Secondary battery and battery pack

Abstract

The invention relates to a secondary battery and a battery pack, the secondary battery comprises a shell and a battery cell, the shell is internally provided with an accommodating cavity, the battery cell is arranged in the accommodating cavity, the outer side wall of the shell is provided with grooves, at least two grooves are arranged at intervals, the outer side wall of the shell is also provided with turbulent flow parts, and a plurality of turbulent flow parts arranged at intervals are arranged in the grooves. The grooves can guide the fluid to transfer heat to the shell in the process of orderly flowing along the extending direction of the grooves, so that other fluids are not easily prevented from subsequently and quickly entering the grooves to transfer heat to the shell. The multiple flow disturbing parts arranged at intervals are used for disturbing laminar flow distribution in the fluid so as to promote rapid transfer of heat in the fluid. Under the influence of the grooves and the turbulent flow parts, the grooves and the turbulent flow parts can synergistically improve the heat transfer efficiency between the shell and the fluid in the grooves.

Description

Technical Field

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

[0002] A secondary battery is a reversible battery that can be used continuously by being charged. The secondary battery generally includes a housing and a battery cell, wherein the battery cell is encapsulated by the housing.

[0003] Secondary batteries need to work reliably within a normal operating temperature range. Generally, the secondary batteries can be immersed in an immersion liquid to transfer heat to the secondary batteries to heat the batteries, or the heat of the secondary batteries can be absorbed by the immersion liquid to dissipate the heat from the batteries.

[0004] The structure of the secondary battery housing in the related art has defects, which makes the efficiency of heat transfer between the secondary battery housing and the immersion liquid low. Summary of the invention

[0005] The present application provides a secondary battery and a battery pack, which have the advantage of high efficiency in heat transfer between a secondary battery housing and an immersion liquid.

[0006] In a first aspect, the present application provides a secondary battery, which includes a shell and a battery cell. A accommodating cavity is provided in the shell, and the battery cell is arranged in the accommodating cavity. The outer wall of the shell is provided with grooves, and at least two grooves are arranged at intervals. The outer wall of the shell is also provided with a spoiler, and multiple spoilers arranged at intervals are arranged in the groove.

[0007] When the secondary battery is immersed in the flowing immersion liquid, part of the fluid of the immersion liquid will enter the groove, and the groove is used to guide this part of the fluid to flow along the extension direction of the groove. When the fluid flows along the extension direction of the groove, heat transfer will occur with the shell.

[0008] Taking the heat dissipation of a secondary battery to the outside as an example, when the fluid flows from one position of the groove (e.g., one end of the groove) to another position (e.g., the other end of the groove) along the groove, it absorbs heat from the shell. Other fluids in the immersion liquid will also flow along the extension direction of the groove and absorb heat from the shell after entering the groove. Therefore, the groove can guide the fluid, and the groove can guide the fluid to absorb heat from the shell in the process of orderly flowing along the extension direction of the groove, so that it is not easy to hinder other fluids from quickly entering the groove to absorb heat from the shell.

[0009] Taking the case of a secondary battery absorbing heat from the outside, the groove can guide the fluid to transfer heat to the shell in the process of orderly flowing along the extension direction of the groove, so that it is not easy to hinder other fluids from quickly entering the groove to transfer heat to the shell. Under this setting, the groove can improve the efficiency of heat transfer between the shell and the immersion liquid.

[0010] The greater the number of grooves, the higher the heat transfer efficiency between the shell and the immersion liquid. The present application does not specifically limit the number of grooves.

[0011] The plurality of flow disruptors disposed at intervals are used to disrupt the laminar flow distribution in the fluid to promote rapid heat transfer in the fluid, thereby increasing the efficiency of heat transfer between the shell and the fluid in the groove.

[0012] According to the above content, it can be known that under the influence of the groove and the spoiler, the groove and the spoiler can synergistically improve the heat transfer efficiency between the shell and the fluid located in the groove.

[0013] Optionally, the spoiler includes a convex structure and / or a concave structure. Both the convex structure and the concave structure can play the role of disturbing the distribution of each laminar flow in the fluid to promote the redistribution of heat in the fluid.

[0014] Optionally, the protrusion structure includes a columnar structure and / or a disc-shaped structure. Both the columnar structure and the disc-shaped structure can play the role of disturbing the distribution of each laminar flow in the fluid to promote the redistribution of heat in the fluid.

[0015] Optionally, at least two rows of spoiler arrays are arranged outside the housing and are located in the same groove. The same spoiler array includes at least two spoilers arranged at intervals along the groove extension direction, and the spoilers of at least two rows of spoiler arrays are arranged in a staggered manner in the groove extension direction. Under this arrangement, the distribution of each layer flow in the fluid can be better disturbed, and the heat redistribution in the fluid can be better promoted.

[0016] Optionally, the groove is extended along the height direction of the secondary battery, or the groove is extended along a direction perpendicular to the height direction. The grooves arranged in any of the above extension directions can play the role of guiding the orderly flow of fluid.

[0017] Optionally, the outer side wall of the shell includes a first outer side wall and a second outer side wall adjacent to each other, the extension direction of the second outer side wall intersects with the extension direction of the first outer side wall, the first outer side wall is provided with a groove and a spoiler, and / or the second outer side wall is provided with a groove and a spoiler.

[0018] The grooves arranged at any of the above positions can guide the fluid to flow in an orderly manner.

[0019] Optionally, the outer side wall of the shell is provided with at least two strip-shaped protrusions arranged at intervals, the extension direction of the strip-shaped protrusions is the same as the extension direction of the groove, and the strip-shaped protrusions are provided on both sides of any groove. On the one hand, the at least two strip-shaped protrusions and the outer side wall are used to enclose and form the groove, and on the other hand, the at least two strip-shaped protrusions are used to increase the contact area between the shell and the immersion liquid, thereby improving the efficiency of heat transfer between the shell and the immersion liquid.

[0020] Optionally, the strip-shaped protrusion includes a first end and a second end spaced apart along its own extension direction, the first end includes a transition slope and / or a transition curved surface, and / or the second end includes a transition slope and / or a transition curved surface. Both the transition slope and the transition curved surface can be used to reduce the flow resistance of the fluid, so that the fluid can flow faster relative to the strip-shaped protrusion.

[0021] In a second aspect, the present application provides a battery pack, which includes the secondary battery described above. The battery pack of the present application also includes the technical effects of the secondary battery in the above content, which will not be repeated here.

[0022] Optionally, the battery pack includes at least two insulating sheets and at least two electrically connected secondary batteries, and each insulating sheet is alternately arranged with each secondary battery, and the insulating sheet protrudes relative to the outer side wall of the secondary battery. Each insulating sheet insulates two adjacent secondary batteries, reducing the risk of electrical breakdown or circuit short circuit between two adjacent secondary batteries. When the fluid encounters a structure in which the insulating sheet protrudes relative to the outer side wall of the secondary battery, it is disturbed to redistribute the heat in the fluid, thereby improving the efficiency of heat transfer between the fluid and the secondary battery.

[0023] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A schematic structural diagram of a secondary battery provided in the present application in a first specific embodiment; Figure 2 for Figure 1 A schematic diagram of the partially enlarged structure of the A1 part; Figure 3 It is a schematic diagram of laminar flow distribution when the fluid flows in the groove; Figure 4 Schematic diagram of laminar flow distribution of fluid when passing through the spoiler; Figure 5a is a schematic structural diagram of a spoiler in one embodiment; Figure 5b is a schematic structural diagram of a spoiler in another embodiment; Figure 5c is a schematic structural diagram of a spoiler in yet another embodiment; Figure 6 is a schematic diagram of the spoiler array; Figure 7 A schematic diagram of the structure of the secondary battery provided in the present application in a second specific embodiment; Figure 8 for Figure 7 A schematic diagram of the local enlarged structure of part A2; Fig. 9 A schematic structural diagram of a secondary battery provided in the present application in a third specific embodiment; Fig.10 A schematic diagram of the structure of the secondary battery provided in the present application in a fourth specific embodiment; Fig.11 for Figure 1 A schematic diagram of the local enlarged structure of part B; Fig.12 is a schematic structural diagram of the first end in another embodiment; Fig.13 for Figure 1 A schematic diagram of the local enlarged structure of part C in the middle; Fig.14 is a schematic cross-sectional structural diagram of a receiving member; Fig.15 for Fig.14 A schematic diagram of the local enlarged structure of part D in the middle; Fig.16 for Figure 1 A schematic diagram of the local enlarged structure of part E in the middle; Fig.17 A schematic diagram of the distribution of secondary batteries and insulating sheets in one embodiment; Fig.18 is a schematic diagram of a partial structure of an insulating sheet in one embodiment; Fig.19 is a schematic structural diagram of an insulating sheet in another embodiment; Fig. 20 It is a schematic diagram of the distribution of secondary batteries in another embodiment.

[0026] Description of reference numerals: 1- Secondary battery; 11- housing; 111-accommodating member; 1111-accommodating chamber; 1112 - lateral wall; 11121- first outer side wall; 11122 - second outer side wall; 1113-groove; 1114- spoiler; 1114a-first groove; 1115- Strip-shaped protrusions; 1115a-second groove; 11151-first end; 11152-second end; 112-top cover; 12-pole assembly; 121- positive electrode column; 122-negative pole; 2-Insulation sheet; 21-Gap; 22- spoiler structure; 201-Laminar Flow 1; 202-Laminar Flow II; 203-Laminar Flow III. DETAILED DESCRIPTION

[0027] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0028] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the protection scope of the present application.

[0029] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0030] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the drawings of this document, directions X, Y and Z are perpendicular to each other, and direction Z refers to the direction from the bottom of the secondary battery to the top pole assembly of the secondary battery.

[0032] In a first aspect, an embodiment of the present application provides a secondary battery, which can be used in electrical equipment such as vehicles, ships or aircraft, or the secondary battery can also be used in an energy storage device.

[0033] The vehicle may be a car, a truck, an all-terrain vehicle, a motorcycle, a tricycle, a two-wheeled vehicle, a tractor or an engineering vehicle. The ship may be a cargo ship, a tanker, a container ship, a bulk carrier, a passenger ship or a special ship. The aircraft may be a drone, an airship or a manned aircraft. The energy storage device may be an energy storage box or an energy storage cabinet.

[0034] Please refer to Figure 1 As shown, the secondary battery 1 includes a shell 11, a pole assembly 12, a battery cell (not shown in the figure) and an electrolyte (not shown in the figure). A housing cavity (not shown in the figure) is provided in the shell 11, and the battery cell (not shown in the figure) and the electrolyte (not shown in the figure) are located in the housing cavity. The pole assembly 12 is provided in the shell 11, and the pole assembly 12 includes a positive pole 121 and a negative pole 122. The positive pole 121 is electrically connected to the positive pole of the battery cell, and the negative pole 122 is electrically connected to the negative pole of the battery cell. The battery cell and the electrolyte are used to generate an electrochemical reaction. In other words, the positive pole of the battery cell and the negative pole of the battery cell are transferred through the electrolyte. The positive pole 121 and the negative pole 122 are used to be electrically connected to an external circuit (not shown in the figure) to form a conductive loop. Under this setting, the battery cell can output electric energy to the external circuit, that is, the battery cell can be discharged, or the battery cell can also obtain electric energy from the external circuit, that is, the battery cell can be charged.

[0035] Since the battery generates heat during the charging and discharging process, if the internal temperature of the secondary battery is too high, the internal pressure of the secondary battery is likely to increase, making the secondary battery prone to explosion. Therefore, the secondary battery requires a good heat dissipation structure to quickly dissipate heat to the outside.

[0036] Since secondary batteries may also be used in low temperature environments, if the internal temperature of the secondary battery is too low, it is easy to cause the reaction rate of the electrochemical reaction to be low, which can easily lead to low discharge efficiency of the battery cell or low charging efficiency of the battery cell. Therefore, secondary batteries also need a good heat absorption structure to quickly absorb heat from the outside.

[0037] The heat dissipation structure and the heat absorption structure are both heat transfer structures in nature. The heat dissipation structure is used to transfer the heat inside the secondary battery to the outside of the secondary battery, and the heat absorption structure is used to transfer the heat outside the secondary battery to the secondary battery. Therefore, the secondary battery needs a good heat transfer structure. When the temperature inside the secondary battery is higher than the temperature outside the secondary battery, the heat transfer structure of the secondary battery can quickly transfer the heat inside the secondary battery to the outside of the secondary battery. When the temperature inside the secondary battery is lower than the temperature outside the secondary battery, the heat transfer structure of the secondary battery can quickly transfer the heat outside the secondary battery to the secondary battery.

[0038] In some practical applications, the secondary battery can be immersed in an immersion liquid. Since the thermal conductivity of the immersion liquid is greater than that of air, the immersion liquid can be used to quickly absorb the heat in the secondary battery to achieve the effect of rapid heat dissipation of the secondary battery, or the immersion liquid can be used to quickly transfer heat to the secondary battery to achieve the effect of rapid heating of the secondary battery. If the immersion liquid can flow relative to the surface of the secondary battery, the efficiency of heat transfer between the immersion liquid and the secondary battery can be higher.

[0039] Please refer to Figure 2 As shown, the outer side wall of the housing 11 may be provided with grooves 1113, and at least two grooves 1113 are arranged at intervals.

[0040] Please refer to Figure 2 As shown, under the condition that the immersion liquid (not shown in the figure) flows, a part of the fluid of the immersion liquid will enter the groove 1113. The groove 1113 is used to guide this part of the fluid to flow along the extension direction of the groove 1113. When the fluid flows along the extension direction of the groove 1113, a heat transfer process will occur with the shell 11. Taking the heat dissipation of the secondary battery 1 to the outside as an example, when the fluid flows from one position of the groove 1113 (for example, one end of the groove 1113) along the groove 1113 to another position (for example, the other end of the groove 1113), it will absorb heat from the shell 11. After the other fluids in the immersion liquid also enter the groove 1113, they will also flow along the extension direction of the groove 1113 and absorb heat from the shell 11. Therefore, the groove 1113 can guide the fluid, and the groove 1113 can guide the fluid to absorb heat from the shell 11 in the process of orderly flowing along the extension direction of the groove 1113, so that it is not easy to hinder other fluids from quickly entering the groove 1113 to absorb heat from the shell 11. Taking the secondary battery 1 absorbing heat from the outside as an example, the groove 1113 can guide the fluid to transfer heat to the shell 11 in the process of orderly flowing along the extension direction of the groove 1113, so that it is not easy to hinder other fluids from quickly entering the groove 1113 to transfer heat to the shell 11. Under this setting, the groove 1113 can improve the efficiency of heat transfer between the shell 11 and the immersion liquid.

[0041] The greater the number of grooves 1113 , the higher the heat transfer efficiency between the housing 11 and the immersion liquid. The embodiment of the present application does not specifically limit the number of grooves 1113 .

[0042] It should be noted that the orderly flow of the fluid in the groove 1113 in the immersion liquid mainly refers to the process in which the fluid can move a corresponding distance along the groove 1113. The orderly flow does not exclude the possibility that a part of the fluid will briefly flow back in the groove 1113 and then flow forward, or that a part of the fluid will temporarily flow disorderly at a certain position in the groove 1113. However, the fluid will eventually flow forward along the groove 1113, thereby facilitating other fluids in the subsequent immersion liquid to enter the groove 1113 one after another to complete the corresponding heat transfer process.

[0043] It should be noted that the fluid in the groove 1113 is distributed in layers. Specifically, during the fluid flow process, there is no mixing between the two layers that shear each other. Figure 3 As shown, the fluid in the groove 1113 may include stacked laminar flow 1 201, laminar flow 202 and laminar flow 3 203, and the boundaries between laminar flow 1 201, laminar flow 202 and laminar flow 3 203 are indicated by bold dashed lines. Of course, the fluid in the groove 1113 may also include other numbers of laminar flows, which are not specifically limited here. Taking laminar flow 1 201, laminar flow 2 202 and laminar flow 3 203 as examples, the wall surface of the shell 11 used to enclose the groove 1113 is closest to laminar flow 1 201, and the efficiency of heat transfer between laminar flow 1 201 and the shell 11 is relatively high, but laminar flow 1 201 and laminar flow 2 202 do not flow in a mixed manner, so that the efficiency of heat transfer between laminar flow 1 201 and laminar flow 2 202 is relatively low. Similarly, laminar flow 2 202 and laminar flow 3 203 do not flow in a mixed manner, so that the efficiency of heat transfer between laminar flow 2 202 and laminar flow 3 203 is also relatively low, thereby making the efficiency of heat transfer between the shell 11 and the fluid in the groove 1113 relatively low. Therefore, please refer to Figure 2 As shown, the outer wall of the housing 11 is further provided with a spoiler 1114, and a plurality of spoilers 1114 arranged at intervals are provided in the groove 1113. The spoiler 1114 is used to disturb the laminar flow 1 201, the laminar flow 202 and the laminar flow 3 203, so that the laminar flow 1 201, the laminar flow 202 and the laminar flow 3 203 are mixed with each other to promote rapid heat transfer in the fluid, so that the efficiency of heat transfer between the housing 11 and the fluid in the groove 1113 is higher.

[0044] Please note that, please refer to Figure 4 As shown, although the laminar flow 1 201, the laminar flow 202 and the laminar flow 3 203 are mixed with each other when passing through the spoiler 1114, a new laminar flow 1 201, a new laminar flow 202 and a new laminar flow 3 203 will be formed after passing through the spoiler 1114, and the new laminar flow 1 201, the new laminar flow 202 and the new laminar flow 3 203 will be mixed with each other again when they meet the next spoiler 1114. Figure 4Middle layer flow 1 201, layer flow 2 202 and layer flow 3 203 are indicated by bold solid lines.

[0045] Please refer to Figure 4 As shown, taking the heat dissipation of the secondary battery to the immersion liquid as an example, the shell 11 transfers heat to the laminar flow 1 201 of the fluid. Before the fluid passes through the spoiler 1114, the efficiency of the laminar flow 1 201 in transferring heat to the laminar flow 2 202 and the laminar flow 3 203 is low. When the fluid passes through the spoiler 1114, the laminar flow 1 201, the laminar flow 202 and the laminar flow 3 203 are mixed, so that the heat absorbed by the laminar flow 1 201 is quickly redistributed in the fluid. After the fluid passes through the spoiler 1114, a new laminar flow 1 201 and a new laminar flow 203 are formed. 2 and the new laminar flow three 203, the new laminar flow one 201 continues to absorb the heat of the shell 11, the heat of the new laminar flow two 202 is higher than the heat of the original laminar flow two 202, and the heat of the new laminar flow three 203 is higher than the heat of the original laminar flow three 203. When the fluid passes through the next spoiler 1114, the new laminar flow one 201, the new laminar flow two 202 and the new laminar flow three 203 are mixed again, thereby promoting the redistribution of heat in the fluid again to increase the rate at which the fluid in the groove 1113 absorbs heat from the shell 11.

[0046] Please refer to Figure 4 As shown, taking the secondary battery absorbing heat from the immersion liquid as an example, the housing 11 absorbs heat from the laminar flow 1 201 of the fluid. Before the fluid passes through the spoiler 1114, the efficiency of the laminar flow 3 203 transferring heat to the laminar flow 2 202 and the laminar flow 1 201 is low. When the fluid passes through the spoiler 1114, the laminar flow 1 201, the laminar flow 2 202 and the laminar flow 3 203 are mixed, so that the heat of the previous laminar flow 3 203 is quickly redistributed in the fluid. After the fluid passes through the spoiler 1114, a new laminar flow 1 201 and a new laminar flow 2 202 are formed. And the new laminar flow three 203, the heat of the new laminar flow one 201 is higher than the heat of the original laminar flow one 201, the heat of the new laminar flow two 202 is higher than the heat of the original laminar flow two 202, the new laminar flow three 203 continues to absorb the heat supplemented by other fluids, and when the fluid passes through the next spoiler 1114, the new laminar flow one 201, the new laminar flow two 202 and the new laminar flow three 203 are mixed again, thereby promoting the redistribution of heat in the fluid again, so as to increase the rate at which the fluid in the groove 1113 transfers heat to the shell 11.

[0047] According to the above content, it can be known that when the fluid in the groove 1113 passes through the plurality of spaced spoilers 1114 , the efficiency of heat transfer between the fluid in the groove 1113 and the housing 11 is relatively high.

[0048] According to the above content, under the above-mentioned settings of the groove 1113 and the spoiler 1114 , the groove 1113 and the spoiler 1114 can synergistically improve the heat transfer efficiency between the shell 11 and the fluid located in the groove 1113 .

[0049] Please refer to Figure 2 As shown, the width W1 of the groove 1113 can be in the range of 1 mm to 2 mm, and the width W1 can specifically be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm.

[0050] In addition, please refer to Figure 2 As shown, the depth D of the groove 1113 can be in the range of 0.8 mm to 1.5 mm, and the height H can specifically be 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm.

[0051] Furthermore, please refer to Figure 2 As shown, the extension of the groove 1113 can be a straight-line extension.

[0052] In other embodiments (not shown in the figures), the groove may extend in an S-shape.

[0053] Optionally, see Figure 2 As shown, the spoiler 1114 includes a protruding structure. The protruding structure can disrupt the distribution of each laminar flow in the fluid, thereby promoting the redistribution of heat in the fluid.

[0054] In other embodiments (not shown in the figures), the spoiler may also include a concave structure, and the concave structure may also disrupt the distribution of the laminar flows in the fluid, thereby promoting the redistribution of heat in the fluid.

[0055] In other embodiments (not shown in the figures), the spoiler may include both a convex structure and a concave structure. For example, the bottom wall of the concave structure is provided with a convex structure, or the surface of the convex structure is provided with a concave structure. The arrangement of this embodiment can also achieve the effect of disrupting the distribution of laminar flows in the fluid to promote the redistribution of heat in the fluid.

[0056] The following content of this article is mainly described by taking the spoiler 1114 including a protruding structure as an example.

[0057] Optionally, see Figure 5a As shown, the protrusion structure 1114 includes a columnar structure.

[0058] The columnar structure may be a cylinder such as a circular cylinder, a quadrangular prism or an elliptical cylinder.

[0059] Optionally, see Figure 5b As shown, the raised structure 1114 comprises a disc-like structure.

[0060] The disk-shaped structure may be a disk such as a circular disk, a rectangular disk or an elliptical disk.

[0061] Optionally, see Figure 5c As shown, the protruding structure 1114 includes two connected parts, one part is a columnar structure, and the other part is a disc-shaped structure.

[0062] Any of the above-mentioned protruding structures 1114 of various structural types can disrupt the distribution of the laminar flows in the fluid to promote the redistribution of heat in the fluid.

[0063] The following content of this article mainly focuses on Figure 5b The protruding structure 1114 shown includes a disk-shaped structure as an example.

[0064] Please refer to Figure 5b As shown, if the protruding structure 1114 includes a disc, the diameter d of the protruding structure 1114 can be in the range of 0.8 mm to 1.4 mm, specifically, the diameter d can be 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm or 1.4 mm. The thickness T of the protruding structure 1114 can be in the range of 0.2 mm to 0.4 mm, specifically, the thickness T can be 0.2 mm, 0.3 mm or 0.4 mm.

[0065] Optionally, see Figure 6 As shown, at least two rows of spoiler arrays are arranged outside the housing 11 and are located in the same groove 1113. The same spoiler array includes at least two spoiler portions 1114 spaced apart along the extending direction of the groove 1113. The spoiler portions 1114 of at least two rows of spoiler arrays are staggered in the extending direction of the groove 1113. Figure 6 In the figure, each spoiler array is indicated by a bold dashed line. For example, a bold dashed line J represents a spoiler array, and the spoiler array represented by the bold dashed line J includes at least two spoilers 1114. A bold dashed line K represents another spoiler array, and the spoiler array represented by the bold dashed line K includes at least two spoilers 1114. Under this setting, when the fluid flows along the groove 1113, the fluid will be squeezed in the direction Y by the spoilers 1114 when it encounters some spoilers 1114 (for example, the spoilers 1114 of the spoiler array J). Of course, when the fluid encounters other spoilers 1114 (for example, the spoilers 1114 of the spoiler array K), it will be squeezed in the direction opposite to the direction Y by the spoilers 1114, so that the two side parts of the fluid in the direction Y can be disturbed with the middle part of the fluid respectively, thereby promoting the two side parts of the fluid in the direction Y to quickly transfer heat with the middle part of the fluid, thereby facilitating the rate of heat transfer between the shell 11 and the immersion liquid.

[0066] Among them, in the same spoiler array, the spacing between the side walls of two adjacent spoilers 1114 is in the range of 2.5mm~4mm, specifically 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm or 4mm.

[0067] Optionally, see Figure 2 As shown, the groove 1113 is extended along the height direction (direction Z) of the secondary battery. When the immersion liquid flows from bottom to top relative to the secondary battery, or when the immersion liquid flows from top to bottom relative to the secondary battery, the groove 1113 can guide a part of the immersion liquid to flow orderly in a direction parallel to the height direction relative to the surface of the secondary battery, thereby improving the rate of heat transfer between the housing 11 and the immersion liquid.

[0068] Please refer to Figure 2 As shown, at least two grooves 1113 are arranged at intervals along a direction parallel to the Y direction.

[0069] Optionally, see Figure 7-Figure 8 As shown, the groove 1113 can also be extended in a direction (direction Y) perpendicular to the height direction (direction Z). When the immersion liquid flows along the direction Y or in the direction opposite to the direction Y relative to the secondary battery, the groove 1113 can guide a part of the immersion liquid to flow orderly in a direction parallel to the direction Y relative to the surface of the secondary battery, thereby improving the rate of heat transfer between the housing 11 and the immersion liquid.

[0070] Please refer to Figure 8 As shown, at least two grooves 1113 are arranged at intervals along a direction parallel to the Z direction.

[0071] Optionally, see Figure 1 and Figure 7 As shown, the outer side wall 1112 of the housing 11 includes a first outer side wall 11121 and a second outer side wall 11122 adjacent to each other. The extension direction of the second outer side wall 11122 (the direction parallel to the direction X) intersects with the extension direction of the first outer side wall 11121 (the direction parallel to the direction Y).

[0072] The outer side wall 1112 of the housing 11 includes two first outer side walls 11121 arranged opposite to each other in the X direction and two second outer side walls 11122 arranged opposite to each other in the Y direction.

[0073] In addition, the first outer side wall 11121 may be provided with a groove 1113 and a spoiler 1114 .

[0074] Furthermore, when at least two secondary batteries are electrically connected to form a battery module, the first outer side wall 11121 of one of the secondary batteries is used to face the first outer side wall 11121 of an adjacent secondary battery.

[0075] In other embodiments, the structure of the secondary battery 1 may also be as follows: Fig. 9 As shown, a groove (not marked in the figure) and a spoiler (not marked in the figure) are arranged on the second outer side wall 11122, the groove extends along the direction Z, and at least two grooves are arranged at intervals in the direction X.

[0076] In other embodiments, the structure of the secondary battery 1 may also be as follows: Fig.10 As shown, a groove (not marked in the figure) and a spoiler (not marked in the figure) are arranged on the second outer side wall 11122, the groove extends along the direction X, and at least two grooves are arranged at intervals in the direction Z.

[0077] In other embodiments (not shown in the figures), the first outer wall and the second outer wall are both provided with grooves and spoilers, and the extension direction of the grooves provided on the first outer wall and the direction of the grooves provided on the second outer wall may be the same or different, and the extension direction of the grooves provided on the first outer wall may be direction X, direction Y or direction Z, and the extension direction of the grooves provided on the second outer wall may be direction X, direction Y or direction Z.

[0078] The grooves arranged in any of the above-mentioned positions and the grooves arranged in any of the above-mentioned extending directions can all play the role of guiding the orderly flow of the fluid.

[0079] The following content of this article mainly focuses on Figure 1-Figure 2 The structure shown is used as an example to introduce a secondary battery.

[0080] Optionally, the outer side wall 1112 of the housing 11 is provided with Fig.11 The at least two strip-shaped protrusions 1115 are arranged at intervals, and the extending direction of the strip-shaped protrusions 1115 is the same as the extending direction of the groove 1113. The strip-shaped protrusions 1115 are arranged on both sides of any groove 1113. On the one hand, the at least two strip-shaped protrusions 1115 and the outer side wall 1112 are used to enclose the groove 1113, and on the other hand, the at least two strip-shaped protrusions 1115 are used to increase the contact area between the shell 11 and the immersion liquid, thereby improving the heat transfer efficiency.

[0081] Please refer to Fig.11 As shown, the height H of the strip protrusion 1115 is in the range of 0.8 mm to 1.5 mm, and the height H can specifically be 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm.

[0082] It should be noted that the height H of the strip-shaped protrusion 1115 is consistent with the depth D of the groove 1113 .

[0083] In addition, please refer to Fig.11 As shown, the width W2 of the strip protrusion 1115 is in the range of 0.5mm~2.5mm, and the width W2 can specifically be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm or 2.5mm.

[0084] Optionally, see Fig.11 As shown, the strip-shaped protrusion 1115 includes a first end 11151, and the first end 11151 includes a transition slope. Since the strip-shaped protrusion 1115 is protruded relative to the outer wall surface of the shell 11, when the fluid of the immersion liquid flows from top to bottom and encounters the first end 11151, the transition slope of the first end 11151 can reduce the resistance of the first end 11151 to the fluid, so that the fluid can flow faster relative to the first end 11151, thereby making the efficiency of heat transfer between the first end 11151 and the fluid higher.

[0085] In other embodiments, please refer to Fig.12 As shown, the first end 11151 may include a transition surface, and the transition surface may also reduce the resistance of the first end 11151 to the fluid.

[0086] Optionally, see Fig.13 As shown, the strip-shaped protrusion 1115 includes a second end 11152, and the second end 11152 includes a transition slope. Since the strip-shaped protrusion 1115 is protruded relative to the outer wall surface of the shell 11, when the fluid of the immersion liquid flows from bottom to top and encounters the second end 11152, the transition slope of the second end 11152 can reduce the resistance of the second end 11152 to the fluid, so that the fluid can flow faster relative to the second end 11152, thereby making the efficiency of heat transfer between the second end 11152 and the fluid higher.

[0087] In other embodiments (not shown in the figures), the second end may include a transition curved surface, and the transition curved surface may also reduce the resistance of the second end to the fluid.

[0088] The first end 11151 and the second end 11152 are spaced apart from each other in the extending direction of the strip-shaped protrusion 1115 .

[0089] Optionally, the spoiler 1114 and the strip-shaped protrusion 1115 may be protruded from the same surface, and the spoiler 1114 and the strip-shaped protrusion 1115 are separate bodies.

[0090] In other embodiments (not shown in the figures), the spoiler may also be a strip-shaped protrusion protruding into the groove.

[0091] In other embodiments (not shown in the figures), the groove may also be recessed in the outer wall of the shell, that is, the outer wall of the shell may not be provided with the strip-shaped protrusions described above, and then the groove may not be formed by the strip-shaped protrusions described above. The groove of this embodiment may also be used to guide the fluid to flow in an orderly manner.

[0092] The following content of this article is mainly described by taking the outer side wall 1112 of the shell 11 being provided with a strip-shaped protrusion 1115 for enclosing and forming a groove 1113 as an example.

[0093] It should be noted that the enclosure described above regarding the formation of the groove by structural enclosure is a semi-enclosed enclosure, that is, an incomplete enclosure.

[0094] Optionally, see Figure 1 As shown, the housing 11 includes a receiving member 111 and a top cover 112 connected to each other. The top cover 112 is used to be penetrated by the pole assembly 12. Fig.14 As shown, the container 111 is provided with a housing chamber 1111, and the housing chamber 1111 is used to accommodate the battery cell (not shown in the figure) and the electrolyte (not shown in the figure). The container 111 has an outer wall 1112, please refer to Fig.15 As shown, the outer side wall 1112 of the container 111 is provided with the groove 1113, spoiler 1114 and strip-shaped protrusion 1115 described above.

[0095] It should be noted that the receiving member 111 can be formed by bending and welding a metal sheet. Before the metal sheet is bent and welded to form the receiving member 111, the metal sheet is punched on one side to form a groove 1113, a spoiler 1114 and a strip-shaped protrusion 1115 on one side of the metal sheet, and the other side of the metal sheet is also formed as shown in FIG. Fig.15 The first groove 1114a corresponding to the spoiler 1114 and the second groove 1115a corresponding to the strip-shaped protrusion 1115 are shown. After the plate member is bent and welded to form the container 111, a accommodating cavity 1111 is formed in the accommodating cavity 1111, and the first groove 1114a and the second groove 1115a are connected to the accommodating cavity 1111. In addition to the accommodating cavity 1111 being able to accommodate electrolyte, the first groove 1114a and the second groove 1115a can also accommodate electrolyte. Compared with the secondary battery in the related art, the secondary battery in the embodiment of the present application can accommodate a larger capacity of electrolyte, and more electrolyte can increase the cycle life of the battery cell.

[0096] Please refer to Fig.15As shown, the wall thickness t of the container 111 is in the range of 0.3 mm to 1.5 mm, and the wall thickness t can specifically be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm.

[0097] Optionally, the material of the housing 11 may include aluminum alloy.

[0098] Optionally, see Fig.16 As shown, if the strip-shaped protrusion 1115 is extended along the height direction (direction Z), there is a set spacing distance L between the top of the container 111 and the end of the strip-shaped protrusion 1115, and the spacing distance L is in the range of 5mm to 10mm. The spacing distance L can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm. Under this setting, when preparing a secondary battery, the strip-shaped protrusion 1115 is not easy to affect the welding of the container 111 and the top cover 112.

[0099] Optionally, see Figure 1 As shown, the size of the secondary battery 1 in direction Y is in the range of 145mm~175mm, and can specifically be 145mm, 146mm, 147mm, 148mm, 149mm, 150mm, 151mm, 152mm, 153mm, 154mm, 155mm, 156mm, 157mm, 158mm, 159mm, 160mm, 161mm, 162mm, 163mm, 164mm, 165mm, 166mm, 167mm, 168mm, 169mm, 170mm, 171mm, 172mm, 173mm, 174mm or 175mm.

[0100] Optionally, see Figure 1 As shown, the size of the secondary battery 1 in direction X is in the range of 40mm~60mm, and can be specifically 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm, 58mm, 59mm or 60mm.

[0101] Optionally, one, two or more battery cells may be placed in the housing cavity of the shell. The battery cell includes a positive electrode sheet, a negative electrode sheet and a separator, the separator is located between the positive electrode sheet and the negative electrode sheet, and the separator acts as an insulator for the adjacent positive electrode sheet and the negative electrode sheet. The negative electrode sheet, the separator and the positive electrode sheet are stacked and wound in sequence.

[0102] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on the surface of the negative electrode current collector, and the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer coated on the surface of the positive electrode current collector. After winding, the negative electrode active material layer, the positive electrode active layer and the separator located between the two constitute a winding structure. The negative electrode current collector can be cut to form a negative electrode tab, and the positive electrode current collector can be cut to form a positive electrode tab. The positive electrode tab and the negative electrode tab can be located at one end of the winding structure, or the positive electrode tab is located at one end of the winding structure and the negative electrode tab is located at the other end of the winding structure. The positive electrode tab is electrically connected to the positive electrode column, and the negative electrode tab is electrically connected to the negative electrode column.

[0103] Optionally, an explosion-proof valve may be provided on the top cover. When the internal pressure of the secondary battery is too high, the explosion-proof valve is used to quickly release the electrolyte to reduce the risk of explosion of the secondary battery.

[0104] The material of the top cover may include at least one of copper, iron and aluminum, and the top cover and the pole assembly are isolated by an insulating member.

[0105] On the second aspect, an embodiment of the present application provides a battery pack, which is the secondary battery described in the above content. Therefore, the battery pack of the embodiment of the present application also includes the technical effects regarding the secondary battery in the above content, which will not be repeated here.

[0106] Among them, the battery pack also includes an immersion liquid box, the secondary battery is in the immersion liquid box, the immersion liquid box contains immersion liquid, the secondary battery is immersed in the immersion liquid, the immersion liquid box is provided with a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel is used for external immersion liquid to enter the immersion liquid box, and the liquid outlet flow channel is used for the immersion liquid in the immersion liquid box to flow out of the immersion liquid box. Under this setting, heat exchange is carried out with the secondary battery through the circulating immersion liquid.

[0107] In addition, the material of the immersion liquid may include at least one of fluorinated liquid, fluorocarbon and hydrocarbon.

[0108] Optionally, see Fig.17 As shown, the battery pack includes at least two electrically connected secondary batteries 1 and at least two insulating sheets 2, and each secondary battery 1 and each insulating sheet 2 are alternately arranged. Each insulating sheet 2 insulates two adjacent secondary batteries 1, thereby reducing the risk of electrical breakdown or circuit short circuit between two adjacent secondary batteries 1.

[0109] The material of the insulating sheet 2 includes insulating polymer materials such as polycarbonate (PC), polypropylene (PP) or polyvinyl chloride (PVC).

[0110] Please refer to Fig.17As shown, the insulating sheet 2 protrudes relative to the outer side wall 1112 of the secondary battery 1. Under this arrangement, when the fluid of the immersion liquid flows along the direction X, the fluid is disturbed when encountering the structure of the insulating sheet 2 protruding relative to the outer side wall 1112 of the secondary battery 1, so as to redistribute the heat in the fluid, thereby improving the heat transfer efficiency between the fluid and the secondary battery 1.

[0111] Please refer to Fig.17 As shown, the length M of the structure in which the insulating sheet 2 protrudes relative to the outer wall 1112 of the secondary battery 1 is in the range of 1mm to 3mm, and the length M can specifically be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm or 3mm.

[0112] Optionally, see Fig.18 As shown, the structure of the insulating sheet 2 protruding relative to the outer side wall 1112 of the secondary battery 1 can be provided with at least two notches 21 spaced apart along the direction Z and at least two spoiler structures 22 spaced apart along the direction Z, and the notches 21 and the spoiler structures 22 are alternately arranged along the direction Z. Each notch 21 can be used for a fluid flowing along the direction X to pass through, and the spoiler structure 22 is used to disrupt the distribution of the fluid when passing through the notch 21, so as to redistribute the heat in the fluid, thereby improving the heat transfer efficiency between the fluid and the secondary battery 1.

[0113] Optionally, see Fig.19 As shown, the spoiler structure 22 includes a curved side wall, which has the advantage of reducing the flow resistance of the fluid flowing along the direction X. The curved side wall of the spoiler structure 22 also bulges into the notch 21. Under this setting, when the fluid passes through the notch 21 along the direction X, the fluid is compressed by the curved side walls of the spoiler structure 22 on both sides to disrupt the laminar flow distribution in the fluid, so as to promote the redistribution of heat in the fluid, thereby improving the heat transfer efficiency between the fluid and the secondary battery 1.

[0114] In other embodiments, please refer to Fig. 20 As shown, at least three secondary batteries 1 can be arranged at intervals along direction X, and any secondary battery 1 protrudes in direction Y relative to other adjacent secondary batteries 1. Under this arrangement, when the fluid of the immersion liquid flows along direction X, the fluid is disturbed when encountering the protruding structure of the secondary battery 1, so that the heat in the fluid is redistributed, thereby improving the heat transfer efficiency between the fluid and the secondary battery 1.

[0115] In a battery pack, the relationship between multiple secondary batteries can be series connection, parallel connection or mixed connection. Mixed connection means that multiple secondary batteries are connected in both series and parallel connection.

[0116] The battery pack may further include a busbar assembly for realizing electrical connection between the plurality of secondary batteries.

[0117] The battery pack may further include a frame assembly for fixing the plurality of secondary batteries.

[0118] The battery pack may further include a battery management unit for monitoring the voltage, current and temperature of the secondary battery.

[0119] In a third aspect, an embodiment of the present application provides an energy storage device, which includes an inverter, a battery management system (BMS), and at least one battery pack described above.

[0120] The inverter is used to convert direct current into alternating current. The inverter has the advantages of high conversion efficiency, fast startup speed, high safety, etc. It also has the functions of short circuit, overload, over / under voltage and over-temperature protection.

[0121] The battery management system is used to make the battery pack operate within a safe operating range. It can control the charging and discharging power of the battery pack according to factors such as ambient temperature, battery status, and power demand, thereby improving the safety of the battery pack and making the working state of the battery pack more reasonable, which is beneficial to improving the battery life and service life of the battery pack.

[0122] Since the energy storage device of the embodiment of the present application includes the battery pack described above, the energy storage device also includes the technical effects related to the battery pack described above.

[0123] Optionally, the energy storage device may specifically be an energy storage box (also known as a large energy storage device, suitable for large-scale industrial production or technical fields such as power distribution). The energy storage box includes a box body, and the box body has a storage space. The inverter, battery management system and battery pack are all in the storage space.

[0124] Optionally, the energy storage device may specifically be an energy storage cabinet (also known as an industrial and commercial energy storage device, suitable for small-scale industrial and commercial electricity needs). The energy storage cabinet includes a cabinet body, and the cabinet body has a storage space. The inverter, battery management system and battery pack are all in the storage space.

[0125] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A secondary battery, characterized in that: The secondary battery comprises: A housing having a receiving cavity disposed therein; A battery cell is disposed in the accommodating cavity; The outer side wall of the shell is provided with grooves, and at least two of the grooves are arranged at intervals; The outer side wall of the shell is also provided with a spoiler, and a plurality of the spoilers arranged at intervals are arranged in the groove.

2. The secondary battery according to claim 1, characterized in that: The spoiler includes a convex structure and / or a concave structure.

3. The secondary battery according to claim 2, characterized in that: The protruding structure includes a columnar structure and / or a disc-shaped structure.

4. The secondary battery according to claim 1, characterized in that: At least two rows of spoiler arrays located in the same groove are arranged outside the shell, and the same spoiler array includes at least two spoiler portions spaced apart along the extending direction of the groove, and the spoiler portions of at least two rows of spoiler arrays are staggered in the extending direction of the groove.

5. The secondary battery according to any one of claims 1 to 4, characterized in that: The groove is extended along a height direction of the secondary battery, or the groove is extended along a direction perpendicular to the height direction.

6. The secondary battery according to any one of claims 1 to 4, characterized in that: The outer side wall of the shell includes a first outer side wall and a second outer side wall adjacent to each other; An extension direction of the second outer side wall intersects with an extension direction of the first outer side wall; The first outer side wall is provided with the groove and the spoiler, and / or the second outer side wall is provided with the groove and the spoiler.

7. The secondary battery according to any one of claims 1 to 4, characterized in that: The outer side wall of the shell is provided with at least two strip-shaped protrusions arranged at intervals, the extension direction of the strip-shaped protrusions is the same as the extension direction of the grooves, and the strip-shaped protrusions are provided on both sides of any groove.

8. The secondary battery according to claim 7, characterized in that: The strip-shaped protrusion comprises a first end and a second end spaced apart along its own extending direction; The first end comprises a transition slope and / or a transition curve; And / or, the second end includes a transition slope and / or a transition curve.

9. A battery pack, characterized in that: The battery pack includes a secondary battery, and the secondary battery is the secondary battery according to any one of claims 1 to 8.

10. The battery pack according to claim 9, characterized in that: The battery pack includes at least two insulating sheets and at least two electrically connected secondary batteries; The insulating sheets and the secondary batteries are arranged alternately; The insulating sheet protrudes relative to an outer side wall of the secondary battery.

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