Immersed liquid-cooled battery pack

Abstract

The present invention discloses an immersion liquid-cooled battery pack. The immersion liquid-cooled battery pack comprises: a shell, at least one battery pack is arranged in the shell, the battery pack comprises a plurality of battery cells arranged at intervals along a first direction; a liquid inlet cavity and a liquid outlet cavity are respectively arranged on both sides of the battery pack along a second direction, and the second direction is perpendicular to the first direction; a liquid inlet is arranged at one end of the two ends of the liquid inlet cavity along the first direction, and a liquid outlet is arranged at one end of the two ends of the liquid outlet cavity along the first direction which is different from the liquid inlet, so that the cooling liquid enters the liquid inlet cavity from the liquid inlet, flows into the liquid outlet cavity after passing through the battery pack, and flows out from the liquid outlet; a flow equalizing plate is arranged between the liquid inlet cavity and the battery pack, the flow equalizing plate is arranged along the first direction, a liquid through hole is arranged on the flow equalizing plate, and a plurality of guide plates arranged at intervals along the second direction are arranged at the liquid through hole. The present invention provides an immersion liquid-cooled battery pack with high heating / cooling efficiency, good uniformity and simple structure.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to an immersion liquid-cooled battery pack. Background Art

[0002] With the rapid growth of the new energy vehicle market in recent years, technologies related to electric vehicles have also developed rapidly. Power batteries are one of the core components of electric vehicles, and their performance is directly related to the working condition of the vehicle.

[0003] When the battery is working, it provides electrical energy through violent chemical reactions. During the charging and discharging process, a large amount of heat is generated, causing the battery temperature to rise. The battery temperature will directly affect the battery's safety, charging and discharging capacity and efficiency, cycle life and other performance, and thus affect the working performance of the entire vehicle. The optimal operating temperature range of the battery is relatively narrow, generally between 15°C and 45°C. If it exceeds this range, the basic performance of the battery will be significantly reduced, affecting the battery life and safety. In addition, single cells usually need to be grouped to meet usage requirements, so the consistency of battery pack temperature is also an important guarantee for the normal performance of the battery. If the battery's cooling system cannot effectively dissipate the heat in a timely and uniform manner, it will cause inconsistent temperature distribution between modules, which will aggravate the internal resistance and capacity inconsistency of the battery, have a negative impact on the service life, and in serious cases, there will be safety hazards.

[0004] Battery thermal management technology is to effectively dissipate heat when the battery temperature is high to prevent thermal runaway accidents, and to preheat the battery when the temperature is low to ensure normal operation of the battery at low temperatures, ensure battery temperature uniformity, and prevent battery performance from decaying too quickly in local high-temperature areas, reducing overall life. As users' expectations for the range of electric vehicles increase, the energy density of battery packs also increases, and the amount of heat dissipation increases. The thermal management of batteries, especially high-temperature heat dissipation, is becoming more and more challenging. Natural cooling and air cooling methods have gradually failed to meet the heat dissipation power requirements, and have been transformed into the currently common indirect liquid cooling (including refrigerants). Regardless of the cooling method used, their temperature uniformity has always been in need of improvement due to structural reasons.

[0005] Natural cooling relies on natural wind blowing, which has a simple structure, low cost, and small space occupation. The disadvantage is that the heat dissipation efficiency is low and it cannot adapt to high-power discharge conditions. The air cooling system has a simple structure and is easy to maintain, but the heat dissipation efficiency is low, the temperature uniformity is not very good, and the dust and water resistance is poor. Liquid cooling is the most used and studied in the industry. By arranging cooling plates at the bottom or around the battery, heat exchange between the battery and the coolant is achieved. The liquid medium has a high heat transfer coefficient, large heat capacity, and fast cooling speed. It has a certain effect on improving the consistency of the battery pack temperature field, but the structure is relatively complex, with more internal structural components, which has a certain limitation on the energy density of the battery pack. In addition, due to the limited contact area between the bottom cooling plate and the battery, the temperature difference of a single cell is still large, which affects the performance of the battery itself. Summary of the invention

[0006] The object of the present invention is to provide an immersion liquid-cooled battery pack to solve the problems of low heating / cooling efficiency, poor uniformity and complex structure of the battery pack cooling device in the prior art.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] An immersion liquid-cooled battery pack, comprising:

[0009] A shell, wherein at least one battery pack is disposed in the shell, wherein the battery pack includes a plurality of battery cells spaced apart along a first direction; a liquid inlet cavity and a liquid outlet cavity are disposed on both sides of the battery pack along a second direction, respectively, and the second direction is perpendicular to the first direction; a liquid inlet is disposed at one end of the two ends of the liquid inlet cavity along the first direction, and a liquid outlet is disposed at one end of the two ends of the liquid outlet cavity along the first direction that is different from the liquid inlet, so that the coolant enters the liquid inlet cavity from the liquid inlet, flows into the liquid outlet cavity after passing through the battery pack, and flows out from the liquid outlet;

[0010] A flow balancing plate is arranged between the liquid inlet cavity and the battery pack, the flow balancing plate is arranged along the first direction, a liquid through hole is arranged on the flow balancing plate, and a plurality of guide plates arranged at intervals along the first direction are arranged in the liquid through hole.

[0011] In an optional embodiment of the present invention, the guide plate includes a first part located in the liquid inlet chamber, and a second part located between the current equalizing plate and the battery pack, the first part is inclined toward the liquid inlet, and the second part is parallel to the battery cell.

[0012] In an optional embodiment of the present invention, the cross-sections of the liquid inlet chamber and the liquid outlet chamber are both wedge-shaped, and of the two ends of the liquid inlet chamber along the first direction, one end where the liquid inlet is set is larger and the other end is smaller, and of the two ends of the liquid outlet chamber along the first direction, one end where the liquid outlet is set is larger and the other end is smaller. The wedge-shaped liquid inlet chamber and the liquid outlet chamber can make the flow resistance and flow rate of the flow channels between the battery cells consistent.

[0013] In an optional embodiment of the present invention, it further includes a bottom bracket arranged at the bottom of the shell, and a slot body extending along the second direction is arranged on the bottom bracket, and the battery cell is clamped in the slot body.

[0014] In an optional embodiment of the present invention, it further includes a top crossbeam arranged on the top of the shell, the top crossbeam is arranged along the first direction, and the top crossbeam abuts against the top of the battery core.

[0015] In an optional embodiment of the present invention, the cross-section of the top crossbeam is a right angle, so that the top crossbeam can be clamped on a corner of the battery cell.

[0016] In an optional embodiment of the present invention, the shell includes a tray and an upper cover covering the tray, the bottom bracket is arranged on the tray, and the top crossbeam is arranged on the upper cover.

[0017] In an optional embodiment of the present invention, in each of the battery packs, the gap between two adjacent battery cells is 2-6 mm.

[0018] In an optional embodiment of the present invention, there are multiple battery packs, and the multiple battery packs are arranged at intervals along the second direction.

[0019] In an optional embodiment of the present invention, the gap between two adjacent battery groups is 10-22 mm.

[0020] The present invention is beneficial in that: a flow equalizing plate is provided in the battery pack, and a plurality of guide plates are provided on the flow equalizing plate at intervals along the first direction, and the guide plates can guide the coolant to the flow channels between the battery cells, so as to improve the uniformity of the fluid flow velocity and direction of each flow channel in the battery pack, prevent the occurrence of flow dead zones, and improve the temperature uniformity of the entire battery pack;

[0021] The insulating coolant replaces the indirect cooling plate, thermal pad, insulation pad, module housing and other structural parts in the existing liquid cooling structure. The structure is simple and compact, the assembly is simple, and the energy density per unit volume of the battery pack is improved;

[0022] The battery cell is in direct contact with the coolant, with high heating and cooling efficiency. The temperature uniformity of a single battery cell is significantly improved compared to indirect cooling.

[0023] Insulating coolant fills the space around the battery cells. When thermal runaway occurs in individual battery cells, early heat has not yet accumulated. The coolant acts as a thermal insulation pad and isolates the air, which can inhibit and cool down the heat diffusion, leaving more safe escape time for the occupants. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of an immersion liquid-cooled battery pack in the present invention;

[0025] Figure 2 is a schematic diagram of the top view of the internal structure of the immersed liquid-cooled battery pack of the present invention;

[0026] Figure 3 It is a schematic diagram of the three-dimensional structure inside the immersed liquid-cooled battery pack of the present invention;

[0027] Figure 4 It is a structural schematic diagram of an embodiment of a current equalizing plate in the present invention;

[0028] Figure 5 It is a schematic structural diagram of a bottom bracket embodiment of the present invention.

[0029] In the figure:

[0030] 1. Upper cover; 2. Tray; 3. Liquid inlet; 4. Liquid outlet; 5. Bottom bracket; 51. Trough body; 52. Retaining edge; 6. Cooling liquid; 7. Flow equalizing plate; 8. Liquid inlet cavity; 9. Liquid outlet cavity; 10. Top crossbeam; 11. Battery cell; 12. First gap; 13. Second gap; 14. Guide vane. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] The present invention provides an immersion liquid-cooled battery pack, please refer to Figures 1 to 4 The immersed liquid-cooled battery includes a housing consisting of an upper cover 1 and a tray 2. At least one battery pack is arranged in the housing. Figure 3 In one embodiment of the present invention, there are three battery packs, each battery pack includes a plurality of battery cells 11 spaced apart along a first direction. In other embodiments, the number of battery packs can be increased or decreased as needed, for example, one, two, four or five battery packs can be provided, which is not limited here. The first direction is the Y direction shown in the accompanying drawings, that is, the front-to-back direction. The X direction shown in the accompanying drawings is defined as the second direction, that is, the left-right direction, and the Z direction is the up-down direction. Of course, the X direction, the Y direction, and the Z direction are perpendicular to each other. As Figure 3 The battery cells 11 are arranged at intervals along the Y direction, so that there is a first gap 12 between the battery cells 11, and the first gap 12 serves as a flow channel in the battery pack. In one embodiment, the first gap 12 is 2-6 mm, and further, the first gap 12 is 3-5 mm. Multiple battery packs are arranged at intervals along the X direction, and there is a second gap 13 between two adjacent battery packs, and the second gap 13 is 10-22 mm, and further, the second gap 13 is 13-20 mm.

[0037] Please refer to Figure 2The battery pack is provided with a liquid inlet cavity 8 and a liquid outlet cavity 9 on both sides along the X direction, respectively. The liquid inlet cavity 8 is provided with a liquid inlet 3, and the liquid outlet cavity 9 is provided with a liquid outlet 4. Specifically, the liquid inlet 3 is provided at one of the two ends of the liquid inlet cavity 8 along the Y direction, and the liquid outlet 4 is provided at one of the two ends of the liquid outlet cavity 9 along the Y direction, which is different from the liquid inlet 3. Figure 2 As shown, the rear end of the liquid inlet cavity 8 is provided with a liquid inlet 3, and the front end of the liquid outlet cavity 9 is provided with a liquid outlet 4. The coolant 6 enters the liquid inlet cavity 8 from the liquid inlet 3, flows from the liquid inlet cavity 8 through the battery pack into the liquid outlet cavity 9, and flows out from the liquid outlet 4, so that the coolant 6 heats or cools the battery cell 11. Specifically, when the battery pack is at a relatively low ambient temperature, the temperature of the battery cell 11 is relatively low, and the coolant 6 heats the battery cell 11 to increase the temperature of the battery cell 11 to reach an ideal working temperature; when the battery pack is at a relatively high ambient temperature or the battery cell 11 is seriously heated, causing the battery pack to heat up, the temperature of the battery cell 11 is relatively high, and the coolant 6 cools the battery cell 11 to reduce the temperature of the battery cell 11 to reach an ideal working temperature.

[0038] Please combine Figures 2 to 4 The submerged liquid-cooled battery of the present invention further comprises a flow balancing plate 7, such as Figure 2 As shown, the flow plate 7 is arranged between the liquid inlet cavity 8 and the battery pack, and the flow plate 7 is arranged along the Y direction. The two ends of the flow plate 7 are respectively installed on the side walls of the front and rear ends of the housing. Please refer to Figure 4 , a liquid hole is provided on the flow equalizing plate 7 for the coolant 6 to pass through, so that the coolant 6 flows from the liquid inlet cavity 8 to the battery cell 11, and a plurality of guide plates 14 are provided in the liquid hole, and the guide plates 14 are arranged at intervals along the Y direction. The guide plates 14 can guide the coolant 6 to the flow channel between the battery cells 11 to improve the uniformity of the fluid flow rate and direction of each flow channel in the battery pack, prevent the occurrence of flow dead zones, and improve the temperature uniformity of the entire battery pack. In one embodiment, the guide plates 14 can be arranged one-to-one with the flow channels between the battery cells 11, and each flow channel corresponds to a guide plate 14.

[0039] In the present invention, an immersion liquid cooling method is adopted to immerse the battery cell 11 in the coolant 6, and the insulating coolant 6 replaces the indirect cooling plate, thermal conductive pad, thermal insulation pad and module shell and other structural parts in the existing liquid cooling structure. The structure is simple and compact, and the assembly is simple. The energy density per unit volume of the battery pack is improved; the battery cell 11 is in direct contact with the coolant 6, and the heating and cooling efficiency is high. The temperature uniformity of the single battery cell 11 is significantly improved compared with the indirect cooling; the insulating coolant 6 fills the space around the battery cell 11. When individual battery cells 11 have thermal runaway, the early heat has not yet accumulated. The coolant 6 acts as an insulating pad and isolates the air, which can inhibit and cool the heat diffusion, and reserve more safe escape time for the occupants.

[0040] Please combine Figure 2 and Figure 4 The guide plate 14 includes two parts, a first part located in the liquid inlet chamber 8, and a second part located between the flow equalizing plate 7 and the battery pack. That is, the two parts of the guide plate 14 are respectively on the left and right sides of the flow equalizing plate 7, the first part is on the left side, and the second part is on the right side. Figure 2 As shown, the first part is inclined toward the liquid inlet 3, and the second part is parallel to the battery cell 11, so as to guide the coolant 6 to the flow channel between the battery cells 11. The first part is inclined toward the liquid inlet 3 and the second part is arranged parallel to the battery cell 11, which has a better flow guiding effect, can evenly improve the uniformity of the fluid flow rate and direction of each flow channel in the battery pack, prevent the occurrence of flow dead zones, and improve the temperature uniformity of the entire battery pack.

[0041] In one embodiment, the guide plate 14 can be formed by stamping on the current balancing plate 7. By stamping the guide plate 14 on the current balancing plate 7, the guide plate 14 and the current balancing plate 7 are formed at the same time, and there is no need to install the two together separately, which simplifies the assembly steps and improves the integrity of the battery pack structure.

[0042] Please refer to Figure 2 The cross-sections of the liquid inlet cavity 8 and the liquid outlet cavity 9 are both wedge-shaped, that is, the projections of the liquid inlet cavity 8 and the liquid outlet cavity 9 in the plane formed by the X direction and the Y direction are wedge-shaped, and of the two ends of the liquid inlet cavity 8 along the Y direction, one end where the liquid inlet 3 is set is larger and the other end is smaller, and of the two ends of the liquid outlet cavity 9 along the Y direction, one end where the liquid outlet 4 is set is larger and the other end is smaller. Figure 2 As shown, the rear end of the liquid inlet cavity 8 is provided with a liquid inlet 3, so the rear end of the liquid inlet cavity 8 is larger than the front end, and the front end of the liquid outlet cavity 9 is provided with a liquid outlet 4, so the front end of the liquid outlet cavity 9 is larger than the rear end. The wedge-shaped liquid inlet cavity 8 and liquid outlet cavity 9 can make the flow resistance and flow rate of the flow channel between each battery cell 11 consistent, thereby improving the temperature uniformity of the entire battery pack.

[0043] For details, please refer to Figure 1 The upper cover 1 is a roughly rectangular structure, including five side walls, namely, two front and rear side walls, two left and right side walls, and a top side wall. The upper cover 1 is placed on the tray 2 to form an internal storage space for the battery pack. Figure 2 The liquid inlet cavity 8 and the liquid outlet cavity 9 are respectively located on the left and right sides of the upper cover 1. The left and right side walls of the upper cover 1 are set to form a non-right angle with the front and rear side walls, so that the liquid inlet cavity 8 and the liquid outlet cavity 9 form a wedge-shaped structure. Figure 2 As shown, the battery pack and the current equalizing plate 7 are perpendicular to the front and rear side walls of the upper cover 1 , and the battery cells 11 in the battery pack are parallel to the front and rear side walls of the upper cover 1 .

[0044] Please refer to Figure 3 and Figure 5The immersed liquid-cooled battery pack further includes a bottom bracket 5, which is disposed at the bottom of the housing. Specifically, the bottom bracket 5 is disposed on the tray 2 for placing the battery cell 11. Figure 5 As shown, a slot 51 extending in the X direction is provided on the bottom bracket 5, and the battery cell 11 is stuck in the slot 51. There are multiple slots 51, each of which extends from the left end to the right end of the tray 2. The multiple slots 51 are arranged at intervals along the front-to-back direction, and the gaps between the slots 51 are the first gaps 12 between the battery cells 11. A circle of retaining edges 52 is also provided around the area where the battery pack is provided on the bottom bracket 5. The retaining edges 52 are used to limit the outer ring of the battery pack as a whole, limit the range of placement of the battery cell 11, and prevent the battery cell 11 from moving outward.

[0045] Please refer to Figure 3 The immersed liquid-cooled battery pack also includes a top crossbeam 10, which is arranged on the top of the shell, that is, the top crossbeam 10 is arranged on the upper cover 1, and the two ends of the top crossbeam 10 are respectively fixed on the front and rear side walls of the upper cover 1. The top crossbeam 10 is arranged along the Y direction, and the top crossbeam 10 abuts against the top of the battery cell 11, and is used to fix and limit the top of the battery cell 11. The two top crossbeams 10 are used to fix a group of battery packs, and the two top crossbeams 10 abut against the left and right sides of the battery pack, respectively. Combined with the fixing and limiting of the bottom of the battery cell 11 by the upper groove body 51 of the bottom bracket 5, the fixing and limiting of the entire battery cell 11 can be achieved.

[0046] In one embodiment, Figure 3 As shown, the cross section of the top crossbeam 10 is a right angle, that is, the projection of the top crossbeam 10 on the plane formed by the X direction and the Z direction is a right angle, so that the top crossbeam 10 can be stuck on a corner of the battery cell 11, and the inner side wall of the top crossbeam 10 fits with the top corner of the battery cell 11, which has a better limiting and fixing effect.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An immersion liquid-cooled battery pack, It is characterized in that include: A shell, wherein at least one battery pack is arranged in the shell, the battery pack comprising a plurality of battery cells (11) arranged at intervals along a first direction; a liquid inlet cavity (8) and a liquid outlet cavity (9) are respectively arranged on both sides of the battery pack along a second direction, the second direction being perpendicular to the first direction; a liquid inlet (3) is arranged at one of the two ends of the liquid inlet cavity (8) along the first direction, and a liquid outlet (4) is arranged at one of the two ends of the liquid outlet cavity (9) along the first direction which is different from the liquid inlet (3), so that a cooling liquid (6) enters the liquid inlet cavity (8) from the liquid inlet (3), flows through the battery pack, flows into the liquid outlet cavity (9), and flows out from the liquid outlet (4); A flow balancing plate (7) is arranged between the liquid inlet cavity (8) and the battery pack, the flow balancing plate (7) is arranged along the first direction, a liquid through hole is arranged on the flow balancing plate (7), and a plurality of guide plates (14) are arranged at intervals along the first direction in the liquid through hole; The guide plate (14) comprises a first portion located in the liquid inlet cavity (8) and a second portion located between the current equalizing plate (7) and the battery pack, the first portion being inclined toward the liquid inlet (3), and the second portion being parallel to the battery cell (11); There are multiple battery packs, and the multiple battery packs are arranged at intervals along the second direction; The guide plates (14) are arranged in one-to-one correspondence with the flow channels between the battery cells (11), and each flow channel corresponds to one guide plate (14); The cross-sections of the liquid inlet chamber (8) and the liquid outlet chamber (9) are both wedge-shaped; of the two ends of the liquid inlet chamber (8) along the first direction, one end where the liquid inlet port (3) is provided is larger and the other end is smaller; of the two ends of the liquid outlet chamber (9) along the first direction, one end where the liquid outlet port (4) is provided is larger and the other end is smaller; the wedge-shaped liquid inlet chamber (8) and the liquid outlet chamber (9) can make the flow resistance and flow rate of the flow channels between the battery cells (11) consistent.

2. The immersion liquid-cooled battery pack according to claim 1, It is characterized in that It also comprises a bottom bracket (5) arranged at the bottom of the housing, the bottom bracket (5) being provided with a slot body (51) extending along the second direction, and the battery cell (11) being clamped in the slot body (51).

3. The immersion liquid-cooled battery pack according to claim 2, It is characterized in that It also comprises a top crossbeam (10) arranged on the top of the shell, the top crossbeam (10) being arranged along the first direction, and the top crossbeam (10) abutting against the top of the battery core (11).

4. The immersion liquid-cooled battery pack according to claim 3, It is characterized in that The cross section of the top crossbeam (10) is a right angle, so that the top crossbeam (10) can be clamped on a corner of the battery core (11).

5. The immersion liquid-cooled battery pack according to claim 4, It is characterized in that The shell comprises a tray (2) and an upper cover (1) covering the tray (2), the bottom bracket (5) is arranged on the tray (2), and the top crossbeam (10) is arranged on the upper cover (1).

6. The immersion liquid-cooled battery pack according to claim 1, It is characterized in that In each of the battery packs, the gap between two adjacent battery cells (11) is 2-6 mm.

7. The immersion liquid-cooled battery pack according to claim 1, It is characterized in that The gap between two adjacent battery groups is 10-22 mm.

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