Battery cell unit, battery cell module, battery pack and electric equipment

Abstract

The utility model relates to the technical field of batteries, and provides a battery cell unit, a battery cell module, a battery pack and electric equipment, the battery cell unit comprises a shell and a battery cell structure, the shell has an accommodating cavity, the battery cell structure is arranged in the accommodating cavity, and a groove is formed in the outer wall surface of the shell. According to the battery cell unit, a temperature control system can be formed in the battery cell module based on the arrangement of the groove, a refrigerant in the temperature control system can exchange heat with the battery cell module more quickly and directly, the heat transfer resistance is small, the heat exchange efficiency is high, and the safety and the performance stability of a battery pack at high temperature and low temperature can be ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell unit, a battery cell module, a battery pack, and an electrical device. Background Technology

[0002] A suitable operating temperature range plays a crucial role in the performance and safety of a battery pack. Therefore, battery packs are usually equipped with thermal management devices to control the temperature of the battery pack.

[0003] The temperature control capability of a battery pack is one of the important factors in evaluating its quality. The thermal management devices in related technologies usually adopt two methods: single-phase immersion liquid cooling or two-phase immersion liquid cooling to control the temperature of the battery pack. The thermal management device is a structure independent of the cell module in the battery pack. The heat conduction capability between the cell module and the thermal management device is affected by both the cell module and the thermal management device, resulting in poor temperature control effect of the thermal management device on the cell module. Utility Model Content

[0004] This application provides a battery cell unit, a battery cell module, a battery pack, and an electrical device, which can solve the technical problem of poor temperature control effect of thermal management devices on battery cell modules.

[0005] The first aspect of this application provides a battery cell unit, comprising:

[0006] The outer shell has a receiving cavity;

[0007] The battery cell structure is disposed within the receiving cavity.

[0008] The outer wall surface of the outer shell has grooves formed therein.

[0009] According to the battery cell unit described in the first aspect of this application, the grooves formed on the outer wall of the casing enable the battery cell unit to form a temperature control system after being assembled into a battery cell module, or to form a temperature control system between the battery cell module and the battery pack casing. This temperature control system is formed by the structure of the battery cell unit itself or by the structure of the casing itself. The refrigerant in the temperature control system can exchange heat with the battery cell module more quickly and directly, with low heat transfer resistance and high heat exchange efficiency. It can quickly dissipate the heat of the battery cell module, control the rapid temperature rise of the battery pack, and thus ensure the heat dissipation effect of the battery pack at high temperatures, thereby ensuring the safety and performance stability of the battery pack at high temperatures. When the battery pack is in a low-temperature environment and needs to be preheated, based on the above-mentioned temperature control system, the temperature can be transferred to the battery cell module more quickly, so that the battery cell module is within a suitable temperature range as soon as possible, ensuring the preheating effect of the battery pack at low temperatures, thereby ensuring the safety and performance stability of the battery pack at low temperatures.

[0010] In one possible implementation, the groove extends along the length of the housing.

[0011] In one possible implementation, the grooves are multiple and spaced apart along the width direction of the housing.

[0012] In one possible implementation, the housing has flush portions at both ends in its width direction, and a plurality of the grooves are disposed between two of the flush portions.

[0013] In one possible implementation, the housing includes a housing wall configured as a continuous undulating structure, the undulating structure including protrusions and recesses, at least one recess forming the groove.

[0014] In one possible implementation, the protrusion includes a first protrusion, a second protrusion, and a third protrusion arranged sequentially, the first protrusion and the third protrusion being of equal height, the second protrusion being lower than the first protrusion, and the recess includes a first recess located between the first protrusion and the second protrusion and a second recess located between the second protrusion and the third protrusion, the first recess and the second recess forming the groove.

[0015] In one possible implementation, the undulating structure includes a sawtooth structure and / or a wavy structure.

[0016] In one possible implementation, the housing includes a housing wall with a raised enclosure plate on the housing wall, and the groove is formed between two adjacent enclosure plates.

[0017] In one possible implementation, the bottom surface of the groove includes a flat surface or a rough surface.

[0018] In one possible implementation, the rough surface includes at least a plurality of protrusions.

[0019] A second aspect of this application provides a battery cell module, comprising:

[0020] At least two battery cell units, wherein the battery cell unit is the battery cell unit described in the first aspect, and the grooves in the two battery cell units are joined together to form a first liquid flow channel.

[0021] According to the battery cell module described in the second aspect of this application, the battery cell module is equipped with a temperature control system, which can improve the temperature control effect of the battery cell module.

[0022] A third aspect of this application provides a battery pack, comprising:

[0023] The shell has a receiving cavity;

[0024] And the battery cell module described in the second aspect, wherein the battery cell module is disposed within the receiving cavity.

[0025] According to the battery pack described in the third aspect of this application, the battery pack is equipped with a temperature control system, which can improve the temperature control effect of the battery pack.

[0026] In one possible implementation, the outer wall of the cell module, where the groove is located, abuts against the inner surface of the housing to form a second fluid flow channel.

[0027] In one possible implementation, the battery pack further includes a liquid inlet structure connected to the cell module, the liquid inlet structure having multiple liquid inlet channels.

[0028] In one possible implementation, the liquid inlet structure includes:

[0029] The inlet chamber forms a flow distribution chamber with a gradually increasing flow area;

[0030] A baffle plate is disposed in the inlet chamber; and

[0031] A current distribution plate is connected to the battery cell module, and the current distribution plate has multiple current distribution holes.

[0032] In one possible implementation, the flow divider has a flow divider channel, and the flow divider hole is located at one end of the flow divider channel near the flow guide plate.

[0033] In one possible implementation, the liquid inlet is formed in the middle of the liquid inlet chamber.

[0034] In one possible implementation, the battery pack further includes a liquid outlet structure connected to the cell module, the liquid outlet structure forming a manifold cavity with a liquid outlet.

[0035] In one possible implementation, the outlet is located at the upper part of the manifold.

[0036] In one possible implementation, the dimension of the busbar gradually increases along the length of the battery module.

[0037] In one possible implementation, the battery pack further includes a heat storage and insulation layer that covers the outer periphery of the housing.

[0038] In one possible implementation, the heat storage and insulation layer includes a heat-conducting frame and a heat storage and insulation material, wherein the heat storage and insulation material is filled in the heat-conducting frame.

[0039] In one possible implementation, the heat storage and insulation layer includes thermally conductive particles and heat storage and insulation material.

[0040] The fourth aspect of this application provides an electrical device including the battery pack described in the third aspect. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A schematic diagram of a battery pack according to an embodiment of this application is shown;

[0043] Figure 2 A cross-sectional view of a battery pack provided according to an embodiment of this application is shown;

[0044] Figure 3 A schematic diagram of a battery cell module according to an embodiment of this application is shown;

[0045] Figure 4 A schematic diagram of a liquid inlet structure according to an embodiment of this application is shown;

[0046] Figure 5 A partial structural schematic diagram of a liquid inlet structure provided according to an embodiment of this application is shown;

[0047] Figure 6 A schematic diagram of a flow divider provided according to an embodiment of this application is shown;

[0048] Figure 7 A schematic diagram of a liquid discharge structure according to an embodiment of this application is shown;

[0049] Figure 8 A top view of the fluid flow path of a battery pack according to an embodiment of this application is shown;

[0050] Figure 9 A front view of the fluid flow path of a battery pack provided according to an embodiment of this application is shown from another angle;

[0051] Figure 10 A schematic diagram of the refrigerant cycle of a battery pack according to an embodiment of this application is shown;

[0052] Figure 11 A schematic diagram of the heat circulation of a heat storage and insulation layer according to an embodiment of this application is shown;

[0053] Figure 12 A schematic diagram of a battery cell unit according to an embodiment of this application is shown;

[0054] Figure 13 A schematic diagram of the bottom surface structure of a groove according to an embodiment of this application is shown;

[0055] Figure 14 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown;

[0056] Figure 15 It shows Figure 14 A magnified view of part A in the middle;

[0057] Figure 16 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown;

[0058] Figure 17 It shows Figure 16 A magnified view of part B in the middle;

[0059] Figure 18 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown;

[0060] Figure 19 It shows Figure 18 A magnified view of a portion of C.

[0061] Figure label:

[0062] 100 - Outer shell; 120 - Flush part; 130 - Outer shell wall; 131 - Recess; 132 - Protrusion; 133 - Raised part;

[0063] 200-cell structure;

[0064] 10 - Shell;

[0065] 20-Cell module; 21-Cell unit; 22-First fluid flow channel; 23-Second fluid flow channel; 21a-Groove; 21b-Wide surface; 21c-Narrow surface;

[0066] 30-Liquid inlet structure; 31-Liquid inlet channel; 32-Liquid inlet cavity; 33-Guide plate; 34-Diverter plate; 32a-Liquid inlet; 32b-Diverter cavity; 34a-Diverter orifice; 34b-Diverter channel;

[0067] 40 - Liquid outlet structure; 41 - Manifold; 42 - Liquid outlet;

[0068] 70 - Heat storage and insulation layer;

[0069] 1000-battery pack;

[0070] 2000-Condenser;

[0071] 3000-Circulation Pump;

[0072] 4000 - Air conditioning system. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0074] With the rapid development of battery technology, the market has higher and higher requirements for various battery performance aspects. For example, when batteries are used in the form of battery packs in electrical equipment such as new energy vehicles, higher requirements are placed on the charging rate and capacity of the battery packs. At the same time, new energy vehicles also have more stringent requirements for the stability and safety of battery packs.

[0075] A suitable operating temperature range plays a crucial role in the aforementioned performance of the battery pack. For example, when the battery pack undergoes high-rate charging and discharging, excessively high temperatures or significant temperature differences between different parts of the battery pack may cause safety issues. Therefore, battery packs are typically equipped with thermal management devices to control their temperature. A battery pack generally includes a casing, cell modules, and the aforementioned thermal management device. The cell modules and thermal management device are usually housed within the casing, with the thermal management device positioned between the cell modules and the casing. This thermal management device controls the temperature of the cell modules through the flow of a refrigerant.

[0076] Thermal management devices in related technologies mainly include two types of liquid cooling: single-phase immersion liquid cooling and two-phase immersion liquid cooling. Single-phase immersion liquid cooling refers to a cooling medium that does not undergo a phase change during flow; the battery cell module can be immersed in the cooling medium, and temperature control is achieved solely through the flow of the cooling medium. In single-phase immersion liquid cooling, adjacent battery cell modules need to be separated by a distance to form a temperature stagnation zone. Flow channels are set between the temperature stagnation zone and each battery cell module, and temperature control is achieved through the flow of the cooling medium within these channels. For this liquid cooling method, the cooling medium needs to flow in a specific direction within the channels. As the flow path increases, the heat exchange capacity of the cooling medium gradually weakens, leading to significant temperature differences between different parts of the battery cell module. This can easily induce safety issues during high-rate charging and discharging of the battery pack.

[0077] Furthermore, due to the separate arrangement of the battery cell modules, the reliability of the connections between them is often insufficient, resulting in a reduction in the overall rigidity of the battery pack. Additionally, to facilitate refrigerant flow, the flow channels often employ smooth wall structures, which provide insufficient disturbance to the refrigerant, thus affecting its heat exchange capacity. Two-phase immersion liquid cooling refers to a refrigerant whose state changes during flow; for example, the refrigerant absorbs heat and becomes gaseous, and then releases heat and becomes gaseous again. Two-phase immersion liquid cooling enhances its heat exchange capacity based on this gas-liquid phase transition. When using two-phase immersion liquid cooling, the battery pack requires a large casing to allow the battery cell modules to be immersed in the liquid pool formed by the refrigerant. When the temperature of the battery cell module rises to the liquid boiling point of the refrigerant, a gas-liquid phase change occurs, carrying away heat from the surface of the battery cell module. The generated vapor rises to the top of the liquid pool, is then piped to a condenser for condensation, and finally flows back to the liquid pool via a circulation pump. In this liquid cooling method, a free liquid surface will form in the liquid pool. For moving parts such as new energy vehicles, this free liquid surface will cause the liquid to slosh and generate impact force, resulting in low system stability.

[0078] Furthermore, in the related technologies, both the single-phase immersion liquid cooling and two-phase immersion liquid cooling methods require an independently set thermal management device to control the temperature. There are many structural layers between the battery cell module and the thermal management device, and the heat conduction capacity between the battery cell module and the thermal management device is affected by both the battery cell module and the thermal management device, and may even be affected by some other intermediate structures. The thermal management device has poor temperature control effect on the battery cell module.

[0079] Based on the above-mentioned situation and problems, this application provides a battery pack and an electrical device including the battery pack. The battery pack is provided with a shell and a cell module. The battery pack can form a temperature control system inside it. The temperature control system is implemented by the local structure of the cell module and / or the local structure of the shell. It does not require an additional independent thermal management device, which can simplify the structure, control costs, and improve the temperature control effect of the temperature control system, so that the battery pack can work within a suitable temperature range, thereby improving the various performances of the battery pack.

[0080] It should be noted that, in the embodiments of this application, the temperature control effect is mainly reflected in multiple aspects such as heat dissipation at high temperatures, preheating at low temperatures, and temperature maintenance at low temperatures. The temperature control system formed by the battery cell module can achieve at least one of the above three aspects.

[0081] The battery pack in this application embodiment can adopt either single-phase immersion liquid cooling or two-phase immersion liquid cooling based on the above-mentioned temperature control system settings, and can correct at least some defects of single-phase immersion liquid cooling and at least some defects of two-phase immersion liquid cooling.

[0082] Figure 1 A schematic diagram of a battery pack according to an embodiment of this application is shown; Figure 2 A cross-sectional view of a battery pack provided according to an embodiment of this application is shown; Figure 3 A schematic diagram of the structure of a battery cell module provided according to an embodiment of this application is shown.

[0083] In the embodiments of this application, please refer to Figures 1 to 2 The battery pack 1000 includes a housing 10 and a cell module 20. The housing 10 is a protective housing for the battery pack 1000 and has an internal cavity. The cell module 20 is disposed in the cavity.

[0084] For the aforementioned battery pack 1000, please refer to... Figure 3 The battery cell module 20 includes multiple battery cell units 21. Multiple battery cell units 21 can be connected in sequence to form the battery cell module 20. The outer wall surface of the battery cell unit 21 is provided with a groove 21a. During the connection process, the groove 21a can be spliced ​​to form a first liquid flow channel 22. The first liquid flow channel 22 can be formed on the connection surface of two adjacent battery cell units 21.

[0085] The number of battery cells 21 included in the battery cell module 20 can be designed according to energy requirements. For example, in some embodiments, the battery cell module 20 may include 10 to 30 battery cells 21.

[0086] In some embodiments, the outer wall of the battery cell module 20 can be configured as a planar structure, and the inner wall of the receiving cavity can be configured as a planar structure, so that the outer wall of the battery cell module 20 can abut against the inner wall of the receiving cavity, and a reliable connection is formed between the battery cell module 20 and the receiving cavity.

[0087] In the above embodiments, the refrigerant can flow in the first liquid flow channel 22, which is formed by the battery cell module 20 itself. The temperature control system formed by the first liquid flow channel 22 can improve the temperature control effect of the battery cell module 20.

[0088] In other embodiments, please refer to Figure 2 and 3 The outer wall of the battery cell module 20 can also form a groove 21a, and the inner wall of the receiving cavity can be set as a planar structure, so that a second liquid flow channel 23 can be formed between the outer wall of the battery cell module 20 and the inner wall of the receiving cavity.

[0089] In the above embodiments, the second liquid flow channel 23, as a temperature control system, together with the aforementioned first liquid flow channel 22, can further improve the temperature control effect of the temperature control system on the cell module 20.

[0090] Combination Figure 1 and Figure 3 Multiple battery cell units 21 are arranged along the Y direction. Each battery cell unit 21 has grooves 21a on both sides along the Y direction, so that a first liquid flow channel 22 can be formed between two adjacent battery cell units 21. The outer wall surface of the outermost battery cell unit 21 facing the inner wall surface of the receiving cavity can form a second liquid flow channel 23 with the inner wall surface. Both the second liquid flow channel 23 and the first liquid flow channel 22 belong to the temperature control system.

[0091] In this embodiment of the application, when the battery pack 1000 is under high-rate charging and discharging conditions, its temperature rises rapidly. Based on the above-mentioned temperature control system, the refrigerant can exchange heat with the cell module 20 more quickly and directly. This results in low heat transfer resistance, high heat exchange efficiency, and rapid heat dissipation from the cell module 20, controlling the rapid temperature rise of the battery pack 1000 and ensuring its heat dissipation effect at high temperatures. This, in turn, ensures the safety and performance stability of the battery pack 1000 at high temperatures. Furthermore, when the battery pack 1000 is in a low-temperature environment and needs preheating, the temperature control system can transfer heat to the cell module 20 more quickly, bringing the cell module 20 to a suitable temperature range as soon as possible. This ensures the preheating effect of the battery pack 1000 at low temperatures, further guaranteeing its safety and performance stability at low temperatures.

[0092] The battery pack 1000 in this embodiment of the application, based on the arrangement of the cell module 20 in the receiving cavity, enables the cell module 20 itself and / or the cell module 20 and the housing 10 to form a temperature control system. The temperature control system has a simple structure and low cost, and can improve the temperature control effect of the temperature control system, so that the battery pack 1000 can work in a suitable temperature range, thereby improving the various performances of the battery pack 1000.

[0093] Figure 4 A schematic diagram of a liquid inlet structure according to an embodiment of this application is shown;

[0094] Figure 5 A partial structural schematic diagram of a liquid inlet structure provided according to an embodiment of this application is shown;

[0095] Figure 6 A schematic diagram of a flow divider provided according to an embodiment of this application is shown.

[0096] In some embodiments, please refer to Figures 1 to 2 , Figures 4 to 6The battery pack 1000 also includes a liquid inlet structure 30, which is connected to the cell module 20 and has multiple liquid inlet channels 31.

[0097] The liquid inlet structure 30 can be connected to the liquid supply system, and the refrigerant or other liquids in the liquid supply system can enter the first liquid flow channel 22 and / or the second liquid flow channel 23 through the liquid inlet structure 30.

[0098] Specifically, the liquid inlet structure 30 needs to be connected between the liquid supply system and the cell module 20. The liquid inlet structure 30 forms a liquid inlet channel 31, through which liquids such as refrigerant can enter the first liquid flow channel 22 in the cell module 20 along the liquid inlet channel 31, or enter the second liquid flow channel 23 between the cell module 20 and the housing 10 along the liquid inlet channel 31.

[0099] In some embodiments, the number of liquid inlet channels 31 can be the same as the number of first liquid flow channels 22. When a second liquid flow channel 23 exists, the number of liquid inlet channels 31 can be the sum of the number of first liquid flow channels 22 and second liquid flow channels 23. Based on the arrangement of the liquid inlet channels 31, the liquid inlet structure 30 can decompose liquids such as refrigerant into multiple liquid streams and enter the first liquid flow channel 22 and / or the second liquid flow channel 23 respectively, thereby improving the uniform distribution of refrigerant and thus improving the temperature control effect.

[0100] In some embodiments, please refer to Figures 4 to 6 The liquid inlet structure 30 includes a liquid inlet cavity 32, a guide plate 33, and a flow divider 34.

[0101] The inlet cavity 32 forms a diversion cavity 32b with a gradually increasing flow area, so as to... Figure 1 Taking the orientation shown as an example, along the X direction, the flow area of ​​the liquid inlet chamber 32 gradually increases. It can be understood that when refrigerant or other liquids enter the liquid inlet chamber 32, the increased flow area can disperse the liquid flow formed by the refrigerant.

[0102] The specific structure of the liquid inlet chamber 32 is not limited; for example, in Figure 1 , Figures 4 to 6 In the example shown, the liquid inlet chamber 32 has a trapezoidal structure. Of course, in other embodiments, the liquid inlet chamber 32 can be designed with other structures.

[0103] The guide plate 33 is installed inside the liquid inlet cavity 32 and can be fixed by welding or mechanical connection. The guide plate 33 has a guide surface that guides the flow direction of the liquid. When the refrigerant flows into the guide plate 33, the guide plate 33 can make the refrigerant flow in a specified direction.

[0104] The guide plate 33 can be a sheet-like structure fixedly installed in the liquid inlet cavity 32. The sheet-like structure forms an angle with the liquid inlet cavity 32. Specifically, the sheet-like structure can be an arc-shaped blade. The sheet-like structure can be installed in pairs or individually.

[0105] The diversion plate 34 is connected to the cell module 20. The diversion plate 34 has a plurality of diversion holes 34a. The diversion holes 34a are connected to the aforementioned first liquid flow channel 22 or second liquid flow channel 23. The refrigerant after passing through the guide plate 33 can enter the first liquid flow channel or the second liquid flow channel 23 along the diversion holes 34a.

[0106] In the liquid inlet structure 30 of the above embodiment, the refrigerant can be dispersed and flow after entering the liquid inlet cavity 32. After being guided by the guide plate 33, the refrigerant can flow in a predetermined direction. A diversion plate 34 is provided in front of the flow direction so that multiple liquid streams can flow evenly into the diversion hole 34a of the diversion plate 34 and enter the first liquid flow channel 22 and / or the second liquid flow channel 23 through the diversion hole 34a, thereby achieving uniform distribution of the refrigerant.

[0107] In some embodiments, please refer to Figure 6 The flow divider 34 has a flow divider channel 34b, and a flow divider hole 34a is located at one end of the flow divider channel 34b near the guide plate 33. The flow divider channel 34b is designed to have a predetermined length.

[0108] Understandably, when the refrigerant enters the diversion channel 34b from the diversion hole 34a, the refrigerant will flow smoothly along the diversion channel 34b, and the overall flow rate and flow of the refrigerant will tend to be stable. At this time, the diversion channel 34b is equivalent to passing through a static pressure chamber before the refrigerant flows into the cell module 20, which can convert the dynamic pressure of the refrigerant into static pressure, thereby improving the refrigerant's control effect on the temperature of the cell module 20.

[0109] In some embodiments, please refer to Figure 5 The liquid inlet chamber 32 has a liquid inlet 32a in its middle position. As mentioned above, the liquid inlet 32a is connected to the liquid supply system. By setting the liquid inlet 32a in the middle position of the liquid inlet chamber 32, the flow area of ​​the liquid inlet chamber 32 can be expanded around the liquid inlet 32a, which can improve the dispersion effect of the liquid inlet chamber 32 on the refrigerant.

[0110] In the above embodiments, the refrigerant flows along the direction of the guide plate 33 and the diversion plate 34. The guide plate 33 and the corresponding diversion hole 34a can form a liquid inlet channel 31. In some embodiments, the liquid inlet 32a, the guide plate 33 and the diversion hole 34a can be arranged in a straight line, so that the refrigerant can quickly flow from the liquid inlet structure 30 into the first liquid flow channel 22 and / or the second liquid flow channel 23, which can shorten the flow path of the refrigerant, thereby achieving more timely and rapid temperature control of the battery cell module 20.

[0111] Figure 7 A schematic diagram of a liquid discharge structure provided according to an embodiment of this application is shown.

[0112] In some embodiments, please refer to Figure 7 The battery pack 1000 also includes a liquid outlet structure 40, which is connected to the cell module 20. The liquid outlet structure 40 forms a manifold 41, and the manifold 41 is provided with a liquid outlet 42.

[0113] After flowing through the first liquid flow channel 22 and / or the second liquid flow channel 23, the refrigerant and other liquids will enter the manifold 41 of the liquid outlet structure 40 for convergence. The converged liquid flow can flow out of the battery pack 1000 from the liquid outlet 42. Under high temperature conditions, the liquid flow can carry away the heat of the cell module 20. Under low temperature conditions, the liquid flow can also transfer heat to the cell module 20.

[0114] It is understandable that when the temperature of the battery pack 1000 is high, the refrigerant may generate bubbles during the flow process. After the refrigerant flows out from the first liquid flow channel 22 and / or the second liquid flow channel 23, it can first converge into the manifold 41. The bubbles in the liquid flow can be eliminated by the convergence and compression between multiple liquid flows, so that the refrigerant can flow out of the battery pack 1000 smoothly.

[0115] In some embodiments, please refer to Figure 7 The outlet 42 is located at the upper part of the manifold 41, which can prolong the time for the refrigerant to pass through the outlet structure 40, thereby improving the effect of eliminating air bubbles.

[0116] In some embodiments, please refer to Figure 7 The dimensions of the busbar 41 gradually increase along the length of the cell module 20, so as to... Figure 1Taking the shown orientation as an example, the manifold 41 has a structure that is larger at the top and smaller at the bottom in the X direction. That is, the lower space of the manifold 41 is small and the upper space is large. This structural form allows the refrigerant to flow in the manifold 41 in a gradually smoother state. This state can improve the elimination effect of bubbles and will not affect the overall time of refrigerant outflow from the liquid outlet structure 40. The reason is that as time goes by, the temperature of the refrigerant is gradually controlled, and the number of bubbles will decrease. The above-mentioned size change of the manifold 41 can match the change trend of bubbles. In the initial time, the small lower space can exert enough pressure on the refrigerant to eliminate bubbles. In the final time, the large upper space, combined with the liquid outlet 42 being located at the top, allows the refrigerant to flow out of the liquid outlet structure 40 quickly.

[0117] Figure 8 A top view of the fluid flow path of a battery pack according to an embodiment of this application is shown; Figure 9 A front view of the fluid flow path from another angle is shown for a battery pack provided according to an embodiment of this application.

[0118] Please refer to Figure 4 and Figure 8 , Figure 9 The refrigerant flows from the inlet 32a into the inlet cavity 32 of the inlet structure 30. Through the action of the guide plate 33 and the diverter 34, the refrigerant can evenly enter the first liquid flow channel 22 and the second liquid flow channel 23. Please refer to... Figure 7 and Figure 8 , Figure 9 When the refrigerant flows along the first liquid flow channel 22 and the second liquid flow channel 23, it can perform temperature control function on the cell module 20, which can be heat dissipation at high temperature or preheating at low temperature. After that, the refrigerant will gather into the manifold 41 of the liquid outlet structure 40 and fill the manifold 41 from bottom to top, and finally flow out of the battery pack 1000 from the liquid outlet 42.

[0119] In accordance with the foregoing, the battery pack 1000 in this embodiment can employ either single-phase immersion liquid cooling or two-phase immersion liquid cooling. When the former is used, the entire temperature control system operates on a single-phase flow, meaning the refrigerant does not undergo a phase change, has a high boiling point, and no bubbles are present during the flow. The refrigerant's own flow carries away heat from the cell module 20 or preheats the cell module 20. As mentioned earlier, the cell module 20 in this embodiment forms the temperature control system with a tightly connected configuration, resulting in high overall rigidity and improving the overall rigidity of the battery pack 1000. When the latter is used, the refrigerant has a lower boiling point. When the heat generated by the cell module 20 is not large, the refrigerant still dissipates heat or preheats the cell module 20 without undergoing a phase change. When the heat generated by the cell module 20 is large, the refrigerant can also undergo a phase change and combine its flow to improve the temperature control effect. At this time, the bubbles generated in the refrigerant can be eliminated by the aforementioned liquid outlet structure 40.

[0120] It is understandable that, based on the above-mentioned adoption of single-phase immersion liquid cooling and two-phase immersion liquid cooling methods, the battery pack 1000 in this application embodiment can adapt to the heat dissipation requirements under different operating conditions.

[0121] In this embodiment of the application, in order to realize the recycling of refrigerant, the battery pack 1000 can be equipped with a condenser 2000, a circulation pump 3000 and other structures, so that the refrigerant can circulate between the liquid supply system and the battery pack 1000.

[0122] Figure 10 A schematic diagram of the refrigerant cycle of a battery pack according to an embodiment of this application is shown. Please refer to... Figure 10 When the refrigerant undergoes a phase change during its flow, it becomes a mixture of gaseous and liquid states. This mixture of refrigerant flows out of the battery pack 1000 from the liquid outlet 42 and passes through the condenser 2000. After the condenser 2000 absorbs heat, the mixture of refrigerant becomes liquid again. Then, the power provided by the circulation pump 3000 allows it to re-enter the battery pack 1000.

[0123] In some embodiments, please refer to Figure 1 and Figure 2 The battery pack 1000 also includes a heat storage and insulation layer 70, which covers the outer periphery of the housing 10.

[0124] The heat storage and insulation layer 70 is made of heat storage and insulation material, and its thickness can be set according to requirements, for example, from 20mm to 50mm. This heat storage and insulation layer 70 can absorb the heat generated by the battery pack 1000 during operation or absorb heat from elsewhere. This heat can maintain the temperature range of the battery pack 1000 in low-temperature environments, thus protecting the battery cell module 20.

[0125] Specifically, the heat generated by the battery cell module 20 can be absorbed by the heat storage and insulation layer 70, which can store some heat. In low-temperature environments such as at night or when starting a new energy vehicle, the heat storage and insulation material can slowly release the heat to maintain the temperature of the battery cell module 20 from getting too low, for example, below 10°C, thus protecting the battery cell module 20. When the heat from the heat storage and insulation layer 70 is insufficient to maintain the temperature of the battery cell module 20, the heating function of the air conditioning system 4000 will supplement the heat storage and insulation layer 70 with heat. At the same time, the heat storage and insulation layer 70 itself has a low thermal conductivity, which can play a good role in heat insulation and insulation, insulating the battery pack 1000 from the external environment, thereby protecting the battery cell module 20 from the effects of high and low temperatures.

[0126] Figure 11 A schematic diagram of the heat circulation of a heat storage and insulation layer according to an embodiment of this application is shown. The heat storage and insulation layer 70 can be connected to an air conditioning system 4000. The heat storage and insulation layer 70 can absorb heat from the battery pack 1000 and also absorb heat from the air conditioning system 4000. The heat absorbed by the heat storage and insulation layer 70 can be used to maintain the temperature of the battery pack 1000 within a suitable temperature range in low-temperature environments.

[0127] The above embodiments utilize the low thermal conductivity of the heat storage and insulation material to insulate the battery pack 1000 from the external environment, reducing the impact of the external environment on the temperature of the battery pack 1000. Forming a heat storage and insulation layer 70 on the outer periphery of the battery pack 1000 can reduce the amount of material used and simplify the arrangement of the heat storage and insulation layer 70.

[0128] In some specific embodiments, the heat storage and insulation layer 70 includes a heat-conducting frame and a heat storage and insulation material, which is filled in the heat-conducting frame.

[0129] The heat storage and insulation material can be selected according to requirements. For example, it can be a phase change heat storage material such as paraffin wax or sodium acetate trihydrate, which can extend the insulation time. The phase change temperature of the heat storage and insulation material can be between 20℃ and 40℃. The heat-conducting frame can be made of metal materials, such as aluminum alloy or copper alloy. The specific structure of the heat-conducting frame is not limited; it can be designed as a porous metal bracket, etc. Filling the heat storage and insulation material into the heat-conducting frame can increase the structural strength of the heat storage and insulation layer by 70%.

[0130] In other specific embodiments, the heat storage and insulation layer 70 includes heat-conducting particles and heat storage and insulation materials. The heat-conducting particles can be particulate materials such as graphene powder and copper powder, which can also improve the structural strength of the heat storage and insulation layer 70.

[0131] Figure 12 A schematic diagram of the structure of a battery cell unit provided according to an embodiment of this application is shown.

[0132] In the embodiments of this application, please refer to Figure 3 and Figure 11 The battery cell unit 21 includes a housing 100 and a battery cell structure 200.

[0133] The outer casing 100 is a protective housing 10 for the battery cell unit 21. The outer casing 100 has a receiving cavity, and the battery cell structure 200 can be disposed in the receiving cavity.

[0134] The cell structure 200 is a functional integration of the cell unit 21, enabling the storage and release of electrical energy. The cell structure 200 includes a positive electrode, a negative electrode, and a separator. The positive electrode has a positive active material, typically lithium-containing, and the negative electrode has a negative active material. The cell structure 200 achieves charge-discharge cycles through the nesting and deintercalation of lithium ions.

[0135] The outer wall of the outer casing 100 has a groove 21a. Based on the groove 21a, the first liquid flow channel 22 mentioned above can be formed between the two cell units 21. The outermost cell unit 21 in the cell module 20 can form a second liquid flow channel 23 with the casing 10 of the battery pack 1000.

[0136] In this embodiment, the cell unit 21 has a groove 21a formed on the outer wall of the housing 100, which enables the cell unit 21 to form a temperature control system after being assembled into the cell module 20, or to form a temperature control system between the cell module 20 and the housing 10. This temperature control system is formed by the structure of the cell unit 21 itself or by the structure of the housing 10 itself. The refrigerant in the temperature control system can exchange heat with the cell module 20 more quickly and directly, resulting in low heat transfer resistance and high heat exchange efficiency. This allows for rapid heat dissipation from the cell module 20 and enables control of the battery temperature. The rapid heating of the battery pack 1000 ensures its heat dissipation at high temperatures, thereby guaranteeing its safety and performance stability. When the battery pack 1000 is in a low-temperature environment and needs to be preheated, the temperature control system allows for faster heat transfer to the cell module 20, bringing it to a suitable temperature range as quickly as possible. This ensures the preheating effect of the battery pack 1000 at low temperatures, thus guaranteeing its safety and performance stability.

[0137] It is understandable that the groove 21a can be formed on various surfaces of the housing 100. Taking the square-structured battery cell 21 as an example, referring to the reference... Figure 1 and Figure 12 The battery cell unit 21 includes a wide surface 21b and a narrow surface 21c. The wide surface 21b corresponds to the length direction of the battery cell unit 21, i.e., the X direction, and the narrow surface 21c corresponds to the width direction, i.e., the Y direction. In other embodiments, the groove 21a may also be selectively arranged on either the wide surface 21b or the narrow surface 21c. Figure 12 In the example shown, a groove 21a is arranged on the wide surface 21b, so that when multiple battery cell units 21 form a battery cell module 20, a first liquid flow channel 22 can be formed between each battery cell unit 21.

[0138] In some embodiments, please refer to Figure 12 The groove 21a extends along the length of the outer shell 100. When the refrigerant flows through the groove 21a, the refrigerant can form a larger contact area with the battery cell unit 21 or the battery cell module 20, thereby improving the temperature control effect of the temperature control system.

[0139] In some embodiments, please refer to Figure 12Multiple grooves 21a are arranged at intervals along the width direction of the outer casing 100. These grooves 21a can be designed as straight lines, each extending along its length, and the multiple grooves 21a are parallel in the width direction. It is understood that the number of grooves 21a can be designed according to the width dimension of the battery cell 21, and to ensure uniform temperature control, the intervals between the grooves 21a can be set to be the same.

[0140] In some embodiments, please refer to Figure 12 The outer casing 100 has flush portions 120 at both ends in its width direction, and a groove 21a is disposed between the two flush portions 120. The flush portions 120 enable the first liquid flow channel 22 to be formed inside the cell module 20 and between the inner wall surface of the cell module 20 and the casing 10, so that each corner of the cell module 20 can form a tight contact with the casing 10, thereby improving the connection reliability between the cell module 20 and the casing 10. In addition, the first liquid flow channel 22 formed in the cell module 20 can block or mitigate heat transfer between two adjacent cell units 21, and can effectively suppress the spread of thermal runaway when a cell unit 21 experiences thermal runaway.

[0141] In conjunction with the foregoing, for a single battery cell 21, the overall surface area of ​​the outer casing 100 is increased due to the recess 21a. This increases the external heat dissipation area of ​​the battery cell 21, thereby improving its heat dissipation performance at high temperatures. Furthermore, the aforementioned structural design of the outer casing 100 also helps to increase its structural strength and rigidity. After multiple battery cell 21s are tightly connected, the rigidity of the battery cell module 20 and the battery pack 1000 can be improved, thus enhancing the performance stability of the battery pack 1000.

[0142] On the other hand, regarding the connection between the cell module 20 and the housing 10, since the first liquid flow channel 22 and the second liquid flow channel 23 are formed by the tight connection between the cell units 21, when the refrigerant flows through the first liquid flow channel 22 and the second liquid flow channel 23, the cell module 20 can be immersed in the refrigerant. During the flow of the refrigerant, it is restricted by the cell units 21 and the housing 10, and no free liquid surface is formed between the cell module 20 and the housing 10. This can prevent the stability problem of the battery pack 1000 caused by the sloshing of the liquid surface, thereby improving the stability of the battery pack 1000 in use.

[0143] Of course, in some embodiments, the flush portion 120 may not be provided, and the groove 21a may be provided circumferentially on the outer wall surface of the housing 100.

[0144] In some embodiments, please refer to Figure 12The outer casing 100 includes an outer casing wall 130, which is configured as a continuous undulating structure, including a protrusion 132 and a recess 131, at least one recess 131 forming a groove 21a.

[0145] The shell 100 with a textured structure can be designed using a one-piece molding method, or the textured structure can be formed on the flat shell 100 using machining.

[0146] In the embodiments of this application, the specific structure of the recess 131 and the convex portion 132 is not limited, and the recess 131 and the convex portion 132 can be serrated, trapezoidal or other shapes.

[0147] In some specific embodiments, the protrusion 132 includes a first protrusion 132, a second protrusion 132 and a third protrusion 132 arranged sequentially. The first protrusion 132 and the third protrusion 132 are of equal height, and the second protrusion 132 is lower than the first protrusion 132. The recess 131 includes a first recess 131 between the first protrusion 132 and the second protrusion 132 and a second recess 131 between the second protrusion 132 and the third protrusion 132. The first recess 131 and the second recess 131 form a groove 21a.

[0148] In this embodiment, the second protrusion 132 and the third protrusion 132 together form a groove 21a, which can increase the capacity of the groove 21a, allowing a large flow of refrigerant to pass through the cell module 20, thereby improving the temperature control effect of the temperature control system.

[0149] In other embodiments, the quantitative relationship between the recesses 131 and the protrusions 132 can also be varied, for example, by forming grooves 21a with more recesses 131.

[0150] In some specific embodiments, the undulating structure includes a sawtooth structure, a wave-like structure, or a combination of both, which can achieve different temperature control effects.

[0151] In other embodiments, the housing 100 includes a housing wall 130, on which a protrusion 133 is provided with a surrounding plate, and a groove 21a is formed between two adjacent surrounding plates.

[0152] By reasonably setting the size of the enclosure plate, the effective heat dissipation area of ​​the cell unit 21 can be further increased, which can improve the heat dissipation effect of the cell module 20 at high temperature.

[0153] Figure 13 A schematic diagram of the bottom surface structure of a groove according to an embodiment of this application is shown; Figure 14 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown; Figure 15 It shows Figure 14A magnified view of part A in the middle; Figure 16 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown; Figure 17 It shows Figure 16 A magnified view of part B in the middle; Figure 18 A schematic diagram of the bottom surface structure of another groove provided according to an embodiment of this application is shown; Figure 19 It shows Figure 18 A magnified view of a portion of C.

[0154] In some embodiments, please refer to Figures 13 to 19 The bottom surface of the groove 21a can be a flat surface to increase the flow rate of the refrigerant in the groove 21a. Alternatively, the bottom surface of the groove 21a can be a rough surface to reduce the generation of air bubbles in the refrigerant.

[0155] The rough surface can be formed by setting protrusions 133 on the bottom surface of the groove 21a. The bottom surface of the groove 21a can be processed by surface treatment processes such as machining, porous sintering or sandblasting to form a rough surface.

[0156] In some embodiments, to form a rough surface, protrusions 133 of different shapes can be provided on the bottom surface of the groove 21a.

[0157] For example, in some specific embodiments, please refer to Figure 14 and Figure 15 The rough surface is a grooved surface. Correspondingly, the shape of the protrusion 133 can be rectangular. A groove is formed between two rectangular protrusions 133. The width h1 of the groove can be 0.01 to 1 mm. The ratio of the width to the depth of the groove can be 1.2:1 to 3:1.

[0158] For example, in some specific embodiments, please refer to Figure 16 and Figure 17 The rough surface is a porous surface. Correspondingly, the shape of the protrusion 133 can also be rectangular or arc-shaped. The height h2 of the protrusion 133 can be 0mm to 2mm (excluding 0mm). The porosity of the porous surface is 0.6 to 0.95. The distance L1 between the protrusions 133 can be 1mm to 3mm.

[0159] For example, in some specific embodiments, please refer to Figure 18 and Figure 19 The rough surface is a porous micro-protrusion 133 surface. Correspondingly, the shape of the protrusion 133 can be conical, the height h3 of the protrusion 133 can be 0mm to 2mm (excluding 0mm), the bottom diameter L2 of the protrusion 133 is 1 to 6mm, and the porosity of the porous micro-protrusion 133 surface is 0.6 to 0.95.

[0160] The aforementioned protrusion 133 structure can form different capillary structures on the bottom surface of the groove 21a. These capillary structures can generate capillary forces, allowing subsequent refrigerant to be quickly replenished to the bubble area after bubbles are formed in the refrigerant. This avoids the problem of impaired heat exchange efficiency caused by a lack of refrigerant replenishment in certain locations in the groove 21a for a long time, and can improve the disturbance effect on the refrigerant, thereby improving the heat exchange efficiency of the refrigerant when it flows in the first liquid flow channel 22 and / or the second liquid flow channel 23.

[0161] In the above embodiments of this application, the number and size of the first liquid flow channel 22 and the second liquid flow channel 23 can be set according to actual needs. For example, the number of the first liquid flow channel 22 and the second liquid flow channel 23 can be set to 2, 3, 4, 6, 8, etc. The width of the first liquid flow channel 22 and the second liquid flow channel 23 along the Z direction can be the same or different. For example, the width can be designed to be 3mm to 10mm. The depth of the first liquid flow channel 22 and the second liquid flow channel 23 along the X direction can be the same or different. For example, the depth can be designed to be 2mm to 20mm, etc.

[0162] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0163] In the description of this application, it should be understood that the terms "comprising" and "having" and any variations thereof used in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0164] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the connection within two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell unit (21), characterized in that, include: The outer casing (100) has a receiving cavity; The battery cell structure (200) is disposed within the receiving cavity. The outer wall surface of the outer shell (100) is formed with a groove (21a).

2. The battery cell unit (21) according to claim 1, characterized in that, The groove (21a) extends along the length of the outer shell (100).

3. The battery cell unit (21) according to claim 2, characterized in that, The grooves (21a) are multiple and are spaced apart along the width direction of the outer shell (100).

4. The battery cell unit (21) according to claim 2, characterized in that, The outer shell (100) has flush portions (120) at both ends in the width direction, and a plurality of grooves (21a) are disposed between two of the flush portions (120).

5. The battery cell unit (21) according to any one of claims 1 to 4, characterized in that, The outer casing (100) includes an outer casing wall (130) configured as a continuous undulating structure, the undulating structure including a protrusion (132) and a recess (131), at least one recess (131) forming the groove (21a).

6. The cell unit (21) according to claim 5, characterized in that, The protrusion (132) includes a first protrusion, a second protrusion and a third protrusion arranged sequentially. The first protrusion and the third protrusion are at the same height, and the second protrusion is lower than the first protrusion. The recess (131) includes a first recess located between the first protrusion and the second protrusion and a second recess located between the second protrusion and the third protrusion. The first recess and the second recess form the groove (21a).

7. The cell unit (21) according to claim 5, characterized in that, The undulating structure includes a sawtooth structure and / or a wavy structure.

8. The battery cell unit (21) according to any one of claims 1 to 4, characterized in that, The outer casing (100) includes an outer casing wall (130), on which a surrounding plate is provided in a protrusion, and the groove (21a) is formed between two adjacent surrounding plates.

9. The battery cell unit (21) according to any one of claims 1 to 4, characterized in that, The bottom surface of the groove (21a) includes a flat surface or a rough surface.

10. The cell unit (21) according to claim 9, characterized in that, The rough surface includes at least a plurality of protrusions (133).

11. A battery cell module (20), characterized in that, include: At least two battery cells (21), wherein the battery cells (21) are any one of the battery cells (21) according to claims 1 to 10, and the grooves (21a) in the two battery cells (21) are joined to form a first liquid flow channel (22).

12. A battery pack (1000), characterized in that, include: The housing (10) has a receiving cavity; And the battery cell module (20) according to claim 11, wherein the battery cell module (20) is disposed within the receiving cavity.

13. The battery pack (1000) according to claim 12, characterized in that, The outer wall surface of the battery cell module (20) with the groove (21a) abuts against the inner surface of the housing (10) to form a second liquid flow channel (23).

14. The battery pack (1000) according to claim 13, characterized in that, The battery pack (1000) also includes a liquid inlet structure (30), which is connected to the cell module (20) and has multiple liquid inlet channels (31).

15. The battery pack (1000) according to claim 14, characterized in that, The liquid inlet structure (30) includes: The inlet chamber (32) forms a flow divider chamber (32b) with a gradually increasing flow area; A guide vane (33) is disposed in the liquid inlet chamber (32); and A shunt plate (34) is connected to the battery cell module (20), and the shunt plate (34) has a plurality of shunt holes (34a).

16. The battery pack (1000) according to claim 15, characterized in that, The flow divider (34) has a flow divider channel (34b), and the flow divider hole (34a) is located at one end of the flow divider channel (34b) near the flow guide plate (33).

17. The battery pack (1000) according to claim 15, characterized in that, The liquid inlet (32) has a liquid inlet (32a) formed in its middle position.

18. The battery pack (1000) according to claim 13, characterized in that, The battery pack (1000) also includes a liquid outlet structure (40), which is connected to the cell module (20). The liquid outlet structure (40) forms a manifold (41), and the manifold (41) is provided with a liquid outlet (42).

19. The battery pack (1000) according to claim 18, characterized in that, The liquid outlet (42) is located at the upper part of the manifold (41).

20. The battery pack (1000) according to claim 18, characterized in that, The size of the busbar (41) gradually increases along the length of the battery cell module (20).

21. The battery pack (1000) according to any one of claims 12 to 20, characterized in that, The battery pack (1000) also includes a heat storage and insulation layer (70), which covers the outer periphery of the housing (10).

22. The battery pack (1000) according to claim 21, characterized in that, The heat storage and insulation layer (70) includes a heat-conducting frame and a heat storage and insulation material, wherein the heat storage and insulation material is filled in the heat-conducting frame.

23. An electrical appliance, characterized in that, Includes the battery pack (1000) according to any one of claims 12 to 22.

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