Battery monomer, battery and electric device

Abstract

The embodiment of the invention provides a battery monomer, a battery and a power utilization device, and the battery monomer (100) comprises an electrode assembly (4) which comprises an electrode main body (41), a first electrode lug (42) and a second electrode lug (43), the first electrode lug (42) and the second electrode lug (43) are opposite in polarity, and the first electrode lug (42) and the second electrode lug (43) are led out from the electrode main body (41); a first output pole and a second output pole, the first output pole being electrically connected to the first tab (42), and the second output pole being electrically connected to the second tab (43); the shell (10) is used for containing the electrode assembly (4), the shell (10) is provided with a pressure relief component (21), the first output electrode and the second output electrode are arranged at one end of the shell (10) in the first direction (z), and the pressure relief component (21) is arranged at the other end of the shell (10).

Description

[0001] This application is a divisional application of the invention patent application with the application number 202380013505.9, the application date of June 28, 2023, and the title of "Battery Cell, Battery and Electric Device". TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0003] Due to the advantages of high energy density, high power density, multiple cycle times and long storage time, lithium ion batteries and other batteries have been widely used in electric vehicles.

[0004] However, improving the safety of batteries during use in electric vehicles has always been a difficult problem in the industry. SUMMARY

[0005] The purpose of the present application is to improve the safety of batteries during use.

[0006] According to a first aspect of the present application, a battery cell is provided, comprising:

[0007] An electrode assembly comprising an electrode body and first and second polar opposite tabs, the first and second tabs being drawn from the electrode body;

[0008] A first output pole and a second output pole, the first output pole being electrically connected to the first tab, and the second output pole being electrically connected to the second tab;

[0009] A housing for accommodating the electrode assembly, the housing being provided with a pressure relief component, along a first direction, the first output pole and the second output pole being arranged at one end of the housing, and the pressure relief component being arranged at the other end of the housing.

[0010] The first output pole and the second output pole are arranged at one end of the shell, and the pressure relief component is arranged at the other end of the shell. When thermal runaway occurs inside the battery monomer, the active substance will be sprayed from the end where the pressure relief component is arranged, away from the first output pole and the second output pole of the battery monomer, and away from the busbar for electrically connecting the plurality of battery monomers, so as to reduce the influence on the electrical connection of the battery monomers when thermal runaway occurs, prevent large-area short circuit or high-pressure sparking in the battery, and prevent the entire power battery system from thermal runaway, even causing fire and explosion, thereby improving the safety of the power battery system.

[0011] In some embodiments, the shell includes a first end wall, a second end wall arranged opposite to the first end wall along a first direction, and a side wall between the first end wall and the second end wall, the first end wall is provided with a first through hole, the electrode lead-out part of the battery monomer is mounted in the first through hole and is insulated from the first end wall, and the second end wall is provided with a pressure relief component; the electrode lead-out part is a first output pole, and the first end wall is a second output pole.

[0012] In this embodiment, the electrode lead-out part and the first end wall are arranged at the same end of the shell, and the pressure relief component is arranged at the other end of the shell. When thermal runaway occurs inside the battery monomer, the active substance will be sprayed from the end where the pressure relief component is arranged, away from the electrode lead-out part and the first end wall of the battery monomer, and away from the busbar for electrically connecting the plurality of battery monomers, so as to reduce the influence on the electrical connection of the battery monomers when thermal runaway occurs.

[0013] In some embodiments, the shell includes a receiving part and an end cover, the receiving part has an opening, and the end cover is used to cover the opening. The receiving part is formed by a first end wall and a side wall, and the end cover is a second end wall.

[0014] In this embodiment, the pressure relief component is arranged on the end cover independent of the receiving part, which can reduce the process difficulty of arranging the pressure relief component, and more conveniently arrange the pressure relief component on the end cover. In addition, it is easier to control the size precision of the weak area of the pressure relief component during processing, so as to improve the setting precision of the opening pressure of the pressure relief component, and the pressure relief component can be reliably opened when the battery monomer occurs thermal runaway, thereby improving the safety of the battery monomer.

[0015] Moreover, since the first output pole and the second output pole are arranged on the first end wall which is integrally arranged with the side wall, instead of being arranged on the end cover, the pulling of the busbar on the joint of the end cover and the side wall is reduced, fatigue at the joint is prevented, the influence of the busbar on the pressure relief component is reduced, the damage to the pressure relief component during normal use of the battery monomer is reduced to a certain extent, and early pressure relief is prevented.

[0016] In some embodiments, the shell comprises a containing part and an end cover, the containing part has an opening, and the end cover is used to cover the opening, the containing part is formed by a second end wall and a side wall, and the end cover is a first end wall.

[0017] In this embodiment, the electrode lead-out part is arranged on the end cover which is independent of the containing part, and the electrode lead-out part can be conveniently installed on the end cover.

[0018] In some embodiments, the first tab is led out from the electrode main body in a direction facing the electrode lead-out part along a first direction, the second tab is led out from the electrode main body in a direction away from the electrode lead-out part along the first direction, the first tab is electrically connected with the electrode lead-out part, and the second tab is electrically connected with the first end wall.

[0019] In this embodiment, the first tab and the second tab are led out from two ends of the electrode main body respectively, the overcurrent capacity can be improved, the insulation reliability between the first tab and the second tab can be easily ensured, and thus the working performance of the battery monomer is improved.

[0020] In some embodiments, the battery monomer further comprises a first busbar and a second busbar, the first tab is electrically connected with the electrode lead-out part through the first busbar, and the second tab is electrically connected with the first end wall through the second busbar.

[0021] In this embodiment, the first tab is electrically connected with the electrode lead-out part through the first busbar, and the second tab is electrically connected with the first end wall through the second busbar, the welding of the tabs can be facilitated, the reliability of the electrical connection between the first tab and the electrode lead-out part, and the reliability of the electrical connection between the second tab and the first end wall are improved.

[0022] In some embodiments, the second busbar is in contact with the side wall, so as to realize the electronic conduction between the second tab and the first end wall.

[0023] In this embodiment, the link of the transmission of electric energy from the second tab to the first end wall is reduced, and the reliability of the transmission of electric energy is improved.

[0024] In some embodiments, the shell comprises a containing part and an end cover, the containing part has an opening, and the end cover is used to cover the opening, the second busbar is connected to the end cover, and the end cover is electrically connected to the side wall, so as to realize the electronic conduction between the second tab and the first end wall.

[0025] The second tab is electrically connected to the end cover, for example, when the electrical connection is achieved by welding, the end cover has a relatively flat welding surface, facilitating welding and better welding effect, and the reliability of the electrical connection between the second tab and the first end cover is improved.

[0026] In some embodiments, the shell comprises a receiving portion having an opening and an end cover for covering the opening, the second current collector is in contact with the side wall, and the end cover is connected to the second current collector to achieve electronic conduction between the second tab and the first end wall.

[0027] This embodiment enables the electrical energy transmitted by the second tab to be transmitted to the first end cover through two conductive paths, and when one of the conductive paths is virtually connected, the electrical energy can continue to be transmitted through the other conductive path, thereby improving the reliability of electrical energy transmission.

[0028] In some embodiments, in the first direction, the second current collector is located between the pressure relief component and the second tab, and the second current collector is provided with a hollow part for gas conduction between the space on the side of the second current collector facing the second tab and the space on the other side facing the pressure relief component.

[0029] This embodiment considers that the electrode lead-out part and the pressure relief component are arranged at opposite ends of the shell, and by providing the second current collector with a hollow part, any area inside the battery monomer can smoothly pass high-temperature and high-pressure gas through the hollow part to the pressure relief component when thermal runaway occurs, so as to be discharged externally in time through the pressure relief component, thereby improving the safety of the battery monomer when thermal runaway occurs.

[0030] In some embodiments, the hollow part comprises at least one fourth through hole, and one of the fourth through holes is arranged at the center position of the second current collector.

[0031] Generally, the gas in the electrode assembly is discharged to the outside of the electrode assembly through the tab side, and by arranging the fourth through hole at the center of the second current collector, the gas discharged from each area of the second tab can reach the fourth through hole in a timely manner, thereby smoothly reaching the pressure relief component.

[0032] In some embodiments, the fourth through hole is provided with a plurality of fourth through holes, and the remaining fourth through holes are distributed around the fourth through hole at the center position.

[0033] This embodiment can reasonably increase the area of the exhaust gas, and to some extent, solve the problem of untimely exhaust caused by blockage at the center position of the second current collector.

[0034] In some embodiments, the hollow part further comprises a plurality of cutouts, the cutouts pass through the second current collector in the first direction, and the plurality of cutouts surround the fourth through hole.

[0035] The embodiment sets multiple cutouts on the basis of the fourth through hole, which can assist the fourth through hole in exhausting, and when thermal runaway occurs in the battery monomer, the airflow can pass through the fourth through hole and the multiple cutouts to reach the pressure relief component. Moreover, the cutouts are in an elongated shape, which can reduce weakening of the strength of the second current collector on the basis of achieving exhaust, and is easy to process.

[0036] In some embodiments, one end of the cutout communicates with the fourth through hole and extends away from the fourth through hole.

[0037] The embodiment can achieve reliable exhaust in the area from the central position to the outer periphery of the second current collector, and when thermal runaway occurs in the battery monomer, the airflow can flow more smoothly and timely to the pressure relief component.

[0038] In some embodiments, the hollow part further includes a score line, and the score line penetrates the second current collector in the first direction.

[0039] The embodiment sets multiple score lines on the basis of the fourth through hole, which can assist the fourth through hole in exhausting, and when thermal runaway occurs in the battery monomer, the airflow can pass through the fourth through hole and the multiple score lines to reach the pressure relief component. Moreover, the score lines can maximize the reduction of weakening of the strength of the second current collector on the basis of achieving exhaust.

[0040] In some embodiments, multiple score lines are provided, one end of the score line communicates with the fourth through hole and extends away from the fourth through hole.

[0041] The embodiment can achieve reliable exhaust in the area from the central position to the outer periphery of the second current collector, and when thermal runaway occurs in the battery monomer, the airflow can flow more smoothly and timely to the pressure relief component.

[0042] In some embodiments, the first tab and the second tab are both led out from one end of the electrode main body facing the electrode lead-out part in the first direction, the first tab is electrically connected with the electrode lead-out part, and the second tab is electrically connected with the first end wall.

[0043] The embodiment leads the first tab and the second tab out from one end of the electrode main body facing the electrode lead-out part, which facilitates electrical connection, and the first tab and the second tab only need to occupy space on a single side of the electrode main body, which can shorten the height of the battery monomer and is conducive to improving the energy density of the battery monomer.

[0044] In some embodiments, the battery monomer further includes a first current collector and a second current collector, the first tab is electrically connected with the electrode lead-out part through the first current collector, and the second tab is electrically connected with the first end wall through the second current collector.

[0045] The electrode lead-out portion includes a base and a main body portion, the base is located between the first end wall and the first current collector, and is used to limit movement of the electrode lead-out portion in the first direction away from the interior of the shell, an insulating piece is provided between the first end wall and the base, and at least a portion of the main body portion is located in the first through hole.

[0046] The electrode lead-out portion of this embodiment can be prevented from being pulled out of the first through hole by the limiting action of the base, and the reliability of the electrical connection between the electrode lead-out portion and the first current collector can be improved. The insulating piece can also achieve insulation between the electrode lead-out portion and the first end wall.

[0047] In some embodiments, in the first direction, the maximum thickness t1 of the base satisfies: 0.6mm≤t1≤1.2mm; and / or the maximum thickness t2 of the first current collector satisfies: 0.3mm≤t2≤0.7mm; and / or the maximum thickness t3 of the second current collector satisfies: 0.3mm≤t3≤0.7mm.

[0048] This embodiment can ensure that gas is discharged through the pressure relief component when the battery monomer experiences thermal runaway, prevent the gas from being sprayed from the side where the electrode lead-out portion and the first end wall are provided, and thus improve the safety of the battery monomer in operation.

[0049] In some embodiments, 0.8mm≤t1≤1mm, and / or 0.4mm≤t2≤0.6mm, and / or 0.4mm≤t3≤0.6mm.

[0050] In some embodiments, the electrode lead-out portion further includes a limiting protrusion, the base and the limiting protrusion are both connected to and protrude from the outer peripheral wall of the main body portion, the limiting protrusion and the base are respectively located on the outer side and the inner side of the first end wall in the first direction, and are used to clamp a portion of the first end wall.

[0051] This embodiment can enable the electrode lead-out portion to be more stably and reliably installed on the first end wall by clamping a portion of the first end wall with the limiting protrusion and the base.

[0052] In some embodiments, the main body portion is provided with a recess, a bottom wall of the recess is connected to the first current collector to achieve electronic conduction between the electrode lead-out portion and the first tab, and an opening of the recess is provided on a side of the main body portion facing and / or facing away from the interior of the shell.

[0053] This embodiment can reduce the thickness of the region where the main body portion is electrically connected to the first current collector, and can improve the reliability of the electrical connection between the main body portion and the first current collector.

[0054] In some embodiments, the bottom wall of the recess is laser welded to the first current collector from the side of the main body portion facing away from the interior of the shell.

[0055] The embodiment reduces the thickness of the main body part and the welding area of the first current collector by setting the recess, and facilitates welding of the main body part and the first current collector from the outside of the electrode lead-out part, thereby improving welding reliability; and metal ions generated by welding cannot enter the shell, thereby improving the reliability of the battery monomer.

[0056] In some embodiments, the shell is cylindrical, the pressure relief component is circular and is arranged at the center of the second end wall, and the pressure relief component has a pressure relief area, and the diameter φ1 of the pressure relief area and the diameter φ of the shell satisfy the following relationship:

[0057] The embodiment sets the ratio of the diameter of the pressure relief area of the pressure relief component to the diameter of the shell, so that when the battery monomer is in thermal runaway, the pressure relief component has sufficient opening area to quickly discharge heat from the battery monomer, preventing damage to the electrode lead-out part or the shell or even thermal leakage; and on the basis of ensuring reliable opening of the pressure relief component, the strength of the end of the shell provided with the pressure relief component is improved, preventing the pressure relief component from opening to cause liquid leakage or abnormal electrical connection due to internal pressure of the battery monomer during normal use.

[0058] In some embodiments, 15mm≤φ≤70mm.

[0059] In some embodiments, the thickness l1 of the first end wall and the thickness l2 of the second end wall satisfy the following relationship: l1≥l2.

[0060] The embodiment makes the thickness of the first end wall greater than the thickness of the second end wall, so that when the battery monomer is in thermal runaway, the deformation of the shell on the side of the pressure relief component is greater than the deformation on the side of the electrode lead-out part and the first end wall, so that the gas generated by thermal runaway is reliably discharged from the pressure relief component on the second end wall, preventing the gas from flowing toward the side of the electrode lead-out part to cause a large deformation of the first end wall, and preventing the shell from being damaged and causing thermal leakage when thermal runaway occurs.

[0061] In some embodiments, l1≥1.5*l2.

[0062] In some embodiments, the thickness l1 of the first end wall ranges from 0.5mm to 1mm, and / or the thickness l2 of the second end wall ranges from 0.3mm to 1mm.

[0063] The embodiment designs appropriate thicknesses for the first end wall and the second end wall, so that when the battery monomer is in thermal runaway, the shell is deformed greatly under the action of the internal high-pressure gas, preventing the shell from being damaged and causing thermal leakage when thermal runaway occurs.

[0064] In some embodiments, 0.6mm≤l1≤0.8mm, and / or 0.5mm≤l2≤0.8mm.

[0065] In some embodiments, the second end wall is provided with grooves, and the area enclosed by the grooves on the second end wall forms a pressure relief component.

[0066] This embodiment enables the pressure relief component to open when the internal pressure exceeds the preset opening pressure of the pressure relief component during thermal runaway of a battery cell. The pressure relief component is then opened by the puncture, and the airflow inside the casing is discharged outward through the opening, thereby improving the safety of the battery cell operation.

[0067] In some embodiments, the thickness l1 of the first end wall and the thickness l3 of the second end wall at the location where the notch is set satisfy the following relationship: l1≥2*l3.

[0068] This embodiment, by setting the dimensional relationship between the thickness of the first end wall and the thickness of the second end wall at the grooved location, can create a weak point at the grooved location with lower strength than the first end wall. When the battery cell experiences thermal runaway, the internal gas can preferentially deform at the weak point, causing the pressure relief component to open quickly, thus allowing the internal gas to be discharged smoothly. Moreover, even if thermal runaway occurs on the side near the electrode lead, the gas can preferentially flow towards the pressure relief component, preventing the area where the first end wall is located from experiencing large deformation under the action of the internal high-pressure gas, preventing the casing from breaking and causing heat leakage during thermal runaway, and improving the safety of the battery cell on the side where the electrode lead and the first end wall are located.

[0069] In some embodiments, l1 ≥ 6 * l3.

[0070] In some embodiments, the pressure relief component is circular and has a pressure relief area, and the diameter φ2 of the first through hole and the diameter φ1 of the pressure relief area satisfy the following relationship: φ2≤φ1.

[0071] In this embodiment, the diameter of the first through hole used for mounting the electrode lead does not exceed the diameter φ of the pressure relief area. This can improve the strength of the first end wall of the housing where the electrode lead is located. When the battery cell experiences thermal runaway, the gas can preferentially flow towards the pressure relief component. This can prevent the area where the first end wall is located from experiencing large deformation under the action of the internal high-pressure gas, prevent the housing from breaking and causing thermal leakage during thermal runaway, and improve the safety of the battery cell on the side where the electrode lead and the first end wall are located.

[0072] In some embodiments, the diameter φ2 of the first through hole is in the range of 8mm≤φ2≤25mm; and / or the diameter φ1 of the pressure relief zone is in the range of 20mm≤φ1≤35mm.

[0073] The embodiment can ensure the strength of the shell at the electrode lead-out part by designing appropriate sizes for the diameters of the first through hole and the pressure relief area, can make the gas flow preferentially towards the pressure relief component when the battery monomer experiences thermal runaway, can prevent the area where the first end wall is located from having a large deformation amount under the action of the internal high-pressure gas, can prevent the shell from breaking and leaking when thermal runaway occurs, and can improve the safety of the battery monomer on the side of the electrode lead-out part and the first end wall.

[0074] In some embodiments, the electrode assembly is formed by winding a first pole piece, a second pole piece, and a separator around a winding axis, the winding axis being consistent with the first direction, the first pole piece and the second pole piece each having a first pole lug and a second pole lug;

[0075] The center of the electrode assembly is provided with a second through hole extending along the first direction, and the pressure relief component is circular and has a pressure relief area, the maximum diameter φ3 of the second through hole and the diameter φ1 of the pressure relief area satisfy the following relationship: φ3≥0.12*φ1.

[0076] The embodiment makes the diameter of the second through hole and the diameter of the pressure relief area satisfy the above relationship, when the battery monomer experiences thermal runaway, the second through hole has sufficient channel size to allow the internal high-pressure gas to flow rapidly to the pressure relief component, so that the pressure relief component is smoothly opened, preventing heat from accumulating inside the battery monomer and being unable to be released, and preventing the shell from having a large deformation and breaking to leak heat, thereby improving the safety of the battery monomer in operation.

[0077] In some embodiments, the shell includes a second end wall, and the pressure relief component is located in the central region of the second end wall.

[0078] The embodiment provides the pressure relief component in the central region of the end cover, when the battery monomer experiences thermal runaway, the internal high-temperature and high-pressure gas flow has a short flow path regardless of the direction to the pressure relief component, so that the pressure relief component is timely opened, improving the reliability and safety of the battery monomer in operation.

[0079] According to a second aspect of the present application, a battery is provided, including the battery monomer of the above-mentioned embodiments.

[0080] In some embodiments, the shell includes a first end wall, the first end wall is provided with a first through hole, the electrode lead-out part of the battery monomer is mounted in the first through hole and is insulated from the first end wall, the electrode lead-out part is a first output pole, and the first end wall is a second output pole.

[0081] The battery further includes a busbar, the battery monomer is provided in plurality, one end of the busbar is electrically connected to the electrode lead-out part of one of the battery monomers, and the other end of the busbar is electrically connected to the first end wall of another battery monomer.

[0082] The embodiment takes the electrode lead-out part as the first output pole of the battery monomer, and takes the first end wall as the second output pole of the battery monomer, and when the series connection, parallel connection or mixed connection of multiple battery monomers inside the battery is implemented, the two ends of the busbar can be directly connected to the electrode lead-out part and the first end wall respectively, and since only one electrode lead-out part is arranged on the first end wall of the shell, the conductive area of the electrode lead-out part can be increased, and the electrical connection of the first end wall can be easily realized through welding or a fastener connection, so that the difficulty of electrical connection of multiple battery monomers can be reduced, the reliability of electrical connection can be improved, and the working performance and reliability of the battery can be ensured.

[0083] In some embodiments, the shell comprises a first end wall provided with a first through hole, and the electrode lead-out part of the battery monomer is mounted in the first through hole and insulated from the first end wall, the electrode lead-out part is the first output pole, and the first end wall is the second output pole.

[0084] The battery further comprises multiple busbars, and in the same battery monomer, the electrode lead-out part is electrically connected to one of the busbars, and the first end wall is electrically connected to another busbar.

[0085] In the embodiment, each battery monomer can be electrically connected to other two battery monomers through two independent busbars, and since the first end wall in the surrounding area of the electrode lead-out part can be used to connect the busbars, different arrangement modes of multiple battery monomers can be adapted.

[0086] In some embodiments, the battery further comprises a support plate and a box assembly, the battery monomer is mounted in the box assembly through the support plate, the support plate is provided with a third through hole for flowing of the discharge of the pressure relief component, the pressure relief component is circular and has a pressure relief area, and the minimum distance D between the pressure relief component and the inner wall of the box assembly and the diameter φ1 of the pressure relief area satisfy the following relationship: 0.4*φ1≤D≤1.2*φ1.

[0087] In the embodiment, by setting a proper distance between the pressure relief component and the inner wall of the box assembly, the internal gas and active material can be effectively discharged when the battery monomer is in thermal runaway, so that the battery can be rapidly cooled, and on the basis of meeting the safety of thermal runaway, the height of the battery monomer can be increased as much as possible, so that the energy density of the battery monomer is increased, and the battery can provide greater power.

[0088] According to a third aspect of the present application, a power utilization device is provided, which comprises the battery of the above-mentioned embodiments, and the battery is used to provide electric energy for the power utilization device.

[0089] In some embodiments, the power utilization device comprises a vehicle, the battery is arranged between a cabin and a vehicle floor, the first output pole and the second output pole are both arranged towards the cabin, and the pressure relief component is arranged towards the vehicle floor.

[0090] The embodiment can make the battery in the case of thermal runaway in use, due to the pressure relief component of the battery monomer being arranged towards the vehicle floor, i.e. downward, if the pressure relief component is opened, the discharge of the battery is sprayed to the lower part of the vehicle, which can reduce the influence of high temperature and high pressure on the cabin and passengers, and improve the safety of the vehicle in use. BRIEF DESCRIPTION OF DRAWINGS

[0091] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by the drawings without creative labor for those skilled in the art.

[0092] Figure 1 The structural schematic diagram of some embodiments of the present application for installing the battery in the vehicle.

[0093] Figure 2 The exploded view of some embodiments of the battery of the present application.

[0094] Figure 3 The structural schematic diagram of some embodiments of the battery monomer of the present application.

[0095] Figure 4 The exploded view of some embodiments of the battery monomer of the present application.

[0096] Figure 5 The sectional view of some embodiments of the battery monomer of the present application.

[0097] Figure 6 The structural schematic diagram of some embodiments of the electrode assembly.

[0098] Figure 7 The end schematic diagram of some embodiments of the electrode assembly.

[0099] Figure 8A , Figure 8B , Figure 8C , Figure 8D and Figure 8E are the structural schematic diagrams of different embodiments of the second current collector.

[0100] Figure 9 The size schematic diagram of some embodiments of the battery monomer of the present application.

[0101] Figure 10 is the enlarged view of A in Figure 9 .

[0102] Figure 11 The structural schematic diagram of electrically connecting two battery monomers.

[0103] Figure 12 Figure 2 is a schematic view of a structure in which a battery cell in the battery is mounted to a box assembly through a support plate.

[0104] In the drawings, the drawings are not drawn according to the actual proportion.

[0105] Label description:

[0106] 100, battery cell; 10, shell; 1, containing part; 11, opening; 12, first through hole; 13, first end wall; 14, second end wall; 15, side wall; 2, end cover; 21, pressure relief part; 22, score; 23, recess; 3, electrode lead-out part; 31, main body part; 32, base; 33, limiting protrusion; 34, recess; 341, first recess; 342, second recess; 343, third through hole; 4, electrode assembly; 41, electrode main body; 42, first tab; 43, second tab; 44, second through hole; 45, first pole piece; 45', first coating layer; 46, second pole piece; 46', second coating layer; 47, separator; 5, first current collector; 6, second current collector; 6', hollow part; 61, fourth through hole; 62, score line; 63, cutout; 7, insulating part; 8, cover plate; K, winding axis; z, first direction; y, second direction; x, third direction;

[0107] 200, battery; 201, box assembly; 201A, box part; 201B, first cover; 201C, second cover; 202, current collector; 202A, first part; 202B, second part; 202C, third part; 203, support plate; 203', third through hole;

[0108] 300, vehicle; 301, cabin; 302, floor. DETAILED DESCRIPTION

[0109] The embodiments of the present application will be further described below in conjunction with the drawings and examples. The detailed description of the following examples and drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, i.e., the present application is not limited to the described examples.

[0110] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0111] The present application uses the description of the orientation or position relationship indicated by "upper", "lower", "top", "bottom", "front", "rear", "inner" and "outer" and the like. This is only for the convenience of describing the present application, and is not intended to indicate or imply that the device referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0112] In addition, the terms "first", "second", "third", and the like, are used only for descriptive purposes and do not imply or imply relative importance. "Vertical" is not strictly vertical, but within the error tolerance. "Parallel" is not strictly parallel, but within the error tolerance. The orientation words appearing in the following description are the directions shown in the figure, and are not limited to the specific structure of the present application.

[0113] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0114] Reference to "embodiments" in this document means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least some embodiments of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiments, nor is it independent or alternative to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0115] The battery cell can include a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The embodiments of the present application are also not limited thereto. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cell, square battery cell and soft package battery cell, and the embodiments of the present application are also not limited thereto.

[0116] Current battery cells generally include a housing and an electrode assembly contained within the housing, and the housing is filled with an electrolyte. The electrode assembly is mainly formed by laminating or winding a first electrode sheet and a second electrode sheet with opposite polarities, and a separator is generally provided between the first electrode sheet and the second electrode sheet. The first electrode sheet and the second electrode sheet are coated with a coated portion constituting a main body of the electrode assembly, and the portions of the first electrode sheet and the second electrode sheet that are not coated each constitute a first electrode tab and a second electrode tab. In a lithium ion battery, the first electrode sheet can be a positive electrode sheet including a positive electrode current collector and positive electrode coating layers provided on both sides of the positive electrode current collector, and the material of the positive electrode current collector can be, for example, aluminum, and the positive electrode coating can be, for example, lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc.; the second electrode sheet can be a negative electrode sheet including a negative electrode current collector and negative electrode coating layers provided on both sides of the negative electrode current collector, and the material of the negative electrode current collector can be, for example, copper, and the negative electrode coating can be, for example, graphite or silicon, etc. The first electrode tab and the second electrode tab can be located together at one end of the main body or at two ends of the main body, respectively. During the charging and discharging process of the battery cell, the positive electrode coating and the negative electrode coating react with the electrolyte, and the electrode tabs connect the electrode lead-out portions to form a current loop.

[0117] The pressure relief component refers to an element or component that is actuated to release the internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The threshold is designed differently according to different design requirements. The threshold can depend on the material of one or several of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell. The pressure relief component can take the form of, for example, a rupture disc, a gas valve, a pressure relief valve, or a safety valve, and can specifically take the form of a pressure-sensitive or temperature-sensitive element or structure, i.e., when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief component performs an action or a weak structure provided in the pressure relief component is broken, thereby forming an opening or passage for the internal pressure or temperature to be released.

[0118] The term "actuation" mentioned in the present application refers to the pressure relief component generating an action or being activated to a certain state, so that the internal pressure and temperature of the battery cell can be released. The action generated by the pressure relief component can include, but is not limited to, at least a part of the pressure relief component being broken, shattered, torn, or opened, etc. When the pressure relief component is actuated, the internal discharge of the battery cell will be discharged outward from the actuated part. In this way, the battery cell can be relieved of pressure and temperature in a controllable manner, thereby avoiding potential more serious accidents.

[0119] Here, the discharge from the battery cell mentioned herein includes, but is not limited to, electrolyte, dissolved or split positive and negative electrode sheets, fragments of the separator, high-temperature and high-pressure gases (such as flammable gases such as CH4, CO, etc.) generated by reactions, flames, etc.

[0120] The current battery has poor safety during use. It is found through research that the safety of the vehicle-mounted power battery is the most important performance requirement. In order to meet the higher endurance mileage, the energy density of the battery monomer is getting higher and higher. The high energy density increases the instability of the internal chemical materials, and the thermal runaway boundary of the battery monomer is lowered. Therefore, the key to ensuring the safety of the entire power battery system and the vehicle lies in that the battery monomer does not spread heat after thermal runaway.

[0121] In a traditional cylindrical battery, in order to simplify the structure of the battery monomer, the positive output pole and the negative output pole are arranged at the same end as the pressure relief component. When the battery monomer has thermal runaway, the substances discharged from the pressure relief component will be sprayed to the area where the busbar is located. The busbar is used to connect the positive output pole and the negative output pole of two battery monomers to realize the connection of multiple battery monomers. Since there are a large number of series and parallel connected battery monomers in the battery pack, the voltage is usually above 100V, and a large area short circuit or high voltage sparking may occur, causing the entire power battery system to catch fire and explode, causing vehicle damage, burning, and even personnel injury.

[0122] In view of the above defects, the inventor thinks that the setting position of the pressure relief component is as far away from the positive output pole and the negative output pole as possible, so as to reduce the influence of high-temperature and high-pressure discharge on the busbar after the battery monomer has thermal runaway, and prevent the thermal runaway of the entire power battery system.

[0123] Based on this improvement idea, the application provides an improved battery monomer. The battery monomer comprises a shell and an electrode assembly; wherein the shell is provided with an electrode lead-out part and a pressure relief component, and the electrode lead-out part and the pressure relief component are arranged at two opposite ends of the shell along a first direction; the electrode assembly is arranged in the shell, and the electrode assembly comprises an electrode main body and first and second polar ears with opposite polarities, the first and second polar ears are led out from the electrode main body, and at least one of the first and second polar ears is electrically connected with the electrode lead-out part.

[0124] The battery monomer of the application embodiment is suitable for a battery and an electric device using the battery.

[0125] The electric device can be a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric automobile, a ship, a spacecraft, an electric toy and an electric tool, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer.

[0126] As Figure 1As shown, the electric device can be a vehicle 300, for example, a new energy vehicle, which can be a pure electric vehicle, a hybrid vehicle, or a range extended vehicle, etc.; or the electric device can also be a drone or a ship, etc. The vehicle 300 can include a cabin 301 and a vehicle floor 302, and the battery 200 is arranged between the cabin 301 and the vehicle floor 302. The battery 200 can be arranged at the bottom, head or tail of the vehicle 300, for providing electric energy for the operation of the motor and other components in the vehicle.

[0127] As shown, Figure 2 The battery 200 includes a battery cell 100. In the battery 200, the battery cell 100 can be one or multiple. If the battery cell 100 is multiple, the multiple battery cells 100 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery cells 100 are connected in series and in parallel. The multiple battery cells 100 can be connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box assembly 201. Alternatively, all the battery cells 100 can be directly connected in series, in parallel, or in a mixed connection, and the whole formed by the battery cells 100 is accommodated in the box assembly 201.

[0128] Figure 2 The battery 200 in the battery 200 further includes a box assembly 201, which is hollow inside and used to accommodate one or more battery cells 100. The box assembly 201 can have different sizes and shapes according to the shape, number, combination mode and other requirements of the accommodated battery cells 100. For example, the box assembly 201 can include a box part 201A, a first cover 201B and a second cover 201C. The box part 201A has openings at opposite ends, and the first cover 201B and the second cover 201C are used to close the openings at the two ends of the box part 201A. For example, according to the arrangement mode of the multiple battery cells 100, the box part 201A has a rectangular cylindrical structure. In order to facilitate the maintenance of the battery 200, the box assembly 201 is detachably mounted on the electric device.

[0129] For example, the battery cell 100 is in a cylindrical shape, and its axis is arranged along a first direction z. The multiple battery cells 100 can be arranged in a rectangular array along a second direction y and a third direction x, and the second direction y is perpendicular to the third direction x.

[0130] Alternatively, the structural member of the electric device forms a space for accommodating the battery cell 100, which is equivalent to the box assembly 201 in the battery 200. For example, when the battery cell 100 is used in the vehicle 300, the frame forms a space for accommodating the battery cell 100.

[0131] The battery cell 100 can be, for example, a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, or a magnesium ion battery, etc.

[0132] The present application provides a battery cell 100, and subsequent embodiments are described taking a cylindrical battery cell 100 as an example. Figure 3 The battery cell 100 is shown in the following figures: Figure 4 The battery cell 100 is shown in the following figures: Figure 5 The battery cell 100 is shown in the following figures.

[0133] In the improved battery cell 100 described above, the electrode lead-out part is defined as an output pole at least partially protruding from the outer wall of the shell 10. In order to subsequently focus on the embodiment of the battery cell 100 outputting electric energy through the electrode lead-out part and the shell, for the convenience of description, the two poles outputting electric energy are defined as the first output pole and the second output pole.

[0134] In some embodiments, the battery cell 100 comprises a shell 10, an electrode assembly 4, a first output pole and a second output pole; wherein the electrode assembly 4 comprises an electrode body 41 and first and second polar opposite tabs 42 and 43, the first and second tabs 42 and 43 are led out from the electrode body 41, the first output pole is electrically connected with the first tab 42, the second output pole is electrically connected with the second tab 43, the shell 10 is used to accommodate the electrode assembly 4, the shell 10 is provided with a pressure relief component 21, along a first direction z, the first output pole and the second output pole are arranged at a first end of the shell, and the pressure relief component 21 is arranged at the other end of the shell 10.

[0135] The shell 10 can be in a thin-walled hollow structure for accommodating the electrode assembly 4. The shell 10 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0136] The first and second output poles are used to input or output electric energy, the first tab 42 and the first output pole, and the second tab 43 and the second output pole can be electrically connected in a manner of welding, elastic contact, etc. The tabs and the output poles can be directly connected, or connected through a current collector.

[0137] The specific structure of the pressure relief component 21 has been described above. Taking the cylindrical battery cell 100 as an example, the first direction z is consistent with the direction of the central axis of the battery cell 100, and the first and second output poles are arranged at the opposite ends of the shell 10 along the first direction z, respectively.

[0138] The electrode assembly 4 is arranged in the shell 10, for example, Figure 6 and Figure 7As shown, the electrode assembly 4 is formed by winding the first and second electrode tabs 45 and 46 with opposite polarities around a winding axis K, which is consistent with the first direction z, and a separator 47, such as a separator film, is generally provided between the first and second electrode tabs 45 and 46. For a cylindrical battery cell 100, the wound electrode assembly 4 can be cylindrical; for a cuboid battery cell 100, the wound electrode assembly 4 can be flat.

[0139] The first electrode tab 45 includes a first current collector, which includes a first body portion and a first tab 42 that protrudes outward from an end surface of the first body portion in the winding direction K. The side surface of the first body portion is provided with a first coating layer 45', which can be provided on both sides of the first body portion, or only on one side of the first body portion for the innermost or outermost electrode tab. The first tab 42 can continuously extend along the length direction of the first electrode tab 45 to form a continuous tab, or the continuous tab can be die-cut to form a sawtooth-shaped tab. For example, the first electrode tab 45 is a positive electrode tab, the first current collector can be made of aluminum, and the first coating layer 45' can include a first active material layer, such as lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate.

[0140] The second electrode tab 46 includes a second current collector, which includes a second body portion and a second tab 43 that protrudes outward from an end surface of the second body portion in the winding direction K. The side surface of the second body portion is provided with a second coating layer 46', which can be provided on both sides of the second body portion, or only on one side of the second body portion for the innermost or outermost electrode tab. The second tab 43 can continuously extend along the length direction of the second electrode tab 46 to form a continuous tab, or the continuous tab can be die-cut to form a sawtooth-shaped tab. For example, the second electrode tab 46 is a negative electrode tab, the second current collector can be made of copper, and the second coating layer 46' can include a second active material layer, such as graphite or silicon. Alternatively, the first electrode tab 45 can also be a negative electrode tab, and the second electrode tab 46 can be a positive electrode tab.

[0141] For the wound electrode assembly 4, the electrode assembly 4 includes the electrode body 41, the first and second tabs 42 and 43, and the first body portion of the first electrode tab 45 and the second body portion of the second electrode tab 46 form the electrode body 41. The first and second tabs 42 and 43 are both drawn from the electrode body 41, for example, the first and second tabs 42 and 43 can be drawn from the two ends of the electrode body 41 along the first direction z, or can be drawn from one end of the electrode body 41 along the first direction z toward the electrode lead portion.

[0142] The first output pole and the second output pole are arranged at one end of the shell 10, and the pressure relief component 21 is arranged at the other end of the shell 10. When thermal runaway occurs inside the battery monomer 100, the active material will be sprayed from the end where the pressure relief component 21 is arranged, away from the first output pole and the second output pole of the battery monomer 100, and away from the busbar for electrically connecting the plurality of battery monomers 100, so as to reduce the influence on the electrical connection of the battery monomer 100 when thermal runaway occurs, prevent large-area short circuit or high-voltage sparking in the battery 200, so as to avoid causing thermal runaway of the entire power battery system, and even cause fire and explosion, and improve the safety of the power battery system. Secondly, the pressure relief component 21 and the output pole are arranged at both ends of the shell 10, and there is a larger space for arranging the pressure relief component 21, which can improve the overcurrent capacity of the output pole, and also facilitate the processing of the pressure relief component 21 and the accurate control of the opening pressure of the pressure relief component 21, and prevent the welding stress from affecting the opening pressure of the pressure relief component 21 when the busbar is welded. In addition, the first output pole and the second output pole are arranged at the same end of the shell 10, which facilitates the installation and connection of the busbar when electrically connecting the plurality of battery monomers 100.

[0143] In some embodiments, as shown in Figure 5 The shell 10 includes a first end wall 13, a second end wall 14 and a side wall 15 arranged opposite along a first direction z, the first end wall 13 is provided with a first through hole 12, the electrode lead-out part 3 of the battery monomer 100 is mounted in the first through hole 12 and is arranged in insulation with the first end wall 13, and the second end wall 14 is provided with a pressure relief component 21; the electrode lead-out part 3 is a first output pole, and the first end wall 13 is a second output pole.

[0144] For example, the shell 10 is in a cylindrical shape, the side wall 15 is in a cylindrical shape with both ends open, and the first end wall 13 and the second end wall 14 are respectively two ends of the cylindrical shape for closing both ends of the side wall 15. The electrode lead-out part 3 is arranged in insulation with the first end wall 13, for example, an insulating part is arranged between the electrode lead-out part 3 and the first end wall 13, or an insulating glue is coated, etc.

[0145] The electrode lead-out part 3 is an output pole protruding from the shell 10, for example, an electrode terminal is used, so as to facilitate the electrical connection between different battery monomers 100 through the busbar. The electrode terminal can be designed as a pole, which can be in a cylindrical shape, a square column structure, or other column structures.

[0146] Alternatively, the electrode lead-out part 3 is a positive output pole, and the first end wall 13 is a negative output pole, because the material of the first tab 42 and the first busbar 5 is aluminum, the electrode lead-out part 3 can correspondingly adopt aluminum material, and there is no need to arrange the electrode lead-out part of the composite material. Alternatively, the electrode lead-out part 3 is a negative output pole, and the first end wall 13 is a positive output pole.

[0147] Optionally, the polarity of the first end wall 13 is the same as the polarity of the outermost one of the first and second polar pieces 45 and 46. The polarity of the side wall 15 is the same as the polarity of the first end wall 13. When there are metal particles between the electrode assembly 4 and the side wall 15, the particles will pierce the separator 47 of the outermost layer of the electrode assembly 4 and then the separator 47, causing the outermost polar piece to be in conduction with the side wall 15. If the polarity of the outermost polar piece is the same as the polarity of the side wall 15, the battery monomer 100 can be prevented from short circuiting, and the safety performance of the battery 200 can be improved.

[0148] In this embodiment, the electrode lead-out portion 3 and the first end wall 13 are arranged at the same end of the shell 10, and the pressure relief component 21 is arranged at the other end of the shell 10. When thermal runaway occurs inside the battery monomer 100, the active material will be ejected from the end where the pressure relief component 21 is arranged, away from the electrode lead-out portion 3 and the first end wall 13 of the battery monomer 100, and thus away from the busbar for electrically connecting the plurality of battery monomers 100, so that the influence on the electrical connection of the battery monomers 100 when thermal runaway occurs can be reduced.

[0149] Furthermore, by taking the electrode lead-out portion 3 as the first output pole of the battery monomer 100 and taking the first end wall 13 as the second output pole of the battery monomer 100, one electrode lead-out portion can be saved, the problem of difficult layout due to the small area of the end of the battery monomer 100 is solved, and the structure of the battery monomer 100 is simplified.

[0150] In some embodiments, as shown in Figure 5 The shell 10 includes a receiving portion 1 and an end cover 2. The receiving portion 1 has an opening 11, and the end cover 2 is used to cover the opening 11. The receiving portion 1 is formed by the first end wall 13 and the side wall 15, and the end cover 2 is the second end wall 14.

[0151] The end cover 2 and the receiving portion 1 are independent components. The end cover 2 can be made of a metal material such as steel or an alloy material. After the electrode assembly 4 is installed, the end cover 2 can be fixed to the receiving portion 1 by welding, bonding or fastening, and the end cover 2 and the receiving portion 1 need to be sealed to prevent air leakage.

[0152] The first end wall 13 and the side wall 15 can be formed by integral molding, which is convenient to process. When the pressure in the battery monomer 100 increases due to thermal runaway, the connection between the first end wall 13 and the side wall 15 has strong pressure resistance, and preferentially releases pressure through the pressure relief component 21 to prevent rupture at the connection between the first end wall 13 and the side wall 15, thereby improving the reliability of pressure relief. Optionally, the first end wall 13 and the side wall 15 are connected as a whole by welding or the like.

[0153] For example, for the cylindrical battery cell 100, the accommodating part 1 can be a cylindrical structure with an opening 11 at one end, and the end cover 2 is a disc-shaped structure for covering the opening 11, and the end of the accommodating part 1 away from the opening 11 is closed.

[0154] For example, the pressure relief component 21 is formed integrally on the end cover 2, that is, a thickness-reduced part is provided on the end cover 2, and the area enclosed by the thickness-reduced part constitutes the pressure relief component 21. For example, the thickness-reduced part can be a notch 22, which can be provided on the inner wall and / or the outer wall of the end cover 2. After the pressure relief component 21 is opened, the pressure relief component 21 is broken at the thickness-reduced part, thereby forming an opening or a channel for the internal pressure or temperature to be released.

[0155] The end of the accommodating part 1 away from the end cover 2 can be provided with a first through hole 12, and the electrode lead-out part 3 can be installed in the first through hole 12 from the inner cavity of the accommodating part 1, and an insulating part 7 is provided between the electrode lead-out part 3 and the accommodating part 1 to achieve insulation between the electrode lead-out part 3 and the accommodating part 1, and the electrode lead-out part 3 is covered by a cover plate 8.

[0156] This embodiment provides the pressure relief component 21 on the end cover 2 which is independent of the accommodating part 1, which can reduce the process difficulty of providing the pressure relief component 21, and is more convenient to integrally provide the pressure relief component 21 on the end cover 2, and it is easier to control the dimensional accuracy of the weak area of the pressure relief component 21 during processing, so as to improve the setting accuracy of the opening pressure of the pressure relief component 21, and the pressure relief component 21 can be reliably opened when the battery cell 100 is in thermal runaway, thereby improving the safety of the battery cell 100 in operation.

[0157] Moreover, since the first output pole and the second output pole are both provided on the first end wall 13 which is integrally provided with the side wall 15, and are not provided on the end cover 2, thereby reducing the pulling of the busbar on the connection between the end cover 2 and the side wall 15, preventing fatigue from being generated at the connection, thereby reducing the influence of the busbar on the pressure relief component 21, to a certain extent, reducing the damage to the pressure relief component 21 during normal use of the battery cell 100, and preventing premature pressure relief.

[0158] In some embodiments, the shell 10 includes: an accommodating part 1 and an end cover 2, the accommodating part 1 has an opening 11, and the end cover 2 is used to cover the opening 11, the accommodating part 1 is formed by a second end wall 14 and a side wall 15, and the end cover 2 is a first end wall 13.

[0159] Optionally, the second end wall 14 and the side wall 15 can be formed by integral molding, which is convenient to process, and the stress at the connection between the second end wall 14 and the side wall 15 is small, so that the pulling stress applied to the pressure relief component 21 can be reduced to avoid causing the scribing precision of the pressure relief component 21, and the pressure relief component 21 can accurately control the opening pressure when thermal runaway occurs inside the battery monomer 100, thereby improving the reliability of pressure relief when thermal runaway occurs.

[0160] In this embodiment, the electrode lead-out part 3 is arranged on the end cover 2 independent of the accommodating part 1, and the electrode lead-out part 3 can be conveniently installed on the end cover 2.

[0161] Optionally, the two ends of the accommodating part 1 are each provided with an opening 11, and the openings 11 at the two ends are each covered by an end cover 2, and the electrode lead-out part 3 and the pressure relief component 21 are respectively arranged on the two end covers 2.

[0162] In some embodiments, as shown in Figure 5 The first tab 42 is led out from the electrode body 41 in a direction of the electrode lead-out part 3 along the first direction z, and the second tab 43 is led out from the electrode body 41 in a direction away from the electrode lead-out part 3 along the first direction z, the first tab 42 is electrically connected with the electrode lead-out part 3, and the second tab 43 is electrically connected with the first end wall 13.

[0163] The first tab 42 and the second tab 43 are respectively led out from the two ends of the electrode body 41 along the first direction z, the first tab 42 is relatively close to the electrode lead-out part 3, and can be directly connected or electrically connected through a current collector, the second tab 43 is relatively far away from the first end wall 13, and can be electrically connected through the side wall 15 of the shell 10, and on this basis, the second tab 43 can also be electrically connected through the second end wall 14 and / or the current collector.

[0164] In this embodiment, the first tab 42 and the second tab 43 are respectively led out from the two ends of the electrode body 41, which can improve the overcurrent capacity and easily ensure the insulation reliability between the first tab 42 and the second tab 43, thereby improving the working performance of the battery monomer 100.

[0165] In some embodiments, the battery monomer 100 further comprises a first current collector 5 and a second current collector 6, the first tab 42 is electrically connected with the electrode lead-out part 3 through the first current collector 5, and the second tab 43 is electrically connected with the first end wall 13 through the second current collector 6.

[0166] In some embodiments, the battery monomer 100 further comprises a first current collector 5 and a second current collector 6, the first tab 42 is electrically connected with the electrode lead-out part 3 through the first current collector 5, and the second tab 43 is electrically connected with the first end wall 13 through the second current collector 6. Figure 5As shown, the first tab 42 can be fixed with the first current collector 5 by welding, and after the electrode assembly 4 and the first current collector 5 are loaded into the accommodating portion 1, the electrode lead-out portion 3 is welded with the first current collector 5 from the outside of the first end cover 13. Alternatively, the first tab 42 can be directly connected with the electrode lead-out portion 3.

[0167] The second tab 43 is far away from the first end wall 13, and can be electrically connected through the side wall 15 of the shell 10. The second tab 43 can be directly connected with the side wall 15, or the second tab 43 can be electrically connected with the side wall 15 through the second current collector 6. Specific implementation manners will be given later.

[0168] In this embodiment, the first tab 42 is electrically connected with the electrode lead-out portion 3 through the first current collector 5, and the second tab 43 is electrically connected with the first end wall 13 through the second current collector 6, which can facilitate the welding of the tabs and improve the reliability of the electrical connection between the first tab 42 and the electrode lead-out portion 3 and the electrical connection between the second tab 43 and the first end wall 13.

[0169] Three implementation manners of electrically connecting the second tab 43 with the side wall 15 through the second current collector 6 will be given below.

[0170] In the first implementation manner, the second current collector 6 is in contact with the side wall 15 to realize the electronic conduction between the second tab 43 and the first end wall 13.

[0171] In the first implementation manner, the second current collector 6 is in contact with the side wall 15 to realize the electronic conduction between the second tab 43 and the first end wall 13.

[0172] This embodiment can reduce the link of transmitting electric energy from the second tab 43 to the first end wall 13, and can improve the reliability of electric energy transmission.

[0173] In the second implementation manner, the shell 10 includes the accommodating portion 1 and the end cover 2, the accommodating portion 1 has the opening 11, and the end cover 2 is used for covering the opening 11. The second current collector 6 is connected to the end cover 2, and the end cover 2 is electrically connected to the side wall 15 to realize the electronic conduction between the second tab 43 and the first end wall 13.

[0174] In this configuration, the second current collector 6 is not in contact with the side wall of the receiving portion 1, and the end cap 2 is connected to the second current collector 6. The electrical energy transmitted by the second electrode tab 43 is transferred to the end cap 2 through the second current collector 6. The end cap 2 and the side wall 15 can be connected by welding or other methods, thus the electrical energy is transferred from the end cap 2 to the side wall 15 of the receiving portion 1 to achieve electrical connection between the second electrode tab 43 and the first end wall 13. The second current collector 6 and the end cap 2 can achieve electronic conduction through tight-fitting contact, or the second current collector 6 can be welded to the end cap 2 from the side of the end cap 2 away from the electrode assembly 4.

[0175] Optionally, the end cap 2 and the second current collector 6 can be connected by welding. To ensure that gas can pass through the second current collector 6 and act on the pressure relief component 21 in the event of thermal runaway of the battery cell 100, a preset distance is maintained between the end cap 2 and the second current collector 6 in the first direction z. To achieve welding between the end cap 2 and the second current collector 6, as follows... Figure 5 As shown, the end cap 2 has a recess 23 that protrudes integrally toward the electrode assembly 4. The recess 23 abuts against the second current collector 6. The recess 23 is located radially outside the pressure relief component 21 and can be welded to the second current collector 6 from the outside of the end cap 2. For example, the recess 23 can be an integral annular structure, coaxially disposed on the outside of the pressure relief component 21, so as to achieve a larger welding area and improve the reliability of electrical connection; or at least one recess 23 can be provided circumferentially around the outer periphery of the pressure relief component 21.

[0176] Optionally, the pressure relief component 21 may be recessed inward by a predetermined distance relative to the outermost wall of the end cap 2 to prevent the battery cell 100 from exerting additional force on the pressure relief component 21 when the end cap 2 is placed downward, thereby protecting the pressure relief component 21.

[0177] In this embodiment, the second tab 43 is electrically connected to the end cap 2. For example, when the electrical connection is achieved by welding, the end cap 2 has a flatter welding surface, which facilitates welding and results in better welding effect, thereby improving the reliability of the electrical connection between the second tab 43 and the first end cap 13.

[0178] In the third implementation, the housing 10 includes a receiving portion 1 and an end cap 2. The receiving portion 1 has an opening 11, and the end cap 2 is used to close the opening 11. The second current collector 6 contacts the side wall 15, and the end cap 2 is connected to the second current collector 6 to realize electronic conduction between the second electrode tab 43 and the first end wall 13.

[0179] The second current collector 6 is in contact with the side wall 15 of the receiving part 1 and is electrically connected to the end cover 2. The electrical energy transmitted by the second electrode 43 can be simultaneously transmitted to the first end cover 13 through the two conductive paths mentioned above.

[0180] The embodiment makes the electric energy transmitted by the second tab 43 be transmitted to the first end cover 13 through two conductive paths, and when one of the conductive paths is virtually connected, the electric energy can be continuously transmitted through the other conductive path, thereby improving the reliability of electric energy transmission.

[0181] In some embodiments, the shell 10 includes a second end wall 14, and the pressure relief component 21 is located in a central region of the second end wall 14.

[0182] The second through hole 44 is provided in the center of the electrode assembly 4 and extends along the first direction z. When the battery monomer 100 is in thermal runaway, most of the internal high-temperature and high-pressure gas flow can reach the pressure relief component 21 along the second through hole 44 and effectively act on the pressure relief component 21, so that the pressure relief component 21 can be reliably opened.

[0183] The embodiment sets the pressure relief component 21 in the central region of the end cover 2. When the battery monomer 100 is in thermal runaway, the internal high-temperature and high-pressure gas flow has a relatively short flow path no matter which direction it reaches the pressure relief component 21, so that the pressure relief component 21 is opened in time, improving the reliability and safety of the battery monomer 100 in operation.

[0184] In some embodiments, as shown in Figures 8A to 8E The second current collector 6 is located between the pressure relief component 21 and the second tab 43 along the first direction z, and the second current collector 6 is provided with a hollow part 6' for gas communication between the space on the side of the second current collector 6 facing the second tab 43 and the space on the other side facing the pressure relief component 21.

[0185] The hollow part 6' is provided in a shape and size that can meet the strength of the second current collector 6 and enable the internal gas of the battery monomer 100 in thermal runaway to quickly and smoothly reach the pressure relief component 21. The second through hole 44 is provided in the center of the electrode assembly 4 and extends along the first direction z. When the battery monomer 100 is in thermal runaway, most of the internal high-temperature and high-pressure gas flow can flow along the second through hole 44 and pass through the hollow part 6' to reach the pressure relief component 21, so that the pressure relief component 21 can be reliably opened.

[0186] The embodiment considers that the electrode lead-out part and the pressure relief component 21 are provided at opposite ends of the shell 10. By providing the hollow part 6' on the second current collector 6, high-temperature and high-pressure gas in any region of the battery monomer 100 in thermal runaway can smoothly pass through the hollow part 6' to reach the pressure relief component 21, so as to be discharged outward in time through the pressure relief component 21, improving the safety of the battery monomer 100 in thermal runaway.

[0187] In some embodiments, as shown in Figures 8A to 8EThe hollow part 6' includes at least one fourth through hole 61, and one fourth through hole 61 is arranged at the center of the second current collector 6. For example, the fourth through hole 61 can be a circular hole, an elliptical hole, or a polygonal hole, etc.

[0188] Generally, the gas in the electrode assembly 4 is discharged to the outside of the electrode assembly 4 through the tab side. By arranging the fourth through hole 61 at the center of the second current collector 6, the gas discharged from each area of the second tab 43 can reach the fourth through hole 61 in time, so as to smoothly reach the pressure relief component 21.

[0189] In some embodiments, as shown in FIG. 6, the fourth through hole 61 is arranged in plurality, and the remaining fourth through holes 61 are distributed around the fourth through hole 61 at the center. For example, the remaining fourth through holes 61 can be uniformly distributed around the fourth through hole 61 at the center, or the remaining fourth through holes 61 are distributed in the area where the second tab 43 is arranged. Figure 8C

[0190] This embodiment can reasonably increase the area of the exhaust, and to some extent solve the problem of untimely exhaust caused by blockage at the center of the second current collector 6.

[0191] In some embodiments, as shown in FIG. 6, the fourth through hole 61 is arranged in plurality, and the remaining fourth through holes 61 are distributed around the fourth through hole 61 at the center. For example, the remaining fourth through holes 61 can be uniformly distributed around the fourth through hole 61 at the center, or the remaining fourth through holes 61 are distributed in the area where the second tab 43 is arranged. Figure 8B Figure 8E This embodiment can reasonably increase the area of the exhaust, and to some extent solve the problem of untimely exhaust caused by blockage at the center of the second current collector 6.

[0192] This embodiment can reasonably increase the area of the exhaust, and to some extent solve the problem of untimely exhaust caused by blockage at the center of the second current collector 6.

[0193] In some embodiments, one end of the cutout 63 is in communication with the fourth through hole 61 and extends away from the fourth through hole 61.

[0194] For example, the second current collector 6 is circular, one end of the cutout 63 is in communication with the fourth through hole 61 and extends away from the fourth through hole 61 along the radial direction of the second current collector 6, and the plurality of cutouts 63 can be uniformly arranged along the circumferential direction. Alternatively, one end of the cutout 63 is not in communication with the fourth through hole 61 and has a preset distance.

[0195] ​​The embodiment can reliably exhaust the area from the center position to the outer periphery of the second current collector 6, and when the battery cell 100 is in thermal runaway, the gas flow can flow more smoothly and timely to the pressure relief component 21.

[0196] In some embodiments, as shown in Figure 8A and Figure 8D The hollow part 6' further includes a score line 62 which penetrates the second current collector 6 along the first direction z.

[0197] For example, the score line 62 is linear, and theoretically, there is no gap between the two side walls forming the score line 62 in the same plane, and in fact, there can be a small gap. Under the action of gas pressure, the second current collector 6 can be deformed at the score line 62, so that a gap is formed between the two side walls of the score line 62. The score line 62 can extend continuously or discontinuously to form a dashed line. The score line 62 can extend along a straight line, for example, along the radial direction of the circular second current collector 6; or the score line 62 extends along a curve, for example, along the circumferential direction of the circular second current collector 6.

[0198] The embodiment sets multiple score lines 62 on the basis of the fourth through hole 61, which can assist the fourth through hole 61 in exhausting, and when the battery cell 100 is in thermal runaway, the gas flow can pass through the fourth through hole 61 and the multiple score lines 62 to reach the pressure relief component 21. Moreover, the score line 62 can maximize the weakening of the strength of the second current collector 6 on the basis of achieving exhaust.

[0199] In some embodiments, multiple score lines 62 are provided, one end of the score line 62 communicates with the fourth through hole 61 and extends away from the fourth through hole 61.

[0200] For example, the second current collector 6 is circular, one end of the score line 62 communicates with the fourth through hole 61 and extends away from the fourth through hole 61 along the radial direction of the second current collector 6, and multiple score lines 62 can be arranged uniformly along the circumferential direction. Alternatively, one end of the cutout 63 does not communicate with the fourth through hole 61 and has a predetermined distance.

[0201] The embodiment can reliably exhaust the area from the center position to the outer periphery of the second current collector 6, and when the battery cell 100 is in thermal runaway, the gas flow can flow more smoothly and timely to the pressure relief component 21.

[0202] The hollow part 6' provided on the second current collector 6 of Figures 8A to 8E will be described below.

[0203] As shown in Figure 8AAs shown, the hollowed-out portion 6' may include a fourth through hole 61 and a scribe line 62 provided on the second current collector 6. For example, the second current collector 6 may be circular, the fourth through hole 61 may be located at the center of the second current collector 6, and the scribe line 62 may penetrate the second current collector 6, with one end of the scribe line 62 communicating with the fourth through hole 61 and the other end extending radially outward. For example, the scribe line 62 may be provided continuously or intermittently, and multiple scribe lines 62 may be provided in a radial pattern. For example, four scribe lines 62 may be provided to form a cross shape.

[0204] This embodiment enables reliable venting from the center of the second manifold 6 to the outer periphery, minimizes the weakening of the strength of the second manifold 6 by the hollowed-out portion 6', and the straight etched line 62 facilitates processing.

[0205] like Figure 8B As shown, the hollow portion 6' may include a fourth through hole 61 and a cut 63 provided on the second current collector 6. For example, the second current collector 6 may be circular, the fourth through hole 61 may be located at the center of the second current collector 6, and the cut 63 may penetrate the second current collector 6 and extend radially. Multiple cuts 63 may be provided and arranged radially; for example, four cuts 63 may be provided to form a cross shape.

[0206] This embodiment can achieve reliable venting from the center of the second manifold 6 to the outer periphery, which can reduce the weakening of the strength of the second manifold 6 while achieving venting, and the straight cut 63 is also easy to process.

[0207] like Figure 8C As shown, the hollow portion 6' may include at least one fourth through hole 61 provided on the second current collector 6. For example, one fourth through hole 61 may be provided. For a circular second current collector 6, the fourth through hole 61 may be provided at the center of the second current collector 6; or multiple fourth through holes 61 may be provided. For example, one fourth through hole 61 is located at the center of the second current collector 6, and the remaining fourth through holes 61 are distributed around the central fourth through hole 61.

[0208] This embodiment can reasonably increase the exhaust area and solve the problem of untimely exhaust caused by blockage at the center of the second manifold 6 to a certain extent. In addition, this hollow part 6' is easy to process.

[0209] like Figure 8D As shown, with Figure 8A The difference lies in that the scribe line 62 is curved; for example, the scribe line 62 is an arc or a circle. The scribe line 62 can be concentrically arranged with the fourth through hole 61. This embodiment can achieve better venting effect in the circumferential direction of the second manifold 6.

[0210] like Figure 8E As shown, with Figure 8BThe difference is that the cutout 63 is curved, for example, the cutout 63 is circular arc or circular, and the cutout 63 can be concentric with the fourth through hole 61. For example, the cutout 63 can be continuous, or the cutout 63 is provided in multiple sections, and the multiple sections of the cutout 63 are arranged at intervals in the outer periphery of the fourth through hole 61. This embodiment can have a better exhaust effect in the circumferential direction of the second current collector 6, and the cutout 63 is easy to process.

[0211] In some embodiments, the first tab 42 and the second tab 43 are both led out from one end of the electrode body 41 facing the electrode lead-out portion 3 in the first direction z, the first tab 42 is electrically connected to the electrode lead-out portion 3, and the second tab 43 is electrically connected to the first end wall 13.

[0212] The first tab 42 and the second tab 43 are led out from the same end of the electrode body 41 in the first direction z, and the distance between the first tab 42 and the electrode lead-out portion 3 and the distance between the second tab 43 and the first end wall 13 are both close, so that the electrical connection can be directly connected or realized through the current collector.

[0213] This embodiment leads the first tab 42 and the second tab 43 out from one end of the electrode body 41 facing the electrode lead-out portion 3, which is convenient for electrical connection, and the first tab 42 and the second tab 43 only need to occupy space on one side of the electrode body 41, which can shorten the height of the battery monomer 100 and is beneficial to improve the energy density of the battery monomer 100.

[0214] In some embodiments, the battery monomer 100 further comprises a first current collector 5 and a second current collector 6, the first tab 42 is electrically connected to the electrode lead-out portion 3 through the first current collector 5, and the second tab 43 is electrically connected to the first end wall 13 through the second current collector 6; the electrode lead-out portion 3 comprises a base 31 and a main body portion 32, the base 31 is located between the first end wall 13 and the first current collector 5 and is used to limit the movement of the electrode lead-out portion 3 in the first direction z away from the inside of the shell 10, an insulating member 7 is arranged between the first end wall 13 and the base 31, and at least a part of the main body portion 32 is located in the first through hole 12.

[0215] The outer diameter of the base 31 is larger than the first through hole 12 as a whole, the base 31 is used to be electrically connected to the first current collector 5, and there is a gap between the base 31 and the first end wall 13. At least a part of the main body portion 32 is located in the first through hole 12, and there is a gap between the main body portion 32 and the inner wall of the first through hole 12. For example, the electrode lead-out portion 3 is in the shape of a stepped cylinder as a whole, the main body portion 32 is inserted into the first through hole 12, and the diameter of the main body portion 32 is smaller than the inner diameter of the first through hole 12, so as to arrange the insulating member 7.

[0216] The insulating member 7 may be C-shaped. The sidewall portion of the first through hole 12 is embedded in the opening of the C-shaped insulating member 7, so that the insulating member 7 surrounds the inner sidewall of the first through hole 12 and the area where the inner and outer surfaces of the first end wall 13 are adjacent to the first through hole 12. The portion of the insulating member 7 located on the first end wall 13 facing the first current collector 5 is attached to the inner surface of the first end wall 13.

[0217] In this embodiment, the electrode lead-out portion 3 can be prevented from coming out of the first through hole 12 by the limiting effect of the base 31, thereby improving the reliability of the electrical connection between the electrode lead-out portion 3 and the first current collector 5. Insulation between the electrode lead-out portion 3 and the first end wall 13 can also be achieved by the insulating member 7.

[0218] In some embodiments, such as Figure 9 As shown, the maximum thickness t1 of the base 31 of the electrode lead-out part 3 is in the range of 0.6mm≤t1≤1.2mm; and / or the maximum thickness t2 of the first current collector 5 is in the range of 0.3mm≤t2≤0.7mm; and / or the maximum thickness t3 of the second current collector 6 is in the range of 0.3mm≤t3≤0.7mm.

[0219] For better results, 0.8mm≤t1≤1mm, 0.4mm≤t2≤0.6mm, and / or 0.4mm≤t3≤0.6mm.

[0220] For example, the maximum thickness t1 of the base 31 can be greater than the maximum thickness t2 of the first current collector 5 or the maximum thickness t3 of the second current collector 6, so as to prevent airflow from being ejected through the mounting position of the electrode lead-out part 3 when thermal runaway occurs in the battery cell 100.

[0221] This embodiment, by setting appropriate thicknesses for the base 31 of the electrode lead-out portion 3, the first current collector 5, and the second current collector 6, ensures that gas is discharged through the pressure relief component 21 when thermal runaway occurs in the battery cell 100, preventing gas from being ejected from the side where the electrode lead-out portion 3 and the first end wall 13 are located, thereby improving the safety of the battery cell 100 operation.

[0222] In some embodiments, the electrode lead-out portion 3 further includes a limiting protrusion 33. The base 31 and the limiting protrusion 33 are both connected to and protrude from the outer peripheral wall of the main body portion 32. The limiting protrusion 33 and the base 31 are located on the outer and inner sides of the first end wall 13 along the first direction z, respectively, and are used to clamp a portion of the first end wall 13.

[0223] The base 31 and the limiting protrusion 33 are both connected to the outer peripheral wall of the main body 32, and a gap is also formed between the limiting protrusion 33 and the outer surface of the first end wall 13, so that the insulating member 7 can be arranged between the limiting protrusion 33 and the first end wall 13. For example, the electrode lead-out portion 3 is in the shape of a stepped cylinder as a whole, the diameters of the base 31 and the limiting protrusion 33 are both greater than the diameter of the main body 32, the diameter of the limiting protrusion 33 is less than the diameter of the base 31, and the diameter of the main body 32 is less than the inner diameter of the first through hole 12.

[0224] A groove is formed between the base 31, the main body 32 and the limiting protrusion 33 on the outer side wall of the electrode lead-out portion 3, the insulating member 7 can be in the shape of a C and embedded in the groove, the openings of the C-shaped insulating member 7 are consistent with the opening direction of the groove, the side wall portion of the first through hole 12 is embedded in the opening of the C-shaped insulating member 7, the first cantilever of the insulating member 7 is located between the first end wall 13 and the base 31, and the first cantilever extends beyond the base 31, the second cantilever is located between the first end wall 13 and the limiting protrusion 33, and the second cantilever extends beyond the limiting protrusion 33, and the side wall portion connecting the first cantilever and the second cantilever is located between the inner wall of the first through hole 12 and the main body 32. The outer ends of the two cantilevers of the insulating member 7 are respectively located in the gap between the electrode lead-out portion 3 and the first end wall 13, so that the insulating member 7 can reliably realize the insulation between the electrode lead-out portion 3 and the first end wall 13, and prevent high-pressure gas from escaping from the gap between the first end wall 13 and the electrode lead-out portion 3 in the case of thermal runaway.

[0225] This embodiment can make the electrode lead-out portion 3 more stably and reliably installed on the first end wall 13 by clamping a part of the first end wall 13 through the limiting protrusion 33 and the base 31.

[0226] In some embodiments, the main body 32 is provided with a recess 34, the bottom wall of the recess 34 is connected to the first current collector 5 to realize the electrical conduction between the electrode lead-out portion 3 and the first tab 42, and the opening of the recess 34 is arranged on the side of the main body 32 facing and / or away from the inside of the shell 10.

[0227] As shown in FIG. 4, the opening of the recess 34 is arranged on the side of the main body 32 away from the inside of the shell 10, so that the bottom wall of the recess 34 is closer to the first current collector 5, facilitating the electrical connection between the two, and the first current collector 5 can be designed as a flat plate structure to reduce the processing difficulty. Figure 5 The recess 34 is in the shape of a step and includes a first recess 341 and a second recess 342, the second recess 342 is arranged on the bottom wall of the first recess 341, the inner diameter of the second recess 342 is less than the inner diameter of the first recess 341, the bottom wall of the second recess 342 is provided with a third through hole 343 for injecting electrolyte into the shell 10, and the cover plate 8 is embedded in the first recess 341 to close the opening of the recess 34 and the third through hole 343.

[0228] The embodiment can reduce the thickness of the electrically connecting area between the body part 32 and the first current collector 5, and improve the reliability of the electrically connecting between the body part 32 and the first current collector 5.

[0229] In some embodiments, the bottom wall of the recess 34 is laser welded with the first current collector 5 from the side of the body part 32 away from the inside of the shell 10.

[0230] The embodiment can reduce the thickness of the welding area between the body part 32 and the first current collector 5, and facilitate the welding between the body part 32 and the first current collector 5 from the outside of the electrode lead part 3, improve the welding reliability, and prevent the metal ions generated by the welding from entering the shell 10, and improve the reliability of the battery monomer 100.

[0231] In some embodiments, as shown in Figure 9 The shell 10 is cylindrical, the pressure relief part 21 is arranged at the center of the second end wall 14 and is circular, and the pressure relief part 21 has a pressure relief area, and the diameter φ1 of the pressure relief area and the diameter φ of the shell 10 satisfy the following relationship:

[0232] The pressure relief part 21 is formed by arranging a thickness reduction part, for example, the thickness reduction part is a notch 22, and the area enclosed by the notch 22 constitutes the pressure relief area. In order to facilitate measurement, the diameter of the circle surrounded by the inner side wall of the notch 22 can be used to represent the diameter φ1 of the pressure relief area. In one structure, the pressure relief part 21 is integrally formed on the second end wall 14, that is, the notch 22 is directly machined on the second end wall 14; in another structure, the pressure relief part 21 is an independent part, and the outer side wall thereof is connected to the second end wall 14 by welding, and the diameter of the outer side wall of the pressure relief part 21 is greater than the maximum diameter of the notch 22, and in this case, the diameter of the pressure relief area is still the diameter of the circle surrounded by the inner side wall of the notch 22.

[0233] When φ1<0.35*φ, the opening area of the pressure relief part 21 is not enough when the heat runaway is triggered near the electrode lead part 3 in the battery monomer 100, and the heat dissipation rate from the battery monomer 100 is too slow, and the electrode lead part 3 or the shell 10 may be damaged or even heat leaked; when φ1>0.85*φ, the proportion of the area occupied by the pressure relief area of the pressure relief part 21 on the second end wall 14 is relatively large, which may cause insufficient strength of the second end wall 14, and the internal gas pressure of the battery monomer 100 during use may cause the pressure relief part 21 to open, and cause liquid leakage and abnormal electrical connection.

[0234] The influence of the diameter design of the pressure relief part 21 on the safety of the battery monomer 100 will be illustrated by Table 1 below, and the unit of the size parameters in the table is mm.

[0235] Table 1 Influence of the pressure relief zone diameter design of the pressure relief component 21 on the safety of the battery monomer 100

[0236]

[0237] In Table 1, for Example 1, The area ratio of the pressure relief zone of the pressure relief component 21 to the end of the shell 10 is small, and when the needle puncture failure test is performed on the side where the electrode lead-out portion 3 and the first end wall 13 are located, the battery monomer 100 is short-circuited, and when internal thermal runaway occurs, since the weak part formed by the pressure relief component 21 is small, for example, the notch is short, the opening difficulty is increased, and even after the pressure relief component 21 is opened, the high-temperature and high-pressure gas is slowly discharged from the pressure relief component 21, the instantaneous high pressure can cause the gas to be discharged toward the side of the electrode lead-out portion, which can cause the electrode lead-out portion to be damaged, thereby causing the electrical connection of the battery monomer 100 to fail. However, since the area of the pressure relief zone of the pressure relief component 21 is small, the strength of the end cover 2 provided with the pressure relief component 21 can be ensured, and liquid leakage is not likely to occur during use. In each table, the side where the electrode lead-out portion 3 and the first end wall 13 are located is referred to as the "electrical connection side".

[0238] For Examples 2-5, The area ratio of the pressure relief zone of the pressure relief component 21 to the end of the shell 10 is large, and when the needle puncture failure test is performed on the side near the electrode lead-out portion 3 and the first end wall 13, the battery monomer 100 is short-circuited, and when internal thermal runaway occurs, since the weak part formed by the pressure relief component 21 is large, for example, the notch is long, the opening difficulty is reduced, and moreover, after the pressure relief component 21 is opened, the high-temperature and high-pressure gas can be quickly discharged from the pressure relief component 21, preventing the gas from being discharged toward the side of the electrode lead-out portion 3, thereby avoiding damage to the electrode lead-out portion 3 and ensuring the electrical connection of the battery monomer 100. However, in Example 6, since the area of the pressure relief component 21 is large, the strength of the end cover 2 provided with the pressure relief component 21 is reduced, and liquid leakage occurs during use.

[0239] This example sets the diameter ratio of the pressure relief zone of the pressure relief component 21 to the diameter of the shell 10, so that when the battery monomer 100 is in thermal runaway, the pressure relief component 21 has sufficient opening area to quickly discharge heat from the battery monomer 100, preventing damage to the electrode lead-out portion or the shell 10 or even thermal leakage; moreover, on the basis of reliable opening of the pressure relief component 21, the strength of the end of the shell 10 provided with the pressure relief component 21 is improved, preventing liquid leakage and abnormal electrical connection of the battery monomer 100 due to opening of the pressure relief component 21 by internal gas pressure during normal use.

[0240] In some examples, the shell 10 is cylindrical and has a diameter of φ, 15 mm ≤ φ ≤ 70 mm.

[0241] In order to achieve a better effect, φ can be selected between 30mm and 55mm. When φ < 15mm and φ > 70mm, the battery 200 is insufficient in power. When the diameter of the shell 10 is too small, the energy density of the battery monomer 100 is small, and when the battery monomers 100 are grouped, for example, for cylindrical battery monomers 100, more space is wasted, resulting in insufficient power of the battery 200. When the diameter of the shell 10 is too large, although the energy density of the battery monomer 100 is improved, it is still possible that one row of battery monomers 100 cannot be accommodated when there is a large space left in the battery 200, and because the number of battery monomers 100 in each row is large, the battery 200 loses a lot of power.

[0242] The following Table 2 illustrates the effect of the design of h and φ on the total power of the battery 200, where the units of h and φ are mm, and the unit of the total power is kWh.

[0243] Table 2 Effect of the design of h and φ on the total power of the battery 200

[0244]

[0245]

[0246] This embodiment can ensure that the battery 200 has sufficient power to meet the power demand, and the battery monomer 100 with a suitable diameter can be selected according to the internal space of the box assembly 201, the space utilization rate in the box assembly 201 can be improved as much as possible, the internal wasted space can be reduced, the total power can be increased as much as possible under the condition of a certain volume of the battery 200, and the energy density of the battery 200 can be improved.

[0247] In some embodiments, as shown in FIG. 1, the electrode lead-out part 3 is arranged at the first end wall 13 of the shell 10, and the pressure relief part 21 is arranged at the second end wall 14 of the shell 10. The thickness l1 of the first end wall 13 and the thickness l2 of the second end wall 14 satisfy the following relationship: l1 ≥ l2. Figure 9

[0248] In the shell 10, the shell 10 can include the accommodating part 1 and the end cover 2, the end cover 2 closes the opening 11 of the accommodating part 1, the pressure relief part 21 is arranged on the end cover 2, the end cover 2 serves as the second end wall 14, the thickness l2 of the second end wall 14 is the thickness of the end cover 2, and the thickness is not the thickness at the notch 22; the first end wall 13 of the shell 10 is the end wall of the accommodating part 1 away from the opening 11, that is, the end wall where the electrode lead-out part 3 of the accommodating part 1 is arranged. The thickness l1 of the first end wall 13 and the thickness l2 of the second end wall 14 are the thicknesses of most of the regions of the end walls. Because a protrusion or a groove can be arranged locally on the first end wall 13 or the second end wall 14, the effect on the main strength of the end wall is small, and therefore, in order to facilitate measurement, the thickness of the end wall is represented by the thickness of the main region of the end wall. ​

[0249] In order to achieve better results, l1≥1.5*l2. When l1

[0250] This embodiment makes the thickness l1 of the first end wall 13 greater than the thickness l2 of the second end wall 14, so that when the battery monomer 100 is in thermal runaway, the deformation of the shell 10 on the side of the pressure relief component 21 is greater than the deformation on the side of the electrode lead-out portion 3 and the first end wall 13, so that the gas generated by thermal runaway can be reliably discharged from the pressure relief component 21 on the second end wall 14, preventing the gas from flowing towards the side of the electrode lead-out portion 3 and causing a large deformation of the first end wall 13, thereby preventing the shell 10 from breaking and leaking when in thermal runaway.

[0251] In some embodiments, the thickness l1 of the first end wall 13 has a size range of 0.5mm≤l1≤1mm; and / or the thickness l2 of the second end wall 14 has a size range of 0.3mm≤l2≤1mm.

[0252] In order to achieve better results, 0.6mm≤l1≤0.8mm, 0.5mm≤l2≤0.8mm.

[0253] This embodiment designs appropriate thicknesses for the first end wall 13 and the second end wall 14, so that when the battery monomer 100 is in thermal runaway, the shell 10 will deform greatly under the action of the internal high-pressure gas, preventing the shell 10 from breaking and leaking when in thermal runaway.

[0254] In some embodiments, as shown in Figs. 1-3, the second end wall 14 is provided with a notch 22, and the area of the second end wall 14 enclosed by the notch 22 forms the pressure relief component 21. Figure 9 and Figure 10 As shown in Figs. 1-3, the second end wall 14 is provided with a notch 22, and the area of the second end wall 14 enclosed by the notch 22 forms the pressure relief component 21.

[0255] The notch 22 can enclose a circle, an ellipse or a polygon, and the extension trajectory of the notch 22 can be closed or not closed.

[0256] This embodiment can break the notch 22 to open the pressure relief component 21 when the battery monomer 100 is in thermal runaway and the internal pressure exceeds the preset opening pressure of the pressure relief component 21, and the gas in the shell 10 is discharged outward through the opening, thereby improving the safety of the battery monomer 100 in operation.

[0257] In some embodiments, the thickness l1 of the first end wall 13 and the thickness l3 of the second end wall 14 at the notch 22 satisfy the following relationship: l1≥2*l3.

[0258] In order to achieve better results, l1≥6*l3.

[0259] The thickness l3 of the second end wall 14 at the location where the score 22 is provided is the distance between the deepest location of the score 22 and the surface of the second end wall 14 away from the score 22.

[0260] This embodiment forms a weak part with lower strength relative to the first end wall 13 at the location of the score 22 by setting the size relationship between the thickness l1 of the first end wall 13 and the thickness l3 of the second end wall 14 at the location where the score 22 is provided. When thermal runaway occurs in the battery monomer 100, the internal gas can be deformed preferentially at the weak part to make the pressure relief component 21 open quickly, so that the internal gas can be discharged smoothly. Even if thermal runaway occurs near the electrode lead-out part, the gas can flow preferentially towards the pressure relief component 21, which can prevent a large deformation of the region where the first end wall 13 is located under the action of the internal high-pressure gas, prevent the shell 10 from breaking and causing thermal leakage when thermal runaway occurs, and improve the safety of the battery monomer 100 at the side where the electrode lead-out part 3 and the first end wall 13 are located.

[0261] In some embodiments, in order to achieve better results, the thickness l1 of the first end wall 13 and the thickness l3 of the second end wall 14 at the location where the score 22 is provided satisfy the following relationship: l1≥6*l3.

[0262] Table 3 Influence of the relationship between the thickness l1 and the thickness l3 on the safety of the battery monomer 100

[0263]

[0264] In Table 3, for Examples 3 and 4, l1<6*l3. When the needle puncture failure test is performed near the side where the electrode lead-out part 3 and the first end wall 13 are located, the battery monomer 100 short-circuits, and when thermal runaway occurs inside, the high-temperature and high-pressure gas flows more easily in the direction towards the first end wall 13 due to the thin thickness of the first end wall 13, causing the first end wall 13 to deform or break, and the instantaneous high pressure causes the gas to be discharged towards the side of the electrode lead-out part 3, which can cause the electrode lead-out part 3 to break, thereby causing the electrical connection of the battery monomer 100 to fail.

[0265] In some embodiments, the electrode lead-out part 3 is provided on the first end wall 13 of the shell 10, the first end wall 13 is provided with a first through hole 12 for mounting the electrode lead-out part 3, the pressure relief component 21 is circular and has a pressure relief area, and the diameter φ2 of the first through hole 12 and the diameter φ1 of the pressure relief area satisfy the following relationship: φ2≤φ1.

[0266] When φ2 > φ1, the deformation amount on the side of the pressure relief component 21 is smaller than the deformation amount on the side of the first end wall 13 when thermal runaway occurs inside the battery monomer 100, and the electrode lead-out portion 3 mounting area is prone to breakage and thermal leakage. To achieve better results, φ2≤0.8*φ1.

[0267] The diameter φ2 of the first through hole 12 for mounting the electrode lead-out portion 3 does not exceed the diameter φ1 of the pressure relief area, which can improve the strength of the shell 10 at the first end wall 13 where the electrode lead-out portion 3 is located, and when the battery monomer 100 undergoes thermal runaway, the gas can flow preferentially towards the pressure relief component 21, preventing the area where the first end wall 13 is located from deforming significantly under the action of internal high-pressure gas, preventing the shell 10 from breaking and leaking when thermal runaway occurs, and improving the safety of the battery monomer 100 on the side of the electrode lead-out portion 3 and the first end wall 13.

[0268] In some embodiments, the diameter φ2 of the first through hole 12 ranges from 8mm to 25mm; and / or the diameter φ1 of the pressure relief area ranges from 20mm to 35mm.

[0269] To achieve better results, 10mm≤φ2≤20mm, 22mm≤φ1≤32mm.

[0270] The first through hole 12 is used to mount the electrode lead-out portion 3. If the size of the first through hole 12 is too small, it will limit the diameter of the electrode lead-out portion 3, affecting the overcurrent capacity of the battery monomer 100; if the size of the first through hole 12 is too large, it will reduce the overall strength of the first end wall 13 of the containing portion 1 away from the end cover 2, and when the battery monomer undergoes thermal runaway, the connection between the first through hole 12 and the electrode lead-out portion 3 is prone to deformation, and gas escaping from this weak point will affect the safety of the side where the electrode lead-out portion 3 and the first end wall 13 are located.

[0271] This embodiment designs appropriate sizes for the diameter φ1 of the first through hole 12 and the pressure relief area, which can ensure the strength of the shell 10 at the end where the electrode lead-out portion 3 is located, and when the battery monomer 100 undergoes thermal runaway, the gas can flow preferentially towards the pressure relief component 21, preventing the area where the first end wall 13 is located from deforming significantly under the action of internal high-pressure gas, preventing the shell 10 from breaking and leaking when thermal runaway occurs, and improving the safety of the battery monomer 100 on the side where the electrode lead-out portion 3 and the first end wall 13 are located.

[0272] In some embodiments, the electrode assembly 4 is wound by a first polar tab 45, a second polar tab 46 and a separator 47 around a winding axis K, the winding axis K is consistent with the first direction z, the first polar tab 45 and the second polar tab 46 have a first polar lug 42 and a second polar lug 43 respectively; the center of the electrode assembly 4 is provided with a second through hole 44 extending along the first direction z, the pressure relief component 21 is circular and has a pressure relief area, the maximum diameter φ3 of the second through hole 44 and the diameter φ1 of the pressure relief area satisfy the following relationship: φ3≥0.12*φ1.

[0273] In order to achieve better results, φ3≥0.15*φ1, so that the gas can quickly reach the pressure relief component 21 along the second through hole 44 when the battery monomer 100 is in thermal runaway.

[0274] Table 4: The influence of the diameter relationship between the second through hole 44 and the pressure relief area on the safety of the battery monomer 100

[0275]

[0276] In example 1 of table 4, φ3<0.12*φ1, when the needle puncture failure test is performed on the side close to the electrode lead-out part 3 and the first end wall 13, the battery monomer 100 is short-circuited, and when the internal thermal runaway occurs, due to the small diameter of the second through hole 44, the high-temperature and high-pressure gas cannot reach the pressure relief component 21 in time along the second through hole 44, and the discharge speed is slow. The instantaneous high pressure will make the gas discharge towards the side of the electrode lead-out part, which will cause the electrode lead-out part to break, thereby causing the electrical connection failure of the battery monomer 100.

[0277] This example makes the diameter φ3 of the second through hole 44 and the diameter φ1 of the pressure relief area satisfy the above relationship, when the battery monomer 100 is in thermal runaway, the second through hole 44 has sufficient channel size to allow the internal high-pressure gas to flow rapidly to the pressure relief component 21, so that the pressure relief component 21 is smoothly opened, preventing the heat from accumulating inside the battery monomer 100 and preventing the shell 10 from deforming and breaking to cause thermal leakage, thereby improving the safety of the battery monomer 100 in operation.

[0278] In some embodiments, the height of the battery monomer 100 along the first direction z is h, and 60mm≤h≤135mm.

[0279] In order to achieve better results, h can be selected between 70mm and 125mm. When h<60mm, the height of the battery monomer 100 is insufficient, resulting in low power of the entire power battery system, when h>135mm, the bottom of the battery 200 is difficult to set the space for the pressure relief component 21 to release the discharge, and the single battery monomer 100 will explode after thermal runaway, causing the entire battery 200 to catch fire and explode.

[0280] The embodiment can ensure that the whole battery system has sufficient power, fully utilize the internal space of the battery 200, and set a space for the pressure relief component 21 to release the exhaust at the bottom region in the battery 200, so that the exhaust of the battery monomer 100 can be smoothly discharged in the case of thermal runaway, and the battery 200 is prevented from catching fire and exploding due to high temperature and high pressure.

[0281] In some embodiments, the shell 10 is cylindrical, and the diameter of the shell 10 is φ and the height is h,

[0282] In order to achieve better results, When The structure of the electrode lead-out part 3 and the pressure relief component 21 arranged at the opposite ends of the shell 10 is not suitable, because when the battery monomer 100 is in an elongated shape, if thermal runaway occurs at a certain point near the electrode lead-out part 3 in the battery monomer 100, the internal gas cannot flow to the end where the pressure relief component 21 is located in time, the heat increases, and the gas is more likely to be sprayed from the area where the electrode lead-out part 3 is located, which can cause the whole power battery system to catch fire and other safety incidents.

[0283] The following Table 5 illustrates The size parameters in the following table are in mm.

[0284] Table 5 The size parameters in the following table are in mm.

[0285]

[0286] In Table 5, for Examples 5, 6 and 9, The ratio of the height to the diameter of the battery monomer 100 is large, and the battery monomer 100 is in an elongated shape. When the needle puncture failure test is performed near the electrode lead-out part 3 and the first end wall 13, the battery monomer 100 short-circuits, and when thermal runaway occurs inside, the high-temperature and high-pressure gas cannot reach the pressure relief component 21 in time or be discharged from the pressure relief component 21, and the gas is discharged towards the side of the electrode lead-out part, which can cause the electrode lead-out part to be damaged, thereby causing the electrical connection of the battery monomer 100 to fail. For other examples, The ratio of the height to the diameter of the battery monomer 100 is moderate, and when the needle puncture failure test is performed near the electrode lead-out part 3 and the first end wall 13, the battery monomer 100 short-circuits, and when thermal runaway occurs inside, the high-temperature and high-pressure gas can reach the pressure relief component 21 in time or be discharged from the pressure relief component 21, which can prevent the gas from being discharged towards the side of the electrode lead-out part, so as to prevent the electrode lead-out part from being damaged and ensure the normal electrical connection of the battery monomer 100.

[0287] The embodiment can make the high-pressure gas in the battery monomer 100 quickly reach the pressure relief component 21 and be smoothly discharged when the thermal runaway occurs in any region inside the battery monomer 100, prevent the high-pressure gas and heat from gathering inside the battery monomer 100, avoid the fire explosion and other events of the entire power battery system, and improve the safety of the battery work.

[0288] In some embodiments, as shown in Figure 11 The shell 10 includes a first end wall 13 provided with a first through hole 12, and the electrode lead-out part 3 of the battery monomer 100 is mounted in the first through hole 12 and insulated from the first end wall 13. The electrode lead-out part 3 is a first output pole, and the first end wall 13 is a second output pole. The battery 200 further includes a busbar 202. The battery monomer 100 is provided in plurality. One end of the busbar 202 is electrically connected to the electrode lead-out part 3 of one of the battery monomers 100, and the other end of the busbar 202 is electrically connected to the first end wall 13 of another battery monomer 100.

[0289] The busbar 202 can be in a thin plate structure and made of a metal conductive material. For example, the busbar 202 can include a first part 202A, a second part 202B, and a third part 202C. The second part 202B is connected between the first part 202A and the third part 202C. The first part 202A is connected to the electrode lead-out part 3 of one of the battery monomers 100, and the third part 202C is connected to the first end wall 13 of another battery monomer 100. The two battery monomers 100 can be arranged adjacently or at intervals. For example, the first part 202A has a shape matching that of the electrode lead-out part 3, such as a circular or rectangular shape. The third part 202C can be rectangular. A notch can be provided on the side of the third part 202C away from the second part 202B to avoid the electrode lead-out part 3 of another battery monomer 100.

[0290] The embodiment takes the electrode lead-out part 3 as the first output pole of the battery monomer 100 and takes the first end wall 13 as the second output pole of the battery monomer 100. When the series connection, parallel connection, or mixed connection of the plurality of battery monomers 100 inside the battery 200 is implemented, the two ends of the busbar 202 can be directly connected to the electrode lead-out part 3 and the first end wall 13, respectively. Since only one electrode lead-out part 3 is provided on the first end wall 13 of the shell 10, the conductive area of the electrode lead-out part 3 can be increased. Moreover, the electrical connection of the first end wall 13 can be easily achieved by welding or by a fastener connection, so that the difficulty of electrical connection of the plurality of battery monomers 100 can be reduced, and the reliability of the electrical connection can be improved, thereby ensuring the working performance and reliability of the battery 200.

[0291] In some embodiments, as shown in Figure 11As shown, the shell 10 includes a first end wall 13, the first end wall 13 is provided with a first through hole 12, the electrode lead-out part 3 of the battery monomer 10 is installed in the first through hole 12 and is insulated from the first end wall 13, the electrode lead-out part 3 is a first output pole, and the first end wall 13 is a second output pole; the battery 200 further includes a plurality of busbars 202, in the same battery monomer 100, the electrode lead-out part 3 is electrically connected with one of the busbars 202, and the first end wall 13 is electrically connected with another busbar 202.

[0292] Each battery monomer 100 in the embodiment can be electrically connected with other two battery monomers 100 through two independent busbars 202, since the first end wall 13 in the peripheral area of the electrode lead-out part 3 can be used to connect the busbar 202, thus being adaptable to different arrangement modes of the plurality of battery monomers 100.

[0293] In some embodiments, as shown, Figure 12 The battery 200 further includes a box assembly 201 and a support plate 203, the battery monomer 100 is installed in the box assembly 201 through the support plate 203, the support plate 203 is provided with a third through hole 203' for the flow of the discharge material escaping from the pressure relief part 21, the pressure relief part 21 is circular and has a pressure relief area, and the minimum distance D between the pressure relief part 21 and the inner wall of the box assembly 201 and the diameter φ1 of the pressure relief area satisfy the following relationship: 0.4*φ1≤D≤1.2*φ1.

[0294] For example, the support plate 203 is arranged on the inner bottom surface of the box assembly 201, the support plate 203 is provided with a plurality of third through holes 203', and the plurality of battery monomers 100 are installed on the support plate 203 with the pressure relief part 21 downward, the pressure relief part 21 and the third through hole 203' have a coincident part, for example, the pressure relief part 21, the third through hole 203' and the end cover 2 are concentrically arranged. The third through hole 203' is used for the flow of the discharge material escaping from the inside of the battery monomer 100 to the discharge channel in the battery 200, and finally can be discharged outside through the pressure relief part on the box assembly 201 of the battery 200.

[0295] The distance D is designed according to the diameter φ1 of the pressure relief area. In order to achieve better results, 0.67*φ1≤D≤φ1. When D<0.4*φ1, the distance D between the pressure relief part 21 and the inner wall of the box assembly 201 is too small, which causes that the active material cannot be effectively sprayed out, and the battery 200 cannot be quickly cooled; when D>1.2*φ1, the distance D between the pressure relief part 21 and the inner wall of the box assembly 201 is too large, which occupies the height of the battery monomer 100 and affects the energy density.

[0296] For example, the size of φ1 ranges from 20mm to 35mm, and is preferably 22mm to 32mm. The size of D ranges from 10mm to 30mm, and is preferably 15mm to 25mm.

[0297] The influence of the design of the distance D on the temperature reduction to the preset temperature after the battery thermal runaway is illustrated by Table 6 below. The units of the size parameters in the following table are mm.

[0298] Table 6 Influence of the design of the distance D in the battery on the temperature after the battery thermal runaway

[0299]

[0300] For example 1, D < 0.67 * φ1, the distance D is too small, and the battery monomer 100 cannot discharge the discharge material in time through the third through hole 203' when the battery monomer 100 thermal runaway, the internal temperature of the battery 200 will rise sharply, and the time required to reduce to 120℃ is twice that of other examples. For example 4, D > 1.2 * φ1, the distance D is too large, although the battery monomer 100 cannot discharge the discharge material in time through the third through hole 203' when the battery monomer 100 thermal runaway, but the thickness of the support plate 203 is large, which obviously reduces the height of the battery monomer 100, which will affect the energy density of the battery monomer 100.

[0301] This example sets a suitable distance D between the pressure relief component 21 and the inner wall of the box assembly 201, which can effectively discharge the internal gas and active material when the battery monomer 100 thermal runaway, so that the battery 200 can be quickly cooled, and on the basis of meeting the thermal runaway safety, the height of the battery monomer 100 is increased as much as possible, thereby increasing the energy density of the battery monomer 100, and the battery 200 can provide more power.

[0302] In some examples, the electric device includes a vehicle 300, and the battery 200 is arranged between the cabin 301 and the vehicle floor 302, and the electrode lead-out portion is arranged towards the cabin 301, and the pressure relief component 21 is arranged towards the vehicle floor 302.

[0303] This example can make the battery 200 in the process of use, when the battery monomer 100 thermal runaway, the pressure relief component 21 of the battery monomer 100 is arranged towards the vehicle floor 302, that is, arranged downwards, if the pressure relief component 21 is opened, the discharge material released by the battery 200 will be sprayed towards the vehicle below, which can reduce the influence of high temperature and high pressure on the cabin 301 and passengers, and improve the safety of the vehicle 300 in use.

[0304] In some specific examples, as shown in Figures 3 to 5 The battery monomer 100 is cylindrical and includes a shell 10, an electrode assembly 4, and an electrode lead-out portion 3. The shell 10 includes a containing portion 1 and an end cover 2. The containing portion 1 is a cylindrical structure, and an opening 11 is arranged at one end along a first direction z (central axis). The end cover 2 closes the opening 11. The containing portion 1 includes a first end wall 13 and a side wall 15, and the end cover 2 serves as a second end wall 14.

[0305] The end cover 2 is integrally provided with a pressure relief part 21, which can be circular and is arranged at the center of the end cover 2. The first end wall 13 is provided with a first through hole 12 arranged at the center of the first end wall 13, and the electrode lead-out part 3 is mounted in the first through hole 12.

[0306] The electrode assembly 4 includes an electrode body 41, a first tab 42 and a second tab 43, which are respectively arranged at two ends of the electrode body 41 along a first direction z, which is consistent with the winding axis. The first tab 42 is electrically connected to the electrode lead-out part 3 through the first current collector 5, and the second tab 42 is electrically connected to the end cover 2 through the second current collector 6, which is welded to the containing part 1 so that the second tab 43 transmits electric energy to the first end wall 13 through the second current collector 6, the end cover 2 and the side wall 15. For example, the electrode lead-out part 3 serves as a positive output pole, and the first end wall 13 serves as a negative output pole, or vice versa.

[0307] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it without departing from the scope of the application, and equivalent components can be substituted therefor. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to a cylindrical electrode assembly (4) comprising an electrode body (41) and first and second polar opposite tabs (42, 43) extending from the electrode body (41); a first and a second output pole, the first output pole being electrically connected to the first tab (42) and the second output pole being electrically connected to the second tab (43); a housing (10) for accommodating the electrode assembly (4), the housing (10) being provided with a pressure relief member (21), the first and the second output pole being arranged at one end of the housing (10) in a first direction (z), and the pressure relief member (21) being arranged at the other end of the housing (10); wherein the housing (10) comprises a first end wall (13), a second end wall (14) and a side wall (15) arranged opposite to each other in the first direction (z), the first end wall (13) being provided with a first through hole (12) for mounting an electrode lead-out part (3) of a battery cell (10) in an insulated manner, the second end wall (14) being provided with the pressure relief member (21); the electrode lead-out part (3) being the first output pole, and the first end wall (13) being the second output pole. The housing (10) comprises an accommodating part (1) having an opening (11) and an end cover (2) for covering the opening (11), the accommodating part (1) being formed by the first end wall (13) and the side wall (15), and the end cover (2) being the second end wall (14). The housing (10) comprises an accommodating part (1) having an opening (11) and an end cover (2) for covering the opening (11), the accommodating part (1) being formed by the second end wall (14) and the side wall (15), and the end cover (2) being the first end wall (13). The first tab (42) extends from the electrode body (41) in a direction facing the electrode lead-out part (3) in the first direction (z), and the second tab (43) extends from the electrode body (41) in a direction away from the electrode lead-out part (3) in the first direction (z), the first tab (42) being electrically connected to the electrode lead-out part (3), and the second tab (43) being electrically connected to the first end wall (13). The application further comprises a first current collector (5) and a second current collector (6), the first tab (42) being electrically connected to the electrode lead-out part (3) through the first current collector (5), and the second tab (43) being electrically connected to the first end wall (13) through the second current collector (6). The second current collector (6) is in contact with the side wall (15) to realize electronic conduction between the second tab (43) and the first end wall (13).

2. The battery cell of claim 1, wherein, ​ 3. The battery cell of claim 1, wherein, ​ 4. The battery cell of claim 1, wherein, ​ 5. The battery cell of claim 4, wherein, ​ 6. The battery cell of claim 5, wherein, ​ 7. The battery cell of claim 5, wherein, The shell (10) comprises a containing part (1) having an opening (11) and an end cover (2) for covering the opening (11), the second current collector (6) is connected to the end cover (2), and the end cover (2) is electrically connected to the side wall (15) to realize electronic conduction between the second tab (43) and the first end wall (13).

8. The battery cell of claim 5, wherein, The shell (10) comprises a containing part (1) having an opening (11) and an end cover (2) for covering the opening (11), the second current collector (6) is in contact with the side wall (15), and the end cover (2) is connected with the second current collector (6) to realize electronic conduction between the second tab (43) and the first end wall (13).

9. The battery cell of claim 5, wherein, Along the first direction (z), the second current collector (6) is located between the pressure relief component (21) and the second tab (43), and the second current collector (6) is provided with a hollow part (6') for gas conduction between the space on one side of the second current collector (6) facing the second tab (43) and the space on the other side facing the pressure relief component (21).

10. The battery cell of claim 9, wherein, The hollow part (6') comprises at least one fourth through hole (61), and one of the fourth through holes (61) is arranged at the center position of the second current collector (6).

11. The battery cell of claim 10, wherein, The fourth through hole (61) is provided with a plurality of fourth through holes (61), and the remaining fourth through holes (61) are distributed around the fourth through hole (61) at the center position.

12. The battery cell of claim 10, wherein, The hollow part (6') further comprises a plurality of cutouts (63) extending through the second current collector (6) along the first direction (z), and the plurality of cutouts (63) are arranged around the fourth through hole (61).

13. The battery cell of claim 12, wherein, One end of the cutout (63) communicates with the fourth through hole (61) and extends away from the fourth through hole (61).

14. The battery cell of claim 10, wherein, The hollow part (6') further comprises a plurality of score lines (62) extending through the second current collector (6) along the first direction (z).

15. The battery cell of claim 14, wherein, The score line (62) is provided with a plurality of score lines (62), one end of the score line (62) communicates with the fourth through hole (61) and extends away from the fourth through hole (61).

16. The battery cell of claim 1, wherein, The first tab (42) and the second tab (43) are both led out from one end of the electrode main body (41) facing the electrode lead-out part (3) along the first direction (z), the first tab (42) is electrically connected to the electrode lead-out part (3), and the second tab (43) is electrically connected to the first end wall (13).

17. The battery cell of claim 1, wherein, Further comprising a first current collector (5) and a second current collector (6), the first tab (42) is electrically connected to the electrode lead-out part (3) through the first current collector (5), and the second tab (43) is electrically connected to the first end wall (13) through the second current collector (6); The electrode lead-out portion (3) comprises a base (31) and a main body portion (32), the base (31) is located between the first end wall (13) and the first current collector (5) and is used to limit the movement of the electrode lead-out portion (3) in the first direction (z) away from the inside of the shell (10), an insulating member (7) is arranged between the first end wall (13) and the base (31), and at least a part of the main body portion (32) is located in the first through hole (12).

18. The battery cell of claim 17, wherein, In the first direction (z), the maximum thickness t1 of the base (31) satisfies: 0.6mm≤t1≤1.2mm; and / or the maximum thickness t2 of the first current collector (5) satisfies: 0.3mm≤t2≤0.7mm; and / or the maximum thickness t3 of the second current collector (6) satisfies: 0.3mm≤t3≤0.7mm.

19. The battery cell of claim 18, wherein, 0.8mm≤t1≤1mm, and / or 0.4mm≤t2≤0.6mm, and / or 0.4mm≤t3≤0.6mm.

20. The battery cell of claim 17, wherein, The electrode lead-out portion (3) further comprises a limiting protrusion (33), the base (31) and the limiting protrusion (33) are both connected to and protrude from the outer peripheral wall of the main body portion (32), and the limiting protrusion (33) and the base (31) are respectively located on the outer side and the inner side of the first end wall (13) in the first direction (z) and are used to clamp a part of the first end wall (13).

21. The battery cell of claim 20, wherein, The main body portion (32) is provided with a recess (34), the bottom wall of the recess (34) is connected to the first current collector (5) to realize the electronic conduction between the electrode lead-out portion (3) and the first tab (42), and the opening of the recess (34) is arranged on the side of the main body portion (32) facing and / or away from the inside of the shell (10).

22. The battery cell of claim 21, wherein, The bottom wall of the recess (34) is laser welded to the first current collector (5) from the side of the main body portion (32) away from the inside of the shell (10).

23. The battery cell of claim 1, wherein, The shell (10) is cylindrical, the pressure relief component (21) is arranged at the center of the second end wall (14) and is circular, the pressure relief component (21) has a pressure relief area, and the diameter φ1 of the pressure relief area and the diameter φ of the shell (10) satisfy the following relationship:

24. The battery cell (100) according to claim 23, characterized in that 15mm≤φ≤70mm.

25. The battery cell of any one of claims 1-24, wherein, The thickness l1 of the first end wall (13) and the thickness l2 of the second end wall (14) satisfy the following relationship: l1≥l2.

26. The battery cell of claim 25, wherein, l1≥1.5*l2。 27. The battery cell of claim 25, wherein, The thickness l1 of the first end wall (13) ranges from 0.5mm to 1mm; and / or the thickness l2 of the second end wall (14) ranges from 0.3mm to 1mm.

28. The battery cell of claim 27, wherein, 0.6mm≤l1≤0.8mm, and / or 0.5mm≤l2≤0.8mm.

29. The battery cell of any one of claims 1-24, wherein, The second end wall (14) is provided with a notch (22), and the area of the second end wall (14) surrounded by the notch (22) forms the pressure relief component (21).

30. The battery cell of claim 29, wherein, The thickness l1 of the first end wall (13) and the thickness l3 of the second end wall (14) at the position where the notch (22) is arranged satisfy the following relationship: l1≥2*l3.

31. The battery cell of claim 30, wherein, l1≥6*l3。 32. The battery cell of any one of claims 1-24, wherein, The pressure relief component (21) is circular and has a pressure relief area, and the diameter φ2 of the first through hole (12) and the diameter φ1 of the pressure relief area satisfy the following relationship: φ2≤φ1.

33. The battery cell of claim 32, wherein, The diameter φ2 of the first through hole (12) ranges from 8mm to 25mm; and / or the diameter φ1 of the pressure relief area ranges from 20mm to 35mm.

34. The battery cell of any one of claims 1-24, wherein, The electrode assembly (4) is wound around a winding axis (K) by a first tab (45), a second tab (46) and a separator (47) with opposite polarities, the winding axis (K) coincides with the first direction (z), the first tab (45) and the second tab (46) have the first lug (42) and the second lug (43) respectively; The center of the electrode assembly (4) is provided with a second through hole (44) extending along the first direction (z), the pressure relief component (21) is circular and has a pressure relief area, the maximum diameter φ3 of the second through hole (44) and the diameter φ1 of the pressure relief area satisfy the following relationship: φ3≥0.12*φ1.

35. The battery cell of any one of claims 1-24, wherein, The shell (10) includes a second end wall (14), and the pressure relief component (21) is located in the central region of the second end wall (14).

36. A battery, comprising: The battery (200) further comprises a plurality of busbars (202), in the same battery monomer (100), the electrode lead-out part (3) is electrically connected with one of the busbars (202), and the first end wall (13) is electrically connected with another busbar (202). The shell (10) includes a first end wall (13), the first end wall (13) is provided with a first through hole (12), and the electrode lead-out part (3) of the battery monomer (10) is mounted in the first through hole (12) and is insulated from the first end wall (13), the electrode lead-out part (3) is the first output pole, and the first end wall (13) is the second output pole.

37. The battery of claim 36, wherein, The battery (200) further comprises a plurality of busbars (202), in the same battery monomer (100), the electrode lead-out part (3) is electrically connected with one of the busbars (202), and the first end wall (13) is electrically connected with another busbar (202). The shell (10) includes a first end wall (13), the first end wall (13) is provided with a first through hole (12), and the electrode lead-out part (3) of the battery monomer (10) is mounted in the first through hole (12) and is insulated from the first end wall (13), the electrode lead-out part (3) is the first output pole, and the first end wall (13) is the second output pole.

38. The battery of claim 36 or 37, wherein, The battery (200) further comprises a plurality of busbars (202), in the same battery monomer (100), the electrode lead-out part (3) is electrically connected with one of the busbars (202), and the first end wall (13) is electrically connected with another busbar (202). ​ 39. The battery of claim 35, wherein, The battery (200) further comprises a support plate (203) and a box assembly (201), the battery cell (100) is installed in the box assembly (201) through the support plate (203), the support plate (203) is provided with a third through hole (203') for the flow of the discharge of the pressure relief component (21), the pressure relief component (21) is circular and has a pressure relief area, and the minimum distance D between the pressure relief component (21) and the inner wall of the box assembly (201) and the diameter φ1 of the pressure relief area satisfy the following relationship: 0.4*φ1≤D≤1.2*φ1.

40. An electrical device, comprising: The battery (200) comprises any one of claims 36-39, and the battery (200) is used to provide electric energy for the electric device.

41. The powered device of claim 40, wherein, The electric device comprises a vehicle (300), the battery (200) is arranged between a cabin (301) and a vehicle floor (302), the first output pole and the second output pole are both arranged towards the cabin (301), and the pressure relief component (21) is arranged towards the vehicle floor (302).

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