Laminated central liquid-cooled lithium battery roll core structure

Abstract

The utility model relates to the technical field of lithium batteries, and particularly provides a laminated central liquid cooling lithium battery roll core structure which comprises a roll core left part, a liquid cooling plate, a roll core right part and an insulating film, the liquid cooling plate comprises a liquid cooling plate main body, a plurality of internal flow channels are arranged in the liquid cooling plate main body, the middle parts of the top end and the bottom end of the liquid cooling plate main body extend upwards to form a welding part, and a plurality of cooling liquid collecting ports communicated with the internal flow channels are formed in the welding part; the liquid cooling plate is located between the roll core left part and the roll core right part and is separated from the roll core left part and the roll core right part through a continuous diaphragm, and the insulating film wraps a stacked structure formed by the roll core left part, the liquid cooling plate and the roll core right part. According to the utility model, the heat dissipation area is multiplied, the heat management efficiency is obviously improved, the operation energy consumption of a battery system is effectively reduced, the energy density of the battery is improved, meanwhile, the production cost and the maintenance cost are lower, the size compatibility is good, and the generalization can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery technical field especially a laminated center liquid -cooled lithium battery roll core structure. BACKGROUND

[0002] Compared with the traditional winding type lithium battery, the laminated lithium battery has higher energy density, longer cycle life, better safety, higher flexibility and better heat dissipation performance, and therefore has broad application prospect and development potential.

[0003] However, the laminated lithium battery also has some challenges, such as further optimization of heat dissipation performance. It is known that due to the scale cluster characteristics of lithium ion batteries applied in energy storage systems, the thermal runaway of single battery will further spread rapidly in the whole battery box and even the whole energy storage system, forming chain combustion and explosion reaction. In order to better prevent the thermal runaway of lithium ion battery, the temperature control of lithium battery during use is very important.

[0004] In the prior art, the temperature control of the laminated lithium battery is mainly through external cooling, such as adding cooling plates at the bottom or side of the lithium battery to indirectly reduce the temperature of the lithium battery during use and improve the high temperature performance. However, the external cooling has the following disadvantages: (1) it will reduce the space utilization of the module or Pack system; (2) the interval between the external liquid cooling channels is relatively large, which needs to be designed and developed according to the volume of the selected battery, and cannot be universalized, so the battery size compatibility is poor; (3) the bottom heat dissipation performance is greatly affected by the heat conduction path, and the heat dissipation path is cooling plate-battery contact surface-battery interior or cooling plate-battery bottom-battery middle-battery top, the heat transfer path is long, and the cooling effect is poor; as for the currently widely used bottom cooling method, the actual temperature difference between the bottom and top of the battery can reach 20℃; (4) the production cost and maintenance cost are high, such as the design and manufacture of heat pipe system are relatively complex and high in cost, and the phase change material may fail after complete melting and needs to be replaced regularly.

[0005] Therefore, the present application is proposed. UTILITY MODEL CONTENT

[0006] In view of the above disadvantages of the prior art, the utility model provides a laminated center liquid-cooled lithium battery roll core structure.

[0007] In order to achieve the above purpose, the utility model adopts the main technical scheme comprising:

[0008] A laminated center liquid-cooled lithium battery roll core structure comprises a roll core left part, a liquid cooling plate, a roll core right part and an insulating film.

[0009] The left part of the winding core is a laminated structure formed by folding the left part of the diaphragm in a "Z" shape and inserting the left part of the negative plate and the left part of the positive plate into the left part of the diaphragm layer by layer alternately, and the plurality of groups of left part of the negative plate and the plurality of groups of left part of the positive plate are wrapped by the left part of the diaphragm.

[0010] The liquid cooling plate comprises a liquid cooling plate body, a plurality of internal flow channels are arranged in the liquid cooling plate body, a welding portion is formed by extending the middle part of the top end and the bottom end of the liquid cooling plate body upward, and a plurality of cooling liquid collection openings in communication with the internal flow channels are arranged in the welding portion.

[0011] The right part of the winding core is a laminated structure formed by folding the right part of the diaphragm in a "Z" shape and inserting the right part of the negative plate and the right part of the positive plate into the right part of the diaphragm layer by layer alternately, and the plurality of groups of right part of the negative plate and the plurality of groups of right part of the positive plate are wrapped by the right part of the diaphragm.

[0012] The left part of the diaphragm and the right part of the diaphragm are the same continuous diaphragm, the liquid cooling plate is located between the left part of the winding core and the right part of the winding core and is separated from the left part of the winding core and the right part of the winding core by the continuous diaphragm, and the insulating film is wrapped outside the laminated structure formed by the left part of the winding core, the liquid cooling plate and the right part of the winding core.

[0013] Preferably, the liquid cooling plate body is a hollow cavity, a plurality of heat exchange structures are arranged in the hollow cavity, and a plurality of internal flow channels are formed between the heat exchange structures and the inner wall of the hollow cavity and between adjacent heat exchange structures.

[0014] Preferably, the heat exchange structure is selected from at least one of a first heat exchange structure, a second heat exchange structure and a third heat exchange structure, the first heat exchange structure is a flat plate, the second heat exchange structure is a corrugated plate, and the third heat exchange structure is a labyrinth structure.

[0015] Preferably, a plurality of vertical distribution and non-penetrating through holes are arranged between the two welding portions.

[0016] Preferably, the welding portion is 5-15mm higher than the top end or the bottom end, and the remaining part of the top end and the bottom end is flush with the left part of the winding core and the right part of the winding core on both sides.

[0017] Preferably, the left part of the winding core and the right part of the winding core are equal in height and width, the ratio of the height of the liquid cooling plate to the height of the left part of the winding core is 1-1.5, the ratio of the width of the liquid cooling plate to the width of the left part of the winding core is 1-1.5, and the ratio of the total area of the internal flow channels to the total area of the outer surface of the liquid cooling plate is 0.5-5.

[0018] Preferably, the surface of the liquid cooling plate body is flat and provided with an insulating layer, the insulating layer comprises a ceramic insulating layer, a PVC insulating layer, a Teflon insulating layer and a polyimide insulating layer, the thickness of the liquid cooling plate body is 3-8mm, and the thickness of the insulating layer is 0.02-0.05mm.

[0019] Preferably, the surface of the left part negative plate and the right part negative plate is distributed with a plurality of indentations; the left part negative plate and the right part negative plate adjacent to the liquid cooling plate body and the left part negative plate and the right part negative plate of the outermost layer are all negative plates with single surface coated with negative electrode paste.

[0020] Preferably, the layer number of the left part negative plate, the left part positive plate, the right part negative plate and the right part positive plate is 20-100 layers; the layer number ratio of the left part negative plate to the right part negative plate and the layer number ratio of the left part positive plate to the right part positive plate are same, and are 0.9-1.1.

[0021] Preferably, the height, the width and the thickness are represented by H, W and T respectively, 100mm≤H≤1000mm, 100mm≤W≤500mm, 10mm≤T≤200mm, 0.2≤H / W≤10, 0.5≤W / T≤50.

[0022] Compared with the prior art, the utility model has at least the following beneficial effects:

[0023] 1. By setting the liquid cooling plate at the middle position, the heat dissipation area is multiplied, the thermal management efficiency is significantly improved, the operation energy consumption of the battery system is effectively reduced, and it is especially suitable for extreme high heat and high cold environment;

[0024] 2. The winding core structure is formed in the way of the laminated sheet, the volume utilization rate of the winding core structure shell is effectively improved, and the energy density of the battery can be further increased;

[0025] 3. The production cost and the maintenance cost of the utility model are low, and the cost involved in the design, manufacturing and maintenance is lower than that of the existing heat pipe system;

[0026] 4. The utility model has good size compatibility and can be universalized. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0028] Figure 1 It is a sectional view along the horizontal direction of the utility model;

[0029] Figure 2 It is Figure 1 It is an enlarged structure schematic view of A in the middle;

[0030] Figure 3 It is Figure 1 It is an enlarged structure schematic view of B in the middle;

[0031] Figure 4 is a schematic view of a three-dimensional structure of the present application;

[0032] Figure 5 is one embodiment of the liquid cooling plate of the present application;

[0033] Figure 6 is another embodiment of the liquid cooling plate of the present application;

[0034] Figure 7 is still another embodiment of the liquid cooling plate of the present application;

[0035] Figure 8 is another embodiment of the liquid cooling plate of the present application.

[0036] In the figure: 1, left part of the core; 11, left part of the diaphragm; 12, left part of the negative plate; 13, left part of the positive plate; 2, liquid cooling plate; 21, main body of the liquid cooling plate; 22, cooling liquid collection port; 23, internal flow channel; 24, first heat exchange structure; 25, second heat exchange structure; 26, third heat exchange structure; 27, through hole; 3, right part of the core; 31, right part of the diaphragm; 32, right part of the negative plate; 33, right part of the positive plate; 4, insulating film. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0038] The structures not described in detail in the following embodiments are all prior art, and the orientation words such as "upper surface", "lower surface", "bottom surface" and the like used for clearly describing the structures of the components are only used to describe the relative position relationship, and are not used to limit the protection scope of the present application. In addition, the terms "first" and "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "several" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0039] As Figures 1-4 Commonly shown: the present application proposes a laminated center liquid cooling lithium battery core structure, comprising: left part of the core 1, liquid cooling plate 2, right part of the core 3 and insulating film 4;

[0040] The left part 1 of the winding core is a laminated structure formed by folding the left part separator 11 in a "Z" shape and inserting the left part negative plate 12 and the left part positive plate 13 into the left part separator 11 alternately layer by layer, and the plurality of groups of left part negative plates 12 and the plurality of groups of left part positive plates 13 are all wrapped by the left part separator 11;

[0041] The liquid cooling plate 2 comprises a liquid cooling plate body 21, a plurality of internal flow channels 23 are arranged in the liquid cooling plate body 21, and a welding portion is formed by extending the middle part of the top end and the bottom end of the liquid cooling plate body 21 upwards, a plurality of cooling liquid collection openings 22 in communication with the internal flow channels 23 are arranged in the welding portion;

[0042] The right part 3 of the winding core is a laminated structure formed by folding the right part separator 31 in a "Z" shape and inserting the right part negative plate 32 and the right part positive plate 33 into the right part separator 31 alternately layer by layer, and the plurality of groups of right part negative plates 32 and the plurality of groups of right part positive plates 33 are all wrapped by the right part separator 31;

[0043] The left part separator 11 and the right part separator 31 are the same continuous separator, the liquid cooling plate 2 is located between the left part 1 and the right part 3 of the winding core and is separated from the left part 1 and the right part 3 of the winding core by the continuous separator, and the insulating film 4 is wrapped outside the laminated structure formed by the left part 1, the liquid cooling plate 2 and the right part 3 of the winding core to play the roles of insulation and strengthening fixation.

[0044] Compared with the prior art, the utility model has the advantages of:

[0045] (1) The cooling structure arranged at the bottom or the side of the lithium battery is creatively designed in the middle part of the battery winding core, so that the heat dissipation area is increased by several times, for example, the heat dissipation contact area of the traditional bottom heat dissipation structure is 12600mm 2 , and the heat dissipation contact area of the utility model is 35700mm 2 , the heat dissipation contact area of the utility model is 2.8 times of the traditional heat dissipation contact area, so that the heat management efficiency can be increased by more than 2.8 times, and the energy consumption of the operation of the battery system can be reduced by more than 2 times, so that the utility model is more suitable for the environment of extreme high heat and extreme cold.

[0046] (2) The winding core structure is formed in a laminated mode, the volume utilization rate of the winding core structure shell is effectively improved, and the energy density of the battery can be further increased, for example, compared with the existing winding mode, the volume utilization rate of the winding core structure shell of the utility model is increased by at least 12%, and the energy density of the lithium battery is effectively improved.

[0047] (3) The system integration cost and the system maintenance cost are lower, the equipment investment required in the integration process is smaller, and the integrated components required are fewer.

[0048] (4) The utility model discloses good size compatibility, and generalization can be achieved.

[0049] Need to explain:

[0050] (1) The liquid cooling plate 2 is generally selected from metal materials to facilitate heat transfer, preferably aluminum materials, which are consistent with the material of the cover plate aluminum shell to facilitate welding.

[0051] (2) The distribution of the internal flow channel 23 in the length direction of the liquid cooling plate body 21 is referred to as the length of the internal flow channel 23, and the distribution of the internal flow channel 23 in the width direction of the liquid cooling plate body 21 is referred to as the width of the internal flow channel 23. The length is generally 2-10 mm, and the width is generally 1-5 mm. The length and the width should not be too small, otherwise the cooling liquid flow will be too small, and the cooling effect will be poor. The length and the width should not be too large, otherwise the size of the internal flow channel will be too large, which will help to improve the cooling effect of the cooling liquid, but will not be conducive to the structural stability of the liquid cooling plate body 21.

[0052] (3) In order to improve the binding effect of the insulation film 4 on the laminated structure formed by the left part of the winding core 1, the liquid cooling plate 2 and the right part of the winding core 3, the continuous diaphragm can be wound several times around the periphery of the laminated structure, and then wrapped with the insulation film 4.

[0053] As a preferred technical solution, in another embodiment of the utility model, the liquid cooling plate body 21 is a hollow cavity, and a plurality of heat exchange structures are arranged in the hollow cavity. The heat exchange structures and the inner wall of the hollow cavity form a plurality of through internal flow channels 23 between the heat exchange structures and the adjacent heat exchange structures.

[0054] The cooling liquid enters the hollow cavity from the cooling liquid collection port 22 and flows in each through internal flow channel 23 to cool the liquid cooling plate body 21. It should be noted that the specific structure of the hollow cavity is not limited, and can be any structure such as a cube, a cuboid, a sphere, a cone, a cylinder, etc. as long as it can provide a flow space for the cooling liquid.

[0055] On the basis of the previous embodiment, the heat exchange structure is selected from at least one of the first heat exchange structure 24, the second heat exchange structure 25 and the third heat exchange structure 26. The first heat exchange structure 24 is a flat plate, the second heat exchange structure 25 is a corrugated plate, and the third heat exchange structure 26 is a labyrinth structure. The above heat exchange structures can be obtained by existing technologies such as welding, extrusion and casting.

[0056] As Figure 5As shown: in this embodiment, the first heat exchange structure 24 is flat, and its front and back surfaces are fixedly connected with the front and back inner walls of the hollow cavity. Adjacent two first heat exchange structures 24 are arranged at a certain distance, so that flow channels are formed between adjacent two first heat exchange structures 24 and between the outermost first heat exchange structure 24 and the inner wall of the hollow cavity. The flow channels are connected with each other, and the cooling liquid flows through the flow channels to cool the liquid cooling plate body 21, thereby reducing the temperature of the battery cell. Figure 5 In addition, the first heat exchange structure 24 and the hollow cavity can also be connected in other ways, such as one-sided connection of adjacent two first heat exchange structures 24 with the hollow cavity. For example, one first heat exchange structure 24 is fixedly connected with the front inner wall of the hollow cavity, and the adjacent other first heat exchange structure 24 is fixedly connected with the rear inner wall of the hollow cavity. In this way, a serpentine flow channel is formed in the hollow cavity, and the cooling liquid flows in a serpentine manner in the hollow cavity to increase the flow process and promote heat exchange, thereby improving the cooling effect of the liquid cooling plate 2.

[0057] As shown in the figure: Figure 6 In order to further improve the cooling effect, the second heat exchange structure 25 is preferably a corrugated plate, which has a larger contact area with the cooling liquid than the flat plate, so that the cooling effect of the liquid cooling plate body 21 is better, and the temperature of the battery cell can be reduced to a greater extent.

[0058] In addition to increasing the contact area of the heat exchange structure with the cooling liquid, the cooling effect can also be improved by optimizing the flow channel. As shown in the figure: Figure 7 The third heat exchange structure 26 is a labyrinth structure, which forms a labyrinth-shaped internal flow channel 23 in the hollow cavity. The cooling liquid repeatedly flows in the internal flow channel 23 and fully and completely contacts and exchanges heat with the liquid cooling plate body 21, so that the cooling effect is better. Of course, other heat exchange structures that can realize the through-flow of the cooling liquid can also be used, and the above structures are only examples.

[0059] In addition, the internal flow channel 23 can also be designed as a non-through structure, as shown in the figure: Figure 8 A plurality of vertical through holes 27 are arranged between the two welding portions and do not penetrate each other. The through holes 27 penetrate the top end and the bottom end of the cooling plate body 21, and the inlet and outlet of the through holes 27 form cooling liquid collection ports 22. The cooling liquid enters one cooling liquid collection port 22 and is discharged from another cooling liquid collection port 22. Generally, the non-through structure has a shorter flow process of the cooling liquid, and the heat exchange is relatively incomplete, so the cooling effect is relatively limited, and it is not as good as the through structure as shown in the figure. Figure 5 、 Figure 6 、 Figure 7

[0060] ​In order to guarantee the welding effect of the welding part and the cover plate, as a preferred technical scheme, in another embodiment of the utility model, the welding part is 5-15mm higher than the top end or the bottom end, and the top end and the rest of the bottom end are flush with the left core part 1 and the right core part 3 on both sides.

[0061] As a preferred technical scheme, in another embodiment of the utility model, the left core part 1 and the right core part 3 are equal in height and width, the ratio of the height of the liquid cooling plate 2 to the height of the left core part 1 is 1-1.5, the ratio of the width of the liquid cooling plate 2 to the width of the left core part 1 is 1-1.5, and the ratio of the total area of the internal flow channel 23 to the total area of the outer surface of the liquid cooling plate 2 is 0.5-5.

[0062] The left core part 1 and the right core part 3 are equal in height and width, which can ensure the battery performance and provide the battery energy density, and the alignment is good and no material is wasted, so that the advantages of the laminated core are maximized. The utility model discloses that through the innovative experiment, when the ratio of the height of the liquid cooling plate 2 to the height of the left core part 1 is 1-1.5, the ratio of the width of the liquid cooling plate 2 to the width of the left core part 1 is 1-1.5, and the ratio of the total area of the internal flow channel 23 to the total area of the outer surface of the liquid cooling plate 2 is 0.5-5, the cooling liquid can be in more sufficient contact with the core, so that the heat generated by the core can be more effectively taken away, the temperature of the core is reduced, the overall heat dissipation efficiency is improved, meanwhile, the flow of the cooling liquid in the internal flow channel 23 is more uniform, the temperature gradient in the core is reduced, and the service life and performance of the core are prolonged. Moreover, the core structure meeting the requirement has large strength and good stability, and the installation and maintenance of the core are facilitated.

[0063] In order to prevent the mechanical damage of the pole piece and the isolation from the current collector, and prevent the occurrence of short circuit, as a preferred technical scheme, in another embodiment of the utility model, the surface of the liquid cooling plate body 21 is smooth and provided with an insulating layer, and the insulating layer comprises a ceramic insulating layer, a PVC insulating layer, a Teflon insulating layer and a polyimide insulating layer. Specifically, the thickness of the liquid cooling plate body 21 is 3-8mm, and the thickness of the insulating layer is 0.02-0.05mm.

[0064] The surface of the liquid cooling plate body 21 is smooth, and the smoothness is preferably not greater than 0.1mm, so that the mechanical damage of the pole piece can be effectively prevented during the processing of the liquid cooling plate body 21 meeting the smoothness requirement. Further, the liquid cooling plate body 21 also needs to be insulated by setting the insulating layer on the basis of the smooth surface, so that the liquid cooling plate body 21 can be isolated from the current collector and prevent the occurrence of short circuit. In addition, the liquid cooling plate body 21 also needs to have considerable corrosion resistance.

[0065] The utility model discloses through several times innovative test found: when the thickness of liquid cooling plate main part 21 is 3-8mm, liquid cooling plate main part 21 has better heat dissipation efficiency, can effectively maintain the temperature stability in the use process of electric core structure.

[0066] As a preferred technical scheme, in a further embodiment of the utility model, the surfaces of the left negative plate 12 and the right negative plate 32 are distributed with a plurality of indentations; the left negative plate 12 and the right negative plate 32 adjacent to the liquid cooling plate main body 21 and the left negative plate 12 and the right negative plate 32 at the outermost layer are negative plates with negative paste coated on one side.

[0067] The two surfaces of the negative plate are distributed with a plurality of indentations, and the existence of the indentations: (1) can increase the surface area of the negative plate without significantly increasing the total volume of the negative plate, which helps to improve the liquid retention capacity of the negative plate and promote heat dissipation; (2) helps to shorten the transmission path of ions in the electrolyte, reduce the transmission resistance of ions, and improve the ion transmission efficiency of the battery; (3) can reduce stress concentration and deformation caused by volume change during charging and discharging, and enhance the structural stability.

[0068] The left negative plate 12 and the right negative plate 32 adjacent to the liquid cooling plate main body 21 and the left negative plate 12 and the right negative plate 32 at the outermost layer are negative plates with negative paste coated on one side, which can reduce the weight of the negative plate on one hand and help to strengthen the contact between the left negative plate 12 and the right negative plate 32 at the outermost layer and the insulating film 4, ensuring the binding effect of the insulating film 4 and preventing quality problems such as edge curling and edge lifting.

[0069] As a preferred technical scheme, in a further embodiment of the utility model, the number of layers of the left negative plate 12, the left positive plate 13, the right negative plate 32 and the right positive plate 33 is 20-100 layers; the ratio of the number of layers of the left negative plate 12 to the right negative plate 32 and the ratio of the number of layers of the left positive plate 13 to the right positive plate 33 are the same, both being 0.9-1.1.

[0070] If the number of layers of the positive plate and the negative plate on both sides of the liquid cooling plate 2 is too large, it will result in the utility model being too thick, exceeding the cooling capacity range of the liquid cooling plate 2, which is not conducive to temperature control during battery operation; if the number of layers of the positive plate and the negative plate on both sides of the liquid cooling plate 2 is too small, it will result in the energy density of the utility model being too low and the battery having poor energy storage capacity; when the number of layers of the plate is 20-100 layers, the winding core structure has high energy density, good energy storage capacity and good temperature control performance.

[0071] In addition, in order to ensure that the heat dissipation path is uniform, the thickness of the left part 1 and the right part 3 of the winding core is as same as possible or close to each other, which is reflected in the number relationship of the pole pieces, that is, the layer number ratio of the left part negative pole piece 12 and the right part negative pole piece 32 and the layer number ratio of the left part positive pole piece 13 and the right part positive pole piece 33 are the same, and are 0.9-1.1.

[0072] As a preferred technical solution, another embodiment of the utility model, high, wide, thick respectively with H, W, T represent, 100mm≤H≤1000mm, 100mm≤W≤500mm, 10mm≤T≤200mm, 0.2≤H / W≤10, 0.5≤W / T≤50.

[0073] When the winding core structure meets the above requirements, it can obtain higher battery energy density and better thermal management performance under the premise of ensuring safety, and is convenient for production, and the production equipment used is more standardized and automated, which helps to obtain higher production efficiency at lower cost, thereby promoting its standardization and compatibility, and meeting the needs of various application scenarios.

[0074] In addition, the utility model also includes positive and negative ears, the positive and negative ears are located at both sides of the liquid cooling plate 2 respectively, and the leading direction of the positive and negative ears can be located at the top end of the winding core structure, or at the bottom end of the winding core structure, or one at the top end and one at the bottom end.

[0075] Although the embodiments of the utility model have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the utility model, and the person skilled in the art can make changes, modifications, replacements and deformations to the above embodiments within the scope of the utility model. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of different embodiments or examples without mutual contradiction.

Claims

1. A laminated center liquid-cooled lithium battery roll core structure, characterized in that, The application relates to a liquid-cooled battery cell, which comprises a left winding core (1), a liquid-cooled plate (2), a right winding core (3) and an insulating film (4). The left winding core (1) is a laminated structure formed by folding a left separator (11) in a "Z" shape and alternately inserting left negative electrode sheets (12) and left positive electrode sheets (13) into the left separator (11) layer by layer, wherein a plurality of groups of the left negative electrode sheets (12) and a plurality of groups of the left positive electrode sheets (13) are wrapped by the left separator (11). The liquid-cooled plate (2) comprises a liquid-cooled plate body (21), a plurality of internal flow channels (23) are arranged in the liquid-cooled plate body (21), and a welding portion is formed by extending the middle part of the top end and the bottom end of the liquid-cooled plate body (21) upwards; a plurality of cooling liquid collection openings (22) in communication with the internal flow channels (23) are arranged in the welding portion. The right winding core (3) is a laminated structure formed by folding a right separator (31) in a "Z" shape and alternately inserting right negative electrode sheets (32) and right positive electrode sheets (33) into the right separator (31) layer by layer, wherein a plurality of groups of the right negative electrode sheets (32) and a plurality of groups of the right positive electrode sheets (33) are wrapped by the right separator (31). The left separator (11) and the right separator (31) are the same continuous separator, the liquid-cooled plate (2) is arranged between the left winding core (1) and the right winding core (3) and is separated from the left winding core (1) and the right winding core (3) by the continuous separator, and the insulating film (4) is wrapped outside the laminated structure formed by the left winding core (1), the liquid-cooled plate (2) and the right winding core (3). The liquid-cooled plate body (21) is a hollow cavity, a plurality of heat exchange structures are arranged in the hollow cavity, and a plurality of internal flow channels (23) are formed between the heat exchange structures and the inner wall of the hollow cavity and between adjacent heat exchange structures.

2. The laminated center liquid-cooled lithium battery jelly-roll core structure of claim 1, wherein, The heat exchange structures are selected from at least one of a first heat exchange structure (24), a second heat exchange structure (25) and a third heat exchange structure (26), the first heat exchange structure (24) is a flat plate, the second heat exchange structure (25) is a corrugated plate, and the third heat exchange structure (26) is a labyrinth structure. 3.The laminated center liquid-cooled lithium battery roll core structure of claim 2, wherein, A plurality of vertical distribution and non-penetrating through holes (27) are arranged between the two welding portions. 4.The laminated center liquid-cooled lithium battery roll core structure of claim 1, wherein, The welding portion is 5-15 mm higher than the top end or the bottom end, and the remaining part of the top end and the bottom end is flush with the left winding core (1) and the right winding core (3) on both sides. 5.The laminated center liquid-cooled lithium battery roll core structure of claim 1, wherein, The left winding core (1) and the right winding core (3) are equal in height and width, the height ratio of the liquid-cooled plate (2) to the left winding core (1) is 1-1.5, the width ratio of the liquid-cooled plate (2) to the left winding core (1) is 1-1.5, and the total area ratio of the internal flow channels (23) to the total area of the outer surface of the liquid-cooled plate (2) is 0.5-5. 6.The laminated center liquid-cooled lithium battery roll core structure of claim 1, wherein, The surface of the liquid-cooled plate body (21) is flat and provided with an insulating layer, the insulating layer comprises a ceramic insulating layer, a PVC insulating layer, a Teflon insulating layer and a polyimide insulating layer, the thickness of the liquid-cooled plate body (21) is 3-8 mm, and the thickness of the insulating layer is 0.02-0.05 mm.

7. The laminated center liquid-cooled lithium battery jelly-roll core structure of claim 1, wherein, ​ 8. The laminated center liquid-cooled lithium battery cell core structure of claim 1, wherein, The surfaces of the left negative electrode sheet (12) and the right negative electrode sheet (32) are distributed with a plurality of indentations; the left negative electrode sheet (12) and the right negative electrode sheet (32) adjacent to the liquid cooling plate body (21) and the outermost left negative electrode sheet (12) and the right negative electrode sheet (32) are single-sided coated with negative electrode slurry.

9. The laminated center liquid-cooled lithium battery cell core structure of any one of claims 1-8, wherein, The number of layers of the left negative electrode sheet (12), the left positive electrode sheet (13), the right negative electrode sheet (32) and the right positive electrode sheet (33) is 20-100 layers; the ratio of the number of layers of the left negative electrode sheet (12) to the right negative electrode sheet (32) and the ratio of the number of layers of the left positive electrode sheet (13) to the right positive electrode sheet (33) are the same, both being 0.9-1.

1. 10.The laminated center liquid-cooled lithium battery roll core structure of claim 9, wherein, The height, width and thickness are represented by H, W and T respectively, 100mm≤H≤1000mm, 100mm≤W≤500mm, 10mm≤T≤200mm, 0.2≤H / W≤10, 0.5≤W / T≤50.

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