Battery monomer, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, and the battery monomer comprises an electrode assembly which comprises a plurality of layers of electrode plates; the shell comprises a shell body and a shell cover, the shell body forms a containing space with an opening, the shell cover is connected with the shell body and seals the opening, the electrode assembly is arranged in the containing space, the shell cover is located on one side of the electrode assembly in the layer thickness direction, and the shell body comprises a first shell wall, a second shell wall and a third shell wall which are connected with one another; the first shell wall and the second shell wall are located between the third shell wall and the shell cover, the length of the first shell wall is larger than that of the second shell wall, the area of the third shell wall is larger than that of the first shell wall and that of the second shell wall, and at least one anti-explosion valve is arranged on the first shell wall at intervals.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, battery devices, and electrical devices. Background Art

[0002] New energy battery devices are being used more and more widely in life and industry. For example, new energy vehicles equipped with battery devices have been widely used. In addition, battery devices are also increasingly being used in energy storage fields.

[0003] In new energy vehicles equipped with batteries, these devices can provide full or partial power. In the energy storage sector, batteries can be installed within the energy storage box or directly at the user's side. As battery applications continue to expand, so too do the demands on their reliability. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a battery cell, a battery device and an electrical device with high reliability.

[0005] According to a first aspect of the present application, a battery cell is provided, which includes an electrode assembly, including a multi-layer electrode sheet; a shell, including a shell and a shell cover, the shell forming a accommodating space with an opening, the shell cover is connected to the shell and closes the opening, the electrode assembly is arranged in the accommodating space, the shell cover is located on one side of the electrode assembly layer thickness direction, the shell includes a first shell wall, a second shell wall and a third shell wall connected to each other, the first shell wall and the second shell wall are located between the third shell wall and the shell cover, the length of the first shell wall is longer than the length of the second shell wall, the area of the third shell wall is larger than the area of the first shell wall and the area of the second shell wall, and at least one explosion-proof valve is provided on the first shell wall.

[0006] The shell cover located on one side in the thickness direction of the electrode assembly is connected to the shell, and is more prone to cracking due to the expansion force of the electrode assembly. At least one explosion-proof valve is arranged on the first shell wall of the shell to relieve pressure in time and reduce the risk of cracking at the connection between the shell cover and the shell. When the battery cell has thermal runaway, the emissions in the shell can be directionally ejected through the explosion-proof valve, reducing the range of emission eruption, reducing the risk of heat diffusion, and reducing the degree of damage to surrounding components, thereby improving the reliability of the battery cell.

[0007] In some embodiments, the battery cell further includes: an electrode terminal disposed on the housing and / or the shell cover, and the first outer shell wall is free of the electrode terminal.

[0008] As a result, the electrode terminals and the explosion-proof valve are not in the same orientation, thereby further reducing the risk of emissions ejected from the explosion-proof valve spreading to the electrode terminals when battery thermal runaway occurs.

[0009] In some embodiments, along the layer thickness direction, the shell cover faces the third outer shell wall, and the outer shell includes a recess formed in the third outer shell wall and recessed along the layer thickness direction.

[0010] By providing a recess in the third outer shell wall of the outer shell, the layout is more compact when multiple battery cells are grouped, improving space utilization and helping to increase the volumetric energy density of the battery device.

[0011] In some embodiments, the electrode assembly includes a tab, and along the layer thickness direction, the recess at least partially overlaps with the tab.

[0012] Since the recess at least partially overlaps with the tab, the space vacated by the tab in the accommodation space of the outer shell is utilized, without additionally occupying other spaces inside the outer shell, which helps to increase the volumetric energy density of the battery cell.

[0013] In some embodiments, the electrode terminal is provided on the shell cover, and along the layer thickness direction, the position of the recess corresponds to that of the electrode terminal.

[0014] In the battery cell, the position of the recess corresponds to that of the electrode terminal, which is convenient for mass production and also convenient for the grouping rate when multiple battery cells are grouped and installed.

[0015] In some embodiments, the second outer shell wall is located on one side of the electrode assembly along a first direction, the first outer shell wall is located on one side of the electrode assembly along a second direction, the second direction is perpendicular to the first direction and perpendicular to the layer thickness direction, and along the length direction of the outer shell, the electrode terminal is provided adjacent to the end of the second outer shell wall, and the length direction is perpendicular to the layer thickness direction.

[0016] By providing the electrode terminal adjacent to the end of the shell cover, it is convenient to connect between multiple battery cells, and at the same time it is also convenient to connect with the tab, improving the installation convenience.

[0017] In some embodiments, the shell cover is welded to the shell body.

[0018] Welding can improve the processing efficiency and the connection is more reliable.

[0019] The second aspect of the embodiments of the present application provides a battery device, including: a box body; and a plurality of battery cells disposed in the box body, and the battery cells are the battery cells mentioned in any of the embodiments of the first aspect above.

[0020] Since the reliability of the battery cell is improved, the reliability of the battery device of the embodiments of the present application is also improved.

[0021] In some embodiments, the battery device further includes at least one battery cell bracket disposed within the box body and between the first outer shell wall and the box body. A through portion is formed on the battery cell bracket. Along a first direction, the projection of the through portion on the first outer shell wall at least partially coincides with the explosion-proof valve. The first direction is consistent with the wall thickness direction of the first outer shell wall and the first direction is perpendicular to the layer thickness direction.

[0022] A through portion for allowing emissions to pass through is formed on the battery cell bracket, enabling the emissions to pass through smoothly, reducing the risk of emissions accumulation, and being able to reduce the impact on the battery cell bracket, enabling the battery cell bracket to perform its original function. Thus, even if a thermal runaway occurs in the battery, the degree of damage to the battery can be minimized to the greatest extent, thereby reducing the risk of battery rupture or explosion.

[0023] In some embodiments, along the wall thickness direction of the first outer shell wall, the explosion-proof valve does not extend beyond the projection of the through portion on the first outer shell wall.

[0024] The explosion-proof valve does not extend beyond the projection of the through portion on the first outer shell wall, such that most of the emissions ejected by the explosion-proof valve are ejected through the through portion, reducing the impact of the emissions on the battery cell bracket, enabling the battery cell bracket to better perform its original function, and being able to reduce the accumulation of emissions. Thus, the degree of damage to the battery is further reduced, thereby further reducing the risk of battery rupture or explosion.

[0025] In some embodiments, the explosion-proof valve is exposed through the through portion and directly faces the inner wall of the box body.

[0026] The ejected matter ejected through the explosion-proof valve passes through the through portion and directly impacts the inner wall of the box body. The box body can sufficiently resist the impact force brought by the emissions and helps reduce the temperature of the emissions, thereby better controlling the risk of large-scale heat spread.

[0027] In some embodiments, the battery device further includes a smoke exhaust passage having a smoke exhaust port communicating with the outside of the battery, and the smoke exhaust passage communicates with the through portion.

[0028] The emissions are guided to the smoke exhaust port through the smoke exhaust passage and thus discharged outside the battery, further reducing the risk of emissions accumulation inside the battery, thereby further reducing the degree of damage to the internal components of the battery and reducing the risk of battery rupture or explosion.

[0029] In some embodiments, the battery cell bracket is formed with a plurality of the through portions, and each explosion-proof valve at least partially coincides with the projection of the through portion on the first outer shell wall.

[0030] Since different batteries may require different numbers of explosion-proof valves, more through-portions are provided on the battery cell bracket to adapt to the needs of more batteries for the number of explosion-proof valves and improve versatility; in addition, the extra through-portions can also pass a small amount of emissions.

[0031] In some embodiments, a plurality of the battery cells are arranged along a first direction, and a battery cell holder is provided corresponding to each of the battery cells; or, the battery cell holder is constructed as an integral structural member, and the battery cell holder is formed with a plurality of the through portions, and the explosion-proof valve of each of the battery cells at least partially overlaps with the projection of the through portion on the first outer shell wall.

[0032] The multiple battery cell brackets are split, allowing for flexible installation by matching the number of battery cell brackets to the number of battery cells. Furthermore, if one battery cell bracket is damaged, such as by impact from emissions, the adverse effects on the remaining battery cell brackets are minimized. The multiple battery cell brackets are integrated into one structure, making installation easier, faster, and more efficient.

[0033] In some embodiments, the battery cell support includes a thermally conductive member and / or an insulating member.

[0034] The battery cell bracket not only serves as a passage for emissions, but also performs heat conduction, insulation and support functions. As a result, it can improve the performance of the battery during normal operation, and reduce the degree of damage to the battery when thermal runaway occurs, thereby reducing the risk of battery rupture or explosion.

[0035] In some embodiments, the plurality of battery cells are arranged along a layer thickness direction, and at least a portion of the electrode terminal of one of two adjacent battery cells is located in the recessed portion of the other battery cell.

[0036] Multiple battery cells are arranged with the electrode terminals of two adjacent battery cells located in the recessed portions, which can reduce the distance between the two adjacent battery cells along the layer thickness direction, so that more battery cells can be accommodated in the box, thereby improving the volume energy density of the battery.

[0037] In some embodiments, the electrode terminals of at least two of the plurality of battery cells are connected via a transition piece that bypasses an end portion of the housing along a second direction perpendicular to the first direction and the layer thickness direction.

[0038] The adapter bypasses the end of the shell in the length direction. When the high-voltage wiring harness is arranged on the side of the shell away from the first shell wall along the first direction of the shell, the adapter is staggered with the high-voltage wiring harness, reducing the space occupied by the high-voltage wiring harness.

[0039] In some embodiments, the adapter includes a first bent portion, a second bent portion, and a connecting portion located between the first bent portion and the second bent portion. The first bent portion and the second bent portion are respectively bent relative to the connecting portion to form a bending cavity, at least a part of the end portion is located in the bending cavity, and the first bent portion and the second bent portion are respectively connected to the electrode terminals of two adjacent battery cells.

[0040] At least a part of the end portion is located in the bending cavity, which can reduce the space in the length direction of the housing and contribute to improving the volume energy density when the battery cells are grouped.

[0041] The end portion is located in the bending cavity, which can reduce the space in the length direction of the housing and contribute to improving the volume energy density when the battery cells are grouped.

[0042] In some embodiments, the size of the explosion-proof valve along the second direction is L1, the size of the explosion-proof valve along the layer thickness direction is H1, the size of the through portion corresponding to the explosion-proof valve along the second direction is L2, the size of the through portion along the first direction is H2, 1 / 4H2 ≤ H1 ≤ 1 / 2H2, 1 / 2L2 ≤ L1 ≤ 3 / 4L2, and the first direction is perpendicular to the second direction and perpendicular to the layer thickness direction.

[0043] The explosion-proof valve and the through portion are set within a suitable size range, which can not only enable the vast majority of emissions to pass through the through portion smoothly, but also enable the battery cell bracket to perform its original function.

[0044] The third aspect of the present application provides an electrical device, which includes the battery cell described in the first aspect or the battery device described in the second aspect, and the battery device can provide electrical energy for the electrical device.

[0045] Through the embodiments of the present application, the reliability of the battery cell and even the battery device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0047] Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

[0048] Figure 2 is a schematic three-dimensional structural diagram of a battery device provided by some embodiments of the present application;

[0049] Figure 3 Schematic three-dimensional structure diagram of a battery cell provided in some embodiments of the present application;

[0050] Figure 4 Schematic diagram of the relative positional relationship between a battery cell and a battery cell bracket provided in some embodiments of the present application;

[0051] Figure 5 Schematic diagram when a battery cell and a battery cell bracket cooperate provided in some embodiments of the present application;

[0052] Figure 6 Schematic structure diagram of a battery cell provided in some embodiments of the present application;

[0053] Figure 7 Schematic diagram of the arrangement of multiple battery cells provided in some embodiments of the present application;

[0054] Figure 8 Schematic diagram of another perspective of the arrangement of multiple battery cells provided in some embodiments of the present application;

[0055] Figure 9 Schematic structure diagram of the connection between an electrode assembly and an electrode terminal provided in some embodiments of the present application;

[0056] Figure 10 Schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application.

[0057] Description of reference numerals

[0058] 1000 - Vehicle; 100 - Battery; 200 - Controller; 300 - Motor;

[0059] 10 - Box body; 11 - First box body; 12 - Second box body; 111 - Bottom wall;

[0060] 20 - Battery cell; 20a - End portion; 21 - Outer shell; 22 - Electrode assembly; 22A - Flat area; 22B - Bent area; 211 - Housing; 211a - First outer shell wall; 211b - Second outer shell wall; 211c - Third outer shell wall; 212 - Shell cover; 213a - Concave portion; 221 - Electrode plate; 221a - Positive electrode plate; 221b - Negative electrode plate; 222 - Tab; 223 - Separator; 2111a - Notch; A - Weld seam;

[0061] 30 - Explosion-proof valve;

[0062] 40 - Electrode terminal;

[0063] 50 - Battery cell bracket; 51 - Passing portion;

[0064] 60 - Adapter; 60a - Bending cavity; 61 - First bending part; 62 - Second bending part; 63 - Connecting part. Detailed implementation mode

[0065] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0066] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description of the specification and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0067] In the description of the embodiments of the present application, technical terms such as "first", "second", "third", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise specifically defined.

[0068] Referring to "embodiment" herein means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0069] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0070] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed, operated or used in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application.

[0071] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0072] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0073] Below, this application is described in detail.

[0074] New energy battery devices are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As the application of power batteries continues to expand, higher requirements are being placed on their reliability.

[0075] Research has found that during the cycle of a battery cell, the electrode assembly in the outer shell will expand and gas will be generated inside the outer shell. As the gas continues to accumulate, the internal air pressure will increase. The shell cover located on the side of the expansion direction of the electrode assembly is subject to the dual effects of the expansion force of the electrode assembly during expansion and the pressure of the gas inside the outer shell. This makes the connection between the shell cover and the shell more prone to cracking, and the cracking position is random, resulting in uncontrollable direction of the emissions in the outer shell when they erupt from the cracking position, which in turn causes the eruption range to expand, thereby causing large-area damage to surrounding components, and ultimately leading to poor reliability of the battery cell.

[0076] To this end, at least one explosion-proof valve is provided in the shell to discharge the gas in the shell in a timely manner so as to release the pressure in time, which can reduce the risk of cracking at the connection between the shell cover and the shell on the side of the expansion direction of the electrode assembly. Therefore, when thermal runaway occurs in the battery cell, the emission is directionally ejected through the explosion-proof valve, which reduces the eruption range and reduces the risk of heat diffusion, thereby reducing the degree of damage to surrounding components and improving the reliability of the battery cell.

[0077] Based on such a design concept, the present application provides a battery cell, comprising: an electrode assembly including multiple layers of electrode sheets; a housing including a housing body and a housing cover, the housing body forming a receiving space with an opening, the housing cover being connected to the housing body and closing the opening, the electrode assembly being disposed in the receiving space, the housing cover being located on one side in the layer thickness direction of the electrode assembly, the housing body including a first housing wall, a second housing wall and a third housing wall connected to each other, the first housing wall and the second housing wall being located between the third housing wall and the housing cover, the length of the first housing wall being longer than that of the second housing wall, the area of the third housing wall being larger than the areas of the first housing wall and the second housing wall, and at least one explosion-proof valve being provided on the first housing wall.

[0078] Providing at least one explosion-proof valve on the first housing wall of the housing body can relieve pressure in a timely manner, reduce the risk of cracking at the connection between the housing cover and the housing body, and when the battery cell undergoes thermal runaway, the emissions can be ejected directionally through the explosion-proof valve, which can reduce the emission ejection range and the degree of damage to surrounding components, thereby improving the reliability of the battery cell.

[0079] The technical solutions described in the embodiments of the present application are applicable to various electrical devices, such as mobile phones, portable devices, laptop computers, battery cars, electric toys, electric tools, vehicles, ships and spacecrafts, etc. For example, spacecrafts include airplanes, rockets, space shuttles and spaceships, etc.

[0080] In the following embodiments, for the convenience of description, a vehicle 1000 of an embodiment of the present application is taken as an example for illustration.

[0081] Figure 1 The structural schematic diagram of the vehicle 1000 provided for some embodiments of the present application. The vehicle ۱۰۰۰ can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. As Figure 1 shown, a battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be disposed at the bottom, the head or the tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000. For example, the battery device 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0082] In some embodiments of the present application, the battery device 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0083] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel, or in a hybrid connection through a busbar component (connector).

[0084] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly may be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by fixing a plurality of battery cells through side support plates and end plates.

[0085] In some embodiments, the battery apparatus may be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0086] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body by fixing the battery module in the box body.

[0087] As an example, the box body may include a first box body and a second box body. The first box body and the second box body are buckled so that a closed space is formed inside the box body to accommodate the battery cell assembly. The "closed" here means covering or closing, which may be sealed or non-sealed. The first box body may be a top cover or a bottom plate.

[0088] As an example, the box body may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0089] As an example, the box body may be part of the chassis structure of a vehicle. For example, the top cover of the box body may become at least part of the floor of the vehicle, or the frame of the box body may become at least part of the cross beam and longitudinal beam of the vehicle.

[0090] In the embodiments of the present application, the battery cell may be a secondary battery, and the secondary battery refers to a battery cell that can activate the active material and continue to be used by charging after discharging the battery cell.

[0091] The battery cell may 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-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application do not limit this.

[0092] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0093] As an example, the battery cell can be a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, and a polygonal battery such as a hexagonal battery. There is no special limitation in the embodiments of the present application.

[0094] In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte.

[0095] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a transition component.

[0096] In some embodiments, the housing is provided with a pressure relief mechanism (eg, an explosion-proof valve) for discharging internal gas from the battery cells.

[0097] For example, a battery cell's internal pressure or temperature reaches a predetermined threshold, triggering the release of internal pressure or temperature. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism activates, or a weakened structure within the pressure relief mechanism is destroyed, thereby creating an opening or channel for the internal pressure or temperature to release. This threshold design varies depending on design requirements. The threshold may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell.

[0098] As an example, the pressure relief mechanism may be integrally formed with the housing.

[0099] As an example, the pressure relief mechanism may also be provided separately from and connected to the housing.

[0100] The "activation" mentioned in this application refers to the action of the pressure relief mechanism or its activation to a certain state, so that the internal pressure and temperature of the battery cell can be released. The action produced by the pressure relief mechanism may include but is not limited to: the movement of components in the pressure relief mechanism to form an exhaust channel, at least a part of the pressure relief mechanism rupturing, breaking, tearing or opening, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell will be discharged outward from the actuated part as emissions. In this way, the pressure and temperature of the battery cell can be relieved under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0101] In some embodiments, when the outer shell is a non-sealed structure, the pressure relief mechanism can be set as a through-hole for discharging the gas inside the battery cell.

[0102] The emissions from the battery cell mentioned in this application include but are not limited to: electrolytes, dissolved or fragmented positive and negative electrode sheets, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, and so on.

[0103] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent short circuit between the positive and negative electrodes and at the same time allow active ions to pass through.

[0104] In some embodiments, the electrode assembly is in a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0105] In some embodiments, the electrode assembly is in a stacked structure.

[0106] As an example, the electrode assembly includes a plurality of electrode sheets, the plurality of electrode sheets including positive electrode sheets and negative electrode sheets. The positive electrode sheets and the negative electrode sheets can be respectively provided in plurality, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately stacked.

[0107] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of stacked folding segments, and a positive electrode sheet is clamped between adjacent folding segments.

[0108] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folding segments.

[0109] As an example, a plurality of separators can be provided and are respectively disposed between any adjacent positive electrode sheet or negative electrode sheet.

[0110] As an example, the separator can be continuously provided and is disposed between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0111] In some embodiments, the shape of the electrode assembly can be flat or prismatic, etc.

[0112] In some embodiments, the electrode assembly is provided with tabs, and the tabs can lead the current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0113] Next, with reference to Figures 2 to 10 Some embodiments of this application will be described in detail.

[0114] An embodiment of the present application provides a battery cell 20, including: an electrode assembly 22, including multiple layers of electrode sheets 221; a housing 21, including a housing body 211 and a housing cover 212, the housing body 211 forms a receiving space with an opening, the housing cover 212 is connected to the housing body 211 and closes the opening, the electrode assembly 22 is disposed in the receiving space, the housing cover 212 is located on one side in the layer thickness direction Y of the electrode assembly 22, the housing body 211 includes a first housing wall 211a, a second housing wall 211b, and a third housing wall 211c that are connected to each other, the first housing wall 211a and the second housing wall 211b are connected between the third housing wall 211c and the housing cover 212, the length of the first housing wall 211a is longer than the length of the second housing wall 211b, the area of the third housing wall 211c is larger than the areas of the first housing wall 211a and the second housing wall 211b, and at least one explosion-proof valve 30 is provided on the first housing wall 211a.

[0115] The electrode assembly 22 includes multiple layers of electrode sheets 221. The multiple layers of electrode sheets 221 may include a positive electrode sheet 221a and a negative electrode sheet 221b, and a separator 223 is sandwiched between the positive electrode sheet 221a and the negative electrode sheet 221b.

[0116] Exemplarily, referring to Figure 10 , the negative electrode sheet 221b, the separator 223, and the positive electrode sheet 221a may be sequentially laminated and wound to form a wound structure, and the wound structure is formed with a flat area 22A and bent areas 22B located on both sides of the flat area 22A along the first direction Z through a compaction process.

[0117] Exemplarily, the negative electrode sheet 221b, the separator 223, and the positive electrode sheet 221a may also be sequentially laminated to form a stacked structure.

[0118] The housing 21 includes a housing body 211 and a housing cover 212, and the housing body 211 forms a receiving space with an opening. Exemplarily, an integral housing body 211 with an opening on one side may be formed by stamping. Of course, the housing body 211 may also be formed by splicing multiple plate members to form a housing body 211 with an opening on one side, for example, the housing body 211 may be formed by welding between multiple plate members.

[0119] The housing cover 212 is connected to the housing body 211 and closes the opening. It may be that the housing cover 212 covers the opening and the housing cover 212 is connected to the opening edge. Exemplarily, the housing cover 212 may be a plate member, and the plate member covers the opening of the housing body 211 and forms a receiving space for accommodating the electrode assembly 22 between the housing cover 212 and the housing body 211. The housing cover 212 may also form a receiving space with an opening facing the housing body 211, and the opening edge of the housing cover 212 is welded to the opening edge of the housing body 211. The housing cover 212 may also have an overlapping part with the opening edge of the housing body 211 and be welded together through the overlapping part.

[0120] The cover 212 and the housing 211 can be connected by welding. Of course, the cover 212 and the housing 211 can also be connected by bonding or other means to close the opening of the housing 211.

[0121] As an example, referring to Figure 3 , the housing 211 is in the shape of a square body and has an annular opening on one side facing the layer thickness direction Y of the electrode assembly 22. The cover 212 covers the annular opening and is welded to the housing 211, thereby forming an annular weld seam A between the cover 212 and the housing 211.

[0122] The housing 211 and the cover 212 can be a steel shell, an aluminum shell, a composite metal shell (such as a copper-aluminum composite shell), etc. The materials of the housing 211 and the cover 212 can be the same or different. The outer shell 21 can be in a prismatic shape or other shapes. The prismatic shape includes a square shape, a blade shape, a multi-prismatic shape, etc. The multi-prismatic shape can be a hexagonal prism shape, and there is no special limitation in this application.

[0123] The cover 212 is located on one side of the electrode assembly 22 in the layer thickness direction Y. In the solution where the electrode assembly 22 is a wound structure, referring to Figure 10 , the thickness direction of the electrode assembly 22 in the flat area 22A is the layer thickness direction Y of the electrode assembly 22. In the solution where the electrode assembly 22 is a stacked structure, the stacking direction of the stacked structure is the layer thickness direction Y of the electrode assembly 22.

[0124] The housing 211 includes a first outer wall 211a, a second outer wall 211b, and a third outer wall 211c that are connected to each other. The first outer wall 211a and the second outer wall 211b are connected between the third outer wall 211c and the cover 212.

[0125] Exemplarily, referring to Figure 3 and Figure 6 , the first outer wall 211a can be perpendicular to the second outer wall 211b and the third outer wall 211c and perpendicular to the cover 212. The second outer wall 211b is connected between the third outer wall 211c and the cover 212. The housing 211 can include two first outer walls 211a that are opposite to each other along the first direction Z, two second outer walls 211b that are opposite to each other along the second direction X, and a third outer wall 211c that is opposite to the cover 212 along the layer thickness direction Y. The third outer wall 211c can be parallel to the cover 212. As an example, the first direction Z can be the width direction of the outer shell 21, the second direction X can be the length direction of the outer shell 21, and the layer thickness direction Y can be the thickness direction of the outer shell 21. Among them, the first direction Z, the second direction X, and the layer thickness direction Y are perpendicular to each other pairwise, and the dimension in the length direction of the outer shell 21 is greater than the dimension in the width direction and greater than the dimension in the thickness direction.

[0126] The length of the first outer shell wall 211a is longer than that of the second outer shell wall 211b, which means that the length of the first outer shell wall 211a along the second direction X is longer than that of the second outer shell wall 211b along the first direction X.

[0127] At least one explosion-proof valve 30 is provided on the first outer shell wall 211a. In some embodiments, a plurality of explosion-proof valves 30 are provided at intervals on the first outer shell wall 211a. A plurality of explosion-proof valves 30 may be provided only on one first outer shell wall 211a, or a plurality of explosion-proof valves 30 may be provided respectively on the two first outer shell walls 211a opposite to each other along the first direction Z. The plurality of explosion-proof valves 30 may be provided at intervals along the second direction X and / or the layer thickness direction Y.

[0128] The area of the third outer shell wall 211c is larger than the areas of the first outer shell wall 211a and the second outer shell wall 211b. The area of the third outer shell wall 211c refers to the projected area of the third outer shell wall 211c on the projection plane perpendicular to the layer thickness direction Y. The area of the first outer shell wall 211a refers to the projected area of the first outer shell wall 211a on the projection plane perpendicular to the first direction Z. The area of the second outer shell wall 211b refers to the projected area of the second outer shell wall 211b on the projection plane perpendicular to the second direction X.

[0129] The area of the first outer shell wall 211a is larger than the areas of the first outer shell wall 211a and the second outer shell wall 211b. Thus, the first outer shell wall 211a is the so-called large surface.

[0130] The area of the third outer shell wall 211c defines the opening size of the housing 211, and the opening size of the housing 211 defines the size of the housing cover 212. Exemplarily, the area of the housing cover 212 covering the opening is equal to the area of the third outer shell wall 211c.

[0131] Providing at least one explosion-proof valve 30 on the first outer shell wall 211a of the housing 211 can relieve pressure in time, reduce the risk of cracking at the connection between the housing cover 212 and the housing 211. When the battery cell 20 undergoes thermal runaway, the emissions inside the outer shell 21 can be ejected directionally through the explosion-proof valve 30, reducing the emission ejection range, reducing the risk of thermal diffusion, and reducing the degree of damage to surrounding components, thereby improving the reliability of the battery cell.

[0132] In some embodiments, the battery cell 20 further includes an electrode terminal 40 connected to the tab 222 of the electrode assembly 22. The electrode terminal 40 is provided on the housing 211 and / or the housing cover 212, and there is no electrode terminal 40 on the first outer shell wall 211a.

[0133] The electrode terminal 4 can be provided only on the housing 211, or only on the housing cover 212, or on both the housing 211 and the housing cover 212 at the same time.

[0134] The first outer shell wall 211a has no electrode terminal 40. It can be understood that one or more explosion-proof valves 30 are provided on the first outer shell wall 211a and no electrode terminal 40 is provided.

[0135] Thus, the electrode terminal 40 and the explosion-proof valve 30 are not on the same outer shell wall, so that when the battery cell 20 undergoes thermal runaway, the risk of the emissions ejected by the explosion-proof valve 30 spreading to the electrode terminal 40 can be further reduced.

[0136] As an example, Figure 3 The case where the electrode terminal 40 is provided on the shell cover 212 and a plurality of explosion-proof valves 30 are provided on the first outer shell wall 211a is shown. Of course, it can be understood that the electrode terminal 40 can also be provided on any one or more outer shell walls other than the first outer shell wall 211a. Thus, the electrode terminal 40 can be avoided from the explosion-proof valve 30, so that when the battery device 100 undergoes thermal runaway, the risk of the emissions ejected by the explosion-proof valve 30 spreading to the electrode terminal 40 can be reduced.

[0137] In some embodiments, along the layer thickness direction Y, the shell cover 212 faces the third outer shell wall 211c, and the outer shell 21 includes a recessed portion 213a ( Figure 7 as shown), the recessed portion 213a is formed on the third outer shell wall 211c and the recessed portion 213a is recessed along the layer thickness direction Y.

[0138] When a plurality of battery cells 20 are arranged in groups along the layer thickness direction Y, referring to Figure 7 , among two adjacent battery cells 20, the recessed portion 213a of one battery cell 20 is used to accommodate at least part of the electrode terminal 40 of the other battery cell 20.

[0139] By providing the recessed portion 213a on the third outer shell wall 211c of the outer shell 21, the overall layout when a plurality of battery cells 20 are grouped is more compact, the space utilization rate is improved, and it helps to increase the volume energy density when a plurality of battery cells 20 are grouped.

[0140] In some embodiments, the electrode assembly 22 includes a tab 222 connected to the electrode terminal 40. Along the layer thickness direction Y, the recessed portion 213a and the tab 222 at least partially overlap.

[0141] It can be understood that along the layer thickness direction Y (which is also the wall thickness direction of the third outer shell wall 211c), the position of the third outer shell wall 211c corresponding to the tab 222 is recessed toward the tab 222 side to form the recessed portion 213a.

[0142] Since the recessed portion 213a and the tab 222 at least partially overlap, the space vacated by the tab 222 in the accommodation space of the outer casing 21 is utilized, without additionally occupying other spaces inside the outer casing 21, which helps to improve the volumetric energy density of the battery cell 20.

[0143] In some embodiments, the electrode terminal 40 may be disposed on the third outer casing wall 211c and at least partially located in the recessed portion 213a. In this way, when a plurality of battery cells 20 are grouped, the electrode terminals 40 of two adjacent battery cells 20 can be directly in contact connection without connection components, reducing space occupation and cost.

[0144] In some embodiments, the electrode terminal 40 is disposed on the cover 212, and along the layer thickness direction Y, the position of the recessed portion 213a corresponds to that of the electrode terminal 40.

[0145] As an example, on the same projection plane perpendicular to the layer thickness direction Y, the projection of the electrode terminal 40 is located within the projection of the recessed portion.

[0146] Of course, along the layer thickness direction Y, the recessed portion 213a and the electrode terminal 40 may not correspond to each other. For example, they are respectively disposed on the third outer casing wall 211c and the cover 212 and are arranged in a staggered manner.

[0147] In the battery cell 20, the position of the recessed portion 213a corresponds to that of the electrode terminal 40, which is convenient for mass production and also convenient for grouping a plurality of battery cells 20, improving the grouping efficiency.

[0148] In some embodiments, the first outer casing wall 211a is located on one side of the electrode assembly 22 along the first direction Z, the second outer casing wall 211b is located on one side of the electrode assembly 22 along the second direction X, the second direction X is perpendicular to the first direction Z and perpendicular to the layer thickness direction Y, and along the second direction X, the electrode terminal 40 is disposed adjacent to the end portion of the cover 212, and the length direction is perpendicular to the layer thickness direction Y.

[0149] The electrode terminal 40 may be disposed at one end portion 20a or both end portions 20a of the cover 212 along the second direction X. As an example, the electrode terminal 40 includes a terminal plate located in the accommodation space of the outer casing 21 and a terminal board located outside the outer casing 21, and the terminal plate and the terminal board are riveted to the cover 212.

[0150] As an example, the tabs 222 of the electrode assembly 22 inside the outer casing 21 are located at both ends along the second direction X, the electrode terminal 40 is disposed adjacent to the end portion 20a of the cover 212, and the recessed portion 213a is also disposed adjacent to the end portion of the third outer casing wall 211c, utilizing the space vacated by the tabs 222 at the end portions in the second direction X in the accommodation space of the outer casing 21.

[0151] By arranging the electrode terminal 40 adjacent to the end 20a of the case cover 212, the space vacated by the tab 222 at the end in the second direction X in the accommodation space of the outer shell 21 can be utilized, which facilitates the connection between the electrode terminals 40 of the plurality of battery cells 20 and improves the installation convenience.

[0152] In some embodiments, the length of the outer shell 21 in the first direction Z ranges from 60 mm to 140 mm, the length of the outer shell 21 in the second direction X ranges from 400 mm to 1400 mm, and the length of the outer shell 21 in the layer thickness direction Y ranges from 15 mm to 35 mm. The first direction Z is perpendicular to the second direction X and perpendicular to the layer thickness direction Y.

[0153] An embodiment of the present application further provides a battery device 100, including: a box body 10; a plurality of battery cells 20 disposed in the box body 10, and the battery cell 20 is the battery cell 20 mentioned in any of the above embodiments.

[0154] Since the reliability of the battery cell 20 is improved, the reliability of the battery device 100 in the embodiment of the present application is also improved.

[0155] In some embodiments, the battery device 100 further includes at least one battery cell bracket 50 disposed in the box body 10 and located between the first outer shell wall 211a and the box body 10. A through portion 51 is formed on the battery cell bracket 50. Along the wall thickness direction of the first outer shell wall 211a (the first direction Z in the figure), the projection of the through portion 51 on the first outer shell wall 211a at least partially coincides with the explosion-proof valve 30.

[0156] The box body 10 is a component mainly used to accommodate and fix the battery cells 20 in the battery device 100, thereby improving the stability of the battery cells 20 and reducing the risk of shaking or displacement of the battery device 100 during movement or use. In addition, the box body 10 can also provide protection for structures such as the battery cells 20. For example, it can isolate rainwater, dust, etc. in a harsh external environment. By way of example, referring to Figure 2 , the box body 10 includes a first box body 11 and a second box body 12. The second box body 12 covers the first box body 11 to form an accommodation space for accommodating one or more battery cells 20, etc. In addition, a thermal management system, a circuit control system, etc. can also be provided in the box body 10. The material of the box body 10 can be stainless steel, aluminum alloy, etc.

[0157] The battery cell support 50 is disposed within the box body 10 and between the first outer shell wall 211a and the box body 10, and the battery cell support 50 can support the battery cell 20. The battery cell support 50 has, for example, a support plate with a certain rigidity, and the support plate can be, for example, a steel plate, an aluminum plate, a plastic plate, etc. It can also be used to transfer heat between the battery cell 20 and the box body 10 to achieve the function of heat transfer, such as a heat conductive pad, etc. It can also be used to insulate between the battery cell 20 and the box body 10, such as an insulating pad, etc.

[0158] A through portion 51 is formed on the battery cell support 50. Along the wall thickness direction of the first outer shell wall 211a, the projection of the through portion 51 on the first outer shell wall 211a at least partially coincides with the explosion-proof valve 30. It can be understood that the projection of the through portion 51 on the first outer shell wall 211a can partially or completely coincide with the outer contour of the explosion-proof valve 30, or the explosion-proof valve 30 is located within the projection of the through portion 51 on the first outer shell wall 211a. When the battery device 100 experiences thermal runaway, the explosion-proof valve 30 opens, and the emissions ejected by the explosion-proof valve 30 pass through the through portion 51. The through portion 51 can be a through hole or a weak structure, such as a thin film or a thin wall with a notch. When the through portion 51 is a weak structure, the emissions ejected by the explosion-proof valve 30 can damage at least part of the weak structure and thus pass through the through portion 51 smoothly.

[0159] The shape of the through portion 51 can be the same as or different from the shape of the explosion-proof valve 30. For example, the shape of the through portion 51 can be circular, oval, square, racetrack-shaped, or other shapes.

[0160] As an example, the first outer shell wall 211a faces the bottom wall 111 of the box body 10 ( Figure 2 as shown), the battery cell support 50 is disposed between the first outer shell wall 211a and the bottom wall 111, the explosion-proof valve 30 provided on the first outer shell wall 211a faces the through portion 51 of the battery cell support 50, and the explosion-proof valve 30 is located within the projection of the through portion 51 on the first outer shell wall 211a. The emissions ejected by the explosion-proof valve 30 are ejected towards the bottom wall 111 of the box body 10, which can reduce the risk of the emissions spreading to the high-voltage lines at the top of the box body 10.

[0161] By forming the through portion 51 on the battery cell support 50 for the emissions ejected by the explosion-proof valve to pass through, the emissions can pass through smoothly, reducing the risk of emissions accumulation, and can reduce the impact on the battery cell support 50, enabling the battery cell support 50 to perform its original function. Thus, even if the battery device 100 experiences thermal runaway, the damage degree to the battery device 100 can be minimized to the greatest extent, thereby reducing the risk of the battery device 100 cracking or exploding.

[0162] In addition, an exhaust channel is formed on the bottom wall 111 of the box body 10, and each exhaust channel corresponds to multiple explosion-proof valves 30 of a battery cell 20. When a battery cell 20 suffers thermal runaway, the emissions ejected by the explosion-proof valve 30 can be discharged in a direction through the exhaust channel, reducing the risk of emissions spreading to other battery cells 20, thereby improving the reliability of the battery device 100.

[0163] In some embodiments, along the wall thickness direction of the first housing wall 211 a (the layer thickness direction Y in the figure), the explosion-proof valve 30 does not exceed the projection of the through portion 51 on the first housing wall 211 a.

[0164] The explosion-proof valve 30 does not exceed the projection of the through portion 51 on the first shell wall 211a. It can be understood that the explosion-proof valve 30 can completely overlap with the projection of the through portion 51 on the first shell wall 211a or be located within the projection of the through portion 51 on the first shell wall 211a.

[0165] The explosion-proof valve 30 does not extend beyond the projection of the through portion 51 on the first housing wall 211a, so that most of the emissions ejected from the explosion-proof valve 30 are ejected through the through portion 51, reducing the impact of the emissions on the battery cell holder 50, allowing the battery cell holder 50 to better perform its original function and reducing the accumulation of emissions, thereby further reducing the degree of damage to the battery device 100 and further reducing the risk of rupture or explosion of the battery device 100.

[0166] In some implementations, the explosion-proof valve 30 is exposed through the through portion 51 and directly faces the inner wall of the housing 10 .

[0167] It can be understood that along the thickness direction of the battery cell holder 50 (the first direction Z in the figure), the through portion 51 penetrates the battery cell holder 50, and there is no other barrier between the through portion 51 and the inner wall of the box body 10, so that the ejection from the explosion-proof valve 30 passes through the through portion 51 and directly impacts the inner wall of the box body 10.

[0168] Typically, the inner wall of the housing 10 has relatively high strength, and the housing 10 is typically exposed to the outside world and can directly exchange heat with the outside world. Thus, the emissions ejected through the explosion-proof valve 30 pass through the through portion 51 and directly impact the inner wall of the housing 10 . The housing 10 can sufficiently resist the impact force of the emissions and help reduce the temperature of the emissions, thereby better reducing the risk of heat spread.

[0169] In some embodiments, the battery device 100 further includes a smoke exhaust channel (not shown), the smoke exhaust channel having a smoke exhaust port communicating with the outside of the battery device 100 , and the smoke exhaust channel communicating with the through portion 51 .

[0170] The exhaust passage can be a structure independent of the box body 10 or a structure formed on the box body 10. In one example, the exhaust passage includes a through hole provided in the bottom wall 111 of the box body 10.

[0171] The emissions are guided through the exhaust passage to the exhaust port and thus discharged outside the battery device 100, further reducing the risk of emissions accumulating inside the battery device 100, thereby further reducing the degree of damage to the internal components of the battery device 100 and also being able to reduce the risk of the battery device 100 bursting or exploding.

[0172] In some embodiments, the battery cell bracket 50 is formed with a plurality of through portions 51, and each explosion-proof valve 30 at least partially coincides with the projection of the through portion 51 on the first outer shell wall 211a.

[0173] The number of explosion-proof valves 30 can be the same as the number of through portions 51, and the plurality of explosion-proof valves 30 and the plurality of through portions 51 can correspond one by one, so that each explosion-proof valve 30 at least partially coincides with the projection of each through portion 51 on the first outer shell wall 211a.

[0174] The number of explosion-proof valves 30 can also be different from the number of through portions 51. For example, the number of explosion-proof valves 30 is more than the number of through portions 51, so that a plurality of explosion-proof valves 30 can correspond to one through portion 51. For example, for every two explosion-proof valves 30 among the plurality of explosion-proof valves 30, the projection on the first outer shell wall 211a of one through portion 51 at least partially coincides. Also for example, the number of explosion-proof valves 30 is less than the number of through portions 51, so that a plurality of explosion-proof valves 30 correspond to some of the plurality of through portions 51, and the remaining through portions 51 are located near the through portions 51 corresponding to the explosion-proof valves 30, such as on both sides along the second direction X of the outer shell.

[0175] As an example, referring to Figure 5 , along the second direction X of the outer shell 21, two explosion-proof valves 30 are provided on the first outer shell wall 211a ( Figure 6 as shown), the battery cell bracket 50 is provided with six through portions 51, and the two explosion-proof valves 30 at least partially coincide with the projection on the first outer shell wall 211a of the second through portion 51 and the fifth through portion 51 among the six through portions 51, the first through portion 51 and the third through portion 51 are respectively located on both sides of the second through portion 51, and the fourth through portion 51 and the sixth through portion 51 are respectively located on both sides of the fifth through portion 51.

[0176] Since the number of explosion-proof valves 30 required by different battery cells 20 may be different, a plurality of through portions 51 are provided on the battery cell bracket 50, which can adapt to the number of explosion-proof valves 30 of more battery cells 20 and improve versatility; in addition, the extra through portions 51 can also be used for passing emissions to reduce the risk of excretion accumulation.

[0177] In some embodiments, a plurality of battery cells 20 are arranged along the layer thickness direction, and battery cell brackets 50 are respectively provided corresponding to each battery cell 20; alternatively, the battery cell brackets 50 are configured as an integral structural member, and the battery cell brackets 50 are formed with a plurality of passing portions 51, and the explosion-proof valves 30 of each battery cell 20 respectively overlap at least partially with the projections of the passing portions 51 on the first outer shell wall 211a.

[0178] Providing the battery cell brackets 50 respectively corresponding to each battery cell 20 can be understood as providing the battery cell brackets 50 respectively between the first outer shell wall 211a of each battery cell 20 and the box body 10, so that the plurality of battery cell brackets 50 are independent components of a split structure.

[0179] A plurality of battery cells 20 are arranged along the layer thickness direction Y to form a battery cell row, and an integral-structured battery cell bracket 50 is provided between the battery cell row and the box body 10, and the passing portions 51 of the integral-structured battery cell bracket 50 respectively correspond to the explosion-proof valves 30 of each battery cell 20.

[0180] The plurality of battery cell brackets 50 are of a split structure, which is convenient for matching the corresponding number of battery cell brackets 50 according to the number of the arranged battery cells 20, and the setting is more flexible; in addition, when one of the battery cell brackets 50 is damaged, for example, damaged by the impact of the discharged substance, it can reduce the adverse impact on the original functions of the other battery cell brackets 50. The plurality of battery cell brackets 50 are integral structural members, and the installation is more convenient and faster, improving the installation efficiency.

[0181] In some embodiments, the battery cell bracket 50 includes a heat-conducting member and / or an insulating member.

[0182] The battery cell bracket 50 can be used to support the battery cell 20, and can also be used to transfer heat between the battery cell 20 and the box body 10 to achieve the function of heat transfer, such as a heat-conducting rubber pad, etc. It can also be used to play an insulating function between the battery cell 20 and the box body 10, such as an insulating rubber pad, graphene, etc.

[0183] The battery cell bracket 50 can not only play the function of allowing the discharged substance to pass through, but also play the functions of heat conduction, insulation and support. Therefore, it can improve the performance of the battery device 100 during normal operation, and can also reduce the damage degree of the battery device 100 and reduce the risk of rupture or explosion of the battery device 100 when thermal runaway of the battery 100 occurs.

[0184] In some embodiments, a plurality of battery cells 20 are arranged along the layer thickness direction Y, and at least a part of the electrode terminal 40 of one battery cell 20 among two adjacent battery cells 20 is located in the recessed portion 213a of the other battery cell 20.

[0185] The position of the recessed portion 213a of each battery cell 20 may or may not correspond to the position of the electrode terminal 40. The electrode terminal 40 may be entirely located within the recessed portion 213a or partially located within the recessed portion 213a. The number of battery cells 20 may be two, three, four, or more.

[0186] When multiple battery cells 20 are arranged and the electrode terminals 40 of two adjacent battery cells 20 are located within the recessed portion 213a, the distance between two adjacent battery cells 20 along the arrangement direction (layer thickness direction Y) can be reduced, the layout is more compact, so that more battery cells 20 can be accommodated in the box 10, and the volumetric energy density of the battery device 100 is improved.

[0187] In some embodiments, the electrode terminals 40 of at least two battery cells 20 among the multiple battery cells 20 are connected by an adapter 60, and the adapter 60 bypasses the end 20a of the housing 21 along the second direction X.

[0188] The electrode terminals 40 of every two adjacent battery cells 20 can be respectively connected by an adapter 60; alternatively, the electrode terminals 40 of every other one or more pairs of battery cells 20 can be respectively connected by an adapter 60. The multiple battery cells 20 can be connected in series or in parallel.

[0189] The adapter 60 bypasses the end 20a of the housing 21 along the second direction X. When a high-voltage wire harness is disposed on the side where the housing 21 is away from the first housing wall 211a along the first direction Z, the adapter 60 avoids the side of the high-voltage wire harness, reducing the occupation of the space of the high-voltage wire harness.

[0190] In some embodiments, the adapter 60 includes a first bent portion 61, a second bent portion 62, and a connecting portion 63 located between the first bent portion 61 and the second bent portion 62. The first bent portion 61 and the second bent portion 62 are respectively bent relative to the connecting portion 63 to form a bending cavity 60a. The end 20a is at least partially located in the bending cavity 60a, and the first bent portion 61 and the second bent portion 62 are respectively connected to the electrode terminals 40 of two adjacent battery cells 20.

[0191] The end 20a is at least partially located in the bending cavity 60a, which can reduce the space in the second direction X, contributing to improving the volumetric energy density when the battery cells 20 are grouped.

[0192] In some embodiments, referring to Figure 5 , the dimension of the explosion-proof valve 30 along the second direction X is L1, the dimension of the explosion-proof valve 30 along the layer thickness direction Y is D1, the dimension of the through portion 51 corresponding to the explosion-proof valve 30 along the second direction X is L2, the dimension of the through portion 51 along the layer thickness Y is H2, 1 / 4H2 ≤ H1 ≤ 1 / 2H2, 1 / 2L2 ≤ L1 ≤ 3 / 4L2.

[0193] The explosion-proof valve 30 and the passing part 51 are set within a suitable size range, which can not only allow the vast majority of emissions to pass through the passing part 51 smoothly, but also enable the battery cell bracket 50 to perform its original functions.

[0194] Next, with reference to Figures 2 to 10 , a specific example of the embodiment of the present application will be described.

[0195] The battery device 100 according to an embodiment of the present application includes a box body 10, a plurality of battery cells 20, an explosion-proof valve 30, and electrode terminals 40. The box body 10 includes a first box body 11 and a second box body 12. The second box body 12 covers the first box body 11 to form an accommodation space for accommodating one or more battery cells 20. The box body 10 has a bottom wall 111 located on the first box body 11. The plurality of battery cells 20 are arranged inside the box body 10 and are arranged in sequence along the layer thickness direction Y. Each battery cell 20 includes a housing 21 and an electrode assembly 22. The housing 21 includes a housing body 211 and a housing cover 212. The housing body 211 includes an accommodation space with an opening. The housing cover 212 is welded to the opening of the housing body 211. The electrode assembly 22 is received in the accommodation space. Among the plurality of housing walls, there are two first housing walls 211a opposite to each other along the first direction Z, two second housing walls 211b opposite to each other along the second direction X, and a third housing wall 211c opposite to the housing cover 212 along the layer thickness direction Y. The housing cover 212 and the third housing wall 211c are the walls with the largest area in the housing 21, that is, the so-called "large surfaces". The length of the first housing wall 211a along the second direction X is longer than the length of the second housing wall 211b along the first direction Z. The large surfaces of the plurality of battery cells 20 face each other and are arranged in sequence. A plurality of explosion-proof valves 30 are arranged on the first housing wall 211a at intervals along the second direction X. Electrode terminals 40 are respectively arranged on the housing cover 212 adjacent to both ends of the housing 21 along the second direction X. The electrode terminals 40 are connected to the tabs 222 of the electrode assembly 22. A battery cell support 50 is arranged between the first housing wall 211a of each battery cell 20 and the bottom wall 111. The battery cell support 50 may include a heat-conducting member and / or an insulating member. A plurality of through portions 51 distributed along the length direction X of the housing are arranged on the battery cell support 50. The through portions 51 penetrate through the battery cell support 50, so that the explosion-proof valves 30 are exposed through their respective through portions 51 and directly face the bottom wall 111. A smoke exhaust passage is formed on the bottom wall 111. The smoke exhaust passage is respectively communicated with the outside of the box body 10 and the through portions 51. The outer contour dimension of the through portion 51 is larger than the outer contour dimension of the explosion-proof valve 30, so that the emissions ejected by the explosion-proof valve 30 can pass through smoothly. When a battery cell 20 has a thermal runaway, the explosion-proof valve 30 of the battery cell 20 ejects a large amount of emissions outward. The emissions are discharged along at least one side of the second direction X through the smoke exhaust passage, thereby reducing the damage risk of other battery cells 20 arranged in the layer thickness direction Y, and thus improving the reliability of the battery device 100.

[0196] Each battery cell 20 further includes a recess 213a provided on the third outer shell wall 211c. The recess 213a is recessed toward the tab 222 side, making use of the remaining space of the tab 222 in the accommodation space without affecting the volumetric energy density of the battery cell 20. The electrode terminal 40 of one battery cell 20 among two adjacent battery cells 20 is located within the recess 213a of the other battery cell 20, so that the gap between two adjacent battery cells 20 along the layer thickness direction Y can be reduced, which helps to improve the volumetric energy density when the battery cells 20 are grouped. The electrode terminals 40 between two adjacent battery cells 20 are connected through an adapter 60 (such as a bus bar). The adapter 60 bypasses the end 20a of the outer shell along the second direction X. Thus, when a high-voltage wire harness is provided on the side where the outer shell 21 is away from the first outer shell wall 211a along the first direction Z, the adapter 60 avoids the side of the high-voltage wire harness, reducing the occupation of the space of the high-voltage wire harness.

[0197] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the present application.

Claims

1. A battery cell, characterized in that, Comprising: An electrode assembly including multiple layers of electrode sheets; A housing including a housing body and a housing cover. The housing body forms a receiving space with an opening, the housing cover is connected to the housing body and closes the opening. The electrode assembly is disposed in the receiving space, and the housing cover is located on one side in the layer thickness direction of the electrode assembly. The housing body includes a first housing wall, a second housing wall, and a third housing wall that are connected to each other. The first housing wall and the second housing wall are located between the third housing wall and the housing cover. The length of the first housing wall is longer than that of the second housing wall, and the area of the third housing wall is larger than the areas of the first housing wall and the second housing wall. At least one explosion-proof valve is provided on the first housing wall.

2. The battery cell according to claim 1, wherein, The battery cell further includes: Electrode terminals, connected to the electrode assembly and disposed on the housing body and / or the housing cover, and there are no electrode terminals on the first housing wall.

3. The battery cell according to claim 2, wherein: Along the layer thickness direction, the housing cover faces the third housing wall. The housing includes a recess formed on the third housing wall and recessed along the layer thickness direction.

4. The battery cell according to claim 3, wherein: The electrode assembly includes tabs, and the tabs are electrically connected to the electrode terminals; Along the layer thickness direction, the recess at least partially overlaps with the tabs.

5. The battery cell according to claim 3 or 4, wherein: The electrode terminals are disposed on the housing cover, and along the layer thickness direction, the position of the recess corresponds to that of the electrode terminals.

6. The battery cell according to claim 5, wherein: The first housing wall is located on one side of the electrode assembly along a first direction, the second housing wall is located on one side of the electrode assembly along a second direction, the second direction is perpendicular to the first direction and perpendicular to the layer thickness direction. Along the second direction, the electrode terminals are disposed adjacent to the end of the housing cover.

7. The battery cell according to any one of claims 1 to 4, wherein: The housing cover is welded to the housing body, and a weld seam is formed at the edge of the opening.

8. The battery cell according to any one of claims 1 to 4, wherein: A plurality of the explosion-proof valves are spaced apart on the first housing wall.

9. A battery device, characterized in that, Comprising: A box body; A plurality of battery cells disposed in the box body, and the battery cells are the battery cells according to any one of claims 1 to 8.

10. The battery device according to claim 9, characterized in that, The battery device further includes: At least one battery cell bracket disposed in the box body and located between the first housing wall and the box body. A through portion is formed on the battery cell bracket. Along the first direction, the projection of the through portion on the first housing wall at least partially coincides with the explosion-proof valve. The first direction is the same as the wall thickness direction of the first housing wall and the first direction is perpendicular to the layer thickness direction.

11. The battery device according to claim 10, wherein: Along the wall thickness direction of the first shell wall, the explosion-proof valve does not exceed the projection of the passing portion on the first shell wall.

12. The battery device according to claim 10 or 11, characterized in that: The explosion-proof valve is exposed through the through portion and directly faces the inner wall of the box.

13. The battery device according to claim 10 or 11, characterized in that: The battery further includes a smoke exhaust channel having a smoke exhaust port communicating with the outside of the battery, and the smoke exhaust channel is communicated with the through portion.

14. The battery device according to claim 10 or 11, characterized in that: The battery cell bracket is formed with a plurality of the through portions, and each of the explosion-proof valves at least partially overlaps with a projection of the through portion on the first housing wall.

15. The battery device according to claim 10 or 11, characterized in that: The plurality of battery cells are arranged along the layer thickness direction, The battery cell holder is provided corresponding to each of the battery cells; or the battery cell holder is constituted as an integral structural member, the battery cell holder is formed with a plurality of the through portions, and the explosion-proof valve of each of the battery cells at least partially overlaps with the projection of the through portion on the first shell wall.

16. The battery device according to claim 10 or 11, characterized in that: The battery cell bracket includes a heat conducting member and / or an insulating member.

17. The battery device according to claim 10 or 11, characterized in that: The plurality of battery cells are arranged along the layer thickness direction, and at least a portion of the electrode terminal of one of two adjacent battery cells is located in the recessed portion of the other battery cell.

18. The battery device according to claim 17, characterized in that The electrode terminals of at least two of the battery cells are connected via a transition piece, and the transition piece bypasses an end portion of the housing along a second direction, the second direction being perpendicular to the first direction and the layer thickness direction.

19. The battery device according to claim 18, wherein: The adapter includes a first bending portion, a second bending portion and a connecting portion located between the first bending portion and the second bending portion, the first bending portion and the second bending portion are respectively bent relative to the connecting portion to form a bending cavity, the end portion is at least partially located in the bending cavity, and the first bending portion and the second bending portion are respectively connected to the electrode terminals of two adjacent battery cells.

20. The battery device according to claim 10 or 11, characterized in that: The size of the explosion-proof valve along the second direction is L1, and the size of the explosion-proof valve along the layer thickness direction is H1. The dimension of the passage portion corresponding to the explosion-proof valve along the second direction is L2, and the dimension of the passage portion along the first direction is H2, 1 / 4H2≤H1≤1 / 2H2, 1 / 2L2≤L1≤3 / 4L2.

21. An electrical device, characterized in that, The electrical device includes the battery cell according to any one of claims 1 to 8 or the battery device according to any one of claims 9 to 20, and the battery device can supply electrical energy to the electrical device.

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