may leak, flowing irregularly and seeping into the weld of the sealing component, corroding the weld mark 501, thus causing seal failure. Furthermore, to prevent electrolyte leakage from the injection hole 1011, some batteries are equipped with a sealing pin 40 to block the injection hole 1011. However, during battery use, vibration occurs, and under the combined action of vibration and gravity, the sealing pin 40 is prone to loosening, leading to electrolyte leakage, which in turn causes corrosion of the weld mark 501 at the sealing component 50, resulting in seal failure. Therefore, in this embodiment, the sealing component 50 is used to compress the body part 401 of the sealing pin 40, and the body part 401 is pressed tightly between the sealing component 50 and the bottom wall of the cavity 1013 to achieve a sufficient seal.

[0115] Optionally, refer to Figure 2 The first tab 302 and / or the second tab 303 are full tabs, which means that the entire current collector edge (or tail) of the cell body 301 is led out as tabs and flattened to achieve full-surface current conduction, thereby improving the battery's overcurrent capacity and production efficiency; in particular, the full tab setting is especially compatible with cylindrical batteries.

[0116] The measurement methods, preparation methods, and embodiments in this application are described below.

[0117] Dimension measurement method: Use measuring instruments such as micrometers or calipers to measure parameters such as length, width, depth, diameter, radius, distance, and thickness. The area is calculated from the aforementioned parameters.

[0118] Battery manufacturing (1) Preparation of the positive electrode: The positive electrode active material, conductive agent acetylene black, and binder PVDF are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, it is cold-pressed and slit to obtain the positive electrode sheet. Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98):(4~1):(4~1).

[0119] (2) Preparation of negative electrode: The negative electrode active material, conductive agent acetylene black, thickener CMC, and binder SBR are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained. The ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96): (4~2): (2~1): (4~1).

[0120] (3) Preparation of electrolyte: Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0121] (4) Preparation of the diaphragm: Polyethylene film is selected as the diaphragm.

[0122] (5) Battery fabrication: The positive electrode, separator, and negative electrode are stacked in sequence and wound to form a bare battery cell, which is then placed in a cylindrical battery casing. The battery is dried, injected with electrolyte, sealed using a sealing component 50, and then subjected to settling, formation, and volume adjustment to obtain the battery.

[0123] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate; the negative electrode active material can be selected from one or more negative electrode active main materials, such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0124] The testing method is as follows: Test Method 1: Deformation of Seal 50 Following the battery preparation method described above, for each embodiment and comparative example, 10 batteries were prepared, with all other test conditions remaining consistent. Before vibration, the distance from the center point of the seal 50 on the side opposite to the battery to the bottom surface of the battery casing was measured in the battery height direction Z (first direction), and recorded as the original height difference L1.

[0125] The battery was mounted on a vibration table according to GB / T2423.43. The testing procedure was conducted according to GB / T2423.56. Random and fixed-frequency vibration loads were applied in each direction, with the loading sequence preferably being: random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the line connecting the front and rear of the battery is the x-axis direction, and the other horizontal direction perpendicular to the x-axis is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc., are shown in the table below.

[0126]

[0127] After the vibration ends, the distance from the center point of the seal 50 on the side opposite to the battery to the bottom surface of the battery casing is measured again in the Z direction of battery height, and recorded as the measured height difference L2. The deformation of the seal 50 of a single battery = |L1-L2|. The average value of the "deformation of the seal 50 of a single battery" of 10 batteries of the same embodiment or comparative example is taken as the deformation of the seal 50 of that embodiment or comparative example.

[0128] If the deformation of seal 50 is greater than 0.2mm, it is unqualified; if the deformation of seal 50 is 0.1mm but less than or equal to 0.2mm, it is qualified; if the deformation of seal 50 is less than or equal to 0.1mm, it is good.

[0129] Test Method 2: Battery leakage rate after cycling Following the battery preparation method described above, for each embodiment and comparative example, 100 batteries were prepared, and all other testing conditions remained consistent.

[0130] The battery was charged at room temperature (25℃) with a constant current of 0.33C to the upper limit voltage of 4.25V, and then discharged with a constant voltage until the current dropped to 0.05C. After resting for 5 minutes, the battery was discharged with a constant current of 0.33C to the lower limit voltage of 2.5V. This constitutes one cycle. After performing 500 charge-discharge cycles on the lithium-ion battery, the junction between the battery casing and the seal 50 was observed for leakage. The leakage rate was calculated as (leakage rate of batteries / 100) * 100%.

[0131] If the battery leakage rate is less than or equal to 2%, the test result is considered good; if the battery leakage rate is less than or equal to 4% but greater than 2%, the test result is considered qualified; if the battery leakage rate is greater than 4%, it is considered unqualified.

[0132] Different systems require corresponding adjustments to their upper and lower voltage limits: Lithium iron phosphate (LFP) - upper limit 3.65V, lower limit 2.5V; Nickel-cobalt-manganese ternary NCM - upper limit 4.25V, lower limit 2.5V; Lithium manganese iron phosphate (LFMP) - upper limit 4.25V, lower limit 2.5V; Lithium nickel manganese oxide - upper limit 4.8V, lower limit 3.5V.

[0133] In this test, the positive electrode active material of the battery was selected as a nickel-cobalt-manganese ternary LiNi0.6Co0.2Mn0.2O2. Other positive electrode materials all met the above test requirements. The mass ratio of positive electrode active material: conductive agent: binder met 96:2:2. The negative electrode active material was selected as artificial graphite. The ratio of negative electrode active material: conductive agent: thickener: binder met 95:2:1:2.

[0134] In the selection of materials for the battery, this application may also select other materials, not limited to the materials limited by the above preparation method. The positive electrode active material may be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt and manganese, and lithium manganese iron phosphate; the negative electrode active material may be selected from one or more negative electrode active main materials, such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0135] The conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P, etc.), carbon nanotubes, graphene, and carbon nanofibers.

[0136] The adhesive includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0137] The solvent can be deionized water, NMP (N-methylpyrrolidone), alcohol, ether, ketone or other types of pyrrolidone, etc.

[0138] The positive electrode current collector foil can be a metal foil or a composite current collector. For example, as a metal foil, it can be made of stainless steel, copper, aluminum, carbon electrodes, carbon, nickel, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0139] The negative electrode current collector foil can be made of stainless steel, copper, aluminum, carbon electrodes, carbon, nickel, or titanium, etc., with a surface silver plating treatment. Composite current collectors may include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming metal materials (aluminum, aluminum alloys, copper, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0140] The example table is as follows:

[0141] Secondly, this application also proposes an electrical device that includes the battery described in the first aspect.

[0142] Understandably, the electrical device proposed in the second aspect has all the technical effects of the battery in the first aspect, and the specific technical effects of the battery will not be elaborated here.

[0143] Furthermore, electrical devices can be, but are not limited to, devices in a wide range of technical fields such as energy storage devices, electronic devices, power tools, and electric vehicles.

[0144] Among them, batteries can serve as the operating power source for electrical devices, or as the driving power source for electrical devices, replacing or partially replacing fuel oil or natural gas to provide driving force for electrical devices.

[0145] It should be understood that the electrical device in this embodiment may also include other components, such as control systems, execution systems, etc., which will not be described in detail here.

[0146] In particular, the term "and / or" in this application should be understood as follows: In the first case, the term “and / or” between the first subject and the second subject includes any of the following meanings: (1) only the first subject; (2) only the second subject; and (3) both the first subject and the second subject.

[0147] In the second case, the term "and / or" between the last two of three or more subjects means including at least one of the subjects. For example, "first subject, second subject and / or third subject" has the same meaning as "first subject and / or second subject and / or third subject", specifically including the following combinations: (1) only the first subject; (2) only the second subject; (3) only the third subject; (4) first subject and second subject and no third subject; (5) first subject and third subject and no second subject; (6) second subject and third subject and no first subject; and (7) first subject, second subject and third subject; Furthermore, the character " / " in this application indicates that the objects before and after it are in an "or" relationship.

[0148] Finally, although the embodiments of this application have been described above in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the concept of this application, and such modifications and variations all fall within the scope of protection of this application.

Claims

1. A battery, characterized in that, include: The housing (10) includes a first end wall (101); A collector plate (20) is disposed inside the housing (10); A battery cell assembly (30) is disposed inside the housing (10) along the height direction (Z) of the battery. The battery cell assembly (30) is disposed above the first end wall (101). The battery cell assembly (30) includes a battery cell body (301) and a first electrode tab (302) electrically led out from the battery cell body (301). The first electrode tab (302) is electrically connected to the current collector (20). The first end wall (101) is provided with a face facing the battery cell body. The protrusion (1012) of the body (301) has a first stepped portion (1014) and an injection hole (1011) penetrating the first stepped portion (1014). The first stepped portion (1014) is welded to the collector plate (20). The protrusion (1012) has a cavity (1013) on the side opposite to the battery cell body (301). The cavity (1013) communicates with the injection hole (1011). The sealing pin (40) includes a connected body portion (401) and an extension portion (402), the extension portion (402) extending into the injection hole (1011) and having an interference fit with the inner wall of the injection hole (1011); the body portion (401) is located inside the cavity (1013); The sealing element (50) is welded to the first end wall (101) to form a first weld line (501), and surrounds and seals the cavity (1013) with the first step portion (1014). The sealing element (50) abuts against the side of the body portion (401) facing away from the cell body (301).

2. The battery according to claim 1, characterized in that, The initial height of the cavity (1013) is H, the thickness of the sealing element (50) extending into the cavity (1013) is h, and after the sealing element (50) covers the cavity (1013), the remaining height in the cavity (1013) is Hh; The initial thickness of the body part (401) is d, the maximum compression coefficient of the body part (401) is ε, the minimum thickness of the body part (401) after being compressed is (dd×ε), and the difference between (dd×ε) and (Hh) is 0 to 2.2 mm.

3. The battery according to claim 1, characterized in that, The first end wall (101) further includes a second step portion (1016) and a side wall (1019), the second step portion (1016) and the side wall (1019) forming a limiting groove (1020), the second step portion (1016) being disposed away from the cell assembly (30) relative to the first step portion (1014), the seal (50) being at least partially located within the limiting groove (1020), and the seal (50) being welded to the limiting groove (1020).

4. The battery according to claim 3, characterized in that, The side of the seal (50) facing away from the cell assembly (30) does not protrude from the side of the first end wall (101) facing away from the cell assembly (30).

5. The battery according to claim 3, characterized in that, The ratio a / b of the depth a of the limiting groove (1020) to the depth b of the cavity (1013) is 0.5-17.

6. The battery according to claim 1, characterized in that, The centerline of the main body (401) coincides with the centerline of the cavity (1013).

7. The battery according to claim 1, characterized in that, Before the seal (50) covers the cavity (1013), on the projection plane perpendicular to the battery height direction (Z), the cross-sectional area of ​​the body part (401) is S1, the cross-sectional area of ​​the cavity (1013) is S2, and S1≥S2 is satisfied.

8. The battery according to claim 1, characterized in that, Along the radial direction of the injection hole (1011), the shortest distance between the edge of the first weld line (501) near the injection hole (1011) and the injection hole (1011) is 3mm to 12mm.

9. The battery according to claim 1, characterized in that, The first stepped portion (1014) is welded to the collector plate (20) to form a second weld line (1021), and the second weld line (1021) is disposed through the first stepped portion (1014).

10. The battery according to claim 9, characterized in that, The second bonding wire (1021) does not penetrate the side of the current collector (20) near the cell assembly (30).

11. The battery according to claim 1, characterized in that, The collector plate (20) is provided with a through hole (201), and the through hole (201) and the liquid injection hole (1011) at least partially overlap in projection along the battery height direction (Z).

12. The battery according to claim 1, characterized in that, The injection hole (1011) protrudes toward the cell assembly (30) and forms an annular flange (1017). The flange (1017) forms a channel (1018) inside and communicates with the injection hole (1011). On the orthographic projection plane in the height direction (Z) of the battery, the orthographic projection of the flange (1017) is located within the orthographic projection range of the first step portion (1014).

13. The battery according to claim 12, characterized in that, The collector plate (20) is provided with a through hole (201), and the flange (1017) is inserted into the through hole (201) along the height direction (Z) of the battery.

14. The battery according to claim 12, characterized in that, The cell body (301) has a core hole (3011) formed at its center. On the positive projection plane of the battery height direction (Z), the projection of the flange (1017) and the projection of the core hole (3011) at least partially coincide.

15. The battery according to claim 14, characterized in that, Along the height direction (Z) of the battery, the flange (1017) is at least partially inserted into the core hole (3011).

16. The battery according to claim 12, characterized in that, Along the height direction (Z) of the battery, the extension (402) of the sealing pin (40) is at least partially inserted into the channel (1018) of the flange (1017).

17. The battery according to claim 16, characterized in that, Along the height direction (Z) of the battery, the extension (402) of the sealing pin (40) extends beyond the channel (1018) of the flange (1017), and the bottom end of the extension (402) is disposed between the end face of the cell body (301) and the bottom end of the flange (1017).

18. The battery according to claim 17, characterized in that, Along the height direction (Z) of the battery, the extension (402) protrudes from the bottom end of the flange (1017) by an amount of 1mm-3mm.

19. The battery according to claim 17, characterized in that, On the positive projection plane in the height direction (Z) of the battery, the projected area of ​​the extension (402) near the end of the cell assembly (30) is smaller than the projected area of ​​the extension (402) away from the cell assembly (30).

20. The battery according to any one of claims 1 to 19, characterized in that, The battery is a cylindrical battery.

21. The battery according to claim 20, characterized in that, The housing (10) further includes a second end wall (102), which is disposed opposite to the first end wall (101) along the battery height direction (Z), and the second end wall (102) is provided with a terminal post (60). The battery cell assembly (30) also includes a second tab (303) electrically led out from the battery cell body (301), the second tab (303) being electrically connected to the terminal post (60).

22. An electrical appliance, characterized in that, Includes the battery as described in any one of claims 1 to 21.

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