Battery monomer, battery and electric device

Abstract

The invention provides a battery cell, a battery and a power utilization device. The battery cell (61) comprises an electrode assembly (10); the shell (20) is provided with a containing cavity and an open end (20b) communicated with the containing cavity; the end cover (30) covers the opening end (20b); the current collecting assembly (40) is electrically connected to the electrode assembly (10) and the shell (20), the containing cavity comprises a pressure relief cavity (pr) and an electrical cavity (e1), the pressure relief cavity (pr) is located between the current collecting assembly (40) and the end cover (30), and the electrical cavity (e1) is configured to contain the electrode assembly (10); wherein the end cover (30) is provided with a pressure relief part (50), at least part of the pressure relief part (50) is arranged on the cavity wall of the pressure relief cavity (pr), and the current collecting assembly (40) is provided with at least one channel communicated with the electrical cavity (e1) and the pressure relief cavity (pr).

Description

Battery cell, battery and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0002] Secondary batteries, especially lithium ion batteries, have the advantages of high voltage, large specific energy, long cycle life, green and pollution-free, wide working temperature range and small self-discharge, and are widely used in portable electronic devices, energy storage devices and power equipment of large new energy electric vehicles, which has great significance for solving human environmental pollution and energy crisis. With the wide application of lithium ion batteries, the use reliability of the battery becomes a problem closely concerned by the producers.

[0003] SUMMARY

[0004] In one aspect of the present disclosure, a battery cell is provided, comprising: an electrode assembly; a shell having a receiving cavity and an open end in communication with the receiving cavity; an end cover covering the open end; a current collecting assembly electrically connected to the electrode assembly and the shell, the receiving cavity comprising a pressure relief cavity and an electrical cavity, the pressure relief cavity being located between the current collecting assembly and the end cover, the electrical cavity being configured to accommodate the electrode assembly; wherein the end cover has a pressure relief portion, at least part of the pressure relief portion being provided on a cavity wall of the pressure relief cavity, and the current collecting assembly has at least one passage communicating the electrical cavity and the pressure relief cavity.

[0005] In the present embodiment, the current collecting assembly is electrically connected to the electrode assembly and the shell to achieve electrical connection between the electrode assembly and the shell, and the pressure relief cavity formed between the current collecting assembly and the end cover having the pressure relief portion can communicate with the electrical cavity accommodating the electrode assembly through the passage on the current collecting assembly, so that the gas generated under the condition of thermal runaway of the electrode assembly can quickly enter the pressure relief cavity to trigger the pressure relief of the pressure relief portion provided at least partially on the cavity wall of the pressure relief cavity, thereby reducing the risk of excessive pressure accumulation in the battery cell causing the shell to expand, deform, rupture, etc.

[0006] In some embodiments, the at least one passage comprises a first passage located at the periphery of the pressure relief cavity.

[0007] In the present embodiment, the first passage located at the periphery of the pressure relief cavity is provided to communicate the receiving cavity and the pressure relief cavity, so that the high-pressure gas and other substances generated inside the battery cell can enter the pressure relief cavity through the first passage at the periphery of the pressure relief cavity, so as to guide the high-pressure gas at the periphery of the pressure relief cavity to quickly enter the pressure relief cavity, thereby improving the pressure relief efficiency.

[0008] In some embodiments, the at least one channel comprises a plurality of the first channels, and the plurality of the first channels are arranged along the periphery of the pressure relief cavity.

[0009] In the present embodiment, by arranging a plurality of the first channels along the periphery of the pressure relief cavity, the pressure relief path can be achieved in multiple directions along the periphery of the pressure relief cavity, thereby improving the pressure relief efficiency of the battery cell and helping to reduce the risk of excessive local pressure inside the battery cell.

[0010] In some embodiments, the plurality of the first channels are arranged at equal intervals along the periphery of the pressure relief cavity.

[0011] In the present embodiment, by arranging the plurality of the first channels at equal intervals along the periphery of the pressure relief cavity, the high-pressure gas can be more uniformly introduced into the pressure relief cavity from the periphery of the pressure relief cavity to achieve pressure relief.

[0012] In some embodiments, the end cover is electrically connected to the shell, the current collecting assembly comprises: a first conductive member welded to the end cover and having a hollow portion penetrating in the thickness direction of the end cover; and a second conductive member electrically connected to the first conductive member and welded to the first tab of the electrode assembly on the side adjacent to the end cover; wherein the end cover, the hollow portion and the second conductive member enclose the pressure relief cavity, and the first channel is arranged between the first conductive member and the second conductive member and communicates with the hollow portion.

[0013] In the present embodiment, the current collecting assembly is electrically connected by the first conductive member and the second conductive member. The first conductive member is welded to the end cover electrically connected to the shell, and the second conductive member is welded to the first tab of the electrode assembly. In this way, the first conductive member and the second conductive member can be adaptively designed for the materials of the end cover and the first tab, respectively, have better welding compatibility, and help to reduce the risk of welding quality caused by the difference in welding performance of the materials during welding. The end cover, the hollow portion of the first conductive member and the second conductive member can form a deeper pressure relief cavity, which helps to improve the gas flow in the pressure relief cavity. By cooperating the first channel arranged between the first conductive member and the second conductive member and the hollow portion on the first conductive member, the pressure relief cavity can receive the high-pressure gas in the battery cell more quickly, thereby improving the pressure relief efficiency.

[0014] In some embodiments, the end cover and the base material of the first tab are different in material; wherein the first conductive member and the end cover are the same in base material, and / or the second conductive member and the first tab are the same in base material.

[0015] In the embodiment, when the base material of the end cover and the first tab are different, the base material of the first conductive member is set to be the same as that of the end cover, so that the end cover and the first conductive member can be easily welded, the electrical conductivity between the end cover and the first conductive member is reduced, and the risk of leakage of the end cover due to poor welding quality is reduced. The base material of the second conductive member is set to be the same as that of the first tab, so that the electrical conductivity between the second conductive member and the first tab is reduced, and the internal resistance of the battery cell is reduced.

[0016] In some embodiments, the base materials of the end cover and the first conductive member are both steel, and the base materials of the first tab and the second conductive member are both copper.

[0017] In the embodiment, the base materials of the end cover and the first conductive member are both set to be steel alloy, which not only improves the welding quality between the end cover and the first conductive member, but also improves the mechanical properties of the end cover and reduces the material cost. The base materials of the first tab and the second conductive member are both set to be copper, which achieves high electrical conductivity.

[0018] In some embodiments, the electrode assembly is a cylindrical electrode assembly, the second conductive member includes a plate body, an edge region of the plate body is welded with the first conductive member, and a notch is formed in the edge region of the plate body, the notch being at least partially exposed to the hollow portion as the first channel.

[0019] In the embodiment, the notch in the edge region of the plate body as the first channel allows the high-pressure gas generated in the electrical cavity under thermal failure or the like to enter the pressure relief cavity from the position exposed to the hollow portion through the notch around the plate body. The edge region of the plate body is welded with the first conductive member, which not only strengthens the current collecting assembly in strength and rigidity, but also simplifies the structure, which is beneficial to manufacturing and assembly.

[0020] In some embodiments, a plurality of notches are formed in the edge region of the plate body, and the plurality of notches are arranged at intervals in the circumferential direction of the plate body.

[0021] In the embodiment, the plurality of first channels are formed by the plurality of notches arranged at intervals in the circumferential direction of the plate body, which realizes the pressure relief path in multiple directions around the pressure relief cavity, thereby improving the pressure relief efficiency of the battery cell and reducing the risk of local overpressure.

[0022] In some embodiments, the plurality of notches are arranged at equal intervals in the circumferential direction of the plate body.

[0023] In the embodiment, the plurality of notches are arranged at equal intervals in the circumferential direction of the plate body, which allows the high-pressure gas to enter the pressure relief cavity more uniformly to achieve pressure relief.

[0024] In some embodiments, the at least one channel further comprises: a second channel opened in the center of the plate body, and a portion of the plate body between the second channel and the edge region is welded with the first tab.

[0025] In the present embodiment, a second channel is opened in the center of the plate body, and the center of the end of the electrode assembly is communicated with the electric cavity and the pressure relief cavity, so that the high-pressure gas generated by the electrode assembly can be more conveniently received. Moreover, the portion of the plate body between the second channel and the edge region is welded with the first tab, so that a larger area of the first tab can be welded, which helps to reduce the difficulty of welding and improve the welding quality.

[0026] In some embodiments, the electrode assembly is a cylindrical electrode assembly, the second conductive member comprises a flat plate portion and a convex portion, the convex portion protrudes from the flat plate portion in a direction away from the electrode assembly, and an inner side of the convex portion forms a concave portion, a normal projection of the concave portion on the first conductive member at least partially overlaps with the hollow portion, and the convex portion is welded with the first conductive member; the first channel is arranged in the convex portion.

[0027] For the battery cell embodiment comprising the cylindrical electrode assembly, the convex portion can form a support structure with higher strength and rigidity, and improve the mechanical properties of the current collecting assembly. Moreover, the concave portion formed in the inner side of the convex portion of the second conductive member can cooperate with the hollow portion of the first conductive member, so that a deeper pressure relief cavity can be formed, which helps to improve the gas flow in the pressure relief cavity. In addition, the welding position between the convex portion and the first conductive member is away from the flat plate portion, so that the influence of welding on the flat plate portion can be reduced.

[0028] In some embodiments, a first groove recessed from the flat plate portion in a direction away from the electrode assembly is formed on one side of the convex portion adjacent to the electrode assembly, an inner side wall of the convex portion is located between the first groove and the concave portion, and a third through hole is arranged in the inner side wall, the first groove and the third through hole serving as at least a part of the first channel.

[0029] In the present embodiment, the first groove is formed on one side of the convex portion of the second conductive member adjacent to the electrode assembly, so that a gap can be formed between the first groove and the first tab, so as to reduce the risk that the first channel on the second conductive member is blocked by the first tab due to the abutting of the first tab. The third through hole is arranged on the inner side wall of the convex portion between the first groove and the concave portion, so as to guide the high-pressure gas flow entering the first groove to the inner side of the concave portion.

[0030] In some embodiments, a plurality of third through holes are arranged between the first groove and the concave portion of the convex portion, and the plurality of third through holes are arranged in a circumferential direction of the second conductive member.

[0031] In the embodiment, the first groove is matched by the plurality of third through holes arranged along the circumference of the second conductive member at intervals between the first groove and the recess, so that the pressure relief path is realized in multiple directions around the pressure relief cavity, thereby improving the pressure relief efficiency of the battery monomer and reducing the risk of excessive local pressure.

[0032] In some embodiments, the plurality of third through holes are arranged at equal intervals along the circumference of the second conductive member.

[0033] In the embodiment, the plurality of third through holes are arranged at equal intervals along the circumference of the second conductive member, so that the high-pressure gas can enter the pressure relief cavity more uniformly to realize pressure relief.

[0034] In some embodiments, the outer side of the convex portion further extends outwardly to form a flange.

[0035] In the embodiment, the flange is extended outwardly from the outer side of the convex portion, so that the extrusion surface area between the bent edge of the convex portion and the tab is increased, thereby reducing the risk of damage to the tab caused by excessive pressure.

[0036] In some embodiments, the end face of the flange adjacent to one side of the electrode assembly is flush with the end face of the flat plate portion adjacent to one side of the electrode assembly.

[0037] In the embodiment, the end face of the flange adjacent to one side of the electrode assembly is flush with the end face of the flat plate portion, so that the extrusion surface area between the bent edge of the convex portion and the tab is further increased.

[0038] In some embodiments, the first conductive member is in the shape of a ring, the outer ring radius of the first conductive member is greater than the maximum distance from the outer sidewall of the convex portion to the center of the recess, the first conductive member, the flange and the convex portion jointly define a second groove on the outer side of the convex portion, the outer sidewall of the convex portion is arranged between the second groove and the first groove, and the fourth through hole is formed in the outer sidewall of the convex portion, and the second groove, the first groove, the fourth through hole and the third through hole serve as at least part of the first channel.

[0039] In the embodiment, the outer ring radius of the first conductive member is greater than the maximum distance from the outer sidewall of the convex portion to the center of the recess, so that the second groove can be formed after the first conductive member and the convex portion are welded, and the fourth through hole formed in the outer sidewall of the convex portion between the second groove and the first groove can guide the high-pressure gas on the outer side of the current collecting assembly, so that the high-pressure gas enters the inner side of the recess via the fourth through hole, the first groove and the third through hole.

[0040] In some embodiments, the outer sidewall of the protrusion is provided with a plurality of fourth through holes between the second groove and the first groove, and a plurality of third through holes between the first groove and the recess, the plurality of third through holes and the plurality of fourth through holes are arranged at intervals along the circumferential direction of the second conductive member, and the plurality of third through holes and the plurality of fourth through holes are at least partially aligned or staggered along the radial direction.

[0041] In the present embodiment, the plurality of fourth through holes and the plurality of third through holes are arranged at equal intervals along the circumferential direction of the second conductive member, and the plurality of third through holes and the plurality of fourth through holes are at least partially aligned or staggered along the radial direction, so that the high-pressure gas in different directions of the flow guide assembly can enter the pressure relief cavity more uniformly to achieve pressure relief.

[0042] In some embodiments, the protrusion is annular and forms the annular first groove.

[0043] In the present embodiment, by making the protrusion annular, the recess with continuous side edges can be enclosed to cooperate with the hollow portion of the first conductive member to form the pressure relief cavity. Moreover, the annular protrusion forms the annular first groove, which can achieve the rectification and flow guiding effect of the high-pressure gas flow in the circumferential direction at different circumferential positions, thereby improving the consistency of the pressure relief speed caused by the internal gas pressure difference of the battery monomer, and further improving the pressure relief efficiency.

[0044] In some embodiments, the protrusion is annular and cooperates with the first conductive member and the protruding edge to enclose the annular second groove.

[0045] In the present embodiment, by making the protrusion annular, the recess with continuous side edges can be enclosed to cooperate with the hollow portion of the first conductive member to form the pressure relief cavity. Moreover, the annular protrusion cooperates with the first conductive member and the protruding edge to enclose the annular second groove, which can achieve the rectification and flow guiding effect of the high-pressure gas flow in the circumferential direction at different circumferential positions on the outer side, thereby improving the consistency of the pressure relief speed caused by the internal gas pressure difference of the battery monomer, and further improving the pressure relief efficiency.

[0046] In some embodiments, the at least one channel further comprises: a second channel opened in the center of the flat plate portion, and the portion of the flat plate portion outside the second channel is welded with the first tab.

[0047] In the present embodiment, the second channel is opened in the center of the flat plate portion, and the end portion of the electrode assembly adjacent to the second channel communicates the electrical cavity and the pressure relief cavity, thereby more conveniently receiving the high-pressure gas generated by the electrode assembly. Moreover, the portion of the flat plate portion outside the second channel is welded with the first tab, which can achieve welding with a larger area of the first tab, thereby helping to reduce the welding difficulty and improve the welding quality.

[0048] In some embodiments, the first portion of the end cover for enclosing the pressure relief cavity protrudes away from the electrode assembly relative to a second portion of the end cover to which the first conductive member is welded.

[0049] In the present embodiment, the first portion of the end cover for enclosing the pressure relief cavity protrudes away from the electrode assembly relative to a second portion of the end cover to which the first conductive member is welded, and the first portion adjacent to the side wall of the electrode assembly side can jointly enclose a relatively deep pressure relief cavity with the hollow portion of the first conductive member and the second conductive member, which is conducive to the flow of gas inside the pressure relief cavity, and the second portion is fixedly connected with the first conductive member, so that the end cover and the current collecting assembly inside the shell are reliably fixed.

[0050] In some embodiments, the shell includes a side wall enclosing the open end and a bottom wall connected with the side wall and opposite to the open end, and an electrode terminal is arranged on the bottom wall, the electrode assembly includes a main body portion and first and second polar opposite tabs, the first tab is arranged at an end of the main body portion adjacent to the end cover side and is electrically connected with the current collecting assembly, and the second tab is arranged at an end of the main body portion adjacent to the bottom wall side and is electrically connected with the electrode terminal.

[0051] In the present embodiment, the first and second tabs of the electrode assembly are polar opposite and are arranged at the side of the main body portion adjacent to the end cover and the side adjacent to the bottom wall of the shell respectively, so that the second tab can be directly or through the current collecting assembly electrically connected with the electrode terminal arranged on the bottom wall, thereby realizing the charging and discharging function of the battery monomer through the electrical connection of the electrode terminal with the external conductor.

[0052] In some embodiments, the bottom wall and the side wall are integrally formed.

[0053] In the present embodiment, by integrally forming the bottom wall and the side wall, the overall sealing performance of the shell can be improved, which is conducive to simplifying the processing and assembly process.

[0054] In one aspect of the present disclosure, a battery is provided, comprising the aforementioned battery monomer.

[0055] The battery using the battery monomer of the aforementioned embodiments has good reliability.

[0056] In one aspect of the present disclosure, a power consuming device is provided, comprising the aforementioned battery.

[0057] The power consuming device using the battery of the aforementioned embodiments has good reliability. BRIEF DESCRIPTION OF DRAWINGS

[0058] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0059] FIG. 1 is a structural schematic diagram of some embodiments of an electrical device according to the present disclosure;

[0060] FIG. 2 is a structural schematic diagram of some embodiments of a battery according to the present disclosure;

[0061] FIG. 3 is a structural schematic diagram of some embodiments of a battery cell according to the present disclosure;

[0062] FIG. 4 is an exploded structural schematic diagram of some embodiments of a battery cell according to the present disclosure;

[0063] FIG. 5 is a structural schematic diagram of the mounting structure of a housing, an end cap, and a current collecting assembly in some embodiments of a battery cell according to the present disclosure;

[0064] FIG. 6A is a structural schematic diagram of a current collecting assembly in some embodiments of a battery cell according to the present disclosure;

[0065] FIG. 6B is a structural schematic diagram of a first conductive member in the embodiment shown in FIG. 6A;

[0066] FIG. 6C is a structural schematic diagram of a second conductive member in the embodiment shown in FIG. 6A;

[0067] FIG. 6D is a sectional schematic diagram of the mounting structure of an end cap, a current collecting assembly, and an electrode assembly in the embodiment shown in FIG. 6A;

[0068] FIG. 7A is a structural schematic diagram of a current collecting assembly in other embodiments of a battery cell according to the present disclosure;

[0069] FIG. 7B is a structural schematic diagram of a first conductive member in the embodiment shown in FIG. 7A;

[0070] FIG. 7C is a structural schematic diagram of a second conductive member in the embodiment shown in FIG. 7A;

[0071] FIG. 7D is a sectional schematic diagram of the mounting structure of an end cap, a current collecting assembly, and an electrode assembly in the embodiment shown in FIG. 7A;

[0072] FIG. 7E is an enlarged schematic diagram of the circled area of the dashed oval A in FIG. 7D;

[0073] FIG. 7F is a dimensional schematic diagram of the current collecting assembly in FIG. 7E.

[0074] 10 - electrode assembly; 11 - body portion; 12 - first tab; 13 - second tab; 14 - central hole; 20 - shell; 20b - open end; 21 - side wall; 22 - bottom wall; 221 - electrode terminal; 30 - end cap; 31 - first portion; 32 - second portion; 40, 40' - current collector assembly; 4A - first passage; 4B - second passage; 41 - first conductive member; 41a - body portion; 42 - second conductive member; 421 - first welding portion; 422 - second welding portion; 42a - plate body; 42b - notch; 42d - flat plate portion; 42e - protruding portion; 42g - recessed portion; 42h - first groove; 42i - third through hole; 42j - protruding edge; 42k - second groove; 42l - fourth through hole; 50 - pressure relief portion; 60 - battery; 61 - battery cell; 62 - box body; 63 - box cover; 70 - vehicle; pr - pressure relief cavity; el - electrical cavity; dr1 - first direction; dr2 - second direction; dr3 - third direction. DETAILED DESCRIPTION

[0075] Embodiments of the present disclosure will be described in further detail below with reference to the accompanying drawings and examples. The detailed description and drawings of the following examples are intended to illustrate the principles of the present disclosure by way of example only and should not be taken in a limiting sense. The scope of the present disclosure is not limited to the described examples.

[0076] In the description of the present disclosure, it should be noted that, unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like is only for the purpose of facilitating the description of the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present disclosure. In addition, the terms "first", "second", "third", etc. are only for the purpose of description and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

[0077] The orientation words appearing in the following description are the directions shown in the drawings, and are not limited to the specific structure of the present disclosure. In the description of the present disclosure, it should also be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, 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 disclosure can be understood according to the specific circumstances.

[0078] Some embodiments of the present application will be described in detail with reference to the drawings. The features described in the following embodiments can be combined with each other in the case of no conflict.

[0079] The "multiple" appearing in the present disclosure refers to two or more (including two).

[0080] In the embodiments of the present disclosure, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0081] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., and the present application is not limited thereto.

[0082] In some related technologies, the welding between the current collecting disc and the end cover is a whole circle of weld, so that a closed space is formed between the current collecting disc and the end cover provided with the pressure relief component, and a center hole is provided on the current collecting disc to receive the high-pressure gas and active material generated by the electrode assembly under the condition of thermal runaway, etc., into the pressure relief cavity to trigger the pressure relief component to achieve pressure relief.

[0083] It has been found through research that the pressure relief cavity formed by such a structure is relatively thin, and the gas flow in the cavity is not smooth, and when thermal runaway or the like occurs, the high-pressure gas and active material generated are difficult to quickly enter the pressure relief cavity from the center hole to trigger the pressure relief component, thereby possibly causing the risk of excessive internal pressure of the battery cell due to the untimely pressure relief of the pressure relief component, which adversely affects the stable and reliable use of the battery cell.

[0084] Therefore, the embodiments of the present disclosure provide a battery cell, a battery and an electric device, which can improve the reliability.

[0085] In one aspect of the present disclosure, a battery cell is provided, comprising:

[0086] an electrode assembly;

[0087] a housing having a receiving cavity and an open end in communication with the receiving cavity;

[0088] an end cover covering the open end;

[0089] a current collecting assembly electrically connected to the electrode assembly and the housing, the receiving cavity comprising a pressure relief cavity and an electrical cavity, the pressure relief cavity being located between the current collecting assembly and the end cover, and the electrical cavity being configured to accommodate the electrode assembly;

[0090] wherein the end cover has a pressure relief portion, at least part of the pressure relief portion being provided on a cavity wall of the pressure relief cavity, and the current collecting assembly has at least one passage in communication with the electrical cavity and the pressure relief cavity.

[0091] In the embodiment, the current collecting assembly is electrically connected with the electrode assembly and the shell to realize the electrical connection between the electrode assembly and the shell, and the pressure relief cavity formed between the current collecting assembly and the end cover with the pressure relief part can realize the communication with the electrical cavity accommodating the electrode assembly through the channel on the current collecting assembly, so that the gas generated in the electrode assembly under the condition of thermal runaway or the like can quickly enter the pressure relief cavity to trigger the pressure relief of the pressure relief part arranged at least partially on the cavity wall of the pressure relief cavity, thereby reducing the risk of overlarge pressure accumulation in the battery monomer, shell expansion and deformation, rupture and the like.

[0092] The battery monomer of the embodiment of the present disclosure can be applied to various batteries. The battery mentioned herein refers to a single physical module including one or more battery monomers to provide higher voltage and capacity.

[0093] In some embodiments, the battery can include a box body and a battery module, the box body being used to provide a containing space for the battery module, and the battery module being installed in the box body. The box body can be made of metal material. The battery module can include multiple battery monomers connected in series, in parallel or in a mixed manner. The battery monomer is the smallest unit constituting the battery. The battery monomer includes an electrode assembly capable of electrochemical reaction.

[0094] In some embodiments, the battery can include a box body and a battery monomer, and the battery monomer is contained in the box body.

[0095] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0096] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet and the like.

[0097] The battery of the embodiment of the present disclosure can be applied to various power consuming devices using batteries. The power consuming device can be a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric vehicle, 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 console, an electric car toy, an electric ship toy and an electric plane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, such as a power drill, a power grinder, a power wrench, a power screwdriver, a power hammer, an impact drill, a concrete vibrator and a power planer. The embodiment of the present disclosure does not particularly limit the above power consuming devices. The battery can be used for power supply of the power consuming device such as a vehicle, for example, to provide power for control or driving of the vehicle.

[0098] FIG. 1 is a structural schematic diagram of some embodiments of an electric device according to the present disclosure. For convenience, the electric device is exemplified as a vehicle. The vehicle 70 can be a fuel vehicle, a gas vehicle, or a new energy vehicle, which can be a pure electric vehicle or a hybrid electric vehicle, etc. The battery 60 can be arranged at the bottom, the front, or the rear of the vehicle 70.

[0099] The battery 60 can be used for power supply of the vehicle 70. For example, the battery 60 can be used as an operating power source of the vehicle 70, and can be used for the circuit system of the vehicle 70, such as the power required for starting, navigation, and operation of the vehicle 70. The battery 60 can not only be used as an operating power source of the vehicle 70, but also be used as a driving power source of the vehicle 70, to replace or partially replace fuel or natural gas to provide driving force for the vehicle 70.

[0100] The vehicle 70 can also be provided with an axle, a wheel, a motor 72, and a controller 71, which is used to control the power supply of the battery 60 to the motor 72. For example, when the battery 60 is used as a driving power source of the vehicle 70, the battery 60 replaces or partially replaces fuel or natural gas to provide the required power for the motor 72 to rotate at a constant speed or accelerate. The motor 72 is used to drive the axle to rotate, so as to drive the wheel to rotate.

[0101] FIG. 2 is a structural schematic diagram of some embodiments of a battery according to the present disclosure. Referring to FIG. 2, in some embodiments, the battery 60 includes a box body 62, a box cover 63 covering the open side of the box body 62, and one or more battery monomers 61 arranged in the box body 62. For convenience of displaying the battery monomers 61 in the box body 62, part of the box cover 63 is hidden in FIG. 2. The box body 62 and the box cover 63 can provide a containing space for the battery monomers 61, and provide functions of cooling, sealing, and anti-impact, etc., and can also avoid the adverse effects of liquid or other foreign matters on the charging and discharging or safety of the battery monomers.

[0102] The box body 62 and the box cover 63 can have various shapes, such as a cuboid or a cylinder, etc. The box body 62 can be a hollow structure with one side open, and the box cover 63 can be a plate structure. The box cover 63 covers the open side of the box body 62, thereby forming an internal containing space. In another embodiment, the box body 62 is a hollow structure with one side open, and the box cover 63 is also a hollow structure with one side open. The open side of the box cover 63 covers the open side of the box body 62, thereby forming an internal containing space.

[0103] The battery monomers 61 in FIG. 2 are electrically connected, such as in series, in parallel, or in a mixed connection, to achieve the required electrical performance parameters of the battery 60. The mixed connection means that there are both series connection and parallel connection among the plurality of battery monomers 61. The adjacent battery monomers 61 can be electrically connected through bus bars. The plurality of battery monomers 61 are arranged in rows, and one or more rows of battery monomers 61 can be arranged in the box body 62 as needed.

[0104] In some embodiments, the battery cells 61 of the battery 60 can be arranged along at least one of the length direction and the width direction of the box 62. According to actual needs, at least one row or one column of battery cells 61 can be provided. According to needs, one or more layers of battery cells 61 can also be provided in the height direction of the battery 60.

[0105] In some embodiments, a plurality of battery cells 61 can be connected in series or in parallel or in a mixed manner to form a battery module, and then a plurality of battery modules can be connected in series or in parallel or in a mixed manner to form an integrated whole, which is accommodated in the box 62. In other embodiments, all battery cells 61 can be directly connected in series or in parallel or in a mixed manner, and then the integrated whole of all battery cells 61 is accommodated in the box.

[0106] FIG. 3 is a structural schematic diagram of a battery cell according to some embodiments of the present disclosure. FIG. 4 is an exploded structural schematic diagram of a battery cell according to some embodiments of the present disclosure. FIG. 5 is a schematic diagram of the mounting structure of a shell, an end cover and a current collecting assembly in some embodiments of a battery cell according to the present disclosure.

[0107] Referring to FIGS. 3-5, the embodiments of the present disclosure provide a battery cell 61, which includes an electrode assembly 10, a shell 20, an end cover 30 and a current collecting assembly 40. The shell 20 has an accommodating cavity accommodating the electrode assembly 10 and an open end 20b communicating with the accommodating cavity. The end cover 30 covers the open end 20b. The current collecting assembly 40 is electrically connected to the electrode assembly 10 and the shell 20. The accommodating cavity includes a pressure relief cavity pr and an electrical cavity el. The pressure relief cavity pr is located between the current collecting assembly 40 and the end cover 30. The electrical cavity el is configured to accommodate the electrode assembly 10. The end cover 30 has a pressure relief portion 50, at least part of which is provided on a cavity wall of the pressure relief cavity pr. The current collecting assembly 40 has at least one passage communicating the electrical cavity el and the pressure relief cavity pr.

[0108] In the present embodiments, the current collecting assembly is electrically connected to the electrode assembly and the shell to achieve electrical connection between the electrode assembly and the shell. The pressure relief cavity formed between the current collecting assembly and the end cover having the pressure relief portion can communicate with the electrical cavity accommodating the electrode assembly through the passage on the current collecting assembly, so that the gas generated in the electrode assembly under the condition of thermal runaway or the like can quickly enter the pressure relief cavity to trigger the pressure relief of the pressure relief portion provided at least on the cavity wall of the pressure relief cavity, thereby reducing the risk of swelling and deformation or rupture of the shell caused by excessive pressure accumulation in the battery cell.

[0109] The electrode assembly 10 can include first and second polar tabs having opposite polarities, and a separator disposed between the first and second polar tabs. In some embodiments, the first polar tab is a positive polar tab, and the second polar tab is a negative polar tab. In other embodiments, the first polar tab is a negative polar tab, and the second polar tab is a positive polar tab. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the positive and negative polar tabs. The separator, disposed between the positive and negative polar tabs, can function to prevent short-circuiting between the positive and negative polar tabs, while allowing the active ions to pass through.

[0110] In some embodiments, the positive polar tab can include a positive current collector substrate, and a positive active material layer disposed on at least one surface of the positive current collector substrate.

[0111] As an example, the positive current collector substrate has two surfaces opposite in the thickness direction thereof, and the positive active material layer is disposed on either one or both of the two opposite surfaces of the positive current collector substrate.

[0112] As an example, the positive current collector substrate can employ a metal foil or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by disposing a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base (e.g., a base of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0113] As an example, the positive active material layer can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present disclosure is not limited to these materials, and other conventional materials that can be used as a battery positive active material layer can also be used. These positive active material layers can be used alone or in combination with two or more. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which can also be referred to as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to as NCM 333LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to as NCM 523 LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM 211 LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM 622 LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), and modified compounds thereof.

[0114] In some embodiments, the negative electrode tab can include a negative current collector substrate.

[0115] As an example, the negative current collector substrate can employ a metal foil, a foam metal, or a composite current collector. For example, as a metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, a carbon, nickel, or titanium, or the like can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, or a foam carbon, or the like. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by disposing a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, or the like) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0116] In some embodiments, the negative electrode tab can include a negative current collector substrate and a negative active material layer disposed on at least one surface of the negative current collector substrate.

[0117] As an example, the negative current collector substrate has two surfaces opposite in the thickness direction thereof, and the negative active material layer is disposed on either one or both of the two opposite surfaces of the negative current collector substrate.

[0118] As an example, the negative active material layer can employ a negative active material layer for a battery cell known in the art. As an example, the negative active material layer can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present disclosure is not limited to these materials, and other conventional materials that can be used as a battery negative active material layer can also be used. These negative active material layers can be used alone only one or two or more can be used in combination.

[0119] In some embodiments, the material of the positive current collector substrate can be aluminum, and the material of the negative current collector substrate can be copper.

[0120] In some embodiments, the separator is a separator film. The present disclosure does not have a particular limitation on the type of separator film, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0121] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive electrode sheet and the negative electrode sheet, or can be attached to the surface of the positive electrode sheet and / or the surface of the negative electrode sheet while being located between the positive electrode sheet and the negative electrode sheet.

[0122] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is provided between the positive electrode sheet and the negative electrode sheet, and functions to transport ions and separate the positive and negative electrodes.

[0123] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The present disclosure does not have a particular limitation on the type of electrolyte, and can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0124] As an example, the liquid electrolyte includes an electrolyte salt and a solvent.

[0125] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bistrifluoromethylsulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium bisoxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorodioxalate phosphate.

[0126] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and a crown ether.

[0127] As an example, the gel-state electrolyte includes a polymer as a backbone network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0128] As an example, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0129] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0130] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0131] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0132] In some embodiments, the electrode assembly includes a main body portion 11. The main body portion 11 can be a main body portion of a jelly-roll structure in which a positive electrode sheet, a negative electrode sheet, and a separator are wound, or a main body portion of a stack structure in which the positive electrode sheet, the negative electrode sheet, and the separator are overlapped. One or more of the positive electrode sheet and the negative electrode sheet can be provided, respectively. As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets are alternately provided in the thickness direction of the electrode sheet.

[0133] In some embodiments, the main body 11 can have a cylindrical shape, a flat shape, or a multi-prism shape, etc. The end of the main body 11 can be provided with a first tab 12 and a second tab 13. The first tab 12 can be formed by cutting or cutting the current collector substrate of the first electrode plate, or can be connected to the side of the current collector substrate of the first electrode plate by welding. The second tab 13 can be formed by cutting or cutting the current collector substrate of the second electrode plate, or can be connected to the side of the current collector substrate of the second electrode plate by welding.

[0134] For embodiments in which the first electrode plate is a positive electrode plate and the second electrode plate is a negative electrode plate, the first electrode plate includes a positive electrode tab as the first tab, and the second electrode plate includes a negative electrode tab as the second tab. For embodiments in which the first electrode plate is a negative electrode plate and the second electrode plate is a positive electrode plate, the first electrode plate includes a negative electrode tab as the first tab, and the second electrode plate includes a positive electrode tab as the second tab.

[0135] The shell 20 is used to package the electrode assembly 10, electrolyte, etc. The shell 20 can be a steel shell, an aluminum shell, a composite metal shell (such as a copper-aluminum composite shell), etc.

[0136] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, and the prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, such as a hexagonal prism battery cell, etc.

[0137] The shell 20 has a receiving cavity that can accommodate the electrode assembly 10, electrolyte, etc., and the shell 20 has an open end 20b that communicates with the receiving cavity, so as to load the electrode assembly 10, etc. The end cover 30 is arranged at the open end 20b, and is used to cover the open end 20b, so that the open end 20b is sealingly connected with the end cover 30.

[0138] The current collecting assembly 40 is electrically connected with the shell 20, for example, through the end cover 30 and the shell 20, or directly with the shell 20. The receiving cavity includes a pressure relief cavity pr located between the current collecting assembly 40 and the end cover 30, and an electrical cavity el configured to accommodate the electrode assembly 10.

[0139] For embodiments in which the end cover 30 is electrically connected with the shell 20, the current collecting assembly 40 can be fixedly connected and electrically connected with the end cover 30 by welding, etc., and fixedly connected and electrically connected with the tabs of the electrode assembly 10 by welding, etc.

[0140] In assembling the battery cell, the electrode assembly 10 and the current collecting assembly 40 can be placed into the shell 20, and the electrolyte is filled into the shell 20, and then the end cover 30 is covered on the open end of the shell 20, so as to complete the assembly of the battery cell 20.

[0141] The end cover 30 has a pressure relief portion 50, at least part of which is provided on the cavity wall of the pressure relief cavity pr. The pressure relief portion refers to an element or component that is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold. The threshold is designed differently according to different design requirements. The threshold can depend on the material of one or more of the positive electrode plate, the negative electrode plate, the electrolyte, and the separator film in the battery cell. The pressure relief portion can take the form of, for example, a pressure relief valve, 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 portion performs an action or a weak structure provided in the pressure relief portion is broken, thereby forming an opening or passage for the internal pressure or temperature to be released.

[0142] When the electrode assembly experiences thermal runaway or the like, high-temperature and high-pressure gas is generated and enters the pressure relief cavity, and the gas can also contain active substances. When the pressure in the pressure relief cavity pr exceeds the design threshold, the pressure relief portion 50 releases the internal pressure, and the discharge from the battery cell is discharged. The discharge from the battery cell mentioned here includes but is not limited to: electrolyte, dissolved or split positive and negative electrode plates, separator film fragments, high-temperature and high-pressure gas generated by reaction (such as CH4, CO, and other flammable gases), flames, and the like.

[0143] At least one channel on the current collecting assembly 40 can achieve communication between the electrical cavity el and the pressure relief cavity pr, so that the pressure relief cavity pr can receive the high-temperature and high-pressure gas generated inside the battery cell via the at least one channel when the electrode assembly experiences thermal runaway or the like.

[0144] For the end cover, the pressure relief portion can be integrally formed with the body of the end cover, or can be fixedly connected to the body of the end cover by welding or the like. In FIG. 5, one implementation structure of the pressure relief portion 50 is shown, which forms a weak area by providing an arc-shaped groove on the surface of the end cover 30, so that when the pressure in the pressure relief cavity pr reaches a value that can break the weak area, the part of the end cover 30 is broken to form a discharge passage.

[0145] In the present embodiment, the current collecting assembly 40 is electrically connected with the electrode assembly 10 and the shell 20 to achieve electrical connection between the electrode assembly 10 and the shell 20, and the pressure relief cavity pr formed between the current collecting assembly 40 and the end cover 30 having the pressure relief portion 50 can achieve communication with the electrical cavity el containing the electrode assembly 10 through the channel on the current collecting assembly 40, so that the gas generated when the electrode assembly 10 experiences thermal runaway or the like can quickly enter the pressure relief cavity pr to trigger the pressure relief portion 50 provided at least on the cavity wall of the pressure relief cavity pr to release pressure, thereby reducing the risk of the shell 20 swelling, deforming, rupturing, and the like due to excessive internal pressure accumulation in the battery cell 61.

[0146] Referring to FIG. 4, in some embodiments, the shell 20 includes a side wall 21 surrounding the open end 20b and a bottom wall 22 connected with the side wall 21 and opposite to the open end 20b, and an electrode terminal 221 is arranged on the bottom wall 22, the electrode assembly 10 includes a main body 11 and first and second tabs 12 and 13 with opposite polarities, the first tab 12 is arranged at an end of the main body 11 adjacent to one side of the end cover 30 and is electrically connected with the current collecting assembly 40, and the second tab 13 is arranged at an end of the main body 11 adjacent to one side of the bottom wall 22 and is electrically connected with the electrode terminal 221.

[0147] In the present embodiment, the first and second tabs 12 and 13 of the electrode assembly 10 have opposite polarities and are arranged at ends of the main body 11 adjacent to the end cover 30 and the bottom wall 22 of the shell 20 respectively, so that the second tab 13 can be electrically connected with the electrode terminal 221 arranged on the bottom wall 22 directly or through the current collecting assembly 40', and the shell 20 and the electrode terminal 221 can be electrically connected with external conductors respectively to realize the charging and discharging function.

[0148] In FIG. 4, the shell 20 is cylindrical, the first and second tabs 12 and 13 are located at two ends of the main body 11 in a first direction dr1, and the end cover 30 and the electrode terminal 221 are located at two ends of the shell 20 in the first direction dr1 and are adjacent to the first and second tabs 12 and 13 respectively. The current collecting assembly 40' can also be arranged in the shell 20, and the current collecting assembly 40' is electrically connected with the electrode terminal 221 and the second tab 13 of the electrode assembly 10.

[0149] In other embodiments, the shell 20 is prismatic, and the first and second tabs 12 and 13 can be located at the same end of the main body 11 in the first direction dr1 or at two ends in a second direction dr2 or a third direction dr3 perpendicular to the first direction dr1.

[0150] In some embodiments, the bottom wall 22 and the side wall 21 are integrally formed.

[0151] In the present embodiment, by integrally forming the bottom wall 22 and the side wall 21, the overall sealing performance of the shell 20 can be improved, and the processing and assembly process can be simplified.

[0152] Referring to FIG. 5, in some embodiments, the at least one channel includes a first channel 4A located at a periphery of the pressure relief cavity pr.

[0153] In the present embodiment, the first channel 4A is arranged along the periphery of the pressure relief cavity pr, and the high-pressure gas and other substances generated inside the battery cell 61 can enter the pressure relief cavity pr through the first channel 4A along the periphery of the pressure relief cavity pr, so as to guide the high-pressure gas at the periphery of the pressure relief cavity pr to quickly enter the pressure relief cavity pr, thereby improving the pressure relief efficiency.

[0154] In some embodiments, the at least one channel includes a plurality of first channels 4A arranged along the periphery of the pressure relief cavity pr.

[0155] Since the failure position of the battery cell 61 cannot be determined in advance in the case of thermal runaway and the like, the plurality of first channels 4A arranged along the periphery of the pressure relief cavity pr can achieve pressure relief paths in multiple directions along the periphery of the pressure relief cavity pr, thereby improving the pressure relief efficiency of the battery cell 61, reducing the risk of excessive local pressure inside the battery cell 61, meeting the pressure relief requirements under various failure positions, and improving the consistency of the explosion-proof performance of the battery cell 61.

[0156] FIG. 6A is a structural schematic diagram of a current collecting assembly in some embodiments of the battery cell according to the present disclosure. FIG. 6B is a structural schematic diagram of a first conductive member in the embodiment shown in FIG. 6A. FIG. 6C is a structural schematic diagram of a second conductive member in the embodiment shown in FIG. 6A. FIG. 6D is a sectional schematic diagram of the mounting structure of the end cover, the current collecting assembly, and the electrode assembly in the embodiment shown in FIG. 6A.

[0157] Referring to FIGS. 6A-6D, in some embodiments, the end cover 30 is electrically connected to the shell 20, and the current collecting assembly 40 includes a first conductive member 41 and a second conductive member 42. The first conductive member 41 is welded to the end cover 30 and has a hollow portion 41a extending through the thickness of the end cover 30. The second conductive member 42 is electrically connected to the first conductive member 41 and is welded to the first tab 12 of the electrode assembly 10 adjacent to the side of the end cover 30. The end cover 30, the hollow portion 41a, and the second conductive member 42 enclose the pressure relief cavity pr, and the first channel 4A is arranged between the first conductive member 41 and the second conductive member 42 and communicates with the hollow portion 41a.

[0158] The first channel 4A is arranged between the first conductive member 41 and the second conductive member 42. The first channel 4A can be located on the first conductive member 41 or on the second conductive member 42, or a part of the first channel 4A can be located on the first conductive member 41 and the other part can be located on the second conductive member 42.

[0159] In the embodiment, the current collecting assembly 40 is electrically connected by the first conductive member 41 and the second conductive member 42. The first conductive member 41 is welded with the end cover 30 of the electric connection shell 20, and the second conductive member 42 is welded with the first tab 12 of the electrode assembly. Thus, the first conductive member 41 and the second conductive member 42 can be respectively designed according to the materials of the end cover 30 and the first tab 12, have better welding compatibility, and help to reduce the welding quality risk caused by the difference in welding performance of the materials.

[0160] The end cover 30, the hollow portion 41a of the first conductive member 41, and the second conductive member 42 can form a deeper pressure relief cavity pr, help to improve the gas flow in the pressure relief cavity pr, and through the cooperation of the first channel between the first conductive member and the second conductive member and the hollow portion 41a on the first conductive member 41, the pressure relief cavity pr can more quickly receive the high-pressure gas in the battery monomer 61, and the pressure relief efficiency is improved.

[0161] In some embodiments, the end cover 30 and the first tab 12 are different in base material, the first conductive member 41 and the end cover 30 are the same in base material. In some embodiments, the end cover 30 and the first tab 12 are different in base material, the second conductive member 42 and the first tab 12 are the same in base material. In some embodiments, the end cover 30 and the first tab 12 are different in base material, the first conductive member 41 and the end cover 30 are the same in base material, and the second conductive member 42 and the first tab 12 are the same in base material.

[0162] In the embodiment, for the case that the end cover 30 and the first tab 12 are different in base material, the base material of the first conductive member 41 is set to be the same as that of the end cover 30, so that the end cover 30 and the first conductive member 41 can more easily obtain good welding quality, help to reduce the conductivity between the end cover 30 and the first conductive member 41, and reduce the risk of end cover leakage caused by poor welding quality. The base material of the second conductive member 42 is set to be the same as that of the first tab 12, which helps to reduce the conductivity between the second conductive member 42 and the first tab 12, thereby reducing the internal resistance of the battery monomer 61.

[0163] Herein, the base material of the same refers to the material containing the same main element, and the mass percentage of the main element is greater than the mass percentage of other elements in the material. For example, the main element of aluminum single substance and various grades of aluminum alloy is aluminum. If the material of the end cover and the first conductive part is aluminum alloy, and the main element is aluminum, it means that the base material of the end cover and the first conductive part is the same. For another example, the material of the second conductive part is copper alloy, and the material of the first tab is copper single substance, and the main element is copper, which means that the base material of the second conductive part and the first tab is the same.

[0164] The base material of the different refers to the material containing different main elements, and the mass percentage of the main element is greater than the mass percentage of other elements in the material. For example, if the material of the end cover is steel, and the main element is iron, and the material of the first tab is copper single substance, and the main element is copper, which means that the base material of the end cover and the first tab is different. In some embodiments, the base material of the end cover 30 and the first tab 12 is the same, and the first conductive part 41 and the second conductive part 42 can be arranged to be the same as the base material of the first tab 12.

[0165] In some embodiments, the base material of the end cover 30 and the first conductive part 41 is steel, and the base material of the first tab 12 and the second conductive part 42 is copper.

[0166] In the embodiment, the base material of the end cover 30 and the first tab 12 is different, the base material of the end cover is steel, and the base material of the first tab 12 is copper. By arranging the base material of the end cover 30 and the first conductive part 41 to be steel, it can improve the welding quality between the two, improve the mechanical properties of the end cover 30, and reduce the material cost. By arranging the base material of the first tab 12 and the second conductive part 42 to be copper, it can achieve high conductivity.

[0167] Referring to FIG. 6D, in some embodiments, the first part 31 of the end cover 30 for enclosing the pressure relief cavity pr protrudes in a direction away from the electrode assembly 10 relative to the second part 32 of the end cover 30 welded with the first conductive part 41.

[0168] In the present embodiment, the first portion 31 for enclosing the pressure relief chamber pr on the end cover 30 protrudes in a direction away from the electrode assembly 10 relative to the second portion 32 on the end cover 30 which is welded with the first conductive member 41, and the first portion 31 adjacent to the side wall on one side of the electrode assembly 10 can jointly enclose a relatively deep pressure relief chamber pr with the hollow portion 41a of the first conductive member 41 and the second conductive member 42, which is beneficial to the gas flow inside the pressure relief chamber pr, while the second portion 32 is fixedly connected with the first conductive member 41, so that the end cover 30 and the current collecting assembly 40 inside the shell 20 can be reliably fixed.

[0169] Referring to FIGS. 6C and 6D, in some embodiments, the second conductive member 42 has a first welding portion 421 and a second welding portion 422, the first welding portion 421 is welded with the first tab 12, and the second welding portion 422 at least partially surrounds the first welding portion 421 and is welded with the first conductive member 41.

[0170] In the present embodiment, the second welding portion 422 at least partially surrounds the first welding portion 421, so that the first welding portion 421 welded with the first tab and the second welding portion 422 welded with the first conductive member 41 are staggered, which can reduce the interference between the two groups of welding relationships, thereby facilitating the reduction of welding difficulty. The first channel can be located between the first welding portion 421 and the second welding portion 422, so as to guide the high-pressure gas generated between the first tab 12 and the shell 20 to enter the pressure relief chamber pr.

[0171] In FIG. 6C, in order to facilitate the illustration of the first welding portion 421 and the second welding portion 422 of the second conductive member 42, the first welding portion 421 and the second welding portion 422 are divided by a dashed line with shading. The shape and size of the outer circle of the dashed line coincide with the hollow portion 41a of the first conductive member 41 in FIG. 6B. The portion of the second conductive member 42 located radially inside the dashed line is the first welding portion 421, and the portion located radially outside the dashed line is the second welding portion 422.

[0172] Referring to FIGS. 6A-6C, in some embodiments, the electrode assembly 10 is a cylindrical electrode assembly 10, and the second conductive member 42 includes a plate body 42a, an edge region (which can serve as the second welding portion 422) of the plate body 42a is welded with the first conductive member 41, and a notch 42b is provided, the notch 42b serves as the first channel 4A and is at least partially exposed to the hollow portion 41a.

[0173] In the present embodiment, the edge region of the plate body 42a is provided with a notch 42b as the first passage 4A, so that the high-pressure gas generated in the electrical cavity el in the case of thermal runaway or the like can enter the pressure relief cavity pr from the position exposed to the hollow portion 41a through the notch 42b from the periphery of the plate body 42a. The edge region of the plate body 42a is welded to the first conductive member 41, which not only can strengthen the current collecting assembly 40 in strength and rigidity, but also is relatively simple in structure, which is conducive to manufacturing and assembly.

[0174] Referring to FIG. 6C, in some embodiments, the at least one passage further comprises: a second passage 4B opened in the center of the plate body 42a, and the part of the plate body 42a between the second passage 4B and the edge region is welded to the first tab 12.

[0175] In the present embodiment, the center of the plate body 42a is provided with a second passage 4B, which is in communication with the electrical cavity el and the pressure relief cavity adjacent to the center of the end of the electrode assembly 10, so as to more conveniently receive the high-pressure gas generated by the electrode assembly 10. Moreover, the part of the plate body 42a between the second passage 4B and the edge region (which can be a first welding portion 421) is welded to the first tab 12, which can realize welding of a larger area with the first tab 12, and is helpful to reduce the welding difficulty and improve the welding quality.

[0176] In FIG. 6A, the first conductive member 41 is in surface contact with the second conductive member 42 and can be fixedly connected by welding. The first conductive member 41 and the second conductive member 42 can adopt different base materials. Both the first conductive member 41 and the second conductive member 42 are located in the shell 20, so even if the welding performance of the two is not as good as that of the same material, the airtightness of the end cover welding position will not be affected.

[0177] In FIG. 6B, the first conductive member 41 is a ring-shaped plate body with a hollow portion 41a, and the hollow portion 41a is a space surrounded by an inner ring of a circular ring shape. In FIGS. 6A and 6C, the plate body 42a in the second conductive member 42 is circular as a whole, which can form good planar contact with the ring-shaped plate body, so as to form a larger area of fixed connection and electrical connection after welding, which is conducive to improving the mechanical properties and electrical conductivity. The plate body 42a in the second conductive member 42 is provided with a second passage 4B in the center and a notch 42b in the edge region. It can be seen that part of the second passage 4B and the notch 42b can be exposed to the hollow portion 41a of the first conductive member 41. The second passage 4B can also be used for positioning during electrolyte inlet.

[0178] In FIG. 6D, the process of high-pressure gas entering the pressure relief chamber pr from the center hole 14 of the electrode assembly 10 through the second channel 4B and from the side through the gap 42b into the pressure relief chamber pr surrounded by the plate body 42a, the first conductive member 41 and the end cover 30 is schematically shown by a plurality of short black hollow arrows. The part of the end cover 30 section is filled with no pattern to show the area corresponding to the pressure relief part 50.

[0179] In order to expose a part of the gap 42b to the hollow part 41a of the first conductive member 41, the minimum distance from the gap 42 to the center of the plate body 42a can be less than the radius of the hollow part 41a.

[0180] Referring to FIGS. 6A and 6C, in some embodiments, the edge region of the plate body 42a is provided with a plurality of gaps 42b, which are arranged at intervals along the circumference of the plate body 42a.

[0181] In the present embodiment, the plurality of first channels 4A are formed by the plurality of gaps 42b arranged at intervals along the circumference of the plate body 42a, which can achieve the pressure relief path in multiple directions around the pressure relief chamber pr, thereby improving the pressure relief efficiency of the battery monomer 61 and reducing the risk of local overpressure.

[0182] In FIG. 6C, the edge region of the plate body 42a is provided with four gaps 42b, and each gap 42b has three straight edges arranged vertically in sequence. In other embodiments, the number of gaps 42b can be less or more, the shape of each gap 42b can be the same or different, the size of each gap 42b can be the same or different, and the gap 42b can have at least one straight edge, at least one arc-shaped edge, or a combination of straight edge segments and arc-shaped edge segments.

[0183] Referring to FIG. 6C, in some embodiments, the plurality of gaps 42b are arranged at equal intervals along the circumference of the plate body 42a.

[0184] In the present embodiment, the plurality of gaps 42b are arranged at equal intervals along the circumference of the plate body 42a, which can make the high-pressure gas enter the pressure relief chamber pr more uniformly to achieve pressure relief.

[0185] In FIG. 6C, the four gaps 42b are uniformly distributed at intervals of 90° in the edge region of the plate body 42a. The size of each gap 42b is the same, and the shape is also the same.

[0186] In other embodiments, the plurality of gaps 42b can be symmetrical with respect to the center of the plate body 42a or a straight line passing through the center in the edge region of the plate body 42a. This is also conducive to making the high-pressure gas enter the pressure relief chamber pr more uniformly to achieve pressure relief.

[0187] FIG. 7A is a schematic diagram of the structure of the current collecting assembly in some other embodiments of the battery cell according to the present disclosure. FIG. 7B is a schematic diagram of the structure of the first conductive member in the embodiment shown in FIG. 7A. FIG. 7C is a schematic diagram of the structure of the second conductive member in the embodiment shown in FIG. 7A. FIG. 7D is a schematic diagram of the cross section of the mounting structure of the end cover, the current collecting assembly and the electrode assembly in the embodiment shown in FIG. 7A. FIG. 7E is a schematic diagram of the enlarged view of the selected area of the dashed oval A in FIG. 7D. FIG. 7F is a schematic diagram of the dimensions of the current collecting assembly in FIG. 7E.

[0188] Referring to FIGS. 7A-7E, in some embodiments, the electrode assembly 10 is a cylindrical electrode assembly 10, the second conductive member 42 includes a flat portion 42d and a convex portion 42e, the convex portion 42e protrudes from the flat portion 42d in a direction away from the electrode assembly 10, forms a concave portion 42g on the inner side, the orthographic projection of the concave portion 42g on the first conductive member 41 at least partially overlaps with the hollow portion 41a, and the convex portion 42e is welded with the first conductive member 41; the first channel 4A is arranged in the convex portion 42e.

[0189] For the battery cell embodiments containing the cylindrical electrode assembly, the convex portion 42e can form a support structure with higher strength and rigidity, improve the mechanical properties of the current collecting assembly 40, and the concave portion 42g formed on the inner side of the convex portion 42e of the second conductive member 42 can cooperate with the hollow portion 41a of the first conductive member 41 to form a deeper pressure relief cavity pr, which helps to improve the gas flow in the pressure relief cavity pr; in addition, the welding between the convex portion 42e (which can serve as the second welding portion 422) and the first conductive member 41 is away from the flat portion 42e, which can reduce the impact of welding at this position on the flat portion 42e.

[0190] In some embodiments, the convex portion 42e is formed with a first groove 42h recessed from the flat portion 42d in a direction away from the electrode assembly 10 on one side adjacent to the electrode assembly 10, the inner side wall of the convex portion 42e is located between the first annular groove 42h and the concave portion 42g, and a third through hole 42i is arranged in the inner side wall, and the first annular groove 42h and the third through hole 42i serve as at least part of the first channel 4A.

[0191] In the present embodiment, the second conductive member 42 forms the first groove 42h on one side adjacent to the electrode assembly 10 with the convex portion 42e, so that the first groove 42h can form a gap with the first tab 12 to reduce the risk of the first channel 4A on the second conductive member 42 being blocked by the first tab 12 due to the adhesion of the first tab 12.

[0192] The third through hole is arranged on the inner side wall of the protrusion between the recessed portion 42g and the first groove 42h, and can guide the high-pressure gas flow entering the first groove 42h to the inner side of the recessed portion 42g.

[0193] Referring to FIG. 7C, in some embodiments, the at least one channel further comprises a second channel 4B opened in the center of the flat plate portion 42d, and the portion of the flat plate portion 42d outside the second channel 4B is welded with the first tab 12.

[0194] In the present embodiment, the second channel 4B is opened in the center of the flat plate portion 42d, and the portion of the flat plate portion 42d outside the second channel 4B (which can be the first welding portion 421) is welded with the first tab 12, so that a larger area of the first tab 12 can be welded, which helps to reduce the difficulty of welding and improve the welding quality.

[0195] In some embodiments, the protrusion 42e is annular and forms the annular first groove 42h.

[0196] In the present embodiment, by making the protrusion 42e annular, the recessed portion 42g with continuous side edges can be enclosed, so as to cooperate with the hollow portion 41a of the first conductive member 41 to form the pressure relief cavity pr. Moreover, the annular protrusion 42e forms the annular first groove 42h, which can realize the rectification and flow guiding effect of the high-pressure gas flow in the circumferential direction at different circumferential positions, thereby improving the consistency of the pressure relief speed caused by the difference in gas pressure inside the battery monomer, and further improving the pressure relief efficiency.

[0197] The structure that the annular protrusion 42e surrounds the circular flat plate portion 42d can be obtained by stamping the circular plate, thereby facilitating the improvement of production efficiency. In other embodiments, the annular protrusion 42e and the circular flat plate portion 42d can be independently manufactured and fixedly connected by welding or the like.

[0198] In FIG. 7A, the annular protrusion 42e as the second welding portion 422 is in surface contact with the first conductive member 41 and is fixedly connected by welding. The first conductive member 41 and the second conductive member 42 can adopt different base materials, and the first conductive member 41 and the second conductive member 42 fixed by welding are both located in the shell 20, which does not affect the sealing performance of the end cover.

[0199] In FIG. 7B, the first conductive member 41 has a hollow portion 41a, and the whole is a circular ring. The hollow portion 41a is a space surrounded by the inner ring of the circular ring. In FIG. 7A and FIG. 7C, the annular convex portion 42e is convex upward relative to the flat plate portion 42d, and the convex portion 42e has an annular flat surface to form a good flat surface contact with the first conductive member 41, so as to form a larger area of fixed connection and electrical connection after welding, which is beneficial to improve the mechanical properties and electrical properties.

[0200] In FIG. 7D, the convex portion 42e and the flat plate portion 42d surround a concave portion 42g on the upper side of the flat plate portion 42d. The orthographic projection of the concave portion 42g on the first conductive member 41 at least partially overlaps the hollow portion 41a. The lower side of the annular convex portion 42e is formed with a first groove 42h, and a third through hole 42i is provided between the first groove 42h and the concave portion 42g.

[0201] In FIG. 7D, the process of entering the pressure relief cavity pr surrounded by the concave portion 42g, the hollow portion 41a and the end cover 30 from the center hole 14 of the electrode assembly 10 through the second channel 4B, and entering the pressure relief cavity pr from the side through the first groove 42h and the third through hole 42i is schematically shown by a plurality of black short hollow arrows. The area corresponding to the pressure relief portion 50 is schematically shown by the part without pattern filling in the cross section of the end cover 30.

[0202] Referring to FIG. 7A and FIG. 7C, in some embodiments, the convex portion 42e is provided with a plurality of third through holes 42i between the first groove 42h and the concave portion 42g, and the plurality of third through holes 42i are arranged at intervals along the circumference of the second conductive member 42.

[0203] In the present embodiment, a plurality of first channels 4A are formed by the first groove 42h cooperating with the plurality of third through holes 42i arranged at intervals along the circumference of the second conductive member 42 between the first groove 42h and the concave portion 42g, so that the pressure relief path can be realized in multiple directions around the pressure relief cavity pr, thereby improving the pressure relief efficiency of the battery monomer 61 and reducing the risk of local pressure being too high.

[0204] In some embodiments, the plurality of third through holes 42i are arranged at equal intervals along the circumference of the second conductive member 42.

[0205] In the present embodiment, the plurality of third through holes 42i are arranged at equal intervals along the circumference of the second conductive member 42, so that the high-pressure gas can enter the pressure relief cavity pr more uniformly to realize pressure relief.

[0206] Referring to FIG. 7A and FIG. 7E, in some embodiments, the outer side of the convex portion 42e further extends outwardly to form a flange 42j.

[0207] In the present embodiment, a protruding edge 42j is extended outward from the convex portion 42e. The protruding edge 42j can increase the extrusion surface area between the bent edge of the convex portion 42e and the first tab 12, and reduce the risk of the tab being damaged by excessive pressure.

[0208] Referring to FIGS. 7D and 7E, in some embodiments, the protruding edge 42j is flush with the end surface of the flat plate portion 42d adjacent to one side of the electrode assembly 10.

[0209] In the present embodiment, by making the protruding edge 42j flush with the end surface of the flat plate portion 42d adjacent to one side of the electrode assembly 10, the extrusion surface area between the bent edge of the convex portion 42e and the first tab 12 can be further increased.

[0210] FIG. 7F shows the dimensional relationship of the structure after the end cover and the electrode assembly are hidden based on FIG. 7E. Referring to FIGS. 7E and 7F, in some embodiments, the first conductive member 41 is in the shape of a ring, the outer ring radius D1 of the first conductive member 41 is greater than the maximum distance D2 from the outer sidewall of the convex portion 42e to the center of the recessed portion 42g, the first conductive member 41, the protruding edge 42j, and the convex portion 42e collectively enclose a second groove 42k on the outer side of the convex portion 42e, the outer sidewall of the convex portion 42e is disposed between the second groove 42k and the first groove 42h, and a fourth through hole 42l is formed in the outer sidewall of the convex portion 42e, and the second groove 42k, the first groove 42h, the fourth through hole 42l, and the third through hole 42i serve as at least part of the first channel 4A.

[0211] In the present embodiment, the outer ring radius of the first conductive member 41 is greater than the maximum distance D2 from the outer sidewall of the convex portion 42e to the center of the recessed portion 42g (for a convex portion 42e in the shape of a ring, the maximum distance D2 is the outer ring radius of the convex portion 42e). This can form the second groove 42k after the first conductive member 41 is welded to the convex portion 42e. The fourth through hole 42l formed in the outer sidewall of the convex portion 42e between the second groove 42k and the first groove 42h can guide the high-pressure gas outside the current collecting assembly 40, so that the high-pressure gas enters the inside of the recessed portion 42g via the fourth through hole 42l, the first groove 42h, and the third through hole 42i.

[0212] Referring to FIG. 7E, in some embodiments, the outer sidewall of the protrusion 42e is provided with a plurality of fourth through holes 42l between the second groove 42k and the first groove 42h, and a plurality of third through holes 42i between the first annular groove 42h and the recessed portion 42g. The plurality of third through holes 42i and the plurality of fourth through holes 42l are spaced apart along the circumferential direction of the second conductive member 42, and at least partially aligned or staggered along the radial direction.

[0213] In the present embodiment, the plurality of fourth through holes 42l and the plurality of third through holes 42i are equally spaced apart along the circumferential direction of the second conductive member 42, and the plurality of third through holes 42i and the plurality of fourth through holes 42l are at least partially aligned or staggered along the radial direction, so that the high-pressure gas in different directions of the flow guide assembly can enter the pressure relief cavity pr more uniformly to achieve pressure relief.

[0214] In FIG. 7E, the process of entering the pressure relief cavity pr from the side through the second groove 42k, the fourth through hole 42l, the first groove 42h and the third through hole 42i is also shown by a plurality of black short hollow arrows. In addition, FIG. 7E also shows the case where the third through hole 42i and the fourth through hole 42l are aligned and located in the same cross section.

[0215] In some embodiments, the protrusion 42e is annular, and cooperates with the first conductive member 41 and the protruding edge 42j to enclose an annular second groove 42k.

[0216] In the present embodiment, by making the protrusion 42e annular, the recessed portion 42g with continuous side edges can be enclosed to cooperate with the hollow portion 41a of the first conductive member 41 to form the pressure relief cavity pr. Moreover, the annular protrusion 42e cooperates with the first conductive member 41 and the protruding edge 42j to enclose an annular second groove 42k, which can achieve the functions of rectification and flow guidance in the circumferential direction for the high-pressure gas flow at different circumferential positions on the outside, thereby improving the consistency of the pressure relief speed caused by the pressure difference of the gas inside the battery monomer, and further improving the pressure relief efficiency.

[0217] The various embodiments of the battery monomer 61 described above can be used in various batteries. Therefore, in one aspect of the present disclosure, a battery 60 is provided, comprising the battery monomer 61 of any of the preceding embodiments.

[0218] The battery using the battery monomer of the preceding embodiments has good reliability.

[0219] The various embodiments of the battery 60 described above can be used in various electric devices. Therefore, in one aspect of the present disclosure, an electric device is provided, comprising the battery 60 of any of the preceding embodiments.

[0220] The power consumption device using the battery of the preceding embodiment has good reliability.

[0221] In some specific embodiments, as shown in FIGS. 3-6D, the battery cell 61 comprises an electrode assembly 10, a case 20, an end cover 30, and a current collecting assembly 40. The case 20 has a receiving cavity accommodating the electrode assembly 10 and an open end 20b communicating with the receiving cavity. The end cover 30 covers the open end 20b. The current collecting assembly 40 is electrically connected with the electrode assembly 10, and the current collecting assembly 40 is electrically connected with the case 20 through the end cover 30. The receiving cavity comprises a pressure relief cavity pr and an electrical cavity el, the pressure relief cavity pr is located between the current collecting assembly 40 and the end cover 30, and the electrical cavity el is configured to accommodate the electrode assembly 10. The end cover 30 has a pressure relief portion 50, at least part of the pressure relief portion 50 is provided on the cavity wall of the pressure relief cavity pr. The current collecting assembly 40 has a plurality of passages communicating the electrical cavity el and the pressure relief cavity pr.

[0222] The current collecting assembly 40 comprises a first conductive member 41 and a second conductive member 42. The first conductive member 41 is welded with the end cover 30 and has a hollow portion 41a penetrating in the thickness direction of the end cover 30. The second conductive member 42 is electrically connected with the first conductive member 41 and is welded with the first tab 12 of the electrode assembly 10 at the side adjacent to the end cover 30. A plurality of first passages 4A are located between the first conductive member 41 and the second conductive member 42 and all communicate with the hollow portion 41a. The base material of the end cover 30 and the first conductive member 41 is steel, and the base material of the first tab 12 and the second conductive member 42 is copper.

[0223] The electrode assembly 10 is a cylindrical electrode assembly 10. The second conductive member 42 comprises a plate body 42a, the edge region of the plate body 42a is welded with the first conductive member 41 and is provided with a notch 42b, and the notch 42b is exposed to the hollow portion 41a as the first passage 4A. A second passage 4B is provided in the center of the plate body 42a, and the part of the plate body 42a between the second passage 4B and the edge region is welded with the first tab 12. The edge region of the plate body 42a is provided with a plurality of notches 42b, and the plurality of notches 42b are arranged equidistantly along the circumferential direction of the plate body 42a.

[0224] In other embodiments, as shown in FIGS. 3-4 and 7A-7E, the battery cell 61 includes an electrode assembly 10, a case 20, an end cap 30, and a current collector assembly 40. The case 20 has a receiving cavity accommodating the electrode assembly 10 and an open end 20b communicating with the receiving cavity. The end cap 30 covers the open end 20b. The current collector assembly 40 is electrically connected to the electrode assembly 10, and the current collector assembly 40 is electrically connected to the case 20 through the end cap 30. The receiving cavity includes a pressure relief cavity pr between the current collector assembly 40 and the end cap 30 and an electrical cavity el configured to accommodate the electrode assembly 10. The end cap 30 has a pressure relief portion 50, at least a portion of which is disposed on a cavity wall of the pressure relief cavity pr. The current collector assembly 40 has a plurality of passages communicating the electrical cavity el and the pressure relief cavity pr.

[0225] The current collector assembly 40 includes a first conductive member 41 and a second conductive member 42. The first conductive member 41 is welded to the end cap 30 and has a hollow portion 41a extending through the thickness of the end cap 30. The second conductive member 42 is electrically connected to the first conductive member 41 and is welded to the first tab 12 of the electrode assembly 10 adjacent to the end cap 30. A plurality of first passages 4A are located on the second conductive member 42 and communicate with the hollow portion 41a. The end cap 30 and the first conductive member 41 are made of steel, and the first tab 12 and the second conductive member 42 are made of copper.

[0226] The electrode assembly 10 is a cylindrical electrode assembly 10. The second conductive member 42 includes a flat portion 42d and a protruding portion 42e protruding from the flat portion 42d in a direction away from the electrode assembly 10, forming a recessed portion 42g on the inner side. The orthogonal projection of the recessed portion 42g on the first conductive member 41 at least partially overlaps the hollow portion 41a. The protruding portion 42e is welded to the first conductive member 41.

[0227] The protruding portion 42e is formed with a first groove 42h recessed from the flat portion 42d in a direction away from the electrode assembly 10 on the side adjacent to the electrode assembly 10. An inner side wall of the protruding portion 42e is located between the first groove 42h and the recessed portion 42g and is provided with a third through hole 42i. The first groove 42h and the third through hole 42i serve as at least a portion of the first passages 4A.

[0228] The protruding portion 42e is provided with a plurality of third through holes 42i between the first groove 42h and the recessed portion 42g. The plurality of third through holes 42i are arranged equidistantly along the circumferential direction of the second conductive member 42.

[0229] The outer side of the convex portion 42e further extends outwardly a protruding edge 42j which is flush with the end face of the flat portion 42d adjacent to one side of the electrode assembly 10.

[0230] The first conductive member 41 is in a circular ring shape, and the outer ring radius D1 of the first conductive member 41 is greater than the maximum distance D2 from the outer side wall of the convex portion 42e to the center of the recessed portion 42g. The first conductive member 41, the protruding edge 42j and the convex portion 42e jointly enclose a second groove 42k on the outer side of the convex portion 42e. The outer side wall of the convex portion 42e is disposed between the second groove 42k and the first groove 42h, and fourth through holes 42l are formed in the outer side wall. The second groove 42k, the first groove 42h, the fourth through holes 42l and the third through holes 42i serve as at least part of the first channel 4A.

[0231] The outer side wall of the convex portion 42e is provided with a plurality of fourth through holes 42l between the second groove 42k and the first groove 42h, and a plurality of third through holes 42i between the first groove 42h and the recessed portion 42g. The plurality of third through holes 42i and the plurality of fourth through holes 42l are spaced apart along the circumferential direction of the second conductive member 42, and at least part of the plurality of third through holes 42i and the plurality of fourth through holes 42l are aligned along the radial direction.

[0232] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application rather than limit the same; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, all of them should be covered in the technical solution range of the present application claimed.

Claims

1. A battery cell (61) comprising: an electrode assembly (10); a case (20) having a receiving cavity and an open end (20b) communicating with the receiving cavity; an end cover (30) covering the open end (20b); a current collecting assembly (40) electrically connected to the electrode assembly (10) and the case (20), the receiving cavity including a pressure relief cavity (pr) and an electrical cavity (el), the pressure relief cavity (pr) being located between the current collecting assembly (40) and the end cover (30), the electrical cavity (el) being configured to accommodate the electrode assembly (10); wherein the end cover (30) has a pressure relief portion (50), at least a portion of the pressure relief portion (50) being provided on a cavity wall of the pressure relief cavity (pr), and the current collecting assembly (40) has at least one passage communicating the electrical cavity (el) and the pressure relief cavity (pr).

2. The battery cell (61) of claim 1, wherein, The at least one passage includes a first passage (4A) located at a periphery of the pressure relief cavity (pr).

3. The battery cell (61) according to claim 1 or 2, wherein The at least one passage includes a plurality of the first passages (4A) arranged at intervals along the periphery of the pressure relief cavity (pr).

4. The battery cell (61) of claim 3, wherein, The plurality of the first passages (4A) are arranged at equal intervals along the periphery of the pressure relief cavity (pr).

5. The battery cell (61) according to any one of claims 2-4, wherein, The end cover (30) is electrically connected to the case (20), and the current collecting assembly (40) includes: a first conductive member (41) welded to the end cover (30) and having a hollow portion (41a) extending through in a thickness direction of the end cover (30); and a second conductive member (42) electrically connected to the first conductive member (41) and welded to a first tab (12) of the electrode assembly (10) on a side adjacent to the end cover (30); wherein the end cover (30), the hollow portion (41a) and the second conductive member (42) enclose the pressure relief cavity (pr), the first passage (4A) is provided between the first conductive member (41) and the second conductive member (42) and communicates with the hollow portion (41a).

6. The battery cell (61) of claim 5, wherein, The end cover (30) is made of a material different from that of the first tab (12); wherein the first conductive member (41) is made of the same material as that of the end cover (30), and / or the second conductive member (42) is made of the same material as that of the first tab (12).

7. The battery cell (61) of claim 6, wherein, The end cover (30) and the first conductive member (41) are made of steel, and the first tab (12) and the second conductive member (42) are made of copper.

8. The battery cell (61) according to any one of claims 5-7, wherein, The electrode assembly (10) is a cylindrical electrode assembly, the second conductive member (42) includes a plate body (42a), an edge region of the plate body (42a) is welded to the first conductive member (41) and is provided with a notch (42b), and the notch (42b) is at least partially exposed to the hollow portion (41a) as the first passage (4A).

9. The battery cell (61) of claim 8, wherein, The edge region of the plate body (42a) is provided with a plurality of notches (42b), and the plurality of notches (42b) are arranged at intervals along a circumferential direction of the plate body (42a).

10. The battery cell (61) of claim 9, wherein, The plurality of notches (42b) are arranged at equal intervals along the circumference of the plate body (42a).

11. The battery cell (61) according to any one of claims 8-10, wherein, The at least one channel further comprises a second channel (4B) opened at the center of the plate body (42a), and the portion of the plate body (42a) between the second channel (4B) and the edge region is welded with the first tab (12).

12. The battery cell (61) according to claims 5-7, wherein, The electrode assembly (10) is a cylindrical electrode assembly, the second conductive member (42) comprises a flat plate portion (42d) and a convex portion (42e) protruding from the flat plate portion (42d) in a direction away from the electrode assembly (10) to form a concave portion (42g) on the inner side, the orthographic projection of the concave portion (42g) on the first conductive member (41) at least partially overlaps with the hollow portion (41a), and the convex portion (42e) is welded with the first conductive member (41); and the first channel (4A) is arranged in the convex portion (42e).

13. The battery cell (61) of claim 12, wherein, The convex portion (42e) is formed with a first groove (42h) recessed from the flat plate portion (42d) in a direction away from the electrode assembly (10) on the side adjacent to the electrode assembly (10), the inner side wall of the convex portion (42e) is located between the first groove (42h) and the concave portion (42g), and a third through hole (42i) is arranged therein, and the first groove (42h) and the third through hole (42i) at least partially form the first channel (4A).

14. The battery cell (61) of claim 13, wherein, The convex portion (42e) is formed with a plurality of third through holes (42i) between the first groove (42h) and the concave portion (42g), and the plurality of third through holes (42i) are arranged at equal intervals along the circumference of the second conductive member (42).

15. The battery cell (61) of claim 14, wherein, The plurality of third through holes (42i) are arranged at equal intervals along the circumference of the second conductive member (42).

16. The battery cell (61) according to any one of claims 13-15, wherein, The outer side of the convex portion (42e) further extends outwardly to form a flange (42j).

17. The battery cell (61) of claim 16, wherein, The end face of the flange (42j) on the side adjacent to the electrode assembly (10) is flush with the end face of the flat plate portion (42d) on the side adjacent to the electrode assembly (10).

18. The battery cell (61) according to claim 16 or 17, wherein The first conductive member (41) is in the shape of a ring, the outer ring radius (D1) of the first conductive member (41) is greater than the maximum distance (D2) from the outer side wall of the convex portion (42e) to the center of the concave portion (42g), the first conductive member (41), the flange (42j) and the convex portion (42e) jointly form a second groove (42k) on the outer side of the convex portion (42e), the outer side wall of the convex portion (42e) is located between the second groove (42k) and the first groove (42h), and a fourth through hole (42l) is arranged therein, and the second groove (42k), the first groove (42h), the fourth through hole (42l) and the third through hole (42i) at least partially form the first channel (4A).

19. The battery cell (61) of claim 18, wherein, The outer side wall of the protruding part (42e) is provided with a plurality of fourth through holes (42l) between the second groove (42k) and the first groove (42h), and a plurality of third through holes (42i) between the first groove (42h) and the recessed part (42g), the plurality of third through holes (42i) and the plurality of fourth through holes (42l) are arranged at intervals along the circumference of the second conductive member (42), and the plurality of third through holes (42i) and the plurality of fourth through holes (42l) are at least partially aligned or staggered in the radial direction.

20. The battery cell (61) of any of claims 13-19, wherein, The protruding part (42e) is annular and forms the annular first groove (42h).

21. The battery cell (61) of any of claims 18-19, wherein, The protruding part (42e) is annular and cooperates with the first conductive member (41) and the protruding ridge (42j) to enclose the annular second groove (42k).

22. The battery cell (61) according to any one of claims 12-21, wherein, The at least one channel further comprises a second channel (4B) formed in the center of the flat plate part (42d), and the part of the flat plate part (42d) outside the second channel (4B) is welded to the first tab (12).

23. The battery cell (61) according to any one of claims 5-22, wherein, The first part (31) of the end cover (30) for enclosing the pressure relief cavity (pr) protrudes in a direction away from the electrode assembly (10) relative to the second part (32) of the end cover (30) welded to the first conductive member (41).

24. The battery cell (61) according to any one of claims 1-23, wherein, The shell (20) comprises a side wall (21) enclosing the open end (20b) and a bottom wall (22) connected to the side wall (21) and opposite the open end (20b), and an electrode terminal (221) is arranged on the bottom wall (22), the electrode assembly (10) comprises a main body part (11) and first and second tabs (12, 13) of opposite polarity, the first tab (12) is arranged at the end of the main body part (11) adjacent to the end cover (30) and is electrically connected to the current collecting assembly (40), and the second tab (13) is arranged at the end of the main body part (11) adjacent to the bottom wall (22) and is electrically connected to the electrode terminal (221).

25. The battery cell (61) of claim 24, wherein, The bottom wall (22) and the side wall (21) are integrally formed.

26. A battery (60) comprising: The battery cell (61) according to any one of claims 1-25.

27. An electric device comprising: The battery (60) according to claim 26.

Images