Liquid-cooled battery pack and energy storage system

Abstract

The invention relates to a liquid-cooled battery pack and an energy storage system, the liquid-cooled battery pack comprises a box body and a cold plate, a plurality of battery cells are accommodated in the box body, the box body is filled with a first cooling medium, and the plurality of battery cells are immersed in the first cooling medium in the flowing process; the cold plate is arranged on one side of the box body in a sealing manner, the plurality of battery cells are arranged on the cold plate in parallel, and the cold plate is filled with a flowing second cooling medium; and the flowing direction of the first cooling medium in the box body is opposite to the flowing direction of the second cooling medium in the cold plate. According to the liquid-cooled battery pack provided by the invention, the first cooling medium and the second cooling medium cooperate to carry out cooling treatment on the battery cells, so that the cooling effect of the battery cells can be greatly improved, and the flowing direction of the first cooling medium in the box body is opposite to the flowing direction of the second cooling medium in the cold plate; the temperature control effect of the battery cells at different positions in the box body can be balanced, the temperature of the battery cells at different positions in the box body tends to be consistent, and the temperature uniformity of the battery cells in the liquid-cooled battery pack is improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a liquid-cooled battery pack and an energy storage system. Background Art

[0002] As an important component of the energy storage system, the battery pack includes multiple cells arranged in sequence. The cells will generate heat during the charging and discharging process, causing the cell temperature to rise. If the cell temperature is not controlled, the cell efficiency will be reduced, the life will be shortened, or thermal runaway will occur.

[0003] At present, the following two methods are usually used to cool the battery pack. One is an external cooling system, but this cooling method has a large heat loss and a poor cooling effect. The other is to fill the battery pack with an insulating immersion cooling medium. The cooling medium is in direct contact with the battery cells for heat exchange. During the flow of the cooling medium, the cooling effect of the cooling medium on the battery cells in different areas is obviously different, resulting in a poor cooling effect of the battery pack. Summary of the invention

[0004] Based on this, it is necessary to provide a liquid-cooled battery pack and energy storage system to address the problem of poor cooling effect of existing battery packs.

[0005] A liquid-cooled battery pack, comprising:

[0006] A box body, wherein a plurality of battery cells are accommodated in the box body, and the box body is filled with a first cooling medium, wherein the first cooling medium immerses the plurality of battery cells during the flow process;

[0007] A cold plate, the cold plate is sealed on one side of the box, a plurality of the battery cells are arranged in parallel on the cold plate, and the cold plate is filled with a flowing second cooling medium;

[0008] Wherein, a flow direction of the first cooling medium in the box body is opposite to a flow direction of the second cooling medium in the cold plate.

[0009] In one embodiment, the box body includes a first side panel, a second side panel and a plurality of third side panels, the first side panel, the second side panel and the plurality of third side panels are arranged to form a shell structure, and the first side panel and the second side panel are arranged at intervals;

[0010] The liquid-cooled battery pack also includes a plurality of partition plates, which are spaced apart inside the box along the extension direction of the first side plate, and a flow gap for the first cooling medium to pass through is provided between one of two adjacent partition plates and the first side plate, and a flow gap for the first cooling medium to pass through is provided between the other partition plate and the second side plate.

[0011] In one embodiment, among the two adjacent partition plates, one end of one of the partition plates is abutted against the second side plate, and a flow gap for the first cooling medium to pass through is provided between the other end and the first side plate, and one end of the other partition plate is abutted against the first side plate, and a flow gap for the first cooling medium to pass through is provided between the other end and the second side plate.

[0012] In one of the embodiments, a guide portion is provided at a connection position between the partition plate and the first side plate or the second side plate, and the guide portion is arc-shaped along a flow direction of the first cooling medium.

[0013] In one embodiment, the box body is provided with a first liquid inlet for the first cooling medium to flow in and a first liquid outlet for the first cooling medium to flow out, and the first liquid inlet and the first liquid outlet are spaced apart and arranged on two opposite sides of the box body;

[0014] The cold plate is provided with a second liquid inlet for the second cooling medium to flow in and a second liquid outlet for the second cooling medium to flow out, and the second liquid inlet and the second liquid outlet are spaced apart and arranged on two opposite sides of the cold plate;

[0015] Wherein, the first liquid inlet is close to the second liquid outlet, and the first liquid outlet is close to the second liquid inlet.

[0016] In one of the embodiments, a first flow channel for the first cooling medium to flow is provided in the box body, and the first flow channel is connected to both the first liquid inlet and the first liquid outlet.

[0017] In one embodiment, the width of the first flow channel close to the first liquid inlet is w1, and the width of the first flow channel away from the first liquid inlet is w2, wherein w1>w2.

[0018] In one embodiment, the width of the first flow channel close to the first liquid inlet is w3, and the width of the first flow channel away from the first liquid inlet is w4, wherein w3<w4.

[0019] In one embodiment, a plurality of the battery cell arrays are arranged in the box, the partition plate is inserted between two adjacent columns of battery cells, two adjacent battery cells in the same column of the battery cells are connected by a first connector, and two adjacent columns of the battery cells are connected by a second connector;

[0020] The distance between two adjacent rows of cells is d1, where 15mm≤d1≤25mm;

[0021] The distance between the surface of the battery cells in the same column close to the first side plate and the first side plate is d2, and the distance between the surface of the battery cells in the same column close to the second side plate and the second side plate is d3, wherein 35 mm ≤ d2 ≤ 45 mm, and 50 mm ≤ d3 ≤ 60 mm, or 50 mm ≤ d2 ≤ 60 mm, and 35 mm ≤ d3 ≤ 45 mm;

[0022] The distance between two adjacent battery cells in the same column is d4, wherein 1mm≤d4≤3mm.

[0023] An energy storage system, comprising:

[0024] At least one liquid-cooled battery pack as described in any of the above technical solutions.

[0025] In the above-mentioned liquid-cooled battery pack and energy storage system, several battery cells are immersed in the first cooling medium, and the first cooling medium is filled around any battery cell. The first cooling medium contacts and exchanges heat with the battery cells during the flow process, and the second cooling medium filled in the cold plate can also exchange heat with the battery cells during the flow process. The second cooling medium cooperates with the first cooling medium to cool down the battery cells, which can greatly improve the cooling effect of the battery cells. And because the flow direction of the first cooling medium in the box is opposite to the flow direction of the second cooling medium in the cold plate, it can balance the temperature control effect of the battery cells at different positions in the box, ensure that the temperature of the battery cells at different positions inside the box tends to be consistent, and improve the uniformity of the temperature of the battery cells in the liquid-cooled battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the liquid-cooled battery pack provided in some embodiments.

[0027] Figure 2 Schematic diagram of the structure of the module composed of a box body, a cold plate and a partition plate in a liquid-cooled battery pack provided in some embodiments.

[0028] Figure 3 Schematic diagram of the structure of the partition plate provided in some embodiments.

[0029] Figure 4 A top view of some structures in a liquid-cooled battery pack provided in some embodiments.

[0030] Figure 5 A top view of a portion of the structure in a liquid-cooled battery pack provided in another embodiment.

[0031] Figure 6 A top view of a liquid-cooled battery pack provided in some embodiments.

[0032] Figure 7 A front view of a liquid-cooled battery pack provided in some embodiments.

[0033] Figure 8 for Figure 7 AA section view.

[0034] Fig. 9 Schematic diagram of the structure of the liquid-cooled battery pack provided in some embodiments.

[0035] Reference numerals:

[0036] 100. Liquid-cooled battery pack;

[0037] 110. Box body; 111. First side plate; 112. Second side plate; 113. Third side plate; 114. First liquid inlet; 115. First liquid outlet; 116. First flow channel; 120. Battery cell; 121. First connecting piece; 122. Second connecting piece; 130. Cold plate; 131. Second liquid inlet; 132. Second liquid outlet; 133. Second flow channel; 140. Partition plate; 141. Splitting part; 142. Fitting part; 143. Guide part; 150. Cover plate; 160. Gasket. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0039] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0040] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0044] The technical solution provided by the embodiments of the present application is described below in conjunction with the accompanying drawings.

[0045] See also Figure 1 and Figure 2As shown, the present application provides a liquid-cooled battery pack 100, which includes a box 110 and a cold plate 130. The box 110 accommodates a plurality of battery cells 120, such as the box 110 is a shell-type structure, and the box 110 has a storage space for accommodating a plurality of battery cells 120, wherein the battery cells 120, as an electric energy storage unit, can provide power for a device equipped with the liquid-cooled battery pack 100, and by connecting a plurality of battery cells 120 in parallel or in series, the liquid-cooled battery pack 100 can meet the electric energy requirements in different application scenarios. The box 110 is filled with a first cooling medium, and the first cooling medium immerses a plurality of battery cells 120 during the flow process, that is, when the first cooling medium flows in the box 110, the first cooling medium is filled around any battery cell 120, and the first cooling medium contacts and exchanges heat with the battery cells 120 during the flow process to absorb the heat generated by the battery cells 120 during the charging and discharging process. It should be noted that the pole of the battery cell 120 is higher than the liquid level of the first cooling medium to avoid the first cooling medium from affecting the electrical connection of the battery cell 120 during the flow. Among them, the first cooling medium has the characteristics of insulation, excellent heat transfer performance, and good flow performance, and the first cooling medium does not chemically react with the box 110 and its internal structural parts, such as the first cooling medium is a cooling insulating fluorinated liquid. Of course, in other feasible embodiments, the first cooling medium is not limited to the liquid medium provided above, and the first cooling medium can also be a gas medium such as low-temperature nitrogen, low-temperature argon, etc. The specific form of the first cooling medium is not limited in this application.

[0046] The cold plate 130 is sealed on one side of the box body 110, such as the cold plate 130 is connected to one side of the bottom of the box body 110 by screw connection, clamping, etc. The cold plate 130 and the box body 110 are surrounded to form a storage space for accommodating a plurality of battery cells 120. A plurality of battery cells 120 are arranged side by side on the cold plate 130, and the cold plate 130 is filled with a flowing second cooling medium. The second cooling medium can perform secondary heat exchange on the battery cells 120 during the flow process to further absorb the heat generated by the battery cells 120 during the charging and discharging process. Among them, the second cooling medium has the characteristics of excellent heat transfer performance and good flow performance, and the second cooling medium does not react chemically with the cold plate 130, such as the second cooling medium is cooling water. Of course, in other feasible embodiments, the second cooling medium is not limited to the liquid medium provided above, and the second cooling medium can also be a gas medium such as low-temperature cold air. The specific form of the second cooling medium is not limited in this application.

[0047] Among them, the flow direction of the first cooling medium in the box 110 is opposite to the flow direction of the second cooling medium in the cold plate 130. Since the first cooling medium and the second cooling medium absorb the heat of the battery cell 120 during the flow process, the temperature of the first cooling medium and the second cooling medium gradually increases during the flow process. The flow direction of the first cooling medium in the box 110 is opposite to the flow direction of the second cooling medium in the cold plate 130, which can balance the temperature control effect of the battery cells 120 at different positions in the box 110, ensure that the temperature of the battery cells 120 at different positions inside the box 110 tends to be consistent, and improve the uniformity of the temperature of the battery cells 120 in the liquid-cooled battery pack 100. In addition, the first cooling medium and the second cooling medium cooperate to cool the battery cells 120, which can greatly improve the cooling effect of the battery cells 120.

[0048] In one embodiment, refer to Figure 1 and Figure 2 As shown, the box body 110 includes a first side panel 111, a second side panel 112 and a plurality of third side panels 113. The first side panel 111, the second side panel 112 and the plurality of third side panels 113 are arranged to form a shell structure, and the first side panel 111 and the second side panel 112 are arranged at intervals. Exemplarily, the box body 110 is a rectangular structure, and the box body 110 includes a first side panel 111, a second side panel 112 and two third side panels 113. The first side panel 111, one of the third side panels 113, the second side panel 112 and the other third side panel 113 are connected end to end to form the box body 110, and the first side panel 111 and the second side panel 112 are located on opposite sides of the box body 110.

[0049] The liquid-cooled battery pack 100 further includes a plurality of partition plates 140. The plurality of partition plates 140 are spaced apart inside the box body 110 along the extension direction of the first side plate 111, and a flow gap for the first cooling medium to pass through is provided between one of the two adjacent partition plates 140 and the first side plate 111, and a flow gap for the first cooling medium to pass through is provided between the other partition plate 140 and the second side plate 112, that is, for two adjacent partition plates 140, if a flow gap for the first cooling medium to pass through is provided between one of the partition plates 140 and the first side plate 111, a flow gap for the first cooling medium to pass through is provided between the other partition plate 140 and the second side plate 112. In this way, since the first side plate 111 and the second side plate 112 are located on opposite sides of the box body 110, when the first cooling medium flows inside the box body 110, the first cooling medium flows in an S-shape / snake shape, and the first cooling medium flows along a specified flow channel in the box body 110, which effectively reduces the flow dead zone of the first cooling medium, makes the flow performance of the first cooling medium in the box body 110 better, and can improve the heat exchange effect between the first cooling medium and the battery cell 120 during the flow process, so as to improve the cooling effect of the first cooling medium on the battery cell 120.

[0050] Specifically, see Figure 1 and Figure 2 As shown, among two adjacent partition plates 140, one end of one partition plate 140 is close to the second side plate 112, and a flow gap for the first cooling medium to pass through is provided between the other end of the partition plate 140 and the first side plate 111, and one end of the other partition plate 140 is close to the first side plate 111, and a flow gap for the first cooling medium to pass through is provided between the other end of the partition plate 140 and the second side plate 112. For example, refer to Figure 3 As shown, the partition plate 140 is a T-shaped plate, such as the partition plate 140 includes a dividing portion 141 and a fitting portion 142, and the dividing portion 141 and the fitting portion 142 are perpendicular to each other to form a T-shaped structure, the dividing portion 141 and the side wall of the box body 110 form a flow channel for the first cooling medium to flow, and the fitting portion 142 can be connected to the first side plate 111 or the second side plate 112. When the partition plate 140 is arranged inside the box body 110, the fitting portion 142 is in contact with the first side plate 111, which can increase the contact area between the partition plate 140 and the first side plate 111 or the second side plate 112, and ensure the reliability of the fitting of the partition plate 140 against the first side plate 111 or the second side plate 112, that is, ensure that there is no gap between the fitting portion 141 and the first side plate 111 or the second side plate 112, and the first cooling medium can only pass through the flow gap formed by the partition plate 140 and the first side plate 111 or the second side plate 112, thereby ensuring the uniqueness of the flow path of the first cooling medium inside the box body 110. In this way, one end of the partition plate 140 is placed against the first side plate 111 or the second side plate 112, and there is no gap between one end of the partition plate 140 and the first side plate 111 or the second side plate 112, and one end of the partition plate 140 acts as a barrier to the first cooling medium; there is a gap between the other end of the partition plate 140 and the second side plate 112 or the first side plate 111, which allows the first cooling medium to flow through. That is to say, through the above arrangement, the flow of the first cooling medium inside the box 110 can be made S-shaped / snake-shaped, the flow path of the first cooling medium is limited, the flow dead zone of the first cooling medium is reduced, the flow performance of the first cooling medium in the box 110 is improved, and the heat exchange effect between the first cooling medium and the battery cell 120 is improved.

[0051] Among them, see Figure 4 and Figure 5As shown, the flow gap L between the partition plate 140 and the first side plate 111 or the second side plate 112 is 35mm≤L≤45mm. In this way, it is possible to avoid that a too small flow gap will cause a blocking effect on the flow effect of the first cooling medium, and it is possible to avoid that a too large flow gap will slow down the flow rate of the first cooling medium and affect the heat exchange effect between the first cooling medium and the battery cell 120. In the specific setting, the flow gap L between the partition plate 140 and the first side plate 111 or the second side plate 112 can be any one of 35mm, 38mm, 40mm, 42mm, and 45mm. Of course, the flow gap L between the partition plate 140 and the first side plate 111 or the second side plate 112 is not limited to the specific values ​​provided above, and can also be other values ​​within the range of 35mm~45mm.

[0052] Further, see Figure 1 and Figure 2 As shown, a guide portion 143 is provided at the connection position between the partition plate 140 and the first side plate 111 or the second side plate 112, and the guide portion 143 is in an arc shape along the flow direction of the first cooling medium. In this way, when the first cooling medium flows to the connection position between the partition plate 140 and the first side plate 111 or the second side plate 112 inside the box body 110, the guide portion 143 can guide the flow direction of the first cooling medium, prevent the first cooling medium from a sudden change in flow velocity when passing through the connection position between the partition plate 140 and the first side plate 111 or the second side plate 112, and avoid the first cooling medium from gathering at the connection position between the partition plate 140 and the first side plate 111 or the second side plate 112, thereby reducing the flow dead zone of the first cooling medium, increasing the flow performance of the first cooling medium in the box body 110, so as to improve the heat exchange effect between the first cooling medium and the battery cell 120 during the flow process, and thereby improve the cooling effect of the first cooling medium on the battery cell 120.

[0053] It should be noted that the shape of the guide portion 143 is not limited to the arc shape provided above. The shape of the guide portion 143 can also be a slope, and the guide portion 143 and the partition plate 140 and the side wall of the box body 110 are all at an obtuse angle. The specific shape of the guide portion 143 is not limited in this application.

[0054] In one embodiment, refer to Figure 1 and Figure 2As shown, the housing 110 is provided with a first liquid inlet 114 and a first liquid outlet 115. The first liquid inlet 114 is for the first cooling medium to flow into the housing 110, and the first liquid outlet 115 is for the first cooling medium to flow out of the housing 110. The first liquid inlet 114 and the first liquid outlet 115 are arranged at opposite sides of the housing 110 to increase the distance between the first liquid inlet 114 and the first liquid outlet 115, thereby extending the flow path of the first cooling medium in the housing 110, so that the first cooling medium injected into the housing 110 from the first liquid inlet 114 can stay in the housing 110 for a suitable time and have sufficient heat exchange with the battery cell 120 before flowing out from the first liquid outlet 115, thereby improving the heat exchange effect between the first cooling medium and the battery cell 120. Furthermore, since an S-shaped flow channel is formed between the partition plate 140 and the inner wall of the box body 110, the width of the flow channel is reduced and the flow performance of the first cooling medium in the box body 110 is improved, the flow speed of the first cooling medium inside the box body 110 can be accelerated, and the flow rate of the first cooling medium can be accelerated to quickly take away the heat of the battery cell 120, thereby improving the heat dissipation effect of the battery cell 120.

[0055] Similarly, the cold plate 130 is provided with a second liquid inlet 131 and a second liquid outlet 132, the second liquid inlet 131 is for the second cooling medium to flow into the cold plate 130, and the second liquid outlet 132 is for the second cooling medium to flow out of the cold plate 130. The second liquid inlet 131 and the second liquid outlet 132 are arranged at opposite sides of the cold plate 130 to increase the distance between the second liquid inlet 131 and the second liquid outlet 132, thereby extending the flow path of the second cooling medium in the cold plate 130, so that the second cooling medium injected into the cold plate 130 from the second liquid inlet 131 will flow out from the second liquid outlet 132 only after sufficient heat exchange occurs with the battery cell 120 in the cold plate 130, further improving the heat exchange effect between the second cooling medium and the battery cell 120.

[0056] Since the temperature of the first cooling medium is relatively low when it is injected into the box 110, the temperature of the first cooling medium gradually increases after it flows inside the box 110 and exchanges heat with the battery cell 120, and reaches the highest temperature when the first cooling medium flows out of the box 110, that is, the temperature of the first cooling medium near the first liquid inlet 114 is lower than the temperature of the first cooling medium far from the first liquid inlet 114, and as the first cooling medium flows, the heat exchange and cooling effect of the first cooling medium becomes worse. Similarly, the temperature of the second cooling medium is relatively low when it is injected into the cold plate 130, and the temperature of the second cooling medium gradually increases after it flows inside the cold plate 130 and exchanges heat with the battery cell 120, and reaches the highest temperature when the second cooling medium flows out of the cold plate 130, that is, the temperature of the second cooling medium near the second liquid inlet 131 is lower than the temperature of the second cooling medium far from the second liquid inlet 131, and as the second cooling medium flows, the heat exchange and cooling effect of the second cooling medium becomes worse. Based on this, in the present embodiment, the first liquid inlet 114 is close to the second liquid outlet 132, and the first liquid outlet 115 is close to the second liquid inlet 131. In this way, the flow direction of the first cooling medium in the box 110 is opposite to the flow direction of the second cooling medium in the cold plate 130, the better cooling and cooling effect of the first cooling medium near the first liquid inlet 114 and the worse cooling and cooling effect of the second cooling medium near the second liquid outlet 132 are mutually neutralized, and the worse cooling and cooling effect of the first cooling medium near the first liquid outlet 115 and the better cooling and cooling effect of the second cooling medium near the second liquid inlet 131 are mutually neutralized, which can balance the temperature control effect of the battery cells 120 at different positions in the box 110, ensure that the temperatures of the battery cells 120 at different positions inside the box 110 tend to be consistent, and improve the uniformity of the temperature of the battery cells 120 in the liquid-cooled battery pack 100.

[0057] Further, see Figure 1 and Figure 2 As shown, a first flow channel 116 for the first cooling medium to flow is provided in the box body 110. For example, in this embodiment, the first flow channel 116 is formed by the side wall of the box body 110 and the partition plate 140. The first flow channel 116 is connected to the first liquid inlet 114 and the first liquid outlet 115, so that the first cooling medium injected into the box body 110 through the first liquid inlet 114 flows along a prescribed flow channel in the first flow channel 116, and flows out from the first liquid outlet 115 after heat exchange with the battery cell 120 in the box body 110.

[0058] In one embodiment, refer to Figure 1 , Figure 2 and Figure 4As shown, the width of the first flow channel 116 near the first liquid inlet 114 is w1, and the width of the first flow channel 116 away from the first liquid inlet 114 is w2, wherein w1>w2. Since the temperature of the first cooling medium near the first liquid inlet 114 is relatively low, while the temperature of the first cooling medium far from the first liquid inlet 114 (near the first liquid outlet 115) is relatively high, w1>w2 is set, and the first flow channel 116 is gradually contracted from the first liquid inlet 114 toward the first liquid outlet 115. During the flow of the first cooling medium, more first cooling medium will gather near the first liquid inlet 114, and the first cooling medium near the first liquid inlet 114 will apply fluid pressure to the first cooling medium near the first liquid outlet 115 to accelerate the outflow rate of the first cooling medium near the first liquid outlet 115, so that there is always a supplement of the first cooling medium with a lower temperature near the first liquid outlet 115, and good heat exchange can be performed on the battery cell 120 near the first liquid outlet 115, that is, the first cooling medium can have good heat exchange with the battery cells 120 at different positions during the flow process, so that the battery cells 120 arranged in the box 110 as a whole can be well cooled and cooled.

[0059] Preferably, along the flow direction of the first cooling medium, the width of the first flow channel 116 gradually decreases, so that the flow velocity of the first cooling medium in the first flow channel 116 is uniformly increased, and the battery cells 120 arranged in each area are immersed in the first cooling medium with a smaller temperature difference, thereby balancing the temperature control effect of the battery cells 120 at different positions in the box body 110 and improving the uniformity of the temperature of the battery cells 120 in the liquid-cooled battery pack 100.

[0060] In another embodiment, see Figure 1 , Figure 2 and Figure 5 As shown, the width of the first flow channel 116 near the first liquid inlet 114 is w3, and the width of the first flow channel 116 away from the first liquid inlet 114 is w4, wherein w3<w4. Since the temperature of the first cooling medium near the first liquid inlet 114 is relatively low, and the temperature of the first cooling medium away from the first liquid inlet 114 (near the first liquid outlet 115) is relatively high, w3<w4 is set, and the first flow channel 116 gradually expands from the first liquid inlet 114 toward the first liquid outlet 115. During the flow of the first cooling medium, more first cooling medium can be gathered near the first liquid outlet 115, and more first cooling medium can be used to fully exchange heat with the battery cell 120 near the first liquid outlet 115, so that the battery cells 120 arranged in the box body 110 can be well cooled as a whole.

[0061] Preferably, along the flow direction of the first cooling medium, the width of the first flow channel 116 gradually increases, so that the amount of the first cooling medium accumulated in the first flow channel 116 gradually increases, balancing the temperature control effect of the battery cells 120 at different positions in the box body 110, and improving the uniformity of the temperature of the battery cells 120 in the liquid-cooled battery pack 100.

[0062] In one embodiment, refer to Figure 1 and Figure 2 As shown, the number of the first liquid inlets 114 is greater than the number of the first liquid outlets 115. In this way, a large number of first liquid inlets 114 are provided on the housing 110, and a large amount of the first cooling medium can be introduced into the plurality of first liquid inlets 114. Since a large amount of the first cooling medium is gathered at the first liquid inlets 114, a large amount of the first cooling medium near the first liquid inlets 114 will squeeze the first cooling medium near the first liquid outlet 115 to speed up the outflow rate of the first cooling medium at the first liquid outlet 115, so that the first cooling medium with a lower temperature is always replenished near the first liquid outlet 115, and the battery cell 120 near the first liquid outlet 115 can be well heat exchanged.

[0063] For example, there are two first liquid inlets 114 and one first liquid outlet 115; or there are four first liquid inlets 114 and two first liquid outlets 115. The specific number of the first liquid inlets 114 and the first liquid outlets 115 is not limited in this application.

[0064] Further, see Figure 1 and Figure 2 As shown, the number of the second liquid inlets 131 is greater than the number of the second liquid outlets 132, and the number of the first liquid inlets 114 is greater than the number of the first liquid outlets 115. Since the temperature of the first cooling medium near the first liquid inlet 114 is lower than the temperature of the first cooling medium near the first liquid outlet 115, and the temperature of the second cooling medium near the second liquid inlet 131 is lower than the temperature of the second cooling medium near the second liquid outlet 132, the first liquid inlet 114 is close to the second liquid outlet 132, and the first liquid outlet 115 is close to the second liquid inlet 131, that is, the first cooling medium with a lower temperature gathers at the first liquid inlet 114 and performs good heat exchange with the battery cell 120 near the first liquid inlet 114, and the second cooling medium with a lower temperature gathers at the second liquid inlet 131 and performs good heat exchange with the battery cell 120 near the first liquid outlet 115.

[0065] In the above-mentioned liquid-cooled battery pack 100, the number of the first liquid inlets 114 is set to be greater than the number of the first liquid outlets 115, and the number of the second liquid inlets 131 is set to be greater than the number of the second liquid outlets 132. In this way, a larger amount of the first cooling medium can be introduced into the multiple first liquid inlets 114, and a larger amount of the second cooling medium can be introduced into the multiple second liquid inlets 131. The first cooling medium with a lower temperature is gathered at a position close to the first liquid inlets 114, and the second cooling medium with a lower temperature is gathered at a position close to the second liquid inlets 131. The first cooling medium and the second cooling medium cooperate to have a better cooling effect on the battery cells 120 inside the box 110, and can balance the temperature control effect of the battery cells 120 at different positions inside the box 110. In addition, a larger amount of the first cooling medium near the first liquid inlet 114 will squeeze the first cooling medium near the first liquid outlet 115 to accelerate the outflow rate of the first cooling medium at the first liquid outlet 115, and a larger amount of the second cooling medium near the second liquid inlet 131 will squeeze the second cooling medium near the second liquid outlet 132 to accelerate the outflow rate of the second cooling medium at the second liquid outlet 132, so that there is always a replenishment of the first cooling medium with a lower temperature near the first liquid outlet 115 and there is always a replenishment of the second cooling medium with a lower temperature near the second liquid outlet 132, thereby further improving the heat exchange effect of the battery cell 120 near the first liquid outlet 115.

[0066] For example, the number of the first liquid inlets 114 is two, the number of the first liquid outlet 115 is one, and the number of the second liquid inlets 131 is two, and the number of the first liquid outlet 115 is one; for another example, the number of the first liquid inlets 114 is four, the number of the second liquid outlet 115 is two, and the number of the second liquid inlets 131 is four, and the number of the second liquid outlet 132 is two. The present application does not limit the specific number of the first liquid inlet 114 and the first liquid outlet 115, and the second liquid inlet 131 and the second liquid outlet 132.

[0067] In one embodiment, refer to Figure 1 , Figure 2 and Figure 6 As shown, a plurality of battery cells 120 are arranged in an array in the box 110, and a partition plate 140 is inserted between two adjacent columns of battery cells 120. Two adjacent battery cells 120 in the same column of battery cells 120 are connected by a first connector 121, and two adjacent columns of battery cells 120 are connected by a second connector 122. The first connector 121 and the second connector 122 can connect a plurality of battery cells 120 together to form a battery module, and the plurality of battery cells 120 are arranged in an array in the box 110. The first connector 121 and the second connector 122 can be tabs.

[0068] Preferably, see Figure 1 and Figure 2As shown, the partition plate 140 and the cold plate 130 are integrally formed by injection molding, extrusion, etc., so as to simplify the molding process of the partition plate 140 and the cold plate 130 and improve the structural strength between the partition plate 140 and the cold plate 130. When the cold plate 130 is connected to one side of the bottom of the box body 110, the partition plate 140 is inserted between two adjacent columns of battery cells 120 to guide the first cooling medium to flow between each column of battery cells 120 to perform heat exchange cooling on the battery cells 120.

[0069] Further, see Figure 1 , Figure 2 and Figure 6 As shown, the spacing between two adjacent columns of battery cells 120 is d1, wherein 15mm≤d1≤25mm. In this way, the spacing between two adjacent columns of battery cells 120 is set to 15mm~25mm. On the one hand, there is enough space between two adjacent columns of battery cells 120 for the insertion and installation of the partition plate 140. On the other hand, the first cooling medium can flow to the gap between two adjacent columns of battery cells 120 to fully exchange heat for the battery cells 120. In the specific setting, the spacing d1 between two adjacent columns of battery cells 120 can be any one of 15mm, 18mm, 20mm, 22mm, and 25mm. Of course, the spacing d1 between two adjacent columns of battery cells 120 is not limited to the specific values ​​provided above, and can also be other values ​​within the range of 15mm~25mm.

[0070] In addition, the distance between the surface of the battery cell 120 in the same row close to the first side plate 111 and the first side plate 111 is d2, and the distance between the surface of the battery cell 120 in the same row close to the second side plate 112 and the second side plate 112 is d3. Among them, 35mm≤d2≤45mm, and 50mm≤d3≤60mm, or, 50mm≤d2≤60mm, and 35mm≤d3≤45mm. In this way, a smaller gap is reserved on one side of the battery cell 120 in the same row, and a larger gap is reserved on the other side of the battery cell 120 in the same row. On the basis of not affecting the flow of the first cooling medium, sufficient layout space can be reserved for other components on the side with a larger gap, which is conducive to the functional expansion of the liquid-cooled battery pack 100. In addition, the gap between the battery cell 120 and the side wall of the box body 110 is greater than the spacing between the battery cells 120 in the same row, which is conducive to the flow of the first cooling medium, reduces the dead zone of the flow of the first cooling medium, and improves the cooling effect of the battery cell 120. Among them, in the specific setting, for 35mm≤d2≤45mm and 50mm≤d3≤60mm, d2 can be any one of 35mm, 38mm, 40mm, 42mm, and 45mm, and d3 can be any one of 50mm, 52mm, 55mm, 58mm, and 60mm. Of course, d2 and d3 are not limited to the specific values ​​provided above. d2 can also be other values ​​within the range of 35mm~45mm, and d3 can also be other values ​​within the range of 50mm~60mm. For 50mm≤d2≤60mm and 35mm≤d3≤45mm, d2 can be any one of 50mm, 52mm, 55mm, 58mm, and 60mm, and d3 can be any one of 35mm, 38mm, 40mm, 42mm, and 45mm. Of course, d2 and d3 are not limited to the specific values ​​provided above. d2 can also be other values ​​within the range of 50mm~60mm, and d3 can also be other values ​​within the range of 35mm~45mm.

[0071] Next, the spacing between two adjacent cells 120 in the same column is d4, where 1mm≤d4≤3mm. In this way, the spacing between two adjacent cells 120 in the same column is set to 1mm~3mm. On the one hand, it can ensure that the cells 120 have good insulation performance, and the spacing between two adjacent cells 120 is small, which is conducive to the array arrangement of the cells 120 and the miniaturized design of the liquid-cooled battery pack 100. On the other hand, the first cooling medium can flow to the gap between the two adjacent cells 120 during the flow process, which can ensure that the sides of the two adjacent cells 120 close to each other have sufficient contact area with the first cooling medium, and the cells 120 can be fully heat exchanged. Among them, in the specific setting, the spacing d4 between two adjacent battery cells 120 in the same column of battery cells 120 can be any one of 1mm, 1.5mm, 2mm, 2.5mm, and 3mm. Of course, the spacing d4 between two adjacent battery cells 120 in the same column of battery cells 120 is not limited to the specific values ​​provided above, and can also be other values ​​within the range of 1mm~3mm.

[0072] In one embodiment, refer to Figure 1 and Figure 2 As shown, the number of battery cells 120 near the first liquid inlet 114 is greater than the number of battery cells 120 near the first liquid outlet 115. In this way, since the temperature of the first cooling medium near the first liquid inlet 114 is lower than that of the first cooling medium near the first liquid outlet 115, the battery cells 120 are arranged as close to the first liquid inlet 114 as possible, which can reduce the heat exchange pressure of the first cooling medium near the first liquid outlet 115, so as to improve the heat exchange effect of the first cooling medium on the multiple battery cells 120 inside the box 110.

[0073] In one embodiment, refer to Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, the cold plate 130 is provided with a second flow channel 133 for the flow of a second cooling medium, and the second flow channel 133 is connected to the second liquid inlet 131 and the second liquid outlet 132, so that the second cooling medium injected into the cold plate 130 through the second liquid inlet 131 flows along a prescribed flow channel in the second flow channel 133, and flows out from the second liquid outlet 132 after heat exchange with the battery cell 120 arranged on the cold plate 130.

[0074] The second flow channel 133 is in any one of an S-shape and a curved shape. In this way, the flow of the second cooling medium in the cold plate 130 can be in an S-shape or a curved shape, and the second cooling medium flows along the specified flow channel in the cold plate 130, which effectively reduces the flow dead zone of the second cooling medium, makes the fluidity of the second cooling medium in the cold plate 130 better, and can improve the heat exchange effect between the second cooling medium and the battery cell 120 during the flow process, so as to improve the cooling effect of the second cooling medium on the battery cell 120.

[0075] In one embodiment, refer to Figure 1 , Figure 2 and Fig. 9 As shown, the liquid-cooled battery pack 100 also includes a cover plate 150. The cover plate 150 is detachably connected to the side of the box body 110 away from the cold plate 130. For example, the cold plate 130 is arranged on the bottom side of the box body 110, and the cover plate 150 is arranged on the top side of the box body 110 by screwing, clamping, etc. Through the cover plate 150, a plurality of battery cells 120 can be sealed inside the box body 110, so that the plurality of battery cells 120 form a whole, and prevent the liquid-cooled battery pack 100 from shaking, shifting, and other undesirable phenomena during the transportation and packaging process. Since the cover plate 150 is detachably connected to the box body 110, the battery cells 120 inside the box body 110 can be inspected, replaced, and the like by removing the cover plate 150, so as to reduce the maintenance and use costs of the liquid-cooled battery pack 100. In addition, a gasket 160 is provided at the connection between the partition plate 140 and the cover plate 150 to achieve the sealing reliability of the first flow channel 116, so that the first cooling medium can only flow from the gap between the partition plate 140 and the first side plate 111 or the second side plate 112, thereby limiting the flow path of the first cooling medium, reducing the flow dead zone of the first cooling medium, and improving the heat exchange effect between the first cooling medium and the battery cell 120.

[0076] Also, see Figure 1 and Figure 2 As shown, the present application also provides an energy storage system, which includes at least one liquid-cooled battery pack 100 as described in the above technical solution. In the above energy storage system, the first cooling medium contacts and exchanges heat with the battery cell 120 during the flow process, and the second cooling medium filled in the cold plate 130 can also exchange heat with the battery cell 120 during the flow process. The first cooling medium and the second cooling medium cooperate with each other to cool the battery cell 120, which can greatly improve the cooling effect of the battery cell 120. Since the flow direction of the first cooling medium in the box 110 is opposite to the flow direction of the second cooling medium in the cold plate 130, the temperature control effect of the battery cells 120 at different positions in the box 110 can be balanced, ensuring that the temperatures of the battery cells 120 at different positions inside the box 110 tend to be consistent, and improving the uniformity of the temperature of the battery cells 120 in the energy storage system.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A liquid-cooled battery pack, characterized in that: The liquid-cooled battery pack comprises: A box body, wherein a plurality of battery cells are accommodated in the box body, and the box body is filled with a first cooling medium, wherein the first cooling medium immerses the plurality of battery cells during the flow process; A cold plate, the cold plate is sealed on one side of the box, a plurality of the battery cells are arranged in parallel on the cold plate, and the cold plate is filled with a flowing second cooling medium; Wherein, a flow direction of the first cooling medium in the box body is opposite to a flow direction of the second cooling medium in the cold plate.

2. The liquid-cooled battery pack according to claim 1, characterized in that: The box body comprises a first side plate, a second side plate and a plurality of third side plates, the first side plate, the second side plate and the plurality of third side plates are arranged to form a shell structure, and the first side plate is spaced apart from the second side plate; The liquid-cooled battery pack also includes a plurality of partition plates, which are spaced apart inside the box along the extension direction of the first side plate, and a flow gap for the first cooling medium to pass through is provided between one of two adjacent partition plates and the first side plate, and a flow gap for the first cooling medium to pass through is provided between the other partition plate and the second side plate.

3. The liquid-cooled battery pack according to claim 2, characterized in that: Among the two adjacent partition plates, one end of one of the partition plates is in contact with the second side plate, and a flow gap for the first cooling medium to pass through is provided between the other end and the first side plate; and one end of the other partition plate is in contact with the first side plate, and a flow gap for the first cooling medium to pass through is provided between the other end and the second side plate.

4. The liquid-cooled battery pack according to claim 3, characterized in that: A guide portion is provided at a connection position between the partition plate and the first side plate or the second side plate, and the guide portion is arc-shaped along a flow direction of the first cooling medium.

5. The liquid-cooled battery pack according to claim 1, characterized in that: The box body is provided with a first liquid inlet for the first cooling medium to flow in and a first liquid outlet for the first cooling medium to flow out, and the first liquid inlet and the first liquid outlet are spaced apart and arranged on two opposite sides of the box body; The cold plate is provided with a second liquid inlet for the second cooling medium to flow in and a second liquid outlet for the second cooling medium to flow out, and the second liquid inlet and the second liquid outlet are spaced apart and arranged on two opposite sides of the cold plate; Wherein, the first liquid inlet is close to the second liquid outlet, and the first liquid outlet is close to the second liquid inlet.

6. The liquid-cooled battery pack according to claim 5, characterized in that: A first flow channel for the first cooling medium to flow is disposed in the box body, and the first flow channel is communicated with both the first liquid inlet and the first liquid outlet.

7. The liquid-cooled battery pack according to claim 6, characterized in that: The width of the first flow channel close to the first liquid inlet is w1, and the width of the first flow channel away from the first liquid inlet is w2, wherein w1>w2.

8. The liquid-cooled battery pack according to claim 6, characterized in that: The width of the first flow channel close to the first liquid inlet is w3, and the width of the first flow channel away from the first liquid inlet is w4, wherein w3<w4.

9. The liquid-cooled battery pack according to claim 2, characterized in that: A plurality of the battery cell arrays are arranged in the box, the partition plate is inserted between two adjacent columns of battery cells, two adjacent battery cells in the same column are connected by a first connector, and two adjacent columns of battery cells are connected by a second connector; The distance between two adjacent rows of cells is d1, where 15mm≤d1≤25mm; The distance between the surface of the battery cells in the same column close to the first side plate and the first side plate is d2, and the distance between the surface of the battery cells in the same column close to the second side plate and the second side plate is d3, wherein 35 mm ≤ d2 ≤ 45 mm, and 50 mm ≤ d3 ≤ 60 mm, or 50 mm ≤ d2 ≤ 60 mm, and 35 mm ≤ d3 ≤ 45 mm; The distance between two adjacent battery cells in the same column is d4, wherein 1mm≤d4≤3mm.

10. An energy storage system, characterized in that: The energy storage system comprises: At least one liquid-cooled battery pack as claimed in any one of claims 1 to 9.

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