An immersive liquid-cooled battery module structure and its assembly method

Abstract

The present invention provides an immersive liquid-cooled battery module structure, which includes a hollow housing, and at least one first through hole is formed in one end plate thereof; at least one sleeve is inserted into the first through hole, and at least one sleeve is sealingly connected to the housing for encapsulating a bare battery cell; a partition plate is inserted into the housing, and the partition plate also sleeves on the outer surface of at least one sleeve and is sealingly connected to the sleeve, dividing the internal space of the housing outside each sleeve into a non-communicating first cavity and a second cavity; wherein, heat exchange media are arranged in both the first cavity and the second cavity, and a liquid inlet and a liquid outlet are formed in the housing where the first cavity is located. The heat exchange media in the first cavity and the second cavity respectively exchange heat with different parts of the sleeve and the bare battery cell, and the heat exchange media in the first cavity and the second cavity also exchange heat through the partition plate.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and in particular to an immersion liquid-cooled battery module structure and an assembly method thereof. Background Art

[0002] Existing cylindrical battery cells are generally encapsulated by steel shells, aluminum shells or aluminum-plastic films. After encapsulation, the battery cells are arranged and combined to form a battery module. After the battery modules are densely arranged, the internal space is compact, and the heat dissipation problem needs to be properly solved. In order to dissipate heat from the battery module, some auxiliary heat dissipation structures have emerged on the market. For example, a liquid-cooling plate or a serpentine heat dissipation plate is further provided in the encapsulation structure of the battery module. This will bring the following problems: 1) The existing battery module first encapsulates the bare battery cells into battery cells, and then further arranges and encapsulates the battery cells to form a battery module structure. The multiple encapsulations involve many components and processes, resulting in low assembly efficiency; 2) The liquid-cooling plate or the serpentine heat dissipation plate not only increases the total weight of the battery module and reduces the energy density, but also the liquid-cooling plate or the serpentine heat dissipation plate is generally a flat structure and can only contact with the surface part of each battery cell. This will cause the temperature of the contact part between the battery cell and the liquid-cooling plate to decrease, while the temperature of the part of the battery cell that does not directly contact the liquid-cooling plate is relatively high, which may cause uneven temperature distribution of the battery cell, and in severe cases, may cause phenomena such as battery short circuit.

[0003] Chinese patent document with publication number CN112103594A discloses a structure of an immersion liquid-cooled battery pack. A plurality of battery groups are arranged inside the housing. A bottom bracket is arranged at the bottom of each battery group, a top cross beam is arranged at the top of the battery group, and the square battery cells of each battery group are arranged at intervals along the horizontal extension direction of the top cross beam. There is also a gap between adjacent battery groups. An inlet liquid cavity and an outlet liquid cavity are respectively arranged at both ends of the housing. This solution does not use a liquid-cooling plate, but allows the coolant to flow through the outer surfaces of each battery cell in turn, which can improve the heat exchange effect with the whole battery cell. However, before encapsulation, the bare battery cells still need to be individually encapsulated into square battery cells in advance, and then each square battery cell is installed into the housing one by one. The installation process is still relatively cumbersome. Therefore, it is very necessary to provide an immersion liquid-cooled battery module structure and an assembly method thereof with simple assembly process, good heat exchange effect and heat diffusion suppression function. Summary of the Invention

[0004] In view of this, the present invention provides an immersion liquid-cooled battery module structure and an assembly method thereof with a simple encapsulation structure, good heat exchange effect and heat diffusion suppression function for battery cells.

[0005] The technical solution of the present invention is realized as follows:

[0006] On the one hand, this aspect provides an immersion liquid-cooled battery module structure, including

[0007] A housing, which is a hollow structure, and at least one first through-hole is formed in one end plate thereof;

[0008] At least one sleeve is inserted into the at least one first through-hole and is hermetically connected to the housing; it is used for encapsulating a bare battery cell;

[0009] A partition plate is inserted into the housing. The partition plate also sleeves the outer surface of the at least one sleeve and is hermetically connected to the at least one sleeve; the internal space of the housing outside each sleeve is divided into a non-communicating first cavity and a second cavity;

[0010] Wherein, a heat exchange medium is arranged in both the first cavity and the second cavity, and a liquid inlet and a liquid outlet are formed in the housing where the first cavity is located.

[0011] On the basis of the above technical solutions, preferably, a plurality of first pressure relief openings are further arranged on the end plate of the housing where the at least one first through-hole is formed; the plurality of first pressure relief openings are arranged in a staggered manner with the at least one first through-hole; the plurality of first pressure relief openings in the open state communicate the second cavity with the outside of the housing.

[0012] Preferably, the plurality of first pressure relief openings are linear chute marks, blind holes or annular grooves arranged on the surface of the housing.

[0013] Preferably, connection ribs are further arranged between adjacent sleeves or between the at least one sleeve and the inner surface of the housing; the connection ribs are respectively fixedly connected to the end plate of the housing where the at least one first through-hole is formed or the outer surface of the at least one sleeve; the connection ribs also abut against the partition plate close to the end plate of the housing where at least one first through-hole is formed; the connection ribs, the outer surface of the at least one sleeve, the inner surface of the housing and the end face of the partition plate close to the end plate of the housing where at least one first through-hole is formed enclose the second cavity; the outer surface of the at least one sleeve, the inner surface of the housing and the end face of the partition plate far from the end plate of the housing where at least one first through-hole is formed enclose the first cavity.

[0014] Preferably, the heat exchange medium in the first cavity is different from the heat exchange medium in the second cavity; the heat exchange medium in the first cavity is ethylene glycol solution; the heat exchange medium in the second cavity is perfluorohexanone.

[0015] Preferably, the bare battery cell includes a battery cell body, an upper tab, a lower tab, and a top cover assembly; the battery cell body, the upper tab, and the lower tab are all embedded inside the sleeve; the upper tab is fixedly arranged at one end of the battery cell body close to the end plate of the housing where at least one first through hole is opened; the lower tab is fixedly arranged at the other end of the battery cell body away from the end plate of the housing where at least one first through hole is opened, and the lower tab is fixedly connected to the inner surface of the sleeve away from the end plate of the housing where at least one first through hole is opened; the top cover assembly is fixedly arranged at at least one first through hole of the housing, and the top cover assembly also extends into at least one sleeve and is electrically connected to the upper tab.

[0016] Based on the above technical solutions, preferably, the top cover assembly includes a top cover body, a pole column assembly, a first insulating layer, and a second insulating layer; a third through hole is provided on the top cover body, a first insulating layer is provided on the side of the top cover body close to the sleeve, and a second insulating layer is provided on the side of the top cover body away from the sleeve; the pole column assembly sequentially passes through the second insulating layer, the third through hole, and the first insulating layer and extends into the sleeve, and is electrically connected to the upper tab; the first insulating layer or the second insulating layer is hermetically connected to the pole column assembly and the top cover body; the edge of the first insulating layer also extends along the axial direction of the sleeve and abuts against the contour of the battery cell body.

[0017] Preferably, the pole column assembly includes a pole column body and at least one pressing part, the pole column body is arranged on the side of the top cover body away from the sleeve, a through fourth through hole is provided on the pole column body, the fourth through hole communicates with the third through hole, one end of the pressing part abuts against one end of the pole column body away from the end plate of the housing where at least one first through hole is opened, and the other end of the pressing part sequentially passes through the fourth through hole, the third through hole, and the first insulating layer and is electrically connected to the upper tab.

[0018] Preferably, a second pressure relief port is further provided on the top cover body, and the second pressure relief port is a linear chute notch, a blind hole, or an annular groove provided on the surface of the top cover body away from the housing.

[0019] On the other hand, the present invention also provides an assembly method for an immersion liquid-cooled battery module, including the structure of the immersion liquid-cooled battery module described above, specifically including the following steps:

[0020] S1: Extrude and form the housing, at least one sleeve, and each connecting rib by using a mold;

[0021] S2: Install a partition plate at a suitable position inside the housing, so that the partition plate surrounds the outer surface of each sleeve in the radial direction, and fixedly and hermetically connect the partition plate to the outer surface of each sleeve and the inner surface of the housing; the end face of the partition plate close to the first through hole, the connecting rib, the outer surface of the sleeve, and the inner surface of the housing enclose a second cavity; the end face of the partition plate away from the first through hole, the outer surface of the sleeve, and the inner surface of the housing enclose a first cavity;

[0022] S3: Inject heat exchange medium into the first cavity and the second cavity in a sealed state;

[0023] S4: Place the battery cell body provided with upper and lower tabs into the sleeve, fixedly connect the lower tab of the bare battery cell to the inner surface of the end plate of the sleeve away from the housing where at least one first through hole is opened; fixedly and sealingly install the top cover assembly at each first through hole; make the part of the top cover assembly extending into the first through hole and the sleeve abut against the upper tab of the bare battery cell or the battery cell body, and the pole column assembly of the top cover assembly forms the positive electrode; then inject electrolyte into the sleeve, and an immersed liquid-cooled battery module structure is obtained.

[0024] An immersed liquid-cooled battery module structure and its assembly method provided by the present invention have the following beneficial effects compared with the prior art:

[0025] (1) This solution adopts a structure in which the bare battery cell is directly encapsulated with the housing or the sleeve, skipping the steps of first encapsulating the bare battery cell into a battery cell and then encapsulating the battery cell into the housing, simplifying the assembly process of the battery module; moreover, a second cavity for fixed heat exchange and a first cavity for circulating heat dissipation are provided outside the sleeve for fixing the bare battery cell, and the heat exchange media in different cavities are separated from each other by a partition plate, having better overall heat exchange efficiency;

[0026] (2) The first pressure relief port provided on the cover plate can, when the battery cell has an accidental temperature runaway, enable the heat exchange medium in the second cavity to break open the first pressure relief port and extinguish the fire outside the housing;

[0027] (3) The connecting rib limits the relative positions of the sleeve and the housing and can be used as the installation part of the partition plate; moreover, the connecting rib is located in the second cavity. Compared with the solution of providing connecting ribs in both the first cavity and the second cavity, the resistance to the circulating flow of the heat exchange medium in the first cavity is smaller;

[0028] (4) The bare battery cell is directly encapsulated in the sleeve, the upper tab and the top cover assembly form the positive electrode path, and the lower tab is connected to the housing to form the negative electrode. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a three-dimensional view of an immersed liquid-cooled battery module structure of the present invention;

[0031] Figure 2 Top view of an immersive liquid-cooled battery module structure according to the present invention;

[0032] Figure 3 is Figure 2 Cross-sectional view taken along the A-A direction of;

[0033] Figure 4 Front view of an immersive liquid-cooled battery module structure according to the present invention;

[0034] Figure 5 is Figure 4 Cross-sectional view taken along the B-B direction of;

[0035] Figure 6 Exploded three-dimensional view of an immersive liquid-cooled battery module structure according to the present invention;

[0036] Figure 7 Top view of the housing of an immersive liquid-cooled battery module structure according to the present invention;

[0037] Figure 8 Exploded three-dimensional view of a structure of the cover plate of an immersive liquid-cooled battery module according to the present invention;

[0038] Figure 9 Three-dimensional view of an immersive liquid-cooled battery module structure according to the present invention with the cover plate removed from the housing;

[0039] Figure 10 is Figure 9 Top view of;

[0040] Figure 11 Three-dimensional view of the bare battery cells of an immersive liquid-cooled battery module according to the present invention;

[0041] Figure 12 Three-dimensional view of the top cover assembly of an immersive liquid-cooled battery module structure according to the present invention;

[0042] Figure 13 Top view of the top cover assembly of an immersive liquid-cooled battery module structure according to the present invention;

[0043] Figure 14 is Figure 13 Rotated and enlarged cross-sectional view taken along the C-C direction of;

[0044] Figure 15 is Figure 13 Rotated and enlarged cross-sectional view taken along the D-D direction of;

[0045] Figure 16 Flow chart of an assembly method for an immersive liquid-cooled battery module according to the present invention.

[0046] Reference numerals: 1, housing; 2, sleeve; 3, bare battery cell; 4, separator; 11, liquid inlet; 12, liquid outlet; 13, opening; 14, cover plate; 15, first through hole; 100, first cavity; 200, second cavity; 141, first pressure relief port; 300, connecting rib; 40, second through hole; 31, battery cell body; 32, upper tab; 33, lower tab; 34, top cover assembly; 341, top cover body; 342, terminal assembly; 343, first insulating layer; 344, second insulating layer; 345, second pressure relief port; 3421, terminal body; 3422, pressing portion; 400, third through hole; 500, fourth through hole. Detailed implementation manners

[0047] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] The technical solution of the present invention is implemented as follows:

[0049] On the one hand, as Figure 1 shown in FIG. -10, the present invention provides an immersed liquid-cooled battery module structure,

[0050] which includes the following components:

[0051] The housing 1, which is a hollow structure, and at least one first through hole 15 is provided on one end plate thereof; as can be seen from the accompanying drawings, a liquid inlet 11 and a liquid outlet 12 are respectively provided on two opposite end faces of the housing 1, and an opening 13 is provided on one end plate of the housing 1 between the liquid inlet 11 and the liquid outlet 12. A cover plate 14 for closing the opening 13 is provided at the opening 13. The cover plate 14 is hermetically connected to the housing 1, and a number of through first through holes 15 are provided on the cover plate 14; the liquid inlet 11, the liquid outlet 12 or each first through hole 15 is respectively communicated with the inside of the housing 1; the inside of the housing 1 independently forms a coolant channel and a packaging area for the bare battery cell 3. The housing itself is also a part of the liquid-cooled structure.

[0052] At least one sleeve 2 is inserted into the first through hole 15, and at least one sleeve 2 is hermetically connected to the housing 1; each sleeve 2 is used for encapsulating the bare battery cell 3; as shown in the attached drawings, the axial extension direction of each sleeve 2 is arranged at an angle with the axial direction of the liquid inlet 11 or the liquid outlet 12. Preferably, the axial extension direction of the sleeve 2 is orthogonally arranged with the axial direction of the liquid inlet 11 or the liquid outlet 12. Each sleeve 2 is fixedly and hermetically arranged with the housing 1 at each first through hole 15; the space inside the sleeve 2 forms a region for directly encapsulating the bare battery cell. The end of the sleeve 2 far from the first through hole 15 can also be further extended and fixedly and hermetically connected to the inner surface of the housing 1. To facilitate the assembly of the sleeve 2, the housing 1 can be further disassembled into a combined structure of a bottom plate and a frame body with open sides on both sides, that is, the bottom plate of the housing 1 is fixedly and hermetically connected to one end of each sleeve 2 in the axial extension direction, and the edge of the bottom plate is then hermetically connected to the open edge on one side of the frame body to form the housing 1, and the other open edge of the frame body is the opening 13 and the cover plate 14. Each of the illustrated sleeves 2 is arranged in an array inside the housing 1.

[0053] A partition plate 4 is inserted into the housing 1, and the partition plate 4 also sleeved on the outer surface of each sleeve 2 and is hermetically connected to the sleeve 2; the partition plate 4 divides the internal space of the housing 1 located outside each sleeve 2 into a non-communicating first cavity 100 and a second cavity 200; in order to adapt to the contour of each sleeve 2, a plurality of second through holes 40 corresponding to each first through hole 15 are also provided on the partition plate 4, and the sleeve 2 also passes through the second through holes 40.

[0054] Wherein, heat exchange media are provided in both the first cavity 100 and the second cavity 200. As can be seen from the attached drawings, the heat exchange medium in the first cavity 100 can circulate through the liquid inlet 11 and the liquid outlet 12, and the heat exchange medium in the second cavity cannot circulate, but exchanges heat with the heat exchange medium in the first cavity 100 through the partition plate 4.

[0055] Due to the adoption of the direct encapsulation method of the sleeve 2 and the bare battery cell 3, this solution can simplify the encapsulation process of the bare battery cell 3, from the conventional bare battery cell - battery cell - battery module to the process of bare battery cell - battery module, reducing the intermediate steps and the use of corresponding components. In order to avoid uneven temperature of the bare battery cell during use, heat exchange media are introduced into two cavities respectively. Among them, the heat exchange medium in the first cavity 100 circulates, while the heat exchange medium in the second cavity 200 is enclosed inside the second cavity 200 and indirectly exchanges heat with the heat exchange medium in the first cavity 100 through the partition plate 4. The housing 1, the cover plate 13, the sleeve 2, and the partition plate 4 can all be made of thin aluminum alloy materials. The heat exchange media in the first cavity 100 and the second cavity 200 can be the same or different.

[0056] As Figure 6As shown, on the end plate of the housing 1 where the first through hole 15 is provided, a number of first pressure relief openings 141 are also provided; the number of first pressure relief openings 141 and the number of first through holes 15 are arranged in an alternating manner; the first pressure relief openings 141 in the open state communicate the second cavity 200 with the outside of the housing 1. These first pressure relief openings 141 are provided on the cover plate 14. Under normal conditions, the first pressure relief openings 141 are in a closed state. The first pressure relief openings 141 in the open state communicate the second cavity 200 with the outside of the housing 1, enabling the heat transfer medium inside the second cavity to rush out for pressure relief and achieve on-site fire extinguishing.

[0057] As a preferred embodiment, the heat transfer medium in the first cavity 100 is ethylene glycol solution; the heat transfer medium in the second cavity 200 is perfluoromethylcyclohexane; ethylene glycol and water can be mixed in any proportion, having a good heat transfer effect; perfluoromethylcyclohexane is a liquid at room temperature, its boiling point is 49 °C, and its specific heat capacity is relatively large, and the heat transfer effect is also good. Its fire extinguishing concentration is 4-6%. The first pressure relief openings 141 are linear chute indentations, blind holes or annular grooves provided on the side of the cover plate 14 away from the housing 1. These indentations, blind holes or annular grooves are weakening structures. During normal operation, the heat transfer medium in the first cavity 100 and the heat transfer medium in the second cavity 200 exchange heat with different parts of the sleeve 2 respectively. The circulation of the heat transfer medium in the first cavity 100 will also cool the heat transfer medium in the second cavity 200. When the bare battery cell undergoes local thermal runaway, the perfluoromethylcyclohexane will absorb heat and vaporize, and its volume will expand rapidly, resulting in an increase in pressure in the second cavity 200. The perfluoromethylcyclohexane gas-liquid mixture will push open the first pressure relief openings 141 and come into contact with the cover plate 14 or the outer surface of the housing 1, playing a role in fire extinguishing. The volume of perfluoromethylcyclohexane will increase by dozens of times after vaporization. Therefore, the second cavity 200 should not be set too large. In this solution, the distance of the second cavity 200 along the axial extension direction of the sleeve 2 is less than the distance of the first cavity 100 along the axial extension direction of the sleeve 2. That is, most of the outer surface of the sleeve 2 exchanges heat through the heat transfer medium in the first cavity.

[0058] As Figure 4 、 5 Combined with Figures 7 - 10As shown, connecting ribs 300 are further provided between adjacent sleeves 2 or between the sleeve 2 and the inner surface of the housing 1; the connecting ribs 300 are fixedly connected to the inner surface of the housing 1, the end face of the partition plate 4 close to the opening 15, or the outer surface of the sleeve 2 respectively; the connecting ribs 300, the outer surface of the sleeve 2, the inner surface of the housing 1, and the end face of the partition plate 4 close to the opening 13 enclose a second cavity 200; the outer surface of the sleeve, the inner surface of the housing 1, and the end face of the partition plate away from the opening enclose a first cavity 100. The connecting ribs 300 are used to define the relative positions of the sleeves 2 in the housing 1. As can be seen from the figure, the connecting ribs 300 are used to further fix the positions of the sleeves 2 in the housing 1. The sleeves 2 are arranged in an array. In order to increase the contact area between the heat exchange medium in the second cavity 200 and the sleeves 2 and not hinder the fluidity of the heat exchange medium in the second cavity 200, only one connecting rib 300 is provided between some adjacent sleeves 2, and the number of connecting ribs 300 on the sleeves 2 at the array end and the array center position is relatively large. Since the cross-sectional area of the housing 1 is fixed, the height of the connecting ribs 300 also limits the volume of the second cavity 200. As Figure 7 shown, the cover plate 14 can adopt an integral structure or a split combination structure, Figure 8 and the shown cover plate 14 is formed by splicing three parts.

[0059] If the second cavity 200 is not provided and only the heat exchange medium is filled in the first cavity 100, although a flow path for the heat exchange medium surrounding the sleeves 2 can also be formed, when the sleeves are fixed by the connecting ribs 300 in a single cavity, it will have an adverse effect on the flow of the heat exchange medium in the only first cavity, because the extending direction of the connecting ribs is not completely the same as the flow direction of the heat exchange medium in the first cavity, which may affect the heat transfer efficiency of the surface of the sleeves 2 in the area where the connecting ribs are located, and there is still a potential risk of local overheating of the sleeves 2; on the one hand, the connecting ribs 300 of the present solution fix the relative positions of the sleeves 2 in the housing 1, and on the other hand, the connecting ribs 300, as the limiting components of the partition plate 4, also jointly separate the first cavity 100 and the second cavity 200. The heat exchange medium in the first cavity 100 can only flow in the first cavity and will not be blocked by the connecting ribs 300, and the flow is relatively smooth. The heat exchange medium in the second cavity fully fills the second cavity 200. While having good heat absorption performance itself, it can also fully exchange heat with the heat exchange medium in the first cavity through a relatively large area of the partition plate, and the heat exchange medium flowing quickly in the first cavity also has a good heat exchange effect on the heat exchange medium in the second cavity.

[0060] As Figure 2 —6 combined Figure 11As shown in the figure, the bare battery cell 3 includes a battery cell body 31, an upper tab 32, a lower tab 33, and a top cover assembly 34; the battery cell body 31, the upper tab 32, and the lower tab 33 are all embedded inside the sleeve 2; the upper tab 32 is fixedly arranged at one end of the battery cell body 31 along the axial extension direction of the cover plate 14 of the housing 1; the lower tab 33 is fixedly arranged at the end of the battery cell body 31 away from the cover plate 14 and is electrically connected; the top cover assembly 34 is fixedly arranged at the first through hole 15 of the cover plate 14, and the top cover assembly 34 also extends into the first through hole 15 and is electrically connected to the upper tab 32. The bare battery cell 3 is a wound cylindrical structure, and the upper tab 32 and the lower tab 33 are respectively arranged at both ends of the battery cell body 31 of the bare battery cell along the axial extension direction. The upper tab 32 is electrically connected to the top cover assembly 34 to form a positive electrode path, and the lower tab 33 is connected to the sleeve 2 or the housing 1 to form a negative electrode. Between the upper tab 32 and the top cover assembly 34, or between the lower tab 33 and the housing 1 in this solution, a laser welding method can be used for fixed forming. Both the upper tab 32 and the lower tab 33 adopt a certain bent structure.

[0061] As Figures 12 - 15 shown in the figure, the top cover assembly 34 includes a top cover body 341, a pole column assembly 342, a first insulating layer 343, and a second insulating layer 344; a third through hole 400 that penetrates axially is provided on the top cover assembly 34. A first insulating layer 343 is provided on one side of the top cover body 341 close to the sleeve 2, and a second insulating layer 344 is provided on the side of the top cover body 341 away from the sleeve 2; the pole column assembly 342 sequentially passes through the second insulating layer 344, the third through hole 400, and the first insulating layer 343 and extends into the sleeve 2, and is electrically connected to the upper tab 32; the first insulating layer 343 or the second insulating layer 344 is hermetically connected to the pole column assembly 342 and the top cover body 341; the edge of the first insulating layer 343 also extends along the axial direction of the sleeve 2 and abuts against the contour of the battery cell body 31. The pole column assembly 342 is disposed through the third through hole 400 provided on the top cover body 341. As can be seen from the figure, two different insulating layers are provided between the top cover body 341 and the cover plate 14 and between the top cover body 341 and the pole column assembly 342, which play a role of insulation and sealing. The first insulating layer 343 here can be made of PET material, and the second insulating layer can be made of PP, PC, or ABS material. There may be a gap between the battery cell body 31 and the inner wall of the sleeve 2. Therefore, an extension portion extending along the axial direction of the sleeve is provided at the edge position of the first insulating layer 343. This extension portion can fill the gap between the outer surface of the battery cell body 31 and the inner surface of the sleeve, or abut against the end face of the battery cell body 31 where the upper tab 32 is provided, reducing the probability of the battery cell body shaking in the sleeve. In addition, in order to facilitate the traceability of the battery module, a square groove area is provided on the top cover body 341 for laser etching a two-dimensional code.

[0062] In addition, when a fire or explosion occurs accidentally inside the bare battery cell 3, a second pressure relief port 345 may be further provided on the top cover body 341 to release the pressure inside the bare battery cell. The second pressure relief port 345 is a linear chute notch, a blind hole or an annular groove provided on the surface of the top cover body 341 away from the sleeve 2. The structure of the second pressure relief port 345 is similar to that of the first pressure relief port and is used for pressure relief inside the sleeve 2.

[0063] The terminal assembly 342 includes a terminal body 3421 and at least one pressing part 3422. The terminal body 3421 is provided on the side of the top cover body 341 away from the sleeve 2. A through fourth through hole 500 is provided on the terminal body 3421, and the fourth through hole 500 communicates with the third through hole 400. One end of the pressing part 3422 abuts against the terminal body 3421, and the other end of the pressing part 3422 sequentially passes through the fourth through hole 500 and the third through hole 400. The cross section of the terminal body 3421 is a rounded rectangle, and this structure of the terminal body 3421 is to meet the requirements of current transmission and provide a larger contact area with components such as busbars. On the one hand, the pressing part 3422 presses the terminal body 3421, and on the other hand, it extends into the sleeve to be electrically connected to the upper tab. In this solution, the pressing part 3422 adopts an anchor structure.

[0064] In addition, the present invention also provides an assembly method for an immersion liquid-cooled battery module. As shown in the attached Figure 16 figures, it includes the following steps:

[0065] S1: Use a mold to extrude the part of the housing 1 except the cover plate 14, each sleeve 2 and each connecting rib 300; since the cross-sectional shapes of the various parts of the housing 1 are relatively regular, they can be integrally formed, that is, the aluminum alloy material is extruded; in order to facilitate the subsequent assembly of the separator 4, according to the foregoing content, the housing 1 can be split into a combined structure of a frame body with openings on opposite sides and a bottom plate. The frame body, each sleeve 2 and the connecting rib 300 are all formed at one time, and the workload is greatly reduced. Compared with welding the sleeves 2 one by one and welding the connecting rib 300, the workload is greatly simplified, and a large number of welding, cleaning and inspection processes are eliminated; of course, an additive manufacturing method can also be used, such as 3D printing, to directly obtain the complete housing 1, each sleeve 2 and the connecting rib 300, but the efficiency is much slower than extrusion molding;

[0066] S2: Install a partition plate 4 at a suitable position inside the housing 1, such that the partition plate 4 surrounds the outer surfaces of the sleeves 2 in the radial direction, and fixedly and sealingly connect the partition plate 4 to the outer surfaces of the sleeves 2 and the inner surface of the housing 1; the end face of the partition plate 4 close to the opening 13, the connecting ribs 300, the outer surfaces of the sleeves 2 and the inner surface of the housing 1 enclose a second cavity 200; the end face of the partition plate far from the opening and the outer surfaces of the sleeves 2 and the inner surface of the housing 1 enclose a first cavity 100; after installing the partition plate, the bottom plate can be further installed, and the bottom plate and the frame body are sealed to form a complete housing 1;

[0067] S3: Inject heat exchange media into the first cavity 100 and the second cavity respectively; then cover the cover plate 14 at the opening 13 of the housing 1, and sealingly connect the first through holes 15 on the cover plate 14 to the other ends of the sleeves 2 one by one;

[0068] S4: Place the battery cell body 31 provided with an upper tab 32 and a lower tab 33 into the sleeve 2, and fixedly connect the lower tab 33 to the inner surface of the housing 1 surrounded by the sleeve 2; fixedly and sealingly install a top cover assembly 34 at the first through hole 15 of the cover plate 14; make the part of the top cover assembly 34 extending into the first through hole 15 and the sleeve 2 abut against the upper tab 32 or the battery cell body 31, and the pole column assembly 342 of the top cover assembly 34 forms the positive pole, and the housing 1 as a whole forms the negative pole; inject electrolyte into the sleeve 2, and an immersed liquid-cooled battery module structure is obtained.

[0069] When injecting electrolyte into the sleeve 2, if the second pressure relief port 345 is not assembled in advance, the second pressure relief port 345 can be used to inject electrolyte; if there is a separate electrolyte injection hole on the top cover assembly 34 for injection, after completing the electrolyte injection, block the electrolyte injection hole or sealingly weld the second pressure relief port 345 to the top cover body 341, and an immersed liquid-cooled battery module structure is obtained.

[0070] Since the bare battery cells are directly encapsulated to form a battery module during assembly, compared with the existing method of encapsulating bare battery cells into battery cells and then further encapsulating the battery cells to obtain a battery module, the process is significantly simplified, and the liquid-cooling plate structure is omitted, and fewer components are used, increasing the energy density, and the safety and convenience of the battery module are also reliably guaranteed.

[0071] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An immersive liquid-cooled battery module structure, characterized in that, it includes a housing (1), which is of a hollow structure, and at least one first through hole (15) is opened on one end plate thereof; at least one sleeve (2), which is inserted into the at least one first through hole (15) and is hermetically connected to the housing (1); for encapsulating a bare battery cell (3); a partition plate (4), which is inserted into the housing (1), and the partition plate (4) is also sleeved on the outer surface of the at least one sleeve (2) and is hermetically connected to the at least one sleeve (2); the internal space of the housing (1) outside each sleeve (2) is divided into a non-communicating first cavity (100) and a second cavity (200); wherein, heat exchange media are arranged in both the first cavity (100) and the second cavity (200), and a liquid inlet (11) and a liquid outlet (12) are opened on the housing (1) where the first cavity (100) is located; connection ribs (300) are further arranged between adjacent sleeves (2) or between the at least one sleeve (2) and the inner surface of the housing (1); the connection ribs (300) are respectively fixedly connected to the end plate of the housing (1) where the at least one first through hole (15) is opened or the outer surface of the at least one sleeve (2); the connection ribs (300) also abut against the end face of the partition plate (4) close to the end plate of the housing (1) where the at least one first through hole (15) is opened; the connection ribs (300), the outer surface of the at least one sleeve (2), the inner surface of the housing (1) and the end face of the partition plate (4) close to the end plate of the housing (1) where at least one first through hole (15) is opened enclose to form the second cavity (200); the outer surface of the at least one sleeve (2), the inner surface of the housing (1) and the end face of the partition plate (4) far from the end plate of the housing (1) where at least one first through hole (15) is opened enclose to form the first cavity (100).

2. The immersive liquid-cooled battery module structure according to claim 1, characterized in that, a plurality of first pressure relief ports (141) are further arranged on the end plate of the housing (1) where the at least one first through hole (15) is opened; the plurality of first pressure relief ports (141) are arranged in an alternating manner with the at least one first through hole (15); the plurality of first pressure relief ports (141) in the open state communicate the second cavity (200) with the outside of the housing (1).

3. The immersive liquid-cooled battery module structure according to claim 2, characterized in that, the plurality of first pressure relief ports (141) are linear chute marks, blind holes or annular grooves provided on the surface of the housing (1).

4. The immersive liquid-cooled battery module structure according to claim 1, characterized in that, the heat exchange media in the first cavity (100) and the heat exchange media in the second cavity (200) are different; the heat exchange media in the first cavity (100) is ethylene glycol solution; the heat exchange media in the second cavity (200) is perfluoromethylcyclohexanone.

5. The immersive liquid-cooled battery module structure according to claim 1, characterized in that, The bare battery cell (3) includes a battery cell body (31), an upper tab (32), a lower tab (33), and a top cover assembly (34); the battery cell body (31), the upper tab (32), and the lower tab (33) are all embedded inside the sleeve (2); the upper tab (32) is fixedly arranged at one end of the battery cell body (31) close to the end plate of the housing (1) where at least one first through hole (15) is opened; the lower tab (33) is fixedly arranged at the other end of the battery cell body (31) far from the end plate of the housing (1) where at least one first through hole (15) is opened, and the lower tab (33) is fixedly connected to the inner surface of the sleeve (2) far from the end plate of the housing (1) where at least one first through hole (15) is opened; the top cover assembly (34) is fixedly arranged at at least one first through hole (15) of the housing (1), and the top cover assembly (34) also extends into at least one sleeve (2) and is electrically connected to the upper tab (32).

6. The structure of an immersion liquid-cooled battery module according to claim 5, characterized in that, the top cover assembly (34) includes a top cover body (341), a terminal assembly (342), a first insulating layer (343), and a second insulating layer (344); a third through hole (400) is provided on the top cover body (341), a first insulating layer (343) is provided on the side of the top cover body (341) close to the sleeve (2), and a second insulating layer (344) is provided on the side of the top cover body (341) far from the sleeve (2); the terminal assembly (342) sequentially passes through the second insulating layer (344), the third through hole (400), and the first insulating layer (343) and extends into the sleeve (2), and is electrically connected to the upper tab (32); the first insulating layer (343) or the second insulating layer (344) is hermetically connected to the terminal assembly (342) and the top cover body (341); the edge of the first insulating layer (343) also extends along the axial direction of the sleeve (2) and abuts against the contour of the battery cell body (31).

7. The structure of an immersion liquid-cooled battery module according to claim 6, characterized in that, the terminal assembly (342) includes a terminal body (3421) and at least one pressing portion (3422), the terminal body (3421) is arranged on the side of the top cover body (341) far from the sleeve (2), a through fourth through hole (500) is provided on the terminal body (3421), the fourth through hole (500) communicates with the third through hole (400), one end of the pressing portion (3422) abuts against one end of the terminal body (3421) far from the end plate of the housing (1) where at least one first through hole (15) is opened, and the other end of the pressing portion (3422) sequentially passes through the fourth through hole (500), the third through hole (400), and the first insulating layer (343) and is electrically connected to the upper tab (32).

8. The structure of an immersion liquid-cooled battery module according to claim 6, characterized in that, A second pressure relief port (345) is further provided on the top cover body (341), and the second pressure relief port (345) is a linear chute notch, a blind hole or an annular groove provided on the surface of the top cover body (341) away from the housing (1).

9. An assembly method of an immersion liquid-cooled battery module, which includes the structure of the immersion liquid-cooled battery module according to any one of claims 5-8, and includes the following steps: S1: Extrude and form the housing (1), at least one sleeve (2) and each connecting rib (300) by using a mold; S2: Install a partition plate (4) at a suitable position inside the housing (1), so that the partition plate (4) surrounds the outer surface of each sleeve (2) in the radial direction, and fixedly and sealingly connect the partition plate (4) to the outer surface of each sleeve (2) and the inner surface of the housing (1); the end face of the partition plate (4) close to the first through hole (15), the connecting rib (300), the outer surface of the sleeve (2) and the inner surface of the housing (1) enclose a second cavity (200); the end face of the partition plate (4) away from the first through hole (15) and the outer surface of the sleeve (2) and the inner surface of the housing (1) enclose a first cavity (100); S3: Inject a heat exchange medium into the sealed first cavity (100) and second cavity (200); S4: Place the battery cell body (31) provided with an upper tab (32) and a lower tab (33) into the sleeve (2), and fixedly connect the lower tab (33) of the bare battery cell (3) to the inner surface of the end plate of the sleeve (2) away from the housing (1) provided with at least one first through hole (15); fixedly and sealingly set a top cover assembly (34) at each first through hole (15); make the part of the top cover assembly (34) extending into the first through hole (15) and the sleeve (2) abut against the upper tab (32) of the bare battery cell (3) or the battery cell body (31), and a positive electrode is formed at the top cover assembly (34); then inject electrolyte into the inside of the sleeve (2) to obtain the structure of the immersion liquid-cooled battery module.

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