Battery device

Abstract

The invention belongs to the technical field of batteries, and discloses a battery device which comprises a bottom plate, a frame, a beam, a battery pack and an end plate. The frame is arranged on the bottom plate and forms an accommodating space with the bottom plate; the beams divide the accommodating space into a plurality of sub accommodating spaces; at least one sub-accommodating space is provided with a battery pack, the battery pack comprises a plurality of battery monomers which are stacked, and the height of the battery monomers is greater than that of the beams; end plates are arranged between the battery monomers at the end parts in the stacking direction of the battery monomers and the beams; the ratio of the height of the end plate to the height of the battery monomer is less than or equal to a, the value range of a is greater than or equal to 0.8 and less than or equal to 1.2, and the height range of the battery monomer is 50-300mm; the height of the beam is x mm, the thickness of the end plate is y mm, and x and y meet the relational expression that x * y is larger than or equal to 250 and smaller than or equal to 2280. The battery device provided by the invention has a relatively high space utilization rate, and the risk of lithium precipitation of the battery monomers is relatively low.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery device. Background Art

[0002] The battery device includes a frame and a battery pack arranged within the frame. A beam is provided within the frame, and an end plate is provided between the beam and the battery pack. The end plate is used to fix the battery pack. In order to avoid the functional components of the battery device, the height of the end plate is usually less than the height of the battery pack. In order to ensure the effect of fixing the battery pack, the thickness of the end plate needs to be set larger, resulting in a larger space occupied by the end plate and a lower space utilization rate of the battery device. In addition, when the beam is hit, the impact force is transmitted to the end plate, which will squeeze the battery pack, causing lithium deposition in the battery pack. Summary of the Invention

[0003] The purpose of this application is to provide a battery device to solve the technical problem in the prior art that lithium deposition is prone to occur in battery devices.

[0004] As conceived above, the technical solution adopted by the present invention is:

[0005] A battery device comprising:

[0006] base plate;

[0007] a frame, the frame being arranged on the bottom plate and forming a receiving space with the bottom plate;

[0008] A beam, wherein the beam divides the accommodation space into a plurality of sub-accommodation spaces;

[0009] a battery pack, wherein at least one of the sub-accommodation spaces is provided with the battery pack, the battery pack comprising a plurality of stacked battery cells, the height of the battery cells being greater than the height of the beam;

[0010] an end plate provided between the battery cells and the beam at the end portions of the battery cells in the stacking direction;

[0011] The ratio of the height of the end plate to the height of the battery cell is less than or equal to a, the value range of a is 0.8≤a≤1.2, and the height range of the battery cell is 50mm-300mm; the height of the beam is x mm, the thickness of the end plate is y mm, and x and y satisfy the relationship: 250≤x×y≤2280.

[0012] The above technical solution can achieve the following beneficial effects:

[0013] By controlling the value of a to fall within the above range and the values ​​of x×y to satisfy the above relationship, the end plates can ensure the strength of the battery pack, reducing the risk of the battery pack moving relative to the base plate. The risk of lithium plating in the battery cells can also be reduced, improving the overall structural strength and safety of the battery assembly. Furthermore, the battery assembly has high space utilization, thereby increasing the energy density of the battery assembly. If the value of a is too large, the end plates will be too high above the battery cells, affecting the connection between the battery cells and the current collector. If the value of x×y is too large, the end plates will be too thick, causing them to occupy a large space, reducing the space required for the battery pack and affecting the energy density of the battery assembly. If the beams are too high, the tops of the battery cells will deform due to the high stress, leading to lithium plating, which is detrimental to the safety performance of the battery assembly. If the value of x×y is too small, the end plates will be too thin, affecting the fixation of the battery pack. The beams will apply a large force to the battery cells at the ends through the end plates, increasing the risk of lithium plating in the battery cells. If the beam height is too small, the end plates will be too thin, affecting the fixation of the battery pack, and the beams will apply a large force to the battery cells at the ends through the end plates, increasing the risk of lithium plating in the battery cells. If the beam height is too small, the end plates will not be able to fix the battery pack, which in turn affects the fixation of the battery pack and the structural strength of the battery assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0015] Figure 1 is a schematic structural diagram of a battery device provided by an embodiment of the present invention without showing a battery pack;

[0016] Figure 2 is a cross-sectional view of a portion of the structure of a battery device provided by one embodiment of the present invention;

[0017] Figure 3 is a first structural schematic diagram of a battery pack provided by one embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of the assembly of a single cell and an end plate provided by one embodiment of the present invention;

[0019] Figure 5 is a side view of an end plate and a battery cell provided by one embodiment of the present invention;

[0020] Figure 6 is a cross-sectional view of a battery pack provided by one embodiment of the present invention;

[0021] Figure 7 This is an embodiment of the present invention Figure 6 The enlarged view of point A is shown;

[0022] Figure 8 This is a schematic diagram of the assembly of a battery cell and an end plate provided by one embodiment of the present invention;

[0023] Figure 9 2 is a second structural diagram of a battery pack provided in one embodiment of the present invention.

[0024] In the picture:

[0025] 1. Bottom plate; 2. Frame; 3. Beam; 4. Battery pack; 41. Battery cell; 5. End plate; 51. Reinforcement rib; 52. Inner wall; 53. Outer wall; 6. Buffer pad; 7. Insulation plate; 8. Side plate; 9. Connecting seat; 10. Accommodation space. DETAILED DESCRIPTION

[0026] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0027] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present invention. Therefore, appearances of "in one embodiment" or "in an embodiment" throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0029] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0030] In the present invention, unless otherwise clearly stipulated and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature. In the description of this embodiment, unless otherwise specified, "multiple" specifically refers to two or more.

[0031] In the description of this embodiment, terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate description and simplify operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used only to distinguish in the description and have no special meaning.

[0032] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or there may be an element located in the middle.

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0034] This embodiment provides a battery device that can achieve high space utilization and reduce the risk of lithium plating.

[0035] like Figures 1 to 9 As shown, the battery device includes a base plate 1, a frame 2, a beam 3, and a battery pack 4. The frame 2 is disposed on the base plate 1 and cooperates with the base plate 1 to form a receiving space 10 for accommodating the battery pack 4. The beam 3 is located within the receiving space 10 and divides the receiving space 10 into multiple sub-receiving spaces (not shown).

[0036] Optionally, the bottom plate 1, frame 2, and beam 3 may form a box body (not shown in the figure), and the battery device may further include a box cover (not shown in the figure) connected to the box body. The box body and the box cover cooperate to form a relatively sealed space. Of course, it is understood that the battery device may not include a box cover, and this embodiment is not limited to this.

[0037] In this embodiment, the battery pack 4 is placed in at least one sub-accommodation space. That is, at least one sub-accommodation space is provided with a battery pack 4. For example, each sub-accommodation space is provided with a battery pack 4. Each battery pack 4 includes a plurality of stacked battery cells 41. The stacking direction of the battery cells 41 can be parallel to the plane of the base plate 1. For example, the stacking direction of the battery cells 41 can be the length direction of the frame 2 or the width direction of the frame 2, which is not limited in this embodiment.

[0038] In this embodiment, the battery cell 41 may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but this embodiment is not limited to this.

[0039] A battery cell 41 typically includes a housing (not shown), a battery cell (not shown), and an electrolyte (not shown). The housing is used to house the battery cell and electrolyte and is provided with at least one positive electrode post (not shown) and at least one negative electrode post (not shown). A battery cell includes one or more electrode assemblies, which are formed by stacking or winding positive and negative electrode sheets and separators.

[0040] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode post. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode post to form an electrical connection. Alternatively, the battery cell may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode post to form an electrical connection between the positive electrode tab and the positive electrode post.

[0041] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell may further include a negative electrode adapter sheet. The multiple stacked negative electrode tab sheets are welded to one end of the negative electrode adapter sheet, and the other end of the negative electrode adapter sheet is welded to the negative electrode column to form an electrical connection between the negative electrode tab sheet and the negative electrode column. The material of the separator is not limited, and can be, for example, polypropylene or polyethylene.

[0042] In this embodiment, each battery pack 4 includes battery cells 41 at two ends.

[0043] For example, Figure 2 As shown, the height of the battery cell 41 is greater than the height of the beam 3. The height of the battery cell 41 is perpendicular to the base plate 1, and the height of the beam 3 is perpendicular to the base plate 1. The height of the battery cell 41 is the same as the height of the beam 3. The height of the battery cell 41 is greater than the height of the beam 3. This ensures that the beam 3, while securing the battery cell 41, does not interfere with the electrical connection between the battery cell 41 and the current busbar (not shown), ensuring connection reliability. It should be noted that in this embodiment, the height of the battery cell 41 refers to the shoulder height of the battery cell 41, that is, the height of the battery cell 41 does not include the height of the terminal.

[0044] In some optional embodiments, the multiple battery cells 41 of the battery pack 4 can be electrically connected via a busbar component (e.g., a high- and low-voltage output component) to achieve parallel, series, or mixed connection of the multiple battery cells 41 in the battery pack 4. There can be one or more busbar components, each of which is used to electrically connect at least two battery cells 41.

[0045] In one embodiment, the height of the battery cell 41 ranges from 50 mm to 300 mm, for example, the height of the battery cell 41 is 50 mm, 60 mm, 80 mm, 100 mm, 120 mm, 150 mm, 180 mm, 200 mm, 220 mm, 240 mm, 250 mm, 280 mm, 300 mm, etc.

[0046] like Figure 1As shown, the battery device further includes an end plate 5, which is provided between the battery cells 41 at the end along the stacking direction of the battery cells 41 and the beam 3. The end plate 5 is used to cooperate with the side plate 8 or the cable tie to fix the battery pack 4 to form a module, thereby improving the structural strength of the battery pack 4. The material of the end plate 5 can be a metal material such as aluminum alloy, stainless steel, etc., and can also be made of high-strength plastic, which is not limited in this embodiment. In one embodiment, as Figure 3 As shown, the end plate 5 and the side plate 8 cooperate with each other to fix the battery pack 4.

[0047] In at least one embodiment, the ratio of the height of the end plate 5 to the height of the battery cell 41 is less than or equal to a, where a is in the range of 0.8 ≤ a ≤ 1.2. Based on the value of a, the height of the end plate 5 can be greater than or less than the height of the battery cell 41. For example, the value of a can be 0.8, 0.9, 0.95, 1, 1.1, 1.15, 1.2, etc.

[0048] In this embodiment, the height of the beam 3 is x mm, the thickness of the end plate 5 is y mm, and x and y satisfy the relationship: 250≤x×y≤2280, that is, the product of x and y is greater than or equal to 250 and less than or equal to 2280. For example, the value of x×y can be: 250, 260, 270, 280, 300, 350, 380, 400, 420, 450, 480, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2280, etc.

[0049] The battery device provided in this embodiment, by controlling the value of a to satisfy the above range, and when the value of x×y satisfies the above relationship, can not only ensure the strength of the end plate 5 in fixing the battery pack 4 and reduce the risk of the battery pack 4 moving relative to the base plate 1, but also reduce the risk of lithium plating in the battery cell 41, thereby improving the overall structural strength and safety of the battery device. In addition, the battery device has a high space utilization rate, thereby improving the energy density of the battery device. If the value of a is too large, it means that the end plate 5 is too high above the battery cell 41, which will affect the connection between the battery cell 41 and the busbar. If the value of x×y is too large, the thickness of the end plate 5 is too large, causing the end plate 5 to occupy a larger space, thereby reducing the space for setting the battery pack 4 and affecting the energy density of the battery device. When the beam 3 is too high, the top of the battery cell 41 will be deformed due to the large stress, and lithium plating will occur, which is not conducive to the safety performance of the battery device. If the value of x×y is too small, the thickness of the end plate 5 will be too thin, which will affect the fixation of the battery pack 4, and the beam 3 will apply a large force to the battery cell 41 located at the end through the end plate 5, and the risk of lithium deposition in the battery cell 41 will be higher; if the height of the beam 3 is too small, it will affect the fixation effect of the end plate 5, and then affect the fixation effect of the battery pack 4, and then affect the structural strength of the battery device.

[0050] In at least one embodiment, the ratio of the height of the beam 3 to the height of the end plate 5 is b, with b ranging from 0.5 to 1. Thus, in this embodiment, the height of the beam 3 is less than or equal to the height of the end plate 5. When b falls within the range of 0.5 to 1, the beam 3 provides better support for the end plate 5, thereby enhancing the end plate 5's ability to secure the battery cells 41. This prevents cracking or excessive swelling of the battery cell housing 41 due to expansion of the battery cells 41, reduces the risk of damage to the battery cells 41, and ensures the safety of the battery device.

[0051] The value of b cannot be too large. If it is too large, the height of the beam 3 will be greater than the height of the end plate 5, while the height of the battery cell 41 will be greater than the height of the beam 3. As a result, the height of the end plate 5 will be significantly smaller than the height of the battery cell 41, reducing the contact area between the end plate 5 and the battery cell 41 at the end, thereby reducing the strength of the end plate 5 in securing the battery pack 4. The value of b cannot be too small. If it is too small, the height of the beam 3 will be significantly smaller than the height of the end plate 5, which will affect the support effect of the beam 3 on the end plate 5 and the fixing strength of the battery pack 4. For example, the value of b is 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0052] In at least one embodiment, the height of the battery cell 41 ranges from 80 mm to 200 mm.

[0053] In one embodiment, when the height of the battery cell 41 ranges from 80 mm to 200 mm, x and y satisfy the relationship: 400 ≤ x × y ≤ 2280. When the height of the battery cell 41 ranges from 80 mm to 200 mm, x × y being greater than or equal to 400 and less than or equal to 2280 ensures that the battery device has high energy density and space utilization while also reducing the risk of lithium plating in the battery cell 41. This ensures that the battery device as a whole meets the requirements of structural strength, high energy density, and high safety.

[0054] In one embodiment, the thickness of the end plate 5 ranges from 1mm to 20mm. When the thickness of the end plate 5 is within the range, the end plate 5 can better fix the battery pack 4 and reduce the risk of the battery pack 4 moving relative to the base plate 1. In addition, the space occupied by the end plate 5 is small, so that the battery device has a higher space utilization rate and energy density. In addition, the risk of the battery cell 41 being squeezed by the end plate 5 and causing lithium deposition in the battery cell 41 is also greatly reduced. Furthermore, when the thickness of the end plate 5 is within the range, it is also convenient to install the high and low voltage output components of the battery device. For example, the thickness of the end plate 5 is 1mm, 3mm, 5mm, 7mm, 9mm, 10mm, 12mm, 14mm, 16mm, 18mm, 19mm, 20mm, etc.

[0055] In at least one embodiment, the height of the beam 3 ranges from 40 mm to 290 mm. When the height of the beam 3 is within this range, the beam 3 can better support the end plate 5 and reduce the risk of lithium deposition in the battery cells 41. For example, the height of the beam 3 is 40 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, etc.

[0056] In at least one embodiment, the thickness of the beam 3 in the stacking direction of the battery cells 41 ranges from 10mm to 100mm. In this embodiment, the beam 3 in the stacking direction of the battery cells 41 can be called a crossbeam, that is, the thickness of the crossbeam ranges from 10mm to 100mm. When the thickness of the crossbeam meets the value range, the structural strength of the crossbeam is high and it is not easy to deform in the event of a collision, so it can better support the end plate 5, so that the end plate 5 has a higher fixing strength for the battery pack 4, preventing the battery cell 41 from expanding and deforming, thereby reducing the risk of cracking of the weld of the battery cell 41, thereby reducing the risk of lithium plating of the battery cell 41 and improving the structural strength and safety of the battery device.

[0057] The crossbeam should not be too thick, as it will occupy more space in the accommodating space 10, which is not conducive to improving the energy density of the battery device. The crossbeam should not be too thin, as it will not provide sufficient support for the end plate 5, which will easily cause the welds of the battery cells 41 to crack. For example, the thickness of the crossbeam ranges from 10 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, and 100 mm.

[0058] In at least one embodiment, Figure 8 As shown, the end plate 5 is provided with a reinforcing rib 51, and the end plate 5 includes an inner wall 52 in contact with the battery pack 4. The reinforcing rib 51 is provided on the side of the inner wall 52 of the end plate 5 facing away from the battery pack 4. The reinforcing rib 51 is used to improve the structural strength of the end plate 5, reduce the risk of deformation of the end plate 5 due to the squeezing of the beam 3, and better fix the battery pack 4. By arranging the reinforcing rib 51 on the side of the end plate 5 facing away from the battery pack 4, the reinforcing rib 51 will not directly contact the battery pack 4. The battery pack 4 contacts the plate-shaped end plate 5 to have a larger contact area, thereby improving the uniformity of the end plate 5 when fixing the battery pack 4. Since the end plate 5 is provided with the reinforcing rib 51, the thickness of the end plate 5 can be appropriately reduced, so that the space occupied by the end plate 5 is reduced. On the basis of ensuring that the fixing effect on the battery pack 4 remains unchanged, the energy density of the battery device can be further improved.

[0059] In one embodiment, when the end plate 5 is provided with reinforcing ribs 51, x and y satisfy the relationship: 250≤x×y≤2000. When the value of x×y is within the range, the overall structural strength and safety of the battery device are improved.

[0060] In at least one embodiment, Figure 8 As shown, the inner wall 52 of the end plate 5 contacts the battery cell 41 located at the end. The end plate 5 may also include an outer wall 53 arranged opposite the inner wall 52 in the stacking direction of the battery cell 41. The reinforcing ribs 51 may be connected between the inner wall 52 and the outer wall 53, so that the reinforcing ribs 51 can separate the space between the inner wall 52 and the outer wall 53 to form multiple energy absorption areas (not shown). The energy absorption areas can absorb the extrusion force transmitted to the end plate 5 by the beam 3, so that the force applied by the end plate 5 on the battery cell 41 is small, further reducing the risk of lithium deposition in the battery cell 41. It is understandable that the end plate 5 may also include a side wall (not shown) connected between the inner wall 52 and the outer wall 53, which is not limited in this embodiment.

[0061] In one embodiment, the reinforcing rib 51 is plate-shaped and tilted between the inner wall 52 and the outer wall 53 to provide a higher support and reinforcement effect. Of course, it is understandable that the reinforcing rib 51 can also be strip-shaped, which is not limited in this embodiment.

[0062] In one embodiment, the ratio of the length of the reinforcing rib 51 in the height direction of the end plate 5 to the height of the end plate 5 is in the range of 0.6-0.9. When the ratio of the length of the reinforcing rib 51 in the height direction of the end plate 5 to the height of the end plate 5 meets the value range, the length of the reinforcing rib 51 in the height direction of the end plate 5 is neither too large nor too small, so that the reinforcing rib 51 can increase the structural strength of the end plate 5, thereby ensuring that the end plate 5 is effective in fixing the battery pack 4.

[0063] The ratio of the length of the reinforcing rib 51 in the height direction of the end plate 5 to the height of the end plate 5 cannot be too small. If it is too small, a weak area will appear at the top or bottom of the end plate 5, which will affect the effectiveness of fixing the battery pack 4. If a weak area appears at the top of the end plate 5, it will also increase the risk of squeezing the battery cells 41 and causing lithium deposition in the battery cells 41. For example, the ratio of the length of the reinforcing rib 51 in the height direction of the end plate 5 to the height of the end plate 5 is 0.6, 0.7, 0.8, 0.9, etc.

[0064] In at least one embodiment, Figure 4 As shown, the battery pack 4 further includes a buffer pad 6. The buffer pad 6 is located between two adjacent battery cells 41 and is used to buffer the force between the two battery cells 41, thereby improving the vibration resistance of the battery pack 4. The buffer pad 6 can also have a heat insulation function to reduce the thermal interference of one battery cell 41 on another battery cell 41.

[0065] It should be noted that the cushion pad 6 is typically positioned between the larger surfaces of two battery cells 41. In one embodiment, the area of ​​the cushion pad 6 can be equal to the larger surface area of ​​the battery cells 41, so that the force exerted by the cushion pad 6 on the battery cells 41 is relatively uniform. In other embodiments, the area of ​​the cushion pad 6 can be smaller than the larger surface area of ​​the battery cells 41, and this embodiment is not limited thereto.

[0066] Optionally, the material of the buffer pad 6 may include aerogel, silica gel, polyurethane and the like, which is not limited in this embodiment.

[0067] In one embodiment, when a buffer pad 6 is provided between two battery cells 41, x and y satisfy the relationship: 250 ≤ x × y ≤ 1800. By providing the buffer pad 6, when a battery cell 41 expands, it can squeeze the buffer pad 6 located between the two battery cells 41, thereby reducing the force exerted by the battery cell 41 on the end plate 5. Therefore, when x × y satisfies the relationship, it can ensure a good fixation effect on the battery pack 4. Furthermore, when the end plate 5 squeezes the battery cell 41 located at the end, it can be cushioned by the buffer pad 6, thereby reducing the risk of cracking or excessive swelling of the battery cell 41 shell.

[0068] In at least one embodiment, a buffer pad 6 is provided between any two adjacent battery cells 41. With this arrangement, the buffer pad 6 provides a buffer between any two adjacent battery cells 41, thereby reducing the risk of the housing of each battery cell 41 cracking due to compression, thereby reducing the risk of lithium deposition in each battery cell 41 and improving the safety performance of the battery device.

[0069] In some embodiments, the thickness of the buffer pad 6 ranges from 1 mm to 6 mm. When the thickness of the buffer pad 6 is within this range, the buffer pad 6 can achieve a cushioning effect. Furthermore, the buffer pad 6 does not occupy too much space in the accommodation space 10, so that the accommodation space 10 has more space for the battery cells 41, thereby ensuring the space utilization and energy density of the battery device.

[0070] The thickness of the cushion pad 6 cannot be too small, as this will affect the cushioning effect and increase the risk of cracking between adjacent battery cells 41 due to compression. The thickness of the cushion pad 6 cannot be too large, as this will reduce the energy density of the battery device. For example, the thickness of the cushion pad 6 is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, etc.

[0071] In at least one embodiment, Figure 6 and Figure 7 As shown, the battery pack 4 also includes an insulating plate 7. The insulating plate 7 is disposed between the end plate 5 and the battery cells 41 at the ends of the battery pack 4. That is, an insulating plate 7 is provided between each battery cell 41 at the end and the end plate 5. The insulating plate 7 insulates the battery cells 41 at the end from the end plate 5, reducing the risk of short circuits between the battery pack 4 and the end plate 5. The insulating plate 7 also transfers force between the end plate 5 and the battery cells 41 at the end.

[0072] In one embodiment, the area of ​​the large surface of the insulating plate 7 is larger than the area of ​​the large surface of the end plate 5, that is, the insulating plate 7 has a portion extending beyond the end plate 5, and the portion of the insulating plate 7 extending beyond the end plate 5 can also contact the battery cell 41 located at the end, so that the setting of the insulating plate 7 can increase the force-bearing area of ​​the battery cell 41 at the end, and thus enable the insulating plate 7 to assist the end plate 5 in restraining the battery cell 41 at the end, preventing the shell of the battery cell 41 at the end from extending beyond the top of the end plate 5 and causing the weld to crack, thereby reducing the risk of lithium plating.

[0073] Of course, it is understandable that the area of ​​the large surface of the insulating plate 7 may also be smaller than or equal to the area of ​​the large surface of the end plate 5 , and this embodiment does not limit this.

[0074] Optionally, the insulating plate 7 is made of an insulating material, such as polypropylene, polyimide, or polyester amide.

[0075] In some optional embodiments, the thickness of the insulating plate 7 ranges from 0.5 mm to 3 mm. When the thickness of the insulating plate 7 is within this range, the insulating effect of the insulating plate 7 is ensured. Furthermore, the insulating plate 7 provides a certain structural strength to restrain the portion of the battery cells 41 at the end that protrudes beyond the end plate 5, thereby reducing the risk of weld cracking in the battery cells 41 at the end. Furthermore, the insulating plate 7 occupies a relatively small space, meeting the high energy density requirements of the battery device.

[0076] For example, the thickness of the insulating plate 7 is 0.5 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.8 mm, 3 mm, or the like.

[0077] In one embodiment, the positive electrode plate of the battery cell 41 includes a positive current collector and a positive active material layer disposed on the positive current collector. The positive active material layer is made of lithium nickel cobalt manganese oxide, and x and y satisfy the relationship: 600 ≤ x × y ≤ 2280. During the cyclic charge and discharge process of the battery cell 41, the lithium nickel cobalt manganese oxide active material in the positive electrode plate will undergo significant volume expansion. When x and y satisfy the relationship, the strength of the beam 3 and the end plate 5 securing the battery pack 4 can be ensured, thereby suppressing excessive expansion of the battery cell 41, avoiding weld cracking caused by excessive expansion of the battery cell 41, and improving the structural strength and safety performance of the battery device.

[0078] In at least one embodiment, Figure 9 As shown, the battery pack 4 also includes a connector 9. This connector 9 is located on top of the end plate 5 and is used to input and output electrical energy from the battery pack 4. For example, the connector 9 may be a high- and low-voltage connector. The end plate 5 in this embodiment not only secures the battery pack 4 but also provides a mounting for the connector 9, providing a wide range of functions.

[0079] The battery device provided in this embodiment has high structural strength, reduces the risk of cracking of the welds of the battery cells 41 due to extrusion, has high safety performance, and has high energy density.

[0080] This embodiment uses a battery strength test and a battery temperature rise test to test the structural strength and temperature rise of the battery pack 4 .

[0081] Battery strength test: During the test, different a values ​​and different x×y values ​​are given, and the structural strength of the battery pack 4 is tested to see if it is qualified when the a value and x×y value are different. The a value between 0.8-1.2 and the x×y value between 250-2280 are called embodiments, as shown in Table 1, 21 embodiments are given. The a value outside 0.8-1.2 and the x×y value outside 250-2280 are called comparative examples, and 4 comparative examples are given. For each embodiment and each comparative example, 300 battery cells 41 of the same model are taken, of which 10 battery cells 41 are grouped together, and fixed with end plates 5 and side plates 8 to form a battery pack 4, forming a total of 30 groups of battery packs 4. The battery pack 4 is placed on the bottom plate 1, and a beam 3 is set on the side of the end plate 5 away from the battery cell 41 to be fixed to the bottom plate 1. The ratio of the height of the end plate 5 to the height of the battery cell 41 is a, the height of the beam 3 is x mm, and the thickness of the end plate 5 is y mm. The specific values ​​are shown in Table 1. The embodiment and comparative example are identical except for a and x×y. The battery assembly was discharged at 0.33C to 0% SOC, then charged at 1C to 100% SOC. After 10 minutes of rest, the assembly was discharged again at 1C to 0% SOC and allowed to rest for 10 minutes. After 200 cycles of this 1C charge and 1C discharge cycle, the battery cells 41 in each battery pack 4 were observed for cracking, damage, and bulging (bulges greater than 3 mm in height were considered present). If more than one (i.e., two or more) of the 30 battery packs 4 exhibited these defects, the battery pack was deemed unqualified. If less than one battery pack 4 exhibited these defects, the battery pack was deemed acceptable.

[0082] Battery temperature rise test: During the test, different a values ​​and different x×y values ​​are given, and the temperature rise rate of the battery pack 4 is tested when the a value and x×y value are different. The a value between 0.8-1.2 and the x×y value between 250-2280 are called embodiments. As shown in Table 1, 21 embodiments are given. The a value outside 0.8-1.2 and the x×y value outside 250-2280 are called comparative examples, and 4 comparative examples are given. For each embodiment and each comparative example, 100 battery cells 41 of the same model are taken, of which 10 battery cells 41 are grouped together and fixed with end plates 5 and side plates 8 to form a battery pack 4. The battery pack 4 is placed on the bottom plate 1, and a beam 3 is set on the side of the end plate 5 away from the battery cell 41 to fix it to the bottom plate 1. The ratio of the height of the end plate 5 to the height of the battery cell 41 is a, the height of the beam 3 is x mm, and the thickness of the end plate 5 is y mm. The specific values ​​are shown in Table 1. The embodiment and comparative example are identical except for a and x×y. The battery assembly is discharged at 0.33C to 0% SOC. After standing for 60 minutes, the temperature at this point is measured and recorded as t1. The battery assembly is then charged at 1C to 100% SOC. The temperature at this point is recorded as t2, and the charging time is recorded as T. The temperature rise rate of each battery pack 4 is calculated using the formula: Temperature Rise Rate = (t2 - t1) / T. Ten calculations are performed and the average value is taken. If the temperature rise rate is greater than 1°C / min, the battery is considered unqualified. If the temperature rise rate is less than or equal to 1°C / min, the battery is considered qualified.

[0083] Table 1

[0084]

[0085] Comparing the experimental data from Examples 1-21 with Comparative Examples 1-4 reveals that when a is within the range and x and y satisfy the relationship, the temperature rise rate of the battery pack 4 is low, the fastening strength of the battery cells 41 in the battery pack 4 is strong, and the battery cells 41 do not crack or swell due to cyclic expansion. Comparing the experimental data from Examples 18-21 reveals that when x × y satisfy the formula, an excessively high beam 3 height can affect the installation of the current collector between adjacent battery packs 4. A low beam 3 height can reduce the overall strength of the battery assembly. An excessively high end plate 5 thickness can reduce the energy density of the battery assembly. A low end plate 5 thickness can impede the installation of the connectors 9 (e.g., high and low voltage output components) at the end of the battery pack 4.

[0086] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A battery device, characterized in that include: Bottom plate (1); A frame (2), the frame (2) being arranged on the bottom plate (1) and forming a receiving space (10) with the bottom plate (1); A beam (3), the beam (3) dividing the accommodation space (10) into a plurality of sub-accommodation spaces; A battery pack (4), wherein at least one of the sub-accommodation spaces is provided with the battery pack (4), the battery pack (4) comprising a plurality of stacked battery cells (41), the height of the battery cells (41) being greater than the height of the beam (3); an end plate (5) provided between the battery cell (41) and the beam (3) at an end portion along the stacking direction of the battery cell (41); The ratio of the height of the end plate (5) to the height of the battery cell (41) is less than or equal to a, the value range of a is 0.8≤a≤1.2, and the height range of the battery cell (41) is 50mm-300mm; the height of the beam (3) is x millimeters, the thickness of the end plate (5) is y millimeters, and x and y satisfy the relationship: 250≤x×y≤2280.

2. The battery device according to claim 1, wherein: The ratio of the height of the beam (3) to the height of the end plate (5) is b, and the value range of b is 0.5-1.

3. The battery device according to claim 1, wherein: The height of the battery cell (41) ranges from 80 mm to 200 mm, and x and y satisfy the relationship: 400≤x×y≤2280.

4. The battery device according to claim 1, wherein: The thickness of the beam (3) in the stacking direction of the battery cells (41) ranges from 10 mm to 100 mm.

5. The battery device according to claim 1, wherein: The end plate (5) is provided with a reinforcing rib (51), the end plate (5) includes an inner wall (52) in contact with the battery pack (4), the reinforcing rib (51) is provided on a side of the inner wall (52) facing away from the battery pack (4), and x and y satisfy the relationship: 250≤x×y≤2000.

6. The battery device according to claim 5, characterized in that The ratio of the length of the reinforcing rib (51) in the height direction of the end plate (5) to the height of the end plate (5) is in the range of 0.6-0.

9.

7. The battery device according to claim 1, wherein: The battery pack (4) further comprises a buffer pad (6), wherein the buffer pad (6) is located between two adjacent battery cells (41), and x and y satisfy the relationship: 250≤x×y≤1800.

8. The battery device according to claim 7, characterized in that The buffer pad (6) is provided between any two adjacent battery cells (41).

9. The battery device according to claim 7, wherein: The thickness of the buffer pad (6) ranges from 1 mm to 6 mm.

10. The battery device according to claim 1, wherein: The positive electrode plate of the battery cell (41) comprises a positive electrode current collector and a positive electrode active material layer provided on the positive electrode current collector. The material of the positive electrode active material layer is lithium nickel cobalt manganese oxide, and x and y satisfy the relationship: 600≤x×y≤2280.

11. The battery device according to claim 1, wherein: The battery pack (4) further comprises an insulating plate (7), wherein the insulating plate (7) is arranged between the end plate (5) and the battery cell (41) at the end of the battery pack (4).

12. The battery device according to claim 11, wherein: The thickness of the insulating plate (7) ranges from 0.5 mm to 3 mm.

13. The battery device according to claim 1, wherein: The thickness of the end plate (5) is in the range of 1 mm to 20 mm; and / or the height of the beam (3) is in the range of 40 mm to 290 mm.

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