Battery pack and battery system

Abstract

The present application relates to a battery pack and a battery system. The battery pack comprises: a housing, internally provided with an accommodating space configured to accommodate an immersion liquid, the housing comprising a first end portion and a second end portion disposed opposite to each other, the first end portion being provided with a first liquid inlet, and the second end portion being provided with a first liquid outlet; a battery disposed within the accommodating space; and a liquid cooling plate adjacent to the housing, the liquid cooling plate being configured to accommodate a coolant, the liquid cooling plate comprising a third end portion and a fourth end portion disposed opposite to each other, the third end portion being provided with a second liquid outlet, and the fourth end portion being provided with a second liquid inlet. The first end portion is adjacent to the third end portion, and the second end portion is adjacent to the fourth end portion.

Description

Battery pack and battery system

[0001] The present application claims priority to the Chinese patent application No. 2024113718235, 2024223867867, filed on September 27, 2024, to the Chinese patent office, the whole content of the above application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery pack and a battery system. BACKGROUND

[0003] In a lithium battery system, thermal management technology is a key factor to ensure battery performance and safety. Current battery packs mainly adopt two thermal management schemes of indirect liquid cooling and immersion cooling. TECHNICAL PROBLEM

[0004] Indirect liquid cooling has limited contact area between the cooling medium and the battery cell, which limits the heat dissipation effect and makes it difficult to meet the demand of high-power charging and discharging. Although immersion cooling can increase the contact area between the battery and the cooling medium and improve the temperature uniformity, the liquid does not flow in immersion cooling, and the heat cannot be effectively taken away, which also affects the heat dissipation effect. TECHNICAL SOLUTION

[0005] In a first aspect, the present application provides a battery pack, comprising: a box body, a battery and a liquid cooling plate, the box body is provided with a containing space, the containing space is configured to contain immersion liquid, the box body comprises a first end portion and a second end portion arranged oppositely, the first end portion is provided with a first liquid inlet, and the second end portion is provided with a first liquid outlet; the battery is arranged in the containing space; the liquid cooling plate is adjacent to the box body, the liquid cooling plate is configured to contain cooling liquid, the liquid cooling plate comprises a third end portion and a fourth end portion arranged oppositely, the third end portion is provided with a second liquid outlet, and the fourth end portion is provided with a second liquid inlet; wherein the first end portion and the third end portion are adjacent, and the second end portion and the fourth end portion are adjacent.

[0006] In a second aspect, the present application provides a battery system, comprising a control assembly and the battery pack as described in any one of the above, the control assembly and the battery pack are connected. ADVANTAGEOUS EFFECTS

[0007] The beneficial effects of the present application are: for the batteries in the box, no matter at the first end or the second end of the box, the cooling medium with lower temperature can effectively help the batteries to cool down. The present embodiment carefully arranges the relative positions between the first liquid inlet and the first liquid outlet of the immersion liquid and the second liquid inlet and the second liquid outlet of the cooling liquid, so that the immersion liquid and the cooling liquid of the battery pack cooperate, the batteries in different areas can be fully cooled, which ensures more uniform and effective dispersion of the heat generated by the batteries, reduces the temperature difference on the surface of the batteries, avoids the accumulation of heat in the local part of the batteries, makes the temperature distribution of the whole battery more uniform, and reduces the risk of performance decline and life shortening of the batteries caused by temperature difference. BRIEF DESCRIPTION OF DRAWINGS

[0008] Fig. 1 is a first structure schematic diagram of a battery pack provided by the present application;

[0009] Fig. 2 is a schematic diagram of the internal cross section of the battery pack provided by the present application;

[0010] Fig. 3 is a second structure schematic diagram of the battery pack provided by the present application;

[0011] Fig. 4 is a structure schematic diagram of the battery pack shown in Fig. 1 from another angle;

[0012] Fig. 5 is a third structure schematic diagram of the battery pack provided by the present application;

[0013] Fig. 6 is a structure schematic diagram of the battery pack shown in Fig. 5 from another angle;

[0014] Fig. 7 is a cross section view of the battery pack shown in Fig. 6 along A-A;

[0015] Fig. 8 is a fourth structure schematic diagram of the battery pack provided by the present application;

[0016] Fig. 9 is a structure schematic diagram of the battery pack shown in Fig. 8 from another angle;

[0017] Fig. 10 is a structure schematic diagram of the battery pack shown in Fig. 8 from another angle;

[0018] Fig. 11 is a cross section view of the battery pack shown in Fig. 8 along B-B.

[0019] Embodiment of the present application

[0020] Please refer to Fig. 1, which is a first structure schematic diagram of a battery pack provided by the present application. The battery pack 10 of the present embodiment combines the indirect liquid cooling and the immersion cooling to provide a more effective thermal management scheme. The battery pack 10 includes a box 100, a battery 200 and a liquid cooling plate 300.

[0021] The box 100 is an external structure of the battery pack 10, configured to protect the internal battery 200 and the immersion cooling system. The box 100 is internally provided with an accommodation space, which is configured to accommodate the immersion liquid, which can be in direct contact with the battery 200 in the accommodation space. The box 100 has a first end portion 110 and a second end portion 120 arranged opposite to each other. The first end portion 110 is provided with a first liquid inlet 130, and the second end portion 120 is provided with a first liquid outlet 140. When the immersion liquid is injected into the accommodation space of the box 100 through the first liquid inlet 130, it is in a relatively low temperature state, and as the immersion liquid flows in the accommodation space, the temperature of the immersion liquid gradually rises due to the direct contact between the immersion liquid and the battery 200, and then is discharged from the first liquid outlet 140. In the present embodiment, the immersion liquid in the box 100 is in flow, which can more effectively take away heat and improve the heat dissipation effect.

[0022] The battery 200 is the core part of the battery pack 10, which is arranged in the accommodation space and surrounded by the immersion liquid. The heat generated by the battery 200 during charging and discharging is effectively dissipated by the immersion liquid. The material system of the battery 200 is not limited, which can be a ternary lithium battery, a lithium iron phosphate battery, or a lithium manganese iron phosphate battery. The battery 200 can be a square battery, a cylindrical battery, a soft package battery, etc.

[0023] The liquid cooling plate 300 is adjacent to the box 100 and indirectly contacts the battery 200. The liquid cooling plate 300 can be located at any position of the side, top or bottom of the box 100, and the liquid cooling plate 300 shown in the drawing is located on the bottom of the box 100. The liquid cooling plate 300 contains cooling liquid, which flows inside the liquid cooling plate 300 and can absorb and take away the heat transferred from the battery 200 to the liquid cooling plate 300. The liquid cooling plate 300 also has a third end portion 310 and a fourth end portion 320 arranged opposite to each other. The third end portion 310 is provided with a second liquid outlet 340, and the fourth end portion 320 is provided with a second liquid inlet 330. The cooling liquid enters the liquid cooling plate 300 through the second liquid inlet 330, and is also in a relatively low temperature state when entering the liquid cooling plate 300. As the cooling liquid flows in the liquid cooling plate 300, the temperature of the cooling liquid gradually rises due to the absorption of the heat transferred from the battery 200 to the liquid cooling plate 300, and then is discharged from the second liquid outlet 340.

[0024] The first end portion 110 and the third end portion 310 are adjacent, and the second end portion 120 and the fourth end portion 320 are adjacent. Therefore, the first liquid inlet 130 of the immersion liquid and the second liquid outlet 340 of the cooling liquid are relatively close, and the first liquid outlet 140 of the immersion liquid and the second liquid inlet 330 of the cooling liquid are also relatively close. It can be understood that, although the temperature of the immersion liquid is high at the first liquid outlet 140 of the second end portion 120, which is not conducive to heat dissipation in the area near the second end portion 120 of the box 100, the second liquid inlet 330 close to it injects cooling liquid with a lower temperature, which can effectively help the area near the second end portion 120 to dissipate heat and cool down.

[0025] Similarly, although the temperature of the cooling liquid is high at the second liquid outlet 340 of the third end portion 310, which is not conducive to the third end portion 310 of the liquid cooling plate 300 absorbing the heat of the first end portion 110 of the box 100 adjacent to it, the first liquid inlet 130 close to it injects immersion liquid with a lower temperature, which can effectively help the area near the first end portion 110 to dissipate heat and cool down. Therefore, for the battery 200 in the box 100, there is always a cooling medium with a lower temperature that can effectively help the battery 200 to cool down, whether in the first end portion 110 or the second end portion 120 of the box 100.

[0026] The embodiment carefully arranges the relative positions between the first liquid inlet 130, the first liquid outlet 140 of the immersion liquid, and the second liquid inlet 330, the second liquid outlet 340 of the cooling liquid, so that the immersion liquid and the cooling liquid of the battery pack 10 work together, the battery 200 can be fully cooled in different areas, and the heat generated by the battery 200 can be more evenly and effectively dispersed, the temperature difference on the surface of the battery 200 is reduced, the heat is prevented from accumulating in a local area of the battery 200, the temperature distribution of the entire battery 200 is more uniform, and the risk of performance degradation and life shortening of the battery 200 caused by temperature difference is reduced.

[0027] It should be noted that the liquid cooling plate 300 in the embodiment is adjacent to the box 100, which can be understood as the liquid cooling plate 300 can be adjacent to any side of the box 100, for example, the liquid cooling plate 300 can be adjacent to the top plate, the bottom plate or any other side of the box 100. Moreover, the box 100 can be considered to include two ends, the first end portion 110 and the second end portion 120, regardless of the length direction, the width direction or the height direction. Similarly, the liquid cooling plate 300 can also be considered to include two ends, the third end portion 310 and the fourth end portion 320, regardless of the length direction, the width direction or the height direction.

[0028] Please refer to FIG. 2, which is a schematic diagram of the internal cross section of the battery 200 pack provided in the embodiment of the application.

[0029] In some embodiments, the distance between the first liquid inlet 130 and the second liquid outlet 340 is L1, which can be measured by inserting a vernier caliper into the first liquid inlet 130 and the second liquid outlet 340, respectively. Of course, the distance between the first liquid inlet 130 and the second liquid outlet 340 can also be measured by a ruler or other measuring tools. 1cm≤L1≤10cm, L1 can be 1cm, 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, 8cm, 9cm, 10cm, etc. Within this range, L1 can ensure that the cooling liquid in the liquid cooling plate 300 and the immersion liquid in the cabinet 100 can fully exchange heat, thereby achieving the effect of uniform heating.

[0030] In some embodiments, the distance between the first liquid outlet 140 and the side of the cabinet 100 away from the liquid cooling plate 300 is L2, which is the distance between the first liquid outlet 140 and the top surface of the cabinet 100. L2 can be measured by inserting a vernier caliper into the first liquid outlet 140 and overlapping the top surface of the cabinet 100. Of course, the distance between the first liquid outlet 140 and the top surface of the cabinet 100 can also be measured by a ruler or other measuring tools. 15cm≤L2≤22cm, L2 can be 15cm, 16cm, 17cm, 18cm, 19cm, 20cm, 21cm, 22cm, etc. Within the above range, L2 can make the first liquid outlet 140 higher than or equal to the height of the aluminum row and other accessories above the battery 200, so as to ensure that the immersion liquid fully immerses the battery 200. When exceeding this range, the immersion liquid that has absorbed heat will naturally float upwards in the containment space and is not easy to be discharged due to its low density.

[0031] In some embodiments, the distance between the second liquid inlet 330 and the side of the liquid cooling plate 300 close to the cabinet 100 is L3, which can be the distance between the second liquid inlet 330 and the cabinet 100. The distance between the second liquid outlet 340 and the side of the liquid cooling plate 300 close to the cabinet 100 is L4, which can be the distance between the second liquid outlet 340 and the cabinet 100. Among them, L4≤L3, that is, the second liquid inlet 330 is farther away from the cabinet 100 than the second liquid outlet 340, and the second liquid inlet 330 is lower than the second liquid outlet 340, thereby ensuring that the cooling liquid can be maximally immersed in the liquid cooling plate 300. In addition, 2cm≤L4≤6cm, L4 can be 2cm, 3cm, 4cm, 5cm, 6cm, etc.

[0032] In some embodiments, the height of the box 100 is H1, H1 is the distance between the upper surface and the lower surface of the box 100, the height of the liquid cooling plate 300 is H2, H2 is the distance between the upper surface and the lower surface of the liquid cooling plate 300, 2≤H1 / H2≤5, H1 / H2 can be 2, 3, 4, 5, etc. The height of the box 100 is between 2 times and 5 times the height of the liquid cooling plate 300, and the immersion liquid in the box 100 is between 2 times and 5 times the cooling liquid in the liquid cooling plate 300, so as to ensure that the cooling liquid in the liquid cooling plate 300 and the immersion liquid in the box 100 can be fully exchanged to achieve the effect of uniform heating.

[0033] In some embodiments, the length of the box 100 is D1, D1 is the distance between the left surface and the right surface of the box 100, the length of the liquid cooling plate 300 is D2, D2 is the distance between the left surface and the right surface of the liquid cooling plate 300, 15cm≤D1-D2≤22cm, D1-D2 represents the distance of the liquid cooling plate 300 relative to the box 100, which can be 15cm, 16cm, 17cm, 18cm, 19cm, 20cm, 21cm, 22cm, etc. The liquid cooling plate 300 is shorter than the box 100, and an empty space is formed beside the box 100, which can ensure the space utilization of the battery 200 system.

[0034] Please refer to FIG. 3, which is a second structural diagram of the battery pack provided by the embodiments of the present application. In this embodiment, the position of the first liquid inlet 130 on the first end 110, the position of the first liquid outlet 140 on the second end 120, the position of the second liquid inlet 330 on the fourth end 320, and the position of the second liquid outlet 340 on the third end 310 can be adjusted according to the layout needs. For example, the position of the first liquid inlet 130 on the first end 110 in FIG. 1 and FIG. 3 is different, but it is located on the first end 110; and the position of the first liquid outlet 140 on the second end 120 in FIG. 1 and FIG. 3 is also different, but it is also located on the second end 120. This embodiment does not limit this, as long as the first end 110 where the first liquid inlet 130 is arranged is adjacent to the third end 310 where the second liquid outlet 340 is arranged, and the second end 120 where the first liquid outlet 140 is arranged is adjacent to the fourth end 320 where the second liquid inlet 330 is arranged, then the synergistic effect between the immersion liquid and the cooling liquid can be more uniform and effective for heat dissipation of the battery 200.

[0035] In some embodiments, referring to FIG. 4, which is a structural schematic diagram of the battery pack shown in FIG. 1 from another angle. Along the length direction of the box 100, the first end 110 includes a first end plate 111, and the second end 120 includes a second end plate 121. The first end plate 111 and the second end plate 121 are oppositely arranged. The first liquid inlet 130 is arranged on the first end plate 111, and the first liquid outlet 140 is arranged on the second end plate 121. Along the length direction of the liquid cooling plate 300, the third end 310 includes a third end plate 311, and the fourth end 320 includes a fourth end plate 321. The third end plate 311 and the fourth end plate 321 are oppositely arranged. The second liquid outlet 340 is arranged on the third end plate 311, and the second liquid inlet 330 is arranged on the fourth end plate 321. The third end plate 311 and the first end plate 111 are located on the same side, and the second end plate 121 and the fourth end plate 321 are located on the same side.

[0036] In the present embodiment, the box 100 has two ends along its length direction. The first end 110 is located at one end of the box 100 and includes a first end plate 111. The first end plate 111 is provided with a first liquid inlet 130 for the immersion liquid and is configured to inject the low-temperature immersion liquid. The second end 120 is located at the opposite end of the box 100 and includes a second end plate 121. The second end plate 121 is provided with a first liquid outlet 140 for the immersion liquid and is configured to discharge the immersion liquid with increased temperature after absorbing heat. Similarly, the liquid cooling plate 300 also has two ends along its length direction. The third end 310 is located at one end of the liquid cooling plate 300 and includes a third end plate 311. The third end plate 311 is provided with a second liquid outlet 340 for the cooling liquid and is configured to discharge the cooling liquid with increased temperature after absorbing heat. The fourth end 320 is located at the opposite end of the liquid cooling plate 300 and includes a fourth end plate 321. The fourth end plate 321 is provided with a second liquid inlet 330 for the cooling liquid and is configured to inject the low-temperature cooling liquid. That is, in the present embodiment, the first liquid inlet 130 and the first liquid outlet 140 are arranged along the length direction of the box 100, and the second liquid inlet 330 and the second liquid outlet 340 are also arranged along the length direction of the liquid cooling plate 300. In this way, the flow path of the immersion liquid and the cooling liquid can be made longer, and they have more time to absorb and carry away heat during the flow process, thereby achieving more effective heat dissipation.

[0037] The third end plate 311 and the first end plate 111 are located on the same side, and the second end plate 121 and the fourth end plate 321 are located on the same side. Therefore, the second liquid outlet 340 of the cooling liquid and the first liquid inlet 130 of the immersion liquid are located on the same side and are relatively close in spatial layout, and the second liquid inlet 330 of the cooling liquid and the first liquid outlet 140 of the immersion liquid are also located on the same side and are relatively close in spatial layout. It can be understood that, although the temperature of the immersion liquid near the first liquid outlet 140 is relatively high, the temperature of the cooling liquid near the second liquid inlet 330 located on the same side and relatively close is relatively low, and although the temperature of the cooling liquid near the second liquid outlet 340 is relatively high, the temperature of the immersion liquid near the first liquid inlet 130 located on the same side and relatively close is relatively low, so that in different regions of the battery 200, there is always a cooling medium with a lower temperature to absorb heat, which helps to more evenly and effectively disperse the heat generated by the battery 200 and avoids the accumulation of heat in a local part of the battery 200.

[0038] In some embodiments, please continue to refer to FIG. 1 and FIG. 3, the flow direction of the cooling liquid in the liquid cooling plate 300 is opposite to the flow direction of the immersion liquid in the box body 100. It can be understood that, in the present embodiment, when the immersion liquid is injected into the box body 100 from the first liquid inlet 130 of the first end part 110 and is discharged from the first liquid outlet 140 of the second end part 120, the cooling liquid is injected into the liquid cooling plate 300 from the second liquid inlet 330 of the fourth end part 320 at the same time, and flows out from the second liquid outlet 340 of the third end part 310. Since the first end part 110 and the third end part 310 are adjacent, and the second end part 120 and the fourth end part 320 are adjacent, the flow direction of the cooling liquid in the liquid cooling plate 300 can be opposite to the flow direction of the immersion liquid in the box body 100.

[0039] It can be understood that, along the flow direction of the immersion liquid in the box body 100, the temperature of the immersion liquid gradually rises during the flow process due to the absorption of heat from the battery 200, and along the flow direction of the cooling liquid in the liquid cooling plate 300, the temperature of the cooling liquid also rises after absorbing heat in the liquid cooling plate 300. Since the flow direction of the cooling liquid in the liquid cooling plate 300 is opposite to the flow direction of the immersion liquid in the box body 100, the temperature change trend of the immersion liquid in the box body 100 and the temperature change trend of the cooling liquid in the liquid cooling plate 300 are opposite with respect to the battery 200, so that in different regions on both sides of the battery 200, there is always a cooling medium with a lower temperature to absorb heat, for example, on one side of the battery 200, the temperature of the immersion liquid is relatively high and the temperature of the cooling liquid is relatively low, and on the other side of the battery 200, the temperature of the cooling liquid is relatively high and the temperature of the immersion liquid is relatively low, which helps to more evenly and effectively disperse the heat generated by the battery 200 and reduces the temperature difference on the surface of the battery 200, which can avoid the accumulation of heat in a local part of the battery 200.

[0040] For example, the liquid cooling plate 300 is adjacent to the bottom plate of the box body 100, the immersion liquid enters from the first end plate 111 on the left side of the box body 100, the flow direction of the immersion liquid is from left to right, the initial temperature is low, and the temperature gradually increases along the direction from left to right as the battery 200 absorbs heat. The cooling liquid enters from the fourth end plate 321 on the right side of the liquid cooling plate 300, the flow direction of the cooling liquid is from right to left, the initial temperature is also low, and the temperature gradually increases along the direction from right to left as the battery 200 absorbs heat. During the simultaneous flow of the two cooling media of the immersion liquid and the cooling liquid, the temperature of the immersion liquid is low in the area close to the left side of the battery 200, and the temperature of the immersion liquid is high in the area close to the right side of the battery 200, and at the same time, the temperature of the cooling liquid is high in the area close to the left side of the battery 200, and the temperature of the cooling liquid is low in the area close to the right side of the battery 200. The immersion liquid and the cooling liquid on both sides of the battery 200 can form a dynamic balance of heat exchange, although the temperature of the immersion liquid is high in the area on the right side of the battery 200, which is not conducive to heat dissipation in the area on the right side of the battery 200, but because the temperature of the cooling liquid is low in the area on the right side of the battery 200, the cooling liquid with low temperature can effectively help the area on the right side of the battery 200 to cool down. Similarly, although the temperature of the cooling liquid is high in the area on the left side of the battery 200, which is not conducive to heat dissipation in the area on the left side of the battery 200, but because the temperature of the immersion liquid is low in the area on the left side of the battery 200, the immersion liquid with low temperature can also effectively help the area on the left side of the battery 200 to cool down, so that this reverse flow strategy realizes the complementation of the temperature of the immersion liquid and the cooling liquid during the heat dissipation of the battery 200, and optimizes the overall thermal management effect of the battery pack 10.

[0041] It should be noted that the flow directions of the cooling liquid in the liquid cooling plate 300 and the immersion liquid in the box body 100 in the embodiment refer to the overall flow trend or directionality, but do not limit the specific flow paths of the cooling liquid in the liquid cooling plate 300 and the immersion liquid in the box body 100.

[0042] In some embodiments, the flow path of the immersion liquid in the box body 100 can be changed by adjusting the position of the first liquid inlet 130 on the first end plate 111 and the position of the first liquid outlet 140 on the second end plate 121 to optimize the thermal management performance.

[0043] For example, the first liquid inlet 130 is located on the side of the first end plate 111 close to the liquid cooling plate 300, and the first liquid outlet 140 is located on the side of the second end plate 121 away from the liquid cooling plate 300. For example, the liquid cooling plate 300 is adjacent to the bottom plate of the box body 100, by designing the first liquid outlet 140 and the first liquid inlet 130 to have a height difference, the immersion liquid has more time and space to exchange heat with the surface of the battery 200 before flowing out of the box body 100, so that the immersion liquid has more sufficient contact with the surface of the battery 200, and better heat dissipation effect is obtained, and more uniform heat dissipation is achieved.

[0044] In another example, the liquid cooling plate 300 is also adjacent to the bottom plate of the box 100, the first liquid inlet 130 is located on the side of the first end plate 111 away from the liquid cooling plate 300, and the first liquid outlet 140 is located on the side of the second end plate 121 close to the liquid cooling plate 300. The height of the first liquid inlet 130 can be higher than that of the first liquid outlet 140. It can be understood that the immersion liquid enters from the higher liquid inlet and flows naturally downward during the flow process, which increases the turbulence of the immersion liquid and also improves the contact area and heat exchange efficiency of the immersion liquid and the surface of the battery 200.

[0045] In another example, along the width direction of the box 100, the first liquid inlet 130 is located in the middle of the first end plate 111, and the first liquid outlet 140 is located in the middle of the second end plate 121; and / or along the width direction of the liquid cooling plate 300, the second liquid outlet 340 is located in the middle of the third end plate 311, and the second liquid inlet 330 is located in the middle of the fourth end plate 321. Among them, along the width direction of the box 100, the immersion liquid enters from the middle of the first end plate 111 and flows out from the middle of the second end plate 121. The immersion liquid can uniformly contact different areas of the surface of the battery 200 during the flow process, thereby achieving more uniform heat dissipation. Similarly, along the width direction of the liquid cooling plate 300, the cooling liquid enters from the middle of the fourth end plate 321 and flows out from the middle of the third end plate 311. The cooling liquid can also more uniformly contact different areas of the liquid cooling plate 300 during the flow process, thereby ensuring that the heat transferred from the battery 200 to the liquid cooling plate 300 is uniformly and effectively dissipated, effectively avoiding local hot spots on the surface of the battery 200, and improving the uniformity of heat dissipation.

[0046] Please refer to FIG. 5, FIG. 6 and FIG. 7, FIG. 5 is a third structural schematic diagram of the battery pack provided by the embodiment of the present application; FIG. 6 is a structural schematic diagram of the battery pack shown in FIG. 5 from another angle; and FIG. 7 is a sectional view of the battery pack shown in FIG. 6 along A-A. In some embodiments, the battery pack 10 comprises a plurality of boxes 100 and a plurality of liquid cooling plates 300, the plurality of boxes 100 and the plurality of liquid cooling plates 300 are arranged in a staggered manner, and are arranged along a direction perpendicular to the thickness direction of the liquid cooling plate 300. In the embodiment, the battery pack 10 is composed of a plurality of boxes 100 and a plurality of liquid cooling plates 300, along the thickness direction of the liquid cooling plate 300, or the thickness direction of the box 100, one liquid cooling plate 300 is arranged between two adjacent boxes 100, and one box 100 is arranged between two adjacent liquid cooling plates 300. For example, the liquid cooling plate 300 can be arranged on the top plate of the box 100. Since the plurality of boxes 100 and the plurality of liquid cooling plates 300 are arranged in a staggered manner, except that the top plate of the uppermost box 100 is not adjacent to the liquid cooling plate 300, only the bottom plate is adjacent to the liquid cooling plate 300, the upper and lower sides of each box 100 are provided with the liquid cooling plate 300; in another example, a liquid cooling plate 300 can be additionally arranged on the top plate of the uppermost box 100, so that the upper and lower sides of each box 100 are provided with the liquid cooling plate 300. Therefore, the heat generated by the battery 200 can be absorbed and carried away from the cooling liquid in the upper and lower liquid cooling plates 300 and the immersion liquid in the box 100 from different directions, effectively improving the heat dissipation efficiency. Moreover, since the fourth end portion 320 where the second inlet port 330 of the cooling liquid in the upper and lower liquid cooling plates 300 is located is adjacent to the second end portion 120 where the first outlet port 140 of the immersion liquid is located, and the third end portion 310 where the second outlet port 340 of the cooling liquid is located is adjacent to the first end portion 110 where the first inlet port 130 of the immersion liquid is located, the cooling liquid in the upper and lower liquid cooling plates 300 of each box 100 can flow in the opposite direction relative to the immersion liquid. The cooling liquid in the upper and lower liquid cooling plates 300 and the immersion liquid in the box 100 form different temperature gradients relative to the battery 200, so that in different areas of the battery 200, there is always a cooling medium with a lower temperature to absorb heat, reducing the temperature difference on the surface of the battery 200, and improving the overall heat dissipation effect of the battery pack 10. Moreover, the staggered arrangement of the plurality of boxes 100 and the plurality of liquid cooling plates 300 makes the battery pack 10 easy to expand and modular design, facilitating the adaptation of the battery pack 10 to different scales and needs.

[0047] It should be noted that in some embodiments, the liquid cooling plate 300 can be arranged on the top plate of the box 100, which is not limited in the present embodiment.

[0048] In some embodiments, the liquid cooling plate 300 comprises a cover plate 350 abutting the cabinet 100, and the cover plate 350 also covers the sealed accommodation space. In the present embodiment, the cover plate 350 itself serves as a part of the liquid cooling plate 300 and also seals the cabinet 100, so the cabinet 100 does not need to be additionally provided with a sealing member, and the liquid cooling plate 300 and the cabinet 100 can share the structure of the cover plate 350, which reduces the use of materials of the cabinet 100. For example, the cover plate 350 can also be provided with a small hole, so that the immersion liquid and the cooling liquid at different temperatures can be mixed to some extent, so that heat dissipation can be more uniform.

[0049] It can be understood that when the battery pack 10 comprises only one cabinet 100 and one liquid cooling plate 300, one sealing member of the cabinet 100 can be saved. When the battery pack 10 comprises a plurality of cabinets 100 and a plurality of liquid cooling plates 300, the plurality of cabinets 100 and the plurality of liquid cooling plates 300 are staggered, and the cover plates 350 of the liquid cooling plates 300 on the upper and lower sides of each cabinet 100 can be respectively configured to seal the upper and lower sides of the cabinet 100, so that more sealing members can be saved. For example, when the battery pack 10 comprises four cabinets 100 and four liquid cooling plates 300, seven sealing members can be saved.

[0050] Therefore, the design of integrating the liquid cooling plate 300 and the sealing function of the cabinet 100 in the present embodiment reduces the use of materials, simplifies the overall structure of the battery pack 10, reduces the overall weight of the battery pack 10, improves the volume energy density of the battery pack 10, and simplifies the manufacturing and assembly process, thereby reducing the overall cost.

[0051] Please refer to FIG. 8, FIG. 9, FIG. 10 and FIG. 11, FIG. 8 is a fourth structural schematic diagram of a battery pack provided by an embodiment of the present application; FIG. 9 is a structural schematic diagram of the battery pack shown in FIG. 8 from another angle; FIG. 10 is a structural schematic diagram of the battery pack shown in FIG. 8 from still another angle; and FIG. 10 is a sectional view of the battery pack shown in FIG. 9 along B-B. In some embodiments, the battery pack 10 comprises a plurality of cabinets 100 and a plurality of liquid cooling plates 300, and along the length direction of the cabinet 100, the plurality of cabinets 100 are sequentially abutted; and along the height direction of the cabinet 100, the plurality of cabinets 100 and the plurality of liquid cooling plates 300 are staggered.

[0052] It can be understood that the battery pack 10 includes a plurality of battery units, each of which can include a box 100 and a liquid cooling plate 300 stacked in the same way. In addition to arranging a plurality of battery units in the height direction, the battery pack 10 can also be adjacent to a plurality of battery units arranged in the horizontal direction, thereby increasing the size of the battery pack 10. Therefore, the battery pack 10 in the present embodiment has high modularity and scalability, and can adapt to a variety of different application scenarios. Whether it is an electric vehicle, an energy storage system, or other devices that require high energy density and efficient heat dissipation, the size of the battery pack 10 can be adjusted to meet the needs.

[0053] In some embodiments, each box 100 is provided with a cavity, and adjacent two boxes 100 share a partition plate 150 along the length direction of the box 100 to separate the two cavities.

[0054] In the present embodiment, two adjacent boxes 100 can share a partition plate 150 to further reduce the structural material of the battery pack 10. For example, each row of the battery pack 10 includes three boxes 100, and the middle box 100 shares a partition plate 150 with the left box 100 and the right box 100, respectively. Two partition plates 150 can be saved, which can further reduce the weight of the battery pack 10 and make the array of the entire battery pack 10 more compact.

[0055] In some embodiments, the flow direction of the cooling liquid in adjacent liquid cooling plates 300 is the same along the length direction of the liquid cooling plate 300, and the flow direction of the immersion liquid in adjacent boxes 100 is the same.

[0056] It can be understood that along the length direction of the box 100, the temperature of the immersion liquid gradually increases along the flow direction of the immersion liquid after absorbing the heat of the battery 200. When it is close to the adjacent box 100, the temperature of the immersion liquid is high, which is not conducive to the heat dissipation of the battery 200 in this area. However, the immersion liquid of the adjacent box 100 is in the initial state of flow, and has not flowed through the heat source or has flowed through less heat source, so its temperature is relatively low. The immersion liquid with lower temperature can effectively help to disperse the heat in this area. Therefore, along the length direction of the plurality of boxes 100, the immersion liquid of the adjacent two boxes 100 forms a temperature difference near the connection area of the two boxes 100, which can complementarily cool the battery 200, so that the entire battery pack 10 can be cooled more evenly.

[0057] Exemplarily, the liquid cooling plate 300 is adjacent to the bottom plate of the box 100, and in this embodiment, the battery pack 10 is provided with the liquid cooling plate 300 only on the bottom plate of the first row of boxes 100, and the liquid cooling plate 300 is provided on the upper and lower sides of the other boxes 100, and the liquid cooling plate 300 is provided on the left and right sides of each box 100 except the first row of boxes 100. Among them, on the upper and lower sides of the box 100, the flow direction of the cooling liquid in the liquid cooling plate 300 is opposite to the flow direction of the immersion liquid in the box 100, and on the left and right sides of the box 100, the flow direction of the immersion liquid in the adjacent box 100 is the same as the flow direction of the immersion liquid in the box 100, so that there is always a cooling medium with a lower temperature to absorb heat in the different areas of the battery 200 on the upper, lower, left and right of the box 100, reducing the temperature difference on the surface of the battery 200, and improving the overall heat dissipation effect of the battery pack 10.

[0058] In some embodiments, along the thickness direction of the box 100, the box 100 includes a first side plate 160 close to or away from the liquid cooling plate 300, a portion of the first side plate 160 located at the first end 110 is provided with a first liquid inlet 130, and a portion of the first side plate 160 located at the second end 120 is provided with a second liquid inlet 330; along the length direction of the liquid cooling plate 300, the third end 310 includes a third end plate 311, and the fourth end 320 includes a fourth end plate 321, the third end plate 311 and the fourth end plate 321 are oppositely arranged, the second liquid outlet 340 is arranged on the third end plate 311, and the second liquid inlet 330 is arranged on the fourth end plate 321.

[0059] Among them, the first side plate 160 can be the top plate or the bottom plate of the box 100. Exemplarily, the first side plate 160 is the top plate of the box 100, and the first liquid inlet 130 is arranged on the portion of the first side plate located at the first end 110, and the first liquid outlet 140 is arranged on the portion of the first side plate located at the second end 120, so that the first liquid inlet 130 and the first liquid outlet 140 are arranged at the two ends of the first side plate. It can be understood that the battery pack 10 in this embodiment is horizontally adjacent to multiple boxes 100, and the boxes 100 and the liquid cooling plates 300 are staggered in the height direction, so that the first liquid inlet 130 and the second liquid inlet 330 of the box 100 are arranged at the top plate of the box 100, which can enable each row of boxes 100 to be closely arranged in the horizontal direction, reducing the space waste caused by improper positioning of the first liquid inlet 130 and the first liquid outlet 140.

[0060] It should be noted that the first side plate 160 can also be the bottom plate of the box 100, which is not limited in this embodiment.

[0061] In some embodiments, along the length direction of the liquid cooling plate 300, the adjacent liquid cooling plates 300 are spaced apart and have a spacing space, and at least part of the first liquid inlet 130, the first liquid outlet 140, the second liquid inlet 330 and the second liquid outlet 340 are exposed to the spacing space.

[0062] The liquid cooling plate 300 and the box body 100 are staggered in height, and in the horizontal direction, the plurality of liquid cooling plates 300 are spaced apart, which reserves sufficient space for the first liquid inlet 130, the first liquid outlet 140, the second liquid inlet 330 and the second liquid outlet 340, and ensures the smooth flow of the immersion liquid and the cooling liquid in the battery pack 10. The first liquid inlet 130, the first liquid outlet 140, the second liquid inlet 330 and the second liquid outlet 340 are arranged in the spacing space, which also facilitates the inspection and maintenance of these interfaces.

[0063] In some embodiments, the first liquid inlets 130 of the plurality of box bodies 100 are connected to each other; and / or the second liquid inlets 330 of the plurality of liquid cooling plates 300 are connected to each other.

[0064] For example, by branching from one main pipe to each first liquid inlet 130, and / or by branching from one main pipe to each second liquid inlet 330, it can be ensured that all box bodies 100 can obtain uniform immersion liquid supply, or all liquid cooling plates 300 can obtain uniform cooling liquid supply. The design of the first liquid inlets 130 or the second liquid inlets 330 connected to each other can greatly simplify the pipe layout, reduce the complexity and length of the pipe. This not only reduces the manufacturing cost and maintenance difficulty of the battery pack 10, but also improves the overall aesthetics and space utilization of the battery pack 10.

[0065] The embodiments of the present application also provide a battery system, which comprises a control assembly and the battery pack 10 of any of the above embodiments. The control assembly comprises a battery management system (BMS), a battery disconnect unit (BDU), etc. The battery management system is mainly used for intelligent management and maintenance of each battery cell 300, monitoring the state of the battery, preventing overcharging and overdischarging of the battery, so as to prolong the service life of the battery. The battery management system also controls the flow of the immersion liquid and the flow of the cooling liquid. Specifically, the battery management system can control the flow rate of the immersion liquid according to the temperature of the immersion liquid, and the battery management system can control the flow rate of the cooling liquid according to the temperature of the cooling liquid. The main function of the battery disconnect unit is to receive electric energy from the charging system, and then control the speed and torque of the motor through the controller, so as to realize the driving of the automobile. At the same time, the battery disconnect unit also needs to monitor the state of the battery in real time to ensure the safe operation of the battery. The battery pack 10 combines the indirect liquid cooling and the immersion cooling, which not only gives full play to the advantages of the two cooling technologies, but also makes the second end portion 120 of the first liquid outlet 140 adjacent to the fourth end portion 320 of the second liquid inlet 330, so that in different areas of the battery 200, there is always a cooling medium with lower temperature to absorb heat, reducing the temperature difference on the surface of the battery 200, improving the overall heat dissipation effect of the battery pack 10, and better meeting the heat dissipation demand of the battery system under high power and high density operation. Moreover, the staggered arrangement of the multiple box bodies 100 and the multiple liquid cooling plates 300 can be adjusted in the height direction according to the needs, and the horizontal direction can also be further expanded to increase more box bodies 100 and liquid cooling plates 300 to increase the scale of the battery pack 10. Whether it is an electric vehicle, an energy storage system or other equipment requiring high energy density and efficient heat dissipation, the scale of the battery pack 10 can be adjusted to meet the demand.

[0066] The embodiments of the present application are along the long edge direction of the box body, but are not limited to the long edge direction of the box body, and can be along the short edge direction of the box body. The highlight of the embodiments is to complete heat exchange between hot air and the liquid cooling plate, so as to realize continuous heat exchange between cold air and the heating battery.

Claims

1. A battery pack, comprising: a box having a containing space configured to contain immersion liquid, the box comprising a first end portion and a second end portion arranged oppositely, the first end portion being provided with a first liquid inlet, and the second end portion being provided with a first liquid outlet; a battery arranged in the containing space; a liquid cooling plate adjacent to the box, the liquid cooling plate being configured to contain cooling liquid, the liquid cooling plate comprising a third end portion and a fourth end portion arranged oppositely, the third end portion being provided with a second liquid outlet, and the fourth end portion being provided with a second liquid inlet; wherein the first end portion and the third end portion are adjacent, and the second end portion and the fourth end portion are adjacent. The distance between the first liquid inlet and the second liquid outlet is L1, and 1cm≤L1≤10cm. The distance between the first liquid outlet and the side of the box away from the liquid cooling plate is L2, and 15cm≤L2≤22cm. The distance between the second liquid inlet and the side of the liquid cooling plate close to the box is L3, and the distance between the second liquid outlet and the side of the liquid cooling plate close to the box is L4, wherein L4≤L3, and 2cm≤L4≤6cm. The height of the box is H1, and the height of the liquid cooling plate is H2, and 2≤H1 / H2≤5.

2. The battery pack of claim 1, wherein, The length of the box is D1, and the length of the liquid cooling plate is D2, and 15cm≤D1-D2≤22cm.

3. The battery pack of claim 1, wherein, Along the length direction of the box, the first end portion comprises a first end plate, the second end portion comprises a second end plate, the first end plate and the second end plate are arranged oppositely, the first liquid inlet is arranged on the first end plate, and the first liquid outlet is arranged on the second end plate.

4. The battery pack of claim 1, wherein, Along the length direction of the liquid cooling plate, the third end portion comprises a third end plate, the fourth end portion comprises a fourth end plate, the third end plate and the fourth end plate are arranged oppositely, the second liquid outlet is arranged on the third end plate, and the second liquid inlet is arranged on the fourth end plate, the third end plate and the first end plate are located on the same side, and the second end plate and the fourth end plate are located on the same side.

5. The battery pack of claim 1, wherein, The flow direction of the cooling liquid in the liquid cooling plate is opposite to the flow direction of the immersion liquid in the box.

6. The battery pack of claim 1, wherein, The battery pack comprises a plurality of the boxes and a plurality of the liquid cooling plates, the plurality of the boxes and the plurality of the liquid cooling plates are arranged alternately and along the thickness direction perpendicular to the liquid cooling plate.

7. The battery pack of claim 1, wherein, The liquid cooling plate comprises a cover plate adjacent to the box, and the cover plate also covers and seals the containing space. Along the length direction of the box, the plurality of the boxes are adjacent sequentially.

8. The battery pack of any one of claims 1-7, wherein, Along the length direction of the box, the flow directions of the immersion liquid in the adjacent boxes are the same.

9. The battery pack of claim 1, wherein, Along the length direction of the liquid cooling plate, the flow directions of the cooling liquid in the adjacent liquid cooling plates are the same.

10. The battery pack of claim 1, wherein, Each of the boxes is provided with a chamber, and two adjacent boxes share a partition plate to separate two chambers along the length direction of the box.

11. The battery pack of claim 9, wherein, ​ 12. The battery pack of claim 11, wherein, ​ ​ 13. The battery pack of claim 11, wherein, ​ 14. The battery pack of any one of claims 11-13, wherein, The box includes a first side plate close to or away from the liquid cooling plate along the thickness direction of the box, and a part of the first side plate located at the first end portion is provided with the first liquid inlet, and a part of the first side plate located at the second end portion is provided with the second liquid inlet; Along the length direction of the liquid cooling plate, the third end portion includes a third end plate, and the fourth end portion includes a fourth end plate, the third end plate and the fourth end plate are oppositely arranged, the second liquid outlet is arranged on the third end plate, and the second liquid inlet is arranged on the fourth end plate.

15. The battery pack of claim 14, wherein, Along the length direction of the liquid cooling plate, the adjacent liquid cooling plates are arranged with a spacing and have a spacing space, and at least part of the first liquid inlet, the first liquid outlet, the second liquid inlet and the second liquid outlet are exposed to the spacing space.

16. The battery pack of claim 14, wherein, The first liquid inlets of a plurality of the boxes are communicated with each other; and / or The second liquid inlets of a plurality of the liquid cooling plates are communicated with each other.

17. A battery system, comprising a control assembly and a battery pack according to any one of claims 1-16, wherein the control assembly and the battery pack are connected.

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