Electric pile end plate and electric pile

Abstract

The utility model relates to the technical field of flow battery electric piles, in particular to an electric pile end plate and an electric pile. The galvanic pile end plate is provided with a first compensation convex part and a second compensation convex part, the first compensation convex part is formed by protruding an area, corresponding to an electrode of a single battery, of the end plate towards the electrode direction, and the second compensation convex part is formed by protruding a central area of the first compensation convex part towards the electrode direction; and when the end plate clamps the single battery, the first compensation convex part and the second compensation convex part tend to be flat under the extrusion action of the electrode so as to compensate the outward elastic deformation of the end plate. According to the electric pile end plate and the electric pile, the double pre-convex structures are arranged on the end plate, outward elastic deformation of the end plate caused by an electrode surrounding area and a center area is compensated after the end plate is pressed, the sealing performance of a single battery is ensured after the end plate is assembled and in the operation process of the electric pile, and the risk of electrolyte leakage is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flow battery stack, and particularly relates to a stack end plate and a stack. BACKGROUND

[0002] With the transformation of global energy structure and the rapid development of renewable energy, energy storage technology is a necessary means to improve the quality, output stability and grid safety of photovoltaic and wind power generation, and is crucial to large-scale and stable use of new energy and construction of a new clean power system. The all-vanadium redox flow battery with high safety, long storage time, flexible adaptation and low full life cycle cost per kilowatt-hour is gradually becoming an innovative force in the energy storage field.

[0003] The stack is the most core component of the flow battery, which mainly comprises electrodes, ion-conducting membranes, electrode frames, bipolar plates and end plates. The end plates on both sides fasten all the components into one through fasteners, play a role in fastening the stack, and undertake the important responsibility of maintaining the sealing performance of the stack.

[0004] However, the end plate is connected by screw rods on the four sides, and the middle region of the end plate is not mechanically fixed. During the assembly or operation of the stack, the middle region of the end plate will be subjected to the extrusion force of the electrode, resulting in the outward bulging deformation of the middle region of the end plate, and the deformation amount of the central region of the electrode is larger than that of the edge. The outward bulging deformation of the middle region of the end plate reduces the sealing performance, and there is a risk of electrolyte leakage. CONTENT OF THE UTILITY MODEL

[0005] The present application provides a stack end plate and a stack. The end plate is provided with a double pre-bulging structure, which compensates for the elastic deformation of the end plate outwardly caused by the electrode peripheral region and the central region after being pressed, ensures the sealing performance of the battery monomer after the assembly of the end plate and during the operation of the stack, and reduces the risk of electrolyte leakage.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a stack end plate, which is used for clamping a battery monomer of a stack. The end plate has a first compensation bulging part and a second compensation bulging part. The first compensation bulging part is formed by bulging the region corresponding to the electrode of the battery monomer of the end plate in the direction of the electrode, and the second compensation bulging part is formed by bulging the central region of the first compensation bulging part in the direction of the electrode.

[0008] When the end plate clamps the battery monomer, the first compensation bulging part and the second compensation bulging part tend to be flat under the extrusion action of the electrode, so as to compensate for the elastic deformation of the end plate outwardly.

[0009] In some possible implementation manners, the first compensation bulging part is formed by integrally bulging the region corresponding to the electrode of the battery monomer of the end plate in the direction of the electrode in an arc shape, and the second compensation bulging part is formed by integrally bulging the central region of the first compensation bulging part in the direction of the electrode in an arc shape.

[0010] In some possible implementation manners, the first compensation protrusion has a first concave curved surface and a first convex curved surface on the side away from the electrode and the side towards the electrode respectively, the concave amplitude of the first concave curved surface is consistent with the convex amplitude of the first convex curved surface, the maximum concave depth of the first concave curved surface is A, and 1.5 mm≤A≤2 mm.

[0011] The second compensation protrusion has a second concave curved surface and a second convex curved surface on the side away from the electrode and the side towards the electrode respectively, the concave amplitude of the second concave curved surface is consistent with the convex amplitude of the second convex curved surface, the maximum concave depth of the second concave curved surface is B, and 0.4 mm≤B≤0.5 mm.

[0012] In some possible implementation manners, the projection of the first compensation protrusion along the thickness direction of the end plate is a rectangle, a square, a circle or an oblong, and the projection of the second compensation protrusion is an ellipse, an oblong, a rhombus or a rectangle.

[0013] In some possible implementation manners, the end plate is made of glass fiber, and the thickness of the end plate is H, and 27 mm≤H≤31 mm.

[0014] In some possible implementation manners, the end plate is a cuboid end plate, and the end plate comprises a plurality of glass fiber layers, the plurality of glass fiber layers comprise a first glass fiber layer and a second glass fiber layer, the fiber laying direction of the first glass fiber layer is the width direction of the end plate, and the fiber laying direction of the second glass fiber layer is the length direction of the end plate.

[0015] In some possible implementation manners, the end plate comprises a plurality of groups of glass fiber layers, the plurality of groups of glass fiber layers are stacked along the thickness direction of the end plate, each group of glass fiber layers comprises two first glass fiber layers and one second glass fiber layer, and the two first glass fiber layers and the one second glass fiber layer are stacked in sequence.

[0016] In some possible implementation manners, the end plate comprises a first end plate for mounting a screw rod, and a coaxial first through hole and a limiting hole are arranged on the side surface of the first end plate away from the electrode, the first through hole is used for allowing the rod part of the screw rod to pass through, and the limiting hole is used for limiting the rotation of the head part of the screw rod.

[0017] In some possible implementation manners, the end plate comprises a second end plate for mounting a nut, and a mounting hole is arranged on the side surface of the second end plate away from the electrode, and a gasket for abutting against the nut is arranged in the mounting hole.

[0018] The second aspect of the present application provides a stack, the stack comprising a battery cell and the stack end plate in the first aspect, the end plates on both sides of the battery cell are connected through the fastening assembly, the battery cell is clamped between the end plates on both sides, and the first compensation protrusion and the second compensation protrusion of the end plate tend to be flattened under the extrusion of the electrode of the battery cell, and the elastic deformation of the compensation end plate outward is compensated.

[0019] From the above technical solution, the present application has at least the following beneficial effects:

[0020] The stack end plate provided by the present application sets a double pre-protrusion structure, the second compensation protrusion corresponds to the central region of the electrode, and the first compensation protrusion corresponds to the surrounding region outside the central region of the electrode. After being pressed, the elastic deformation of the end plate outward caused by the electrode surrounding region and the central region is compensated respectively, the sealing of the battery cell after the end plate is assembled is ensured, and in the process of stack operation, the first compensation protrusion and the second compensation protrusion can also compensate the deformation amount of the electrode outward, ensure the sealing of the battery cell in the process of stack operation, reduce the risk of electrolyte leakage, and ensure the safety of the battery.

[0021] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in the present application does not imply that all features and advantages can be achieved in any single embodiment. On the contrary, it can be understood that the description of a feature or a beneficial effect means that the specific technical feature, technical solution or beneficial effect is included in at least one embodiment. Therefore, the description of technical features, technical solutions or beneficial effects in the specification does not necessarily refer to the same embodiment. Further, the technical features, technical solutions and beneficial effects described in the embodiments can be combined in any appropriate manner. Those skilled in the art will understand that the embodiments can be implemented without one or more specific technical features, technical solutions or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects can be identified in specific embodiments that do not embody all embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The schematic diagram of the stack provided by the present application in a specific embodiment;

[0023] Figure 2 The top view of Figure 1 ;

[0024] Figure 3 The sectional view along C-C; Figure 2

[0025] Figure 4 The sectional view of the end plate and the electrode provided by the present application in a specific embodiment;

[0026] Figure 5 ​A schematic view of two groups of glass fiber layers in the end plate provided in the present application;

[0027] Figure 6 A Figure 2 An enlarged view at I in the middle;

[0028] Figure 7 A Figure 1 A schematic view from another perspective;

[0029] Figure 8 A Figure 7 An enlarged view at II in the middle.

[0030] The figure legend: 1-end plate; 11-first compensation convex part; 12-second compensation convex part; 13-first glass fiber layer; 14-second glass fiber layer; 15-first end plate; 151-limiting hole; 16-second end plate; 161-mounting hole; 2-battery monomer; 21-electrode; 3-screw rod; 31-rod part; 32-head part; 4-gasket. DETAILED DESCRIPTION

[0031] The terms "first", "second", and "third" and the like in the specification and the appended claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.

[0032] In the present application embodiments, the words "exemplary" and "for example" are used to mean serving as an example, instance, or illustration, at 5 2 least with respect to the specific embodiment being described. Any embodiment or design scheme described as "exemplary" or "for example" in the present application embodiments should not be construed as preferred or advantageous over other embodiments or design schemes. In fact, any embodiment or design scheme described as "exemplary" or "for example" is intended to convey that the described embodiment or design scheme is one example implementation, at least with respect to the specific embodiment being described, and is used only to 10 illustrate one of numerous possible embodiments or design schemes that can be implemented in accordance with the present application. Thus, the use of "exemplary" or "for example" in the present application does not indicate that a particular embodiment or design scheme is preferred or advantageous over other embodiments or design schemes.

[0033] For the sake of clear and concise description of the following embodiments, first give a brief introduction of the related art:

[0034] A flow battery is an electrochemical energy storage system, whose active materials are stored in external electrolyte tanks in liquid form, and the electrolyte is circulated in the stack for charging and discharging by pumping. Flow battery has important application value in large-scale energy storage field (such as renewable energy grid connection, power grid peak shaving) due to its high safety, long life, easy to expand capacity and other characteristics.

[0035] The flow battery includes a stack, and the end plate of the stack is generally fastened with a screw rod around. The compression force of the electrode area and the thermal flow impact under the operating state of the stack generate extrusion force on the end plate. Since the electrode area of the end plate is not constrained by load, the middle area is prone to large bulging deformation, increasing the risk of electrolyte leakage. Therefore, the end plate is required to have good flatness and small deformation after installation.

[0036] The large flow battery stack end plate is generally made of metal material. In order to ensure that the end plate has good flatness and has small deformation after installation, a relatively thick flat steel plate or a metal plate with reinforcing ribs is usually selected. The metal plate with reinforcing ribs is complicated to process, which will cause the manufacturing cost to rise, and is relatively thick, which is not conducive to assembly and transportation. The electrode area of the pure flat metal plate is prone to excessive convex deformation after the stack is operated. The thick flat metal plate is also relatively thick, which is not conducive to assembly and transportation.

[0037] Therefore, the embodiments of the present application provide a stack end plate and a stack. By setting a double pre-convex structure, the elastic deformation of the end plate outward caused by the electrode surrounding area and the center area is compensated after being pressed, the sealing performance of the battery monomer after the end plate is assembled and during the operation of the stack is ensured, and the risk of electrolyte leakage is reduced. The end plate is made of glass fiber, which reduces the weight compared with the metal plate, and is conducive to assembly and transportation.

[0038] The stack end plate and the stack provided by the embodiments of the present application are introduced as follows:

[0039] Figure 1 As shown in the structure schematic diagram of the stack in a specific embodiment, the stack includes a battery monomer 2 and an end plate 1. The battery monomer 2 has the end plate 1 on both sides, the end plate 1 clamps the battery monomer 2, and the sealing performance of the stack is maintained. The battery monomer 2 includes a bipolar plate, an electrode frame, an electrode 21, and an ion conductive film.

[0040] The embodiments of the present application provide a stack end plate. The end plate 1 is used to clamp the battery monomer 2 of the stack, as shown in the structure schematic diagram of the stack in a specific embodiment. Figures 1-4 As shown, the end plate 1 has a first compensation convex part 11 and a second compensation convex part 12. The first compensation convex part 11 is convexly formed in the direction of the electrode 21 corresponding to the area of the electrode 21 of the battery monomer 2. The second compensation convex part 12 is convexly formed in the direction of the electrode 21 corresponding to the center area of the first compensation convex part 11. When the end plate 1 clamps the battery monomer 2, the first compensation convex part 11 and the second compensation convex part 12 tend to be flat under the extrusion of the electrode 21, so as to compensate the elastic deformation of the end plate 1 outward.

[0041] When the end plate 1 clamps the battery monomer 2, the first compensation convex part 11 corresponds to the electrode 21 area, the electrode 21 extrudes the first compensation convex part 11, so that the first compensation convex part 11 gradually tends to be flat, and then the center area of the electrode 21 extrudes the second compensation convex part 12, so that the second compensation convex part 12 gradually tends to be flat, and finally the whole end plate 1 remains flat.

[0042] The center region of the electrode 21 is deformed more than the surrounding region due to the stacking pressure concentration, the second compensation protrusion 12 is further protruded to the electrode 21 from the first compensation protrusion 11, the double pre-protrusion structure is arranged, the second compensation protrusion 12 corresponds to the center region of the electrode 21, the first compensation protrusion 11 corresponds to the surrounding region except the center region of the electrode 21, and the elastic deformation of the end plate 1 outward caused by the surrounding region and the center region of the electrode 21 is respectively compensated after being pressed, the sealing of the battery monomer 2 after the end plate 1 is assembled is ensured, and the first compensation protrusion 11 and the second compensation protrusion 12 can also compensate the deformation amount of the electrode 21 outward during the operation of the stack, the sealing of the battery monomer 2 during the operation of the stack is ensured, the risk of electrolyte leakage is reduced, and the safety of the battery is ensured.

[0043] In a specific embodiment, with reference to Figure 4 , the first compensation protrusion 11 is formed in an arc shape protruding to the electrode 21 from the region corresponding to the electrode 21 of the battery monomer 2 of the end plate 1, and the second compensation protrusion 12 is formed in an arc shape protruding to the electrode 21 from the center region of the first compensation protrusion 11.

[0044] The first compensation protrusion 11 is arc-shaped as a whole, and the second compensation protrusion 12 is also arc-shaped as a whole, that is, the surfaces of the first compensation protrusion 11 facing and away from the electrode 21 are both arc-shaped curved surfaces, and the surfaces of the second compensation protrusion 12 facing and away from the electrode 21 are also both arc-shaped curved surfaces; the first compensation protrusion 11 and the second compensation protrusion 12 form an arc-shaped transition structure at the junction.

[0045] In this way, the contact pressure distribution between the end plate 1 and the electrode 21 is more uniform, the stress concentration of the first compensation protrusion 11 and the second compensation protrusion 12 on the electrode 21 is reduced, and the electrode 21 is prevented from being damaged.

[0046] Specifically, the side away from the electrode 21 and the side facing the electrode 21 of the first compensation protrusion 11 respectively have a first concave curved surface and a first convex curved surface, the concave amplitude of the first concave curved surface is consistent with the convex amplitude of the first convex curved surface, the maximum concave depth of the first concave curved surface is A, and 1.5mm≤A≤2mm; the side away from the electrode 21 and the side facing the electrode 21 of the second compensation protrusion 12 respectively have a second concave curved surface and a second convex curved surface, the concave amplitude of the second concave curved surface is consistent with the convex amplitude of the second convex curved surface, the maximum concave depth of the second concave curved surface is B, and 0.4mm≤B≤0.5mm.

[0047] In this embodiment, the maximum recess depth of the first recessed surface of the first compensation protrusion 11 is 1.5mm~2mm, and the maximum recess depth of the second recessed surface of the second compensation protrusion 12 is 0.4mm~0.5mm. Such maximum recess depth makes the surface of the end plate 1 close to a plane after installation, and does not cause excessive stress concentration in the center of the electrode 21 due to the installation, which damages the electrode 21.

[0048] In this embodiment, the projection of the first compensation protrusion 11 is a rectangle or a square or a circle or an oblong along the thickness direction of the end plate 1, and the projection of the second compensation protrusion 12 is an ellipse or an oblong or a rhombus or a rectangle.

[0049] In a specific embodiment, as shown in Figure 2 the projection of the first compensation protrusion 11 is a rectangle, and the projection of the second compensation protrusion 12 is an ellipse, and the long axis of the ellipse coincides with the center line of the rectangle.

[0050] The outer boundary length of the first compensation protrusion 11 is L, and the width is K, L can be equal to 1100mm, and K can be equal to 340mm; the long axis length of the second compensation protrusion 12 is M, and the short axis length is N, M can be equal to 660mm, and N can be equal to 200mm; the end plate 1 can be applied to a large-scale flow battery to ensure the sealing performance of the large-scale flow battery after assembly and operation.

[0051] According to the stress analysis of the existing flat end plate, the deformation of the middle region of the end plate is large, and the deformation cloud map is in an elliptical radial shape. Therefore, in this embodiment, the projection of the second compensation protrusion 12 is designed as an ellipse.

[0052] On the basis of ensuring the sealing performance of the battery monomer 2, the weight of the end plate 1 is reduced. In this embodiment, the end plate 1 is made of glass fiber, and the thickness of the end plate 1 is H, 27mm≤H≤31mm.

[0053] Glass fiber has the characteristics of high specific strength and specific stiffness, and the density is about one third of the density of steel. At the same time, it has good corrosion resistance and insulation, and is an advanced composite material with relatively low price.

[0054] The end plate 1 made of glass fiber reduces the weight compared with the traditional metal end plate 1; the thickness of the end plate 1 is 27mm~31mm, which ensures the anti-deformation ability.

[0055] The cross section of the battery monomer 2 is generally rectangular, Figure 1In the embodiment shown, the end plate 1 is provided as a cuboid end plate 1 to better contact the battery monomer 2; the end plate 1 comprises a plurality of glass fiber layers, the plurality of glass fiber layers comprising a first glass fiber layer 13 and a second glass fiber layer 14, the fiber laying direction of the first glass fiber layer 13 being the width direction of the end plate 1, and the fiber laying direction of the second glass fiber layer 14 being the length direction of the end plate 1.

[0056] The width direction of the end plate 1 is set as the 90° direction, and the length direction is set as the 0° direction. In the end plate 1 in this embodiment, the glass fiber layers are all designed with 0° and 90° laying directions when being made, which can reduce the waste of raw materials and reduce the cost of raw materials.

[0057] Specifically, the fiberglass uniaxial prepreg is used as the raw material for production, and the strength direction can be designed.

[0058] In order to ensure the overall rigidity of the end plate 1 made of glass fiber, as shown, Figure 5 The end plate 1 comprises a plurality of glass fiber layers, each of which comprises two first glass fiber layers 13 and one second glass fiber layer 14, and the two first glass fiber layers 13 and the one second glass fiber layer 14 are stacked in sequence, and the plurality of glass fiber layers are stacked along the thickness direction of the end plate 1.

[0059] As shown, Figure 5 Two first glass fiber layers 13 and one second glass fiber layer 14 are repeated and laid as a laminated plate structure unit, which is beneficial to ensure the overall rigidity of the end plate 1 made of glass fiber, and the deformation of the end plate 1 is minimized after assembly.

[0060] In a specific embodiment, two first glass fiber layers 13 and one second glass fiber layer 14 are repeated and laid as a laminated plate structure unit, and the total number of layers is 90, which not only ensures the overall rigidity of the end plate 1, but also does not make the thickness of the end plate 1 too large.

[0061] As shown, Figure 1 The end plates 1 on both sides of the battery monomer 2 are respectively a first end plate 15 and a second end plate 16, and the first end plate 15 and the second end plate 16 are fastened and connected by a screw rod 3 and a nut.

[0062] The first end plate 15 is provided with a plurality of first through holes, and the second end plate 16 is provided with a plurality of second through holes, and the first through holes and the second through holes correspond one by one. The rod part 31 of the screw rod 3 penetrates through the first through hole of the first end plate 15 and the second through hole of the second end plate 16, the head part 32 of the screw rod 3 abuts against the first end plate 15, and the nut is screwed on the rod part 31 of the screw rod 3 from the side of the second end plate 16 away from the electrode 21. After installation is completed, under the pulling action of the screw rod 3 and the nut, the first end plate 15 and the second end plate 16 clamp the battery monomer 2.

[0063] The first and second through holes can be provided in a number of 30, respectively, and the diameter can be 19 mm.

[0064] In order to prevent the head 32 of the screw 3 from rotating, as shown, a limiting hole 151 is provided on the side surface of the first end plate 15 away from the electrode 21, and the limiting hole 151 is coaxially arranged with the first through hole. When installed, the head 32 of the screw 3 is placed in the limiting hole 151, and the limiting hole 151 limits the rotation of the head 32 of the screw 3, preventing the head 32 of the screw 3 from rotating, so that the rod portion 31 of the screw 3 and the nut are displaced in rotation, resulting in a loose connection between the rod portion 31 and the nut. Figure 6

[0065] As shown, the head 32 of the screw 3 is hexagonal, and the limiting hole 151 is oblong. The size of the oblong hole can be 40 mm x 25 mm, and the hole depth is 5 mm. Figure 6

[0066] In other embodiments, the limiting hole 151 can also be rectangular or square.

[0067] In order to prevent the nut from being connected to the screw 3, and the second end plate 16 from being stress concentrated at the corresponding position, as shown, a mounting hole 161 is provided on the side surface of the second end plate 16 away from the electrode 21, and a gasket 4 is arranged in the mounting hole 161 for the nut to abut against. Figures 7-8

[0068] Specifically, the mounting hole 161 can be a counterbore with a diameter of 50 mm and a depth of 5 mm, and a metal gasket 4 with a thickness of 2 mm is bonded.

[0069] In a specific embodiment, the preparation process of the end plate 1 is as follows:

[0070] In order to produce quickly, the end plate 1 is produced by a prepreg molding process, and the preparation process is as follows:

[0071] 1. Cutting the prepreg, cutting the unidirectional prepreg in the 0° direction (the length direction of the end plate 1) and the 90° direction (the width direction of the end plate 1) according to the layering ratio.

[0072] 2. Laying the prepreg according to the layering table, repeating the laying with two layers of the first glass fiber layer 13 and one layer of the second glass fiber layer 14 as a unit, and the total layering is 90 layers.

[0073] 3. Molding, for example, placing the layered glass fiber and resin into a preheated mold, applying high temperature (for example, 120-150°C) and pressure (for example, 15-20 MPa), so that the resin flows and solidifies into a shape.

[0074] ​​​4. Numerical control cutting, for example, using a numerical control machine tool to precisely process the molded end plate blank, control the tool path through the preset program, complete the contour cutting, hole processing and other processes.

[0075] 5. Bonding the metal gasket 4 in the mounting hole 161, and embedding the threaded insert into the pipe connection hole of the end plate 1.

[0076] In this embodiment, the glass fiber composite end plate replaces the original steel material end plate, the weight is reduced from 165 kg to 43 kg, the weight reduction reaches 73.9%, and the lightweight effect is remarkable. At the same time, the surface protrusion of the assembled stack end plate is smaller than that of the metal end plate, which not only reduces the risk of electrolyte leakage, but also ensures the good surface flatness of the end plate.

[0077] The design process of the stack end plate is introduced below, and the following data is for illustration:

[0078] Because the existing steel material end plate will produce obvious protrusion deformation after long-term operation of the stack, the highest protrusion is about 2 mm. The deformation amount of the metal end plate after assembly is simulated by structure simulation and optimization software, and the deformation amount is used as the target for optimization design of the glass fiber composite end plate. In this way, the lightweight effect is achieved while the protrusion deformation amount is reduced.

[0079] First, the existing 1360x630x25mm thickness steel material flat end plate is analyzed by stack assembly CAE (Computer-Aided Engineering). Because the stack installation pressure is about 30kN, 30 screw rods are evenly distributed with a pre-tightening force of 10kN, the protrusion deformation amount and deformation area of the end plate electrode area under the assembled state are obtained.

[0080] CAE analysis is performed on the glass fiber composite flat end plate to obtain the CAE analysis results of the preliminary scheme.

[0081] The raw material of the end plate is a low-cost thermosetting glass fiber uniaxial prepreg. Because the end plate is a cuboid, in order to reduce the waste of raw materials and reduce the cost of raw materials, 0° and 90° layer direction design is adopted.

[0082] The shape of the glass fiber flat end plate is optimized. Under the same modeling, the stiffness of the glass fiber end plate will be much lower than that of the metal end plate, and the deformation will be greater than that of the metal plate. Therefore, the glass fiber plate will be very thick, not only the material cost will increase, but also the volume of the stack will increase greatly, and the weight reduction effect will not be obvious.

[0083] The inner recess of the end plate is designed towards the electrode. According to the protrusion displacement and the protrusion area of the end plate, multiple shape optimization iterative calculations are performed. First, multiple shape variables are created in the deformation area, and then shape optimization is set. Considering that the inner recess design will not cause large extrusion stress concentration on the electrode area during assembly, the height of the inner recess is limited to 2.5 mm, the middle transition area of the inner recess is designed as an ellipse according to the deformation trend, and is smoothly transitioned to the top surface and the inner side edge area of the electrode frame. The end plate in the area outside the electrode frame is all flat, and only the end plate in the electrode area is designed with an inner recess.

[0084] The layer direction ratio is optimized and calculated: the minimum deformation of the assembled end plate is taken as the target, and the fiber layer ratio of the end plate in the width direction is optimized to 66% and the fiber layer ratio in the length direction is optimized to 34%. The end plate with this ratio has the smallest deformation after assembly.

[0085] After iterative optimization by structure simulation and optimization software analysis, the final thickness of the end plate is 29 mm.

[0086] The inner recess design is a long rectangular inner recess, and an elliptical inner recess is arranged in the center of the long rectangular inner recess. The size of the ellipse is 660*200 mm. The maximum inner recess height of the long rectangular inner recess is 2 mm, the height from the elliptical boundary of the inner recess to the top is 0.5 mm, and the elliptical boundary is smoothly transitioned to the surrounding.

[0087] A 5mm counterbore is formed at the outer surface of the first end plate 15 for limiting the rotation displacement of the screw rod, and a 3mm counterbore is formed at the outer surface of the second end plate 16 for installing a metal gasket to prevent the nut from extruding the glass plate and causing local material damage.

[0088] A counterbore is formed at the pipe installation point area of the end plate, and a metal threaded nest is embedded for fixing the pipeline.

[0089] In a second aspect, the embodiments of the present application also provide a stack, which comprises a battery monomer 2 and a stack end plate as described in any of the above embodiments. The end plates 1 on both sides of the battery monomer 2 are connected through a fastening assembly, the battery monomer 2 is clamped between the two end plates 1, and the first compensation protrusion 11 and the second compensation protrusion 12 of the end plate 1 tend to be flat under the extrusion of the electrode 21 of the battery monomer 2, so as to compensate for the elastic deformation of the end plate 1 outward.

[0090] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A stack end plate, characterized in that, the end plate is used for clamping a battery cell of a stack, the end plate has a first compensation protrusion and a second compensation protrusion, the first compensation protrusion is formed by arching the region corresponding to the electrode of the battery cell of the end plate in the direction of the electrode, and the second compensation protrusion is formed by arching the central region of the first compensation protrusion in the direction of the electrode; when the end plate clamps the battery cell, the first compensation protrusion and the second compensation protrusion tend to flatten under the extrusion of the electrode to compensate for the elastic deformation of the end plate outward.

2. The stack end plate of claim 1, wherein the first compensation protrusion is formed by arching the region corresponding to the electrode of the battery cell of the end plate in the direction of the electrode as a whole, and the second compensation protrusion is formed by arching the central region of the first compensation protrusion in the direction of the electrode as a whole.

3. The stack end plate of claim 2, wherein, the side away from the electrode and the side towards the electrode of the first compensation protrusion respectively have a first concave curved surface and a first convex curved surface, the concave amplitude of the first concave curved surface is consistent with the convex amplitude of the first convex curved surface, and the maximum concave depth of the first concave curved surface is A, 1.5mm≤A≤2mm; the side away from the electrode and the side towards the electrode of the second compensation protrusion respectively have a second concave curved surface and a second convex curved surface, the concave amplitude of the second concave curved surface is consistent with the convex amplitude of the second convex curved surface, and the maximum concave depth of the second concave curved surface is B, 0.4mm≤B≤0.5mm.

4. The stack end plate of claim 1, wherein, In the thickness direction of the end plate, the projection of the first compensation protrusion is a rectangle or a square or a circle or an oblong, and the projection of the second compensation protrusion is an ellipse or an oblong or a rhombus or a rectangle.

5. The stack end plate of claim 1, wherein, The end plate is made of glass fiber, and the thickness of the end plate is H, 27mm≤H≤31mm.

6. The stack end plate of claim 5, wherein, The end plate is a rectangular end plate, and the end plate includes a plurality of glass fiber layers, the plurality of glass fiber layers include a first glass fiber layer and a second glass fiber layer, the fiber layer direction of the first glass fiber layer is the width direction of the end plate, and the fiber layer direction of the second glass fiber layer is the length direction of the end plate.

7. The stack end plate of claim 6, wherein, The end plate includes a plurality of groups of glass fiber layers, the plurality of groups of glass fiber layers are stacked in the thickness direction of the end plate, each group of glass fiber layers includes two first glass fiber layers and one second glass fiber layer, and the two first glass fiber layers and the one second glass fiber layer are stacked in turn.

8. The stack end plate of claim 1, wherein, The end plate includes a first end plate for mounting a screw rod, a coaxial first through hole and a limiting hole are formed on the side surface of the first end plate away from the electrode, the first through hole is used for the rod part of the screw rod to pass through, and the limiting hole is used for limiting the rotation of the head part of the screw rod.

9. The stack end plate of claim 1, wherein, The end plate includes a second end plate for mounting a nut, a mounting hole is formed on the side surface of the second end plate away from the electrode, and a gasket for abutting and pressing the nut is arranged in the mounting hole.

10. A stack, characterized by The stack includes a battery cell and the stack end plate of any one of claims 1-9, the end plates on both sides of the battery cell are connected through a fastening assembly, the battery cell is clamped between the end plates on both sides, and the first compensation protrusion and the second compensation protrusion of the end plate tend to flatten under the extrusion of the electrode of the battery cell to compensate for the elastic deformation of the end plate outward.

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