Battery cell module and battery pack

Abstract

The application relates to the technical field of batteries and discloses a battery cell module and a battery pack, which comprise: a plurality of soft package battery cells arranged along the X direction of the battery cell module, and an end plate located on the outer side of the plurality of soft package battery cells along the X direction; the end plate comprises a plate body and a plurality of hollow grooves located on the plate body, the plurality of hollow grooves are recessed inward from the inner side of the plate body; the outer side of the plate body is an outward convex arc surface, and the arc surface and the two ends of the inner side are connected through side surfaces respectively; the plate body is provided with a transverse reinforcing rib and a longitudinal reinforcing rib which are arranged in a cross mode and divide the plate body into a plurality of hollow regions, each hollow region is provided with a plurality of inclined ribs, and the plurality of inclined ribs intersect to enclose a plurality of hollow grooves. Through cooperation of the transverse reinforcing rib, the longitudinal reinforcing rib and the inclined rib, the overall flatness and the torsional resistance of the end plate can be improved, so that the load-bearing capacity of the end plate is ensured. By arranging the plurality of hollow grooves on the plate body, the material consumption of the overall end plate can be reduced, the weight of the end plate is reduced, and the energy density of the battery module is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a cell module and a battery pack. Background Technology

[0002] As an important type of lithium-ion battery, pouch cells have the following key advantages: pouch cells are packaged with aluminum-plastic film, which makes them lighter than steel or aluminum-cased batteries, while also having higher volumetric and gravimetric energy densities, which helps improve the driving range of electric vehicles and the efficiency of portable devices; in the event of safety issues such as thermal runaway, pouch cells usually bulge rather than explode, effectively reducing the risk of accidents and giving users more reaction time.

[0003] In the battery cell module, the module end plate can provide stable structural support for the battery cell module, effectively resist the superimposed expansion force generated by the soft-pack battery cell during the charge and discharge cycle, and prevent the module from deforming; and when the vehicle encounters extreme working conditions such as vibration, impact or extrusion, the end plate can protect the soft-pack battery cell and connector inside the module.

[0004] In related technologies, the end plate structure has low rigidity. During battery pack compression tests, the module end plate is prone to breakage, which can puncture the pouch cells and lead to internal or external short circuits, insulation failure, or leakage from the pouch cells, affecting the safety of the battery pack. Moreover, during daily use, the expansion force of the pouch cells can cause the end plate to break and fail, affecting the cycle life of the battery pack. Summary of the Invention

[0005] In view of this, the present invention provides a cell module and a battery pack to solve the problems of battery pack compression, expansion force, and end plate breakage caused by low end plate stiffness, resulting in short circuits or leakage of soft-pack cells.

[0006] In a first aspect, the present invention provides a battery cell module, comprising: Multiple pouch cells are arranged along the X direction of the cell module; An end plate, along the X direction, is located on the outer sides of both ends of the plurality of pouch cells; the end plate includes a plate body and a plurality of hollowed-out grooves on the plate body, the plate body has an inner side surface near the pouch cell and an outer side surface opposite to the inner side surface, the plurality of hollowed-out grooves are recessed inward from the inner side surface along the X direction; the outer side surface is a convex arc surface, along the Y direction, the arc surface is connected to both ends of the inner side surface through side surfaces respectively; The plate is provided with transverse reinforcing ribs extending along the Y direction and longitudinal reinforcing ribs extending along the Z direction. The transverse reinforcing ribs and the longitudinal reinforcing ribs are intersected and divide the plate into multiple hollow areas. Each hollow area is provided with several oblique ribs, and the several oblique ribs intersect to form several hollow grooves.

[0007] Beneficial effects: By setting several perforated grooves on the plate, with the grooves recessed inward along the X-direction from the inner side of the end plate, material in low-stress areas can be removed while ensuring the load-bearing capacity of the plate. This effectively reduces the overall material usage of the end plate, thus lowering its weight. Furthermore, ensuring the perforated grooves only extend from the inner side of the plate maintains the integrity and continuity of the outer curved surface, preserving the mechanical integrity of the arched structure. This results in a more uniform stress distribution and reduces the risk of stress concentration at weak points in the middle of the end plate.

[0008] Furthermore, by incorporating transverse reinforcing ribs extending along the Y direction and longitudinal reinforcing ribs extending along the Z direction on the plate, the entire end plate is divided into multiple rectangular hollow areas. These intersecting reinforcing ribs construct the overall rigidity framework of the end plate, resisting bending deformation in both the Z and Y directions, ensuring flatness and torsional resistance across the entire size range, thus guaranteeing the overall rigidity of the end plate. Within each rectangular hollow area, several diagonal ribs are provided; these ribs intersect to form multiple independent hollow slots within the hollow area. The diagonal ribs within the hollow areas not only supplement the local load-bearing capacity of the end plate and disperse load components in multiple directions, preventing edge deformation of the rectangular hollow areas, but also, by enclosing the hollow slots, remove material from areas with low stress levels, concentrating material at high-load-bearing rib locations. This ensures the overall rigidity of the end plate while reducing the overall material usage and increasing the energy density of the battery module. It effectively reduces the risk of end plate cracking and fracture under impact load, improves the impact resistance reliability of the structure, and effectively reduces the risk of battery pack compression, expansion force and end plate fracture during daily use caused by low end plate stiffness, resulting in battery pack short circuit or leakage of soft pack cells.

[0009] In some optional embodiments, along the Y direction, the length of the pouch cell is L1 and the length of the end plate is L2, satisfying 1.2L1≤L2≤1.3L1; along the Z direction, the width of the pouch cell is W1 and the width of the end plate is W2, satisfying 1.05W1≤W2≤1.1W1. Along the Y direction, at the longitudinal stiffener, the height H1 of the plate along the X direction satisfies 0.12L2≤H1≤0.18L2; on the side of the plate away from the longitudinal stiffener, the thickness H2 of the plate along the X direction satisfies 0.6H1≤H2≤0.8H1.

[0010] Beneficial effects: By rationally setting the length and width of the end plate, space can be reserved for the tabs of the soft-pack battery cells and the installation space for the side structural components, ensuring that the adhesive layer and buffer material cover the end face of the soft-pack battery cells, while preventing glue and foam from overflowing onto the outside of the end plate. By rationally setting the ratio of the height to the length of the end plate, as well as the thickness of the side of the plate away from the middle, the amount of material used in the end plate can be effectively reduced; moreover, the smooth thickness transition from the end plate end to the middle makes the overall stress distribution of the end plate more uniform, avoiding stress concentration fracture in the middle and reducing the risk of failure due to excessive thinness at the end.

[0011] In some optional embodiments, the sidewall thickness of the plate along the X direction is T1, which satisfies 3mm≤T1≤4mm; the thickness of the transverse stiffener is T2, which satisfies 2T1≤T2≤3T1.

[0012] Beneficial effects: By rationally setting the sidewall thickness along the X-direction of the plate, the overall structural strength of the end plate can be effectively increased, enhancing its load-bearing capacity. This also avoids increasing the overall weight of the end plate due to excessively thick sidewalls, reducing the space occupied by the end plate for the pouch cells and thus improving the volumetric energy density of the cell module. By rationally setting the width of the transverse reinforcing ribs, the concentrated load at the edges is evenly distributed to the overall structure of the end plate, reducing local stress peaks. Under the long-term cyclic alternating expansion force of the pouch cells, this effectively reduces the formation of fatigue cracks and significantly increases the service life of the end plate.

[0013] In some optional embodiments, within the hollowed-out area, the oblique ribs include a first oblique rib, a second oblique rib, and a third oblique rib in the YZ plane. The distance W3 between the first oblique rib and the second oblique rib satisfies 0.06L2≤W3≤0.08L2; the distance W4 between the second oblique rib and the third oblique rib satisfies 0.08L2≤W4≤0.1L2.

[0014] Beneficial effects: By rationally setting the distances between the first, second, and third inclined ribs, the density of the inclined ribs can be appropriately determined, thus allowing for the optimal size of the perforated grooves within the perforated area. This helps to minimize the overall material usage of the end plate while ensuring its load-bearing capacity, thereby reducing its overall weight. Simultaneously, when the end plate is subjected to expansion forces or external compressive forces, the force can be evenly distributed across the end plate, improving the overall load-bearing uniformity of the perforated area without increasing the total weight of the end plate, achieving a balance between end plate rigidity and lightweight design.

[0015] In some optional embodiments, the oblique ribs further include a fourth oblique rib, a fifth oblique rib, and a sixth oblique rib in the YZ plane. The hollow groove formed by the second oblique rib, the third oblique rib, the fifth oblique rib, and the sixth oblique rib is provided with a cross reinforcing rib, and the ends of the cross reinforcing ribs are respectively connected to the intersection of the oblique ribs.

[0016] Beneficial effects: By setting cross-shaped reinforcing ribs, a single large-sized hollow groove can be divided into four triangular sub-regions, thereby improving the anti-bulging and anti-buckling capacity of the diagonal ribs. This effectively suppresses local deformation of the sidewall area under cyclic expansion loads and reduces the risk of rib tearing or end plate cracking due to local instability. Furthermore, by connecting the four ends of the cross-shaped reinforcing ribs to the intersection nodes of the diagonal ribs, the cross-shaped reinforcing ribs and the original diagonal rib skeleton form a continuous force transmission whole. This can evenly distribute irregular impact loads to the surrounding diagonal rib skeleton and disperse the concentrated stress at the intersection points in four directions, which is beneficial to improving the fatigue life of the end plate under long-term cyclic expansion.

[0017] In some optional embodiments, the included angle α formed by the intersection of two adjacent diagonal ribs satisfies 90°≤α≤150°; the thickness T3 of the diagonal rib satisfies 2.4mm≤T3≤3.2mm.

[0018] Beneficial effects: By rationally setting the included angle formed after the intersection of two adjacent diagonal ribs, several diagonal ribs can be intersected within the hollowed-out area, ensuring a sufficient number of intersection nodes within the hollowed-out area. This guarantees that the diagonal ribs have sufficient supporting stiffness and force transmission path, thereby improving the overall load-bearing capacity of the plate. By rationally setting the thickness of the diagonal ribs, the cross-sectional area of ​​the diagonal ribs can be increased, thereby enhancing their load-bearing capacity. This is beneficial for improving the overall structural strength of the end plate and reducing the overall material usage of the end plate, thus reducing its overall weight.

[0019] In some alternative embodiments, the connection between two adjacent diagonal ribs has a chamfer r1, the radius of which r1 satisfies r1≥1.5mm; The connection between the side surface and the arc surface is chamfered with a radius r2, and the radius of the chamfer r2 satisfies r2≥2mm.

[0020] Beneficial effects: By changing the corner at the connection between two diagonal ribs to a rounded corner with a radius greater than or equal to 1.5mm, the stress flow can smoothly transition along the arc, significantly reducing the peak stress at the diagonal rib connection. This significantly improves the fatigue reliability of the diagonal rib mesh under long-term alternating expansion, preventing rib failure from the node. By setting chamfers at the connection between the side and the arc surface and appropriately setting the radius of the chamfer, the rounded chamfers can smoothly transition stress through the arc surface, effectively reducing the peak stress at the corner, significantly improving the fatigue life of the end plate, and adapting to the alternating expansion load throughout the entire life cycle of the pouch cell.

[0021] In some optional embodiments, the plate body is further provided with annular reinforcing ribs, which are located in the middle of the plate body and are respectively connected to the transverse reinforcing ribs, the longitudinal reinforcing ribs and the diagonal ribs; The inner ring radius r3 of the annular reinforcing rib satisfies 10mm≤r3≤15mm, and the outer ring radius r4 of the annular reinforcing rib satisfies 1.5r3≤r4≤2r3.

[0022] Beneficial effects: By reasonably setting the inner and outer radii of the annular reinforcing ribs, the thickness of the annular reinforcing ribs can be ensured to meet the usage requirements, and the annular reinforcing ribs can be prevented from interfering with the layout space of the surrounding diagonal rib grid. This ensures the overall load-bearing capacity of the end plate, improves the stability of the overall structure of the end plate, and helps to reduce the overall weight of the end plate, making it easier to achieve lightweight design of the end plate.

[0023] In some alternative embodiments, the plate is symmetrically arranged with the transverse stiffeners and the longitudinal stiffeners as the center of symmetry in the YZ plane.

[0024] Beneficial effects: By symmetrically setting the plate with transverse and longitudinal reinforcing ribs as the center of symmetry, when the expansion force of the pouch cell is evenly applied to the inner side of the end plate, the pressure distribution of the end plate on the end face of the pouch cell is uniform, and there will be no situation of excessive pressure on one side and insufficient constraint on the other side. This can reduce the risk of local encapsulation failure or electrolyte leakage of the pouch cell due to uneven stress, while ensuring uniform expansion of the entire interface of the pouch cell and maintaining the stability of the cycle life of the pouch cell.

[0025] Secondly, the present invention also provides a battery pack, comprising: at least one cell module as described above.

[0026] Beneficial effects: Since the battery pack includes the aforementioned cell modules, it has the same effects as the cell modules, which will not be elaborated here. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a battery pack according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a soft-pack battery cell in a battery cell module according to an embodiment of the present invention; Figure 3 This is a front view of the inner side of the end plate of a battery cell module according to an embodiment of the present invention; Figure 4 for Figure 3 A diagram showing the markings on the mid-end plate; Figure 5 This is a top view schematic diagram of a battery cell module mid-end board according to an embodiment of the present invention; Figure 6 for Figure 5 Cross-sectional view along the middle AA; Figure 7 for Figure 6 A magnified view of part B in the image.

[0029] Explanation of reference numerals in the attached figures: 10. End plate; 100. Plate body; 101. Transverse reinforcing rib; 102. Longitudinal reinforcing rib; 110. Hollowed-out groove; 111. Cross reinforcing rib; 120. Inner side; 130. Curved surface; 140. Side; 150. Diagonal rib; 151. First diagonal rib; 152. Second diagonal rib; 153. Third diagonal rib; 154. Fourth diagonal rib; 155. Fifth diagonal rib; 156. Sixth diagonal rib; 160. Annular reinforcing rib; 170. Fixing hole; 20. Soft-pack battery cell; 30. Box body; 40. Cover plate. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] According to embodiments of the present invention, in one aspect, such as Figures 2 to 7As shown, a battery cell module is provided, including: a plurality of soft-pack battery cells arranged along the X direction of the battery cell module; an end plate 10 located on the outer side of both ends of the plurality of soft-pack battery cells along the X direction; the end plate 10 includes a plate body 100 and a plurality of hollow grooves 110 located on the plate body 100, the plate body 100 having an inner side surface 120 near the soft-pack battery cell side and an outer side surface opposite to the inner side surface 120, and the plurality of hollow grooves 110 being recessed inward from the inner side surface 120 along the X direction; The outer surface is a convex arc surface 130. Along the Y direction, the two ends of the arc surface 130 and the inner surface 120 are connected by the side surface 140 respectively. The plate body 100 is provided with transverse reinforcing ribs 101 extending along the Y direction and longitudinal reinforcing ribs 102 extending along the Z direction. The transverse reinforcing ribs 101 and longitudinal reinforcing ribs 102 are intersected and divide the plate body 100 into multiple hollow areas. Each hollow area is provided with several oblique ribs 150. The several oblique ribs 150 intersect to form several hollow grooves 110.

[0032] In this embodiment, the X direction is the length direction of the cell module, i.e., the arrangement direction of the pouch cells 20, and multiple pouch cells 20 are arranged sequentially along the X direction. The Y direction is the width direction of the cell module. The Z direction is the height direction of the cell module. An end plate 10 is arranged on the outermost side of the pouch cells along the X direction of the cell module to constrain the pouch cells 20 from both ends and withstand the expansion force and external extrusion force of the pouch cells 20. The end plate 10 includes a plate body 100, on which a plurality of hollow grooves 110 are provided.

[0033] Along the X direction, the flat surface of the end plate 10 closest to the soft-pack battery cell 20 is the inner surface 120, and the side wall containing the inner surface 120 is the inner wall. The inner wall is in contact with the large surface of the soft-pack battery cell 20 to transmit expansion force. The side of the end plate 10 facing away from the soft-pack battery cell 20 is the outer surface, and the side wall containing the outer edge is the outer wall. The outer surface is an arc surface 130 that gradually convexes outward from both ends in the Y direction towards the middle of the plate body 100. That is, the thickness of the plate body 100 gradually increases in the direction extending from the two sides 140 of the plate body 100 towards the middle of the plate body 100. When the expansion of the soft-pack battery cell 20 exerts an outward thrust on the inner surface 120, or when external compression exerts an inward pressure on the arc surface 130, the arched structure will convert the load perpendicular to the plate surface into stress along the tangent direction of the arc surface 130, so that under the same weight or the same material, the load-bearing capacity of the arched end plate is higher than that of the flat end plate.

[0034] Furthermore, the perforated groove 110 is recessed inward along the X direction from the inner side 120 of the end plate 10. This allows for the removal of material from low-stress areas while maintaining the load-bearing capacity of the plate 100, effectively reducing the overall material usage of the end plate 10, thereby lowering its weight and increasing the energy density of the battery module. Simultaneously, by ensuring that the perforated groove 110 only recesses from the inner side 120 of the plate 100, the outer arc surface 130 of the plate 100 remains intact and continuous, preserving the mechanical integrity of the arched structure, resulting in a more uniform stress distribution and reducing the risk of stress concentration at weak points in the middle of the end plate 10.

[0035] Furthermore, the plate 100 is provided with transverse reinforcing ribs 101 extending along the Y direction and longitudinal reinforcing ribs 102 extending along the Z direction. The transverse reinforcing ribs 101 and longitudinal reinforcing ribs 102 intersect each other perpendicularly, dividing the entire end plate 10 into multiple rectangular hollow areas. The intersecting reinforcing ribs form the overall rigidity frame of the end plate 10, which can resist bending deformation in the Z and Y directions respectively, ensuring the flatness and torsional resistance of the end plate 10 throughout its entire size range, thereby ensuring the overall rigidity of the end plate 10.

[0036] Within each rectangular hollow area, several diagonal ribs 150 are provided; these ribs intersect to form multiple independent hollow grooves 110 within the hollow area. The diagonal ribs 150 within the hollow area not only supplement the local load-bearing capacity of the end plate 10 and disperse load components from multiple directions, preventing edge deformation of the rectangular hollow area, but also, by enclosing the hollow grooves 110, remove material from areas with low stress levels and concentrate material at high-load-bearing rib positions. This ensures the overall rigidity of the end plate 10 while reducing the overall material usage. This effectively reduces the risk of cracks and fractures in the end plate 10 under impact loads, improves the impact resistance reliability of the structure, and effectively reduces the risks of battery pack compression and expansion forces due to insufficient rigidity of the end plate 10, as well as the risk of short circuits or leakage of the pouch cells 20 caused by breakage of the end plate 10 during daily use.

[0037] In one embodiment, along the Y direction, the length of the pouch cell is L1, and the length of the end plate 10 is L2, satisfying 1.2L1≤L2≤1.3L1; along the Z direction, the width of the pouch cell is W1, and the width of the end plate 10 is W2, satisfying 1.05W1≤W2≤1.1W1; along the Y direction, at the longitudinal reinforcing rib 102, the height H1 of the plate 100 along the X direction satisfies 0.12L2≤H1≤0.18L2; on the side of the plate 100 away from the longitudinal reinforcing rib 102, the thickness of the plate 100 along the X direction is H2, satisfying 0.6H1≤H2≤0.8H1.

[0038] In this embodiment, along the Y direction, the length L1 of the pouch cell 20 is the long side dimension of the large surface of the pouch cell 20, and it is in the same direction as the length direction of the end plate 10 itself. The positive and negative tabs of the pouch cell 20 are led out from the two sides along the length direction. Along the Z direction, the width of the pouch cell 20 is the short side dimension of the large surface of the pouch cell 20, and it is in the same direction as the width direction of the end plate 10 itself. Along the Y direction, the length L2 of the end plate 10 is the length dimension of the end plate 10 itself. Along the Z direction, the width W2 of the end plate 10 is the width dimension of the end plate 10 itself. At the longitudinal reinforcing rib 102, the height H1 of the plate body 100 along the X direction is the dimension of the end plate 10 along the stacking direction of the pouch cells 20, referring to the maximum thickness at the central axis O of the end plate 10; moreover, the thickness of the end plate 10 determines the bending stiffness of the end plate 10 along the stacking direction of the pouch cells 20. H2 is the thickness of the outermost edge of plate 100 along the Y direction, which is the minimum value of the gradual change in thickness of end plate 10.

[0039] The length L1 of the pouch cell 20 can be any value or a value between any two of the following: 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, and 200mm. The width W1 of the pouch cell 20 can be any value or a value between any two of the following: 75mm, 80mm, 85mm, 90mm, 95mm, and 100mm.

[0040] Furthermore, the length L2 of the end plate 10 can be any value from 1.2L1, 1.21L1, 1.22L1, 1.23L1, 1.24L1, 1.25L1, 1.26L1, 1.27L1, 1.28L1, 1.29L1, and 1.3L1, or a value between any two of these values. If the length of the end plate 10 is too small, such as less than 1.2L1, the space between the tab and the connecting structure may be insufficient, increasing the assembly difficulty of the pouch cell 20 and making it prone to tab interference or insufficient connection strength. If the length of the end plate 10 is too large, such as greater than 1.3L1, it will waste the lateral space of the cell module and directly reduce the volumetric energy density of the cell module.

[0041] By appropriately setting the length of the end plate 10, space can be reserved for the tabs of the pouch cell 20 and the installation space for the side structural components. The positive and negative tabs of the pouch cell 20 extend from both sides in the Y direction and need to be bent before connecting to the busbar or adapter plate. The part of the end plate 10 that extends beyond the pouch cell 20 provides a safety space for the tab bending and electrical connection components, preventing the tabs from being squeezed by the end plate 10 and causing a short circuit. The two sides 140 of the end plate 10 along the Y direction are the connection positions of the cell module frame, used to connect with the side plate or strap. The end plate 10 needs to extend beyond the main body of the pouch cell 20 to arrange the connection structure, thus forming a complete constraint frame.

[0042] The width W2 of the end plate 10 can be any value from 1.05W1, 1.06W1, 1.07W1, 1.08W1, 1.09W1, and 1.1W1, or a value between any two of these. If the width of the end plate 10 is too small, such as less than 1.05W1, the allowance in the width direction of the end plate 10 will be insufficient, and the glue may overflow. If the width of the end plate 10 is too large, such as greater than 1.1W1, it will increase the volume of the end plate 10, encroach on the installation space of the soft-pack battery cell 20, and reduce the assembly efficiency of the battery cell module.

[0043] Since structural adhesive or buffer foam and insulating sheets are usually applied between the pouch cell 20 and the end plate 10, by reasonably setting the width of the end plate 10, such as leaving a width margin of 5%-10%, it can be ensured that the adhesive layer and buffer material cover the end face of the pouch cell 20, while preventing adhesive and foam from overflowing to the outside of the end plate 10. Moreover, small components such as sampling line fixing seats, temperature sensors, and insulation limiting bosses are usually arranged on the upper and lower edges of the end plate 10 in the width direction. Therefore, the end plate 10 needs to extend slightly beyond the arrangement space of the pouch cell 20 to facilitate the installation of edge components.

[0044] The height H1 of the end plate 10 can be any value from 0.12L2, 0.13L2, 0.14L2, 0.15L2, 0.16L2, 0.17L2, 0.18L2, or any value between two of these. If the thickness of the end plate 10 is too small, such as less than 0.12L2, the overall stiffness of the end plate 10 will be too low, resulting in excessive deformation under long-term expansion loads, and even fatigue fracture, triggering safety risks such as leakage and short circuits in the pouch cell 20. If the thickness of the end plate 10 is too large, such as greater than 0.18L2, the weight and volume of the end plate 10 will increase, the material utilization rate will decrease, and thus the energy density of the cell module will be sacrificed.

[0045] By reasonably setting the ratio of the height to the length of the end plate 10, and combining it with the gradual thickness design of the end plate 10, the thickness of the highest stress zone in the middle falls within the range of 12%-18%, so that the end plate 10 can withstand the long-term cyclic expansion force of the soft-pack battery cell 20, and can also resist the concentrated load of external extrusion, thereby effectively reducing the risk of breakage caused by the low stiffness of the end plate 10.

[0046] The thickness H2 of plate 100 can be any value among 0.6H1, 0.65H1, 0.7H1, 0.75H1, and 0.8H1, or a value between any two of these values.

[0047] If H2 is too small, such as less than 0.6H1, the cross-sectional strength at the connection point of the end plate 10 will be insufficient. When the module side plate, straps, or fasteners are connected to the connection point of the end plate 10, failure modes such as strap tearing, riveting detachment, or end breakage are likely to occur, thus losing the ability to constrain the soft-pack cell 20. If H2 is too large, such as greater than 0.8H1, the overall thickness difference of the end plate 10 will be too small, approaching that of a conventional end plate 10 with equal thickness. This will result in a large amount of material redundancy in the low-stress area of ​​the end plate 10, which will increase the weight of the end plate 10, increase material costs, and also encroach on the space of the cell module and reduce the volumetric energy density.

[0048] By reasonably setting the thickness of the side of the plate 100 away from the middle of the plate 100, the material usage of the end plate 10 can be effectively reduced while ensuring the end bearing capacity. Moreover, the smooth thickness transition from the end to the middle of the end plate 10 makes the overall stress distribution of the end plate 10 more uniform, which not only avoids stress concentration fracture in the middle, but also reduces the risk of failure due to excessive thinness at the end.

[0049] In one embodiment, the sidewall thickness of the plate 100 along the X direction is T1, which satisfies 3mm≤T1≤4mm; the thickness of the transverse reinforcing rib 101 is T2, which satisfies 2T1≤T2≤3T1.

[0050] In this embodiment, the sidewall thickness of the plate 100 along the X direction, T1, refers to the wall thickness of the inner and outer walls of the end plate 10, and is the basic wall thickness of the end plate 10 frame. The sidewall thickness T1 of the plate 100 along the X direction can be any value among 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, and 4mm, or a value between any two values. By reasonably setting the sidewall thickness of the plate 100 along the X direction, the overall structural strength of the end plate 10 can be effectively increased, the load-bearing capacity of the end plate 10 can be improved, and the increase in the overall weight of the end plate 10 due to excessive sidewall thickness can be avoided. This reduces the space occupied by the end plate 10 for the arrangement of the soft-pack battery cells, which is beneficial to improving the volumetric energy density of the battery cell module.

[0051] Along the Z-direction, the thickness T2 of the transverse reinforcing rib 101 can be any value from 2T1, 2.1T1, 2.2T1, 2.3T1, 2.4T1, 2.5T1, 2.6T1, 2.7T1, 2.8T1, 2.9T1, and 3T1, or a value between any two of these values. If the thickness of the transverse reinforcing rib 101 is too small, such as less than 2T1, the bending deformation in the middle of the end plate 10 under load will be too large. This will not only weaken the load-bearing advantage of the arch structure but also lead to increased stress concentration in the hollow area. Under the alternating expansion load of long-term charge-discharge cycles, the reinforcing rib is prone to fatigue fracture, ultimately causing the end plate 10 to fail as a whole. If the thickness of the transverse reinforcing rib 101 is too large, such as greater than 3T1, the transverse reinforcing rib 101 will significantly encroach on the area of ​​the hollow area, thereby relatively increasing the overall material usage of the end plate 10. This will increase the material cost and reduce the volumetric or weight energy density of the battery module.

[0052] The transverse stiffener 101 can serve as a force transmission skeleton. By reasonably setting the width of the transverse stiffener 101, the concentrated load at the edge can be evenly distributed to the overall structure of the end plate 10, reducing the local stress peak. Under the long-term cyclic alternating expansion force of the soft-pack battery cell 20, the generation of fatigue cracks can be effectively reduced, and the service life of the end plate 10 can be effectively increased.

[0053] It is understandable that the longitudinal stiffener 102 serves as the main stiffener along the Z direction of the plate 100. The thickness of the longitudinal stiffener 102 can be the same as the thickness of the transverse stiffener 101, so as to better distribute the concentrated load at the edge evenly to the overall structure of the end plate 10 and further reduce the local stress peak on the plate 100.

[0054] In one embodiment, within the hollowed-out area, the diagonal rib 150 includes a first diagonal rib 151, a second diagonal rib 152, and a third diagonal rib 153 in the YZ plane. The distance W3 between the first diagonal rib 151 and the second diagonal rib 152 satisfies 0.06L2≤W3≤0.08L2; the distance W4 between the second diagonal rib 152 and the third diagonal rib 153 satisfies 0.08L2≤W4≤0.1L2.

[0055] In this embodiment, the oblique ribs 150 include a first oblique rib 151, a second oblique rib 152, and a third oblique rib 153 in the YZ plane; wherein the first oblique rib 151, the second oblique rib 152, and the third oblique rib 153 can be parallel to each other. The distance W3 between the first oblique rib 151 and the second oblique rib 152 can be any value among 0.06L2, 0.065L2, 0.07L2, 0.075L2, and 0.08L2, or a value between any two values. If W3 is too small, such as less than 0.06L2, the opening size of the hollow groove 110 will be too small, which will relatively increase the difficulty of mold processing. Moreover, if the oblique ribs 150 are too dense, it will lead to an increase in stress concentration points, which will make it easier for fatigue cracks to occur at the root of the reinforcing rib under alternating expansion loads, and at the same time reduce the weight reduction effect of the end plate 10. If W3 is too large, such as greater than 0.08L2, the span of the side wall of the hollow area will be too large, resulting in a decrease in the local bending and bulging resistance of the plate 100. When subjected to the expansion force of the soft-pack battery cell, the side wall area will show obvious deformation, which will not only weaken the overall load-bearing effect of the end plate 10, but also generate additional stress concentration at the junction of the reinforcing rib and the side wall, thereby causing local cracking.

[0056] The distance W4 between the second diagonal rib 152 and the third diagonal rib 153 can be any value among 0.08L2, 0.085L2, 0.09L2, 0.095L2, and 0.1L2, or any value between any two. If W is too small, such as less than 0.08L2, the density of the diagonal ribs 150 in the hollow area will increase, thereby increasing the overall weight of the end plate 10. If W is too large, such as greater than 0.1L2, the unsupported span of the side wall area will be too large, which will break the grid force transmission path of the diagonal ribs 150, and the load cannot be evenly distributed on the main reinforcing rib skeleton; at the same time, if the size of the hollow groove 110 is too large, it will also reduce the impact resistance of the end plate 10.

[0057] By rationally setting the distances between the first inclined rib 151, the second inclined rib 152, and the third inclined rib 153, the density of the inclined ribs 150 can be rationally set, thereby rationally setting the dimensions of the hollow groove 110 within the hollow area. This helps to minimize the overall material usage of the end plate 10 while ensuring its load-bearing capacity, thus reducing the overall weight of the end plate 10. Simultaneously, when the end plate 10 is subjected to expansion force or external extrusion force, the force can be evenly distributed across the end plate 10, thereby improving the overall load-bearing uniformity of the hollow area without increasing the total weight of the end plate 10, achieving a balance between the rigidity and lightweight of the end plate 10.

[0058] In one embodiment, the oblique rib 150 further includes a fourth oblique rib 154, a fifth oblique rib 155, and a sixth oblique rib 156 in the YZ plane. The hollow groove 110 formed by the second oblique rib 152, the third oblique rib 153, the fifth oblique rib 155, and the sixth oblique rib 156 is provided with a cross reinforcing rib 111, and the ends of the cross reinforcing rib 111 are respectively connected to the junction of the oblique rib 150.

[0059] In this embodiment, the oblique ribs 150 also include a fourth oblique rib 154, a fifth oblique rib 155, and a sixth oblique rib 156 in the YZ plane; wherein the fourth oblique rib 154, the fifth oblique rib 155, and the sixth oblique rib 156 can be parallel to each other. Within the hollow area, the oblique ribs 150 are divided into two intersecting inclined directions, which together enclose independent hollow grooves 110. A cross-shaped reinforcing rib 111 is provided in the hollow groove 110 formed by the second oblique rib 152, the third oblique rib 153, the fifth oblique rib 155, and the sixth oblique rib 156; this hollow groove 110 is the groove with the largest span and area in the hollow area, and is also the location with relatively weak local rigidity. By setting cross-shaped reinforcing ribs 111, a single large-sized hollow groove 110 can be divided into four triangular sub-regions, thereby improving the anti-bulging and anti-buckling capacity of the diagonal rib 150, effectively suppressing the local deformation of the side wall area under cyclic expansion load, and reducing the risk of reinforcing rib tearing or end plate 10 cracking due to local instability.

[0060] Furthermore, the four ends of the cross stiffener 111 are respectively connected to the intersection nodes of the diagonal ribs 150, instead of overlapping in the middle section of the diagonal ribs 150. This is equivalent to adding two directions of support constraints at the intersection of the diagonal ribs 150 and supplementing the force transmission paths along the Y and Z directions. This ensures that the cross stiffener 111 and the original diagonal rib 150 skeleton form a continuous force transmission whole. It can evenly distribute the irregular impact load to the surrounding diagonal rib 150 skeleton and disperse the concentrated stress at the intersection in four directions, which is beneficial to improving the fatigue life of the end plate 10 under long-term cyclic expansion.

[0061] In one embodiment, the included angle α formed after the intersection of two adjacent diagonal ribs 150 satisfies 90°≤α≤150°; the thickness T3 of the diagonal rib 150 satisfies 2.4mm≤T3≤3.2mm.

[0062] In this embodiment, the included angle α formed by the intersection of two adjacent diagonal ribs 150 can be any value among 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, and 150°, or a value between any two values. By reasonably setting the included angle formed by the intersection of two adjacent diagonal ribs 150, several diagonal ribs 150 can be intersected and arranged in the hollow area, ensuring that several diagonal ribs 150 have a sufficient number of intersection nodes in the hollow area, thereby ensuring that the diagonal ribs 150 have sufficient supporting stiffness and force transmission path, so as to improve the overall load-bearing capacity of the plate 100.

[0063] The thickness T3 of the diagonal rib 150 can be any value or a value between any two of the following: 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, and 3.2mm. If the thickness of the diagonal rib 150 is too small, such as less than 2.4mm, the cross-sectional area of ​​the diagonal rib 150 will be insufficient, resulting in insufficient load-bearing capacity. Under long-term cyclic expansion alternating loads, the fatigue life of the diagonal rib 150 will be shortened, and fracture failure will easily occur. If the thickness of the diagonal rib 150 is too large, such as greater than 3.2mm, it will significantly increase the material usage of the diagonal rib 150 and the weight of the end plate 10, which is not conducive to the lightweight design of the end plate 10.

[0064] By reasonably setting the thickness of the inclined rib 150, the cross-sectional area of ​​the inclined rib 150 can be increased to enhance its load-bearing capacity, which is beneficial to improving the overall structural strength of the end plate 10 and reducing the overall material usage of the end plate 10, thereby reducing the overall weight of the end plate 10.

[0065] In one embodiment, the connection between two adjacent diagonal ribs 150 has a chamfer r1, the radius of which r1 satisfies r1≥1.5mm; the connection between the side surface 140 and the arc surface 130 has a chamfer r2, the radius of which r2 satisfies r2≥2mm.

[0066] In this embodiment, chamfer r1 is located at the intersection of the diagonal ribs 150 within the hollowed-out area, and is the rounded corner at the inner angle formed by the intersection of two diagonal ribs 150. Chamfer r2 is located at the intersection edge of the side surface 140 and the outwardly convex arc surface 130 at both ends of the end plate 10 along the Y direction, that is, at the corner of the arch foot of the arch structure. The chamfer r1 at the connection between two adjacent diagonal ribs 150 can be any value of 1.5mm, 1.7mm, 2mm, 2.2mm, 2.5mm, 2.7mm, 3mm, 3.2mm, 3.5mm, 3.7mm, 4mm or a value between any two values; and the radius of the chamfer can also be any value greater than 4mm. By changing the corner at the connection between two diagonal ribs 150 to a rounded corner with a radius greater than or equal to 1.5 mm, the stress flow can smoothly transition along the arc, and the peak stress at the connection of diagonal ribs 150 is greatly reduced. This can significantly improve the fatigue reliability of the diagonal rib 150 mesh under long-term alternating expansion and prevent the ribs from breaking at the nodes.

[0067] The radius of the chamfer r2 represents the radius of the rounded transition between the inner side 140 and the arc surface 130130 of the end plate 10. This is to eliminate stress concentration at the sharp corners of the inner side of the end plate 10 and reduce the risk of cracking. The radius of the chamfer r2 can be any value or a value between any two of the following: 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, and 4mm. Furthermore, the radius of the chamfer can also be any value greater than 4mm. By setting chamfers at the connection between the side 140 and the arc surface 130130 and appropriately setting the radius of the chamfer, the rounded corners can smoothly transition stress through the arc surface 130, effectively reducing peak corner stress, significantly improving the fatigue life of the end plate 10, and adapting to the alternating expansion loads throughout the entire life cycle of the soft-pack battery cell 20.

[0068] In one embodiment, the plate 100 is further provided with annular reinforcing ribs 160. The annular reinforcing ribs 160 are located in the middle of the plate 100 and are respectively connected to the transverse reinforcing ribs 101, the longitudinal reinforcing ribs 102 and the diagonal ribs 150. The inner ring radius r3 of the annular reinforcing ribs 160 satisfies 10mm≤r3≤15mm, and the outer ring radius r4 of the annular reinforcing ribs 160 satisfies 1.5r3≤r4≤2r3.

[0069] In this embodiment, the annular reinforcing rib 160 is located in the geometric center region along the YZ plane of the end plate 10. This is the point where the bending moment is greatest and the stress is most concentrated when the entire end plate 10 is subjected to the expansion force of the soft-pack battery cell and external extrusion pressure. It corresponds to the intersection of the transverse reinforcing rib 101 and the longitudinal reinforcing rib 102. The annular reinforcing rib 160 is connected to the transverse reinforcing rib 101, the longitudinal reinforcing rib 102, and the peripheral diagonal ribs 150, effectively connecting the main load-bearing skeleton and the secondary diagonal ribs 150 mesh in a closed-loop, synergistic load-bearing system in the high-stress area. The annular closed-loop structure of the annular reinforcing rib 160 can transform concentrated stress at a single point into stress evenly distributed along the circumferential direction, thereby effectively reducing stress peak values. Furthermore, the annular reinforcing rib 160 can also unify the loads of the transverse reinforcing ribs 101, the longitudinal reinforcing ribs 102, and the peripheral diagonal ribs 150 into the ring body and then evenly distribute and transfer them, avoiding load superposition or stress imbalance at the intersection of various reinforcing ribs, which is beneficial to improving the synergistic load-bearing efficiency of each reinforcing rib.

[0070] Furthermore, the inner ring radius r3 of the annular reinforcing rib 160 can be any value or a value between any two of the following: 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, and 15mm. If the inner ring radius of the annular reinforcing rib 160 is too small, such as less than 10mm, the effective area of ​​the annular reinforcement of the annular reinforcing rib 160 will be too narrow, failing to fully cover the high-stress area in the middle of the end plate 10, thus weakening the stress dispersion effect. If the inner ring radius of the annular reinforcing rib 160 is too large, such as greater than 15mm, the annular reinforcing rib 160 will exceed the reasonable range of the high-stress area in the middle, causing unnecessary material waste; at the same time, it will compress the layout space of the surrounding diagonal ribs 150 grid, destroying the original equal strength design of the non-uniform diagonal ribs 150, resulting in relatively insufficient stiffness in the outer area of ​​the annular reinforcing rib 160.

[0071] The outer ring radius r4 of the annular reinforcing rib 160 can be any value from 1.5r3, 1.6r3, 1.7r3, 1.8r3, 1.9r3, 2r3, or any value between two of these. If the outer ring radius r4 of the annular reinforcing rib 160 is too small, such as less than 1.5r3, the thickness of the annular reinforcing rib 160 will be too small, and the radial bearing section of the annular reinforcing rib 160 itself will be insufficient, resulting in insufficient compressive or tensile strength to meet the load requirements, and the ring body is prone to breakage. If the outer ring radius r4 of the annular reinforcing rib 160 is too large, such as greater than 2r3, it will increase the overall material usage of the end plate 10 and squeeze the weight reduction space of the surrounding hollow area, which is not conducive to the lightweight design of the end plate 10.

[0072] By reasonably setting the inner and outer radii of the annular reinforcing rib 160, the thickness of the annular reinforcing rib 160 can be ensured to meet the usage requirements, and the annular reinforcing rib 160 can be prevented from interfering with the layout space of the surrounding diagonal ribs 150 grid. This ensures the overall load-bearing capacity of the end plate 10, improves the stability of the overall structure of the end plate 10, and helps to reduce the overall weight of the end plate 10, making it easier to achieve a lightweight design of the end plate 10.

[0073] In one embodiment, in the YZ plane, the plate 100 is symmetrically arranged with the transverse reinforcing rib 101 and the longitudinal reinforcing rib 102 as the center of symmetry.

[0074] In this embodiment, the transverse reinforcing rib 101 extending along the Y direction is the axis of symmetry of the end plate 10 along the Z direction. The plate body 100 is centered on the transverse reinforcing rib 101, making all internal structures such as the hollow groove 110, diagonal rib 150, and chamfer in the upper and lower halves of the plate body 100 mirror symmetrical. The longitudinal reinforcing rib 102 extending along the Z direction is the axis of symmetry of the end plate 10 along the Y direction. With the longitudinal reinforcing rib 102 centered on the left and right sides of the plate body 100 as the center line, the rib structure in the left and right halves is mirror symmetrical. By symmetrically arranging the plate 100 with the transverse reinforcing rib 101 and the longitudinal reinforcing rib 102 as the center of symmetry, when the expansion force of the soft-pack battery cell is uniformly applied to the inner side 120 of the end plate 10, the pressure distribution of the end plate 10 on the end face of the soft-pack battery cell is uniform, and there will be no situation where the pressure on one side is too large and the constraint on the other side is insufficient. This can reduce the risk of local encapsulation failure or electrolyte leakage of the soft-pack battery cell due to uneven force, while ensuring that the expansion of the entire interface of the soft-pack battery cell is consistent and maintaining the stability of the cycle life of the soft-pack battery cell.

[0075] In one embodiment, along the Y direction, the two ends of the plate 100 are respectively provided with fixing holes 170. The inner diameter d1 of the fixing hole 170 satisfies 4mm≤d1≤10mm; the outer diameter d2 of the fixing hole 170 satisfies 2d1≤d2≤3d1.

[0076] In this embodiment, fixing holes 170 are formed at both ends of the plate 100 along the Y direction and extend through the end plate 10 along the Z direction, serving as mechanical fastening mounting positions for the battery cell module. The fixing holes 170 are through holes for the battery cell module tie rod bolts. Matching bolts and nuts can tighten the end plates 10 at both ends, forming a continuous clamping constraint on the soft-pack battery cell, providing preload force for the soft-pack battery cell 20, and forming the mechanical connection basis for the end plate 10 to achieve anti-expansion and anti-compression functions.

[0077] The inner diameter d1 of the fixing hole 170 can be any value of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between any two values; the outer diameter d2 of the fixing hole 170 can be any value of 2d1, 2.2d1, 2.4d1, 2.6d1, 2.8d1, 3d1 or any value between any two values.

[0078] If the inner or outer diameter of the fixing hole 170 is too small, the tensile and shear strength of the bolt section will be insufficient. Under long-term alternating loads, the bolt is prone to fatigue fracture, preload decay and loosening, which will eventually cause the end plate 10 to lose its clamping constraint on the soft-pack battery cell 20, triggering safety problems such as uncontrolled expansion, displacement and leakage of the soft-pack battery cell 20. Moreover, the smaller the hole diameter, the smaller the contact area between the bolt end face and the end plate 10, and the higher the local compressive stress at the hole edge under preload. This can easily lead to crushing of the hole rib plate and plastic deformation, resulting in clamping force failure.

[0079] If the inner or outer diameter of the fixing hole 170 is too large, it will cut off the effective cross-section of the reinforcing ribs around the fixing hole 170, causing stress concentration around the fixing hole 170 to increase. This will make the end plate 10 prone to tearing failure along the fixing hole 170, thus compromising the reliability of the end plate 10 connection. Moreover, an excessively large fixing hole 170 means that larger bolt materials are required, leading to higher costs and a significant increase in the required tightening torque. This also increases the requirements for assembly equipment and processes, hindering the reduction of material costs during mass production. By reasonably setting the radius of the fixing hole 170 and selecting appropriate bolt materials, it is beneficial to reduce the cost of bolt materials and make the bolt tightening torque relatively reasonable, thereby reducing the requirements for assembly equipment and processes.

[0080] As shown in Tables 1 and 2, experiments were conducted on the battery cell module provided in this invention, and the experimental results are as follows.

[0081] Table 1

[0082] Table 2

[0083] As shown in Tables 1 and 2, and in conjunction with Examples 1 to 6, the end plate 10 has sufficient strength to meet the usage requirements and works seamlessly with the soft-pack battery cell 20, thereby improving the volumetric energy density of the battery cell module; and the overall weight of the end plate 10 is reduced.

[0084] As shown in Comparative Examples 1 and 2, when L2 / L1 is 1 and W2 / W1 is 1, the allowance in the width direction of the end plate 10 is insufficient, resulting in glue overflow during assembly; due to assembly tolerances or expansion of the soft-pack battery cells, the aluminum-plastic film sealing edge is squeezed; and the electrode tab connection strength is low. When L2 / L1 is 1.5 and W2 / W1 is 1.3, the volumetric energy density of the battery cell module decreases, the grouping efficiency decreases, and the risks of drop and random vibration conditions increase.

[0085] As shown in Comparative Examples 3 and 4, when T1 is 3.2 mm and T2 / T1 is 1.8, the stiffness of end plate 10 is too low. Under long-term expansion load, excessive deformation will occur, leading to a rapid decrease in the module assembly force and a reduction in the overall cycle life of the package; fatigue fracture will occur in end plate 10. When T1 is 5 mm and T2 / T1 is 3.2, end plate 10 meets the stiffness requirements, but the overall weight and volume of end plate 10 increase, resulting in increased cost and a decrease in the energy density of the entire package.

[0086] As shown in Comparative Examples 5 and 6, when r3 is 7mm and r4 / r3 is 1.3, the stiffness of end plate 10 is too low, resulting in ring fracture at the annular reinforcing rib 160. When r3 is 18mm and r4 / r3 is 2.2, the material usage of end plate 10 increases, leading to an increase in the overall weight of end plate 10; excessive stiffness and small deformation result in excessive expansion force of the module, causing a drop in the capacity of the soft-pack battery cell.

[0087] According to an embodiment of the present invention, on the other hand, such as Figure 1 As shown, a battery pack is also provided, including at least one cell module, a housing 30, and a cover plate 40. Specifically, several cell modules are regularly arranged within the housing 30 to ensure efficient space utilization of the battery pack; multiple cell modules can be connected in series, parallel, or in a mixed configuration via a busbar to form a battery pack. Each cell module has several pouch cells 20 arranged sequentially along the X-direction, and end plates 10 are provided at both ends of the cell module. Side plates are provided on both sides of the cell module to protect the pouch cells 20. The cover plate 40 is located above the cell module and is fixedly connected to the housing 30, thereby sealing the cell module within the housing 30.

[0088] The technical solutions described in the embodiments of the present invention are applicable to various electrical devices that use battery packs.

[0089] Electrical equipment can be vehicles, ships, spacecraft, etc. Vehicles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. This invention does not impose any special limitations on the aforementioned electrical equipment.

[0090] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of the present invention.

[0091] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery pack is installed inside the vehicle, and the battery pack can be located at the bottom, front, or rear of the vehicle. The battery pack can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor. The controller is used to control the battery pack to power the motor, for example, to meet the power needs of starting, navigation, and driving the vehicle. In other embodiments of the invention, the battery pack can not only serve as the vehicle's operating power source but also as the vehicle's drive power source, replacing or partially replacing gasoline or natural gas to provide driving force for the vehicle.

[0092] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell module, characterized in that, include: Multiple pouch cells are arranged along the X direction of the cell module; An end plate, along the X direction, is located on the outer sides of both ends of the plurality of pouch cells; the end plate includes a plate body and a plurality of hollowed-out grooves on the plate body, the plate body has an inner side surface near the pouch cell and an outer side surface opposite to the inner side surface, the plurality of hollowed-out grooves are recessed inward from the inner side surface along the X direction; the outer side surface is a convex arc surface, along the Y direction, the arc surface is connected to both ends of the inner side surface through side surfaces respectively; The plate is provided with transverse reinforcing ribs extending along the Y direction and longitudinal reinforcing ribs extending along the Z direction. The transverse reinforcing ribs and the longitudinal reinforcing ribs are intersected and divide the plate into multiple hollow areas. Each hollow area is provided with several oblique ribs, and the several oblique ribs intersect to form several hollow grooves.

2. The battery cell module according to claim 1, characterized in that, Along the Y direction, the length of the pouch cell is L1, and the length of the end plate is L2, satisfying 1.2L1≤L2≤1.3L1; along the Z direction, the width of the pouch cell is W1, and the width of the end plate is W2, satisfying 1.05W1≤W2≤1.1W1. Along the Y direction, at the longitudinal stiffener, the height H1 of the plate along the X direction satisfies 0.12L2≤H1≤0.18L2; on the side of the plate away from the longitudinal stiffener, the thickness H2 of the plate along the X direction satisfies 0.6H1≤H2≤0.8H1.

3. The battery cell module according to claim 2, characterized in that, The thickness of the sidewall of the plate along the X direction is T1, which satisfies 3mm≤T1≤4mm; the thickness of the transverse reinforcing rib is T2, which satisfies 2T1≤T2≤3T1.

4. The cell module according to any one of claims 1 to 3, characterized in that, Within the hollowed-out area, the oblique ribs include a first oblique rib, a second oblique rib, and a third oblique rib in the YZ plane. The distance W3 between the first oblique rib and the second oblique rib satisfies 0.06L2≤W3≤0.08L2; the distance W4 between the second oblique rib and the third oblique rib satisfies 0.08L2≤W4≤0.1L2.

5. The battery cell module according to claim 4, characterized in that, The oblique ribs also include a fourth oblique rib, a fifth oblique rib, and a sixth oblique rib in the YZ plane. The hollow groove formed by the second oblique rib, the third oblique rib, the fifth oblique rib, and the sixth oblique rib is provided with a cross reinforcing rib, and the ends of the cross reinforcing ribs are respectively connected to the intersection of the oblique ribs.

6. The cell module according to claim 1, characterized in that, The included angle α formed by the intersection of two adjacent diagonal ribs satisfies 90°≤α≤150°; the thickness T3 of the diagonal rib satisfies 2.4mm≤T3≤3.2mm.

7. The cell module according to claim 1, characterized in that, The connection between two adjacent diagonal ribs has a chamfer r1, and the radius of the chamfer r1 satisfies r1≥1.5mm; The connection between the side surface and the arc surface is chamfered with a radius r2, and the radius of the chamfer r2 satisfies r2≥2mm.

8. The battery cell module according to claim 1, characterized in that, The plate is also provided with annular reinforcing ribs, which are located in the middle of the plate and are respectively connected to the transverse reinforcing ribs, the longitudinal reinforcing ribs and the diagonal ribs; The inner ring radius r3 of the annular reinforcing rib satisfies 10mm≤r3≤15mm, and the outer ring radius r4 of the annular reinforcing rib satisfies 1.5r3≤r4≤2r3.

9. The cell module according to claim 1, characterized in that, Within the YZ plane, the plate body is symmetrically arranged with the transverse reinforcing ribs and the longitudinal reinforcing ribs as the centers of symmetry, respectively.

10. A battery pack, characterized in that, include: At least one battery cell module as described in any one of claims 1 to 9.

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