Battery pack and energy storage device

Abstract

The utility model discloses a battery pack and energy storage equipment, and relates to the technical field of energy storage equipment. The battery pack comprises a box body, a battery module and a plurality of pulley assemblies, the battery module is arranged in the box body; the multiple pulley assemblies are sequentially arranged on the bottom face of the box body in the installation direction of the battery pack, and the sizes of pulleys of the multiple pulley assemblies are sequentially increased in the installation direction of the battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage devices, in particular to a battery pack and an energy storage device. BACKGROUND

[0002] In order to balance the fluctuations of wind power generation and photovoltaic power generation in time and region, the prior art provides a peak clipping and valley filling technology mainly using energy storage batteries to reduce the fluctuations of power supply and ensure power supply. In order to adapt to huge power in GWH, the batteries are generally managed in the form of cell-battery pack or module-battery cluster.

[0003] Each battery pack of the battery cluster is generally installed to the cluster frame of the energy storage cabinet by assembly. However, in order to facilitate installation, there is generally a gap between the cluster frame and the battery pack. During the installation process of the battery pack, the position cannot be uniformly positioned, and it is difficult to fix the position of the battery pack. CONTENT OF THE UTILITY MODEL

[0004] The embodiments of the present application provide a battery pack and an energy storage device. A plurality of pulleys with different sizes are arranged on the bottom surface of the box body. When the battery pack is pushed into the battery pack containing space, the plurality of pulleys with different sizes can realize installation positioning and fix the installation position of the battery pack.

[0005] The battery pack of the embodiments of the present application comprises a box body, a battery module and a plurality of pulley assemblies. The battery module is arranged in the box body. The plurality of pulley assemblies are sequentially arranged on the bottom surface of the box body along the installation direction of the battery pack. The sizes of the pulleys of the plurality of pulley assemblies increase sequentially along the installation direction of the battery pack.

[0006] The energy storage device of the present application comprises a cabinet body and the battery pack of any one of the above embodiments. The cabinet body comprises a plurality of battery pack containing spaces.

[0007] In the battery pack and the energy storage device of the embodiments of the present application, a plurality of pulley assemblies are arranged on the bottom surface of the battery pack. The plurality of pulley assemblies are sequentially arranged along the installation direction of the battery pack. When the battery pack is pushed into the corresponding battery pack containing space, the pulleys can realize line-surface contact with the battery pack containing space, and the assembly and disassembly are relatively simple.

[0008] In addition, an installation groove opposite to the pulley is generally arranged in the battery pack containing space. When the battery pack is completely pushed into the battery pack containing space, the pulley is just sunk into the corresponding installation groove, so as to realize positioning installation of the battery pack, fix the installation position of the battery pack, and make the bottom surface of the battery pack contact with the bearing surface of the battery pack containing space. When the battery pack is not completely pushed in, the different sizes of the pulleys can avoid being stuck in the wrong installation groove, so as to avoid the problem of difficult installation of the battery pack.

[0009] Therefore, the positioning and installation of the battery pack are facilitated, and the assembly and disassembly of the battery pack are facilitated

[0010] Additional aspects and advantages of the embodiments of the present application will be in part apparent and in part pointed out below in the description of the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0011] The above and / or additional aspects and advantages of the embodiments of the present application will become apparent and be readily appreciated from the description of the embodiments of the present application, taken in conjunction with the drawings.

[0012] Figure 1 is a first perspective structural schematic view of a battery pack according to some embodiments of the present application.

[0013] Figure 2 is a second perspective structural schematic view of a battery pack according to some embodiments of the present application.

[0014] Figure 3 is a first plan schematic view of a battery pack according to some embodiments of the present application.

[0015] Figure 4 is a second plan schematic view of a battery pack according to some embodiments of the present application.

[0016] Figure 5 is a perspective structural schematic view of an energy storage device according to some embodiments of the present application.

[0017] Figure 6 is a first plan schematic view of an energy storage device according to some embodiments of the present application.

[0018] Figure 7 is a second plan schematic view of a cabinet of an energy storage device according to some embodiments of the present application.

[0019] Main element symbols:

[0020] Energy storage device 100;

[0021] Battery pack 10, cabinet 11, bottom surface 111, side surface 112, top surface 113, pulley groove 114, battery module 12, pulley assembly 13, pulley 131, fixing plate 132, through hole 1321;

[0022] Cabinet 20, support 21, support member 22, track surface 221, mounting groove 222, limiting block 223, flange 224, limiting member 223, battery pack containing space 23, fixing block 24, bolt 25. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be further described below with reference to the drawings. The same or similar reference numerals in different drawings denote the same or similar elements or elements having the same or similar functions.

[0024] In addition, the embodiments of the present application described below in conjunction with the drawings are exemplary and are only used to explain the embodiments of the present application and cannot be understood as a limitation of the present application.

[0025] In the present application, unless explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact through an intermediate medium. Moreover, the first feature can be directly above or obliquely above the second feature, or only indicate that the first feature is higher than the second feature in horizontal height. The first feature can be directly below or obliquely below the second feature, or only indicate that the first feature is lower than the second feature in horizontal height.

[0026] Please refer to Figures 1 to 4 The battery pack 10 of the present application comprises a box body 11, a battery module 12 and a plurality of pulley assemblies 13. The battery module 12 is arranged in the box body 11, and the battery module 12 comprises a plurality of battery monomers; the plurality of pulley assemblies 13 are sequentially arranged on the bottom surface 111 of the box body 11 along the installation direction (such as the y direction shown) of the battery pack 10. Figure 5 As shown in the figure, the sizes of the pulleys 131 of the plurality of pulley assemblies 13 increase sequentially along the installation direction of the battery pack 10.

[0027] The battery pack 10 and the energy storage device 100 of the embodiments of the present application are provided with the plurality of pulley assemblies 13 on the bottom surface 111 of the battery pack 10, and the plurality of pulley assemblies 13 are sequentially arranged along the installation direction of the battery pack 10. When the battery pack 10 is pushed into the corresponding battery pack containing space, the pulley 131 can realize line-surface contact with the battery pack containing space, and the assembly and disassembly are relatively simple.

[0028] And the battery pack containing space is generally provided with an installation groove opposite to the pulley 131. In the case that the battery pack 10 is completely pushed into the battery pack containing space, the pulley 131 just falls into the corresponding installation groove, so as to realize the positioning installation of the battery pack 10, so that the bottom surface 111 of the battery pack 10 is in contact with the bearing surface of the battery pack containing space. When the battery pack 10 is not completely pushed in, the different sizes of the pulleys 131 can avoid the pulley 131 from being stuck in the wrong installation groove, thereby avoiding the problem of difficult installation of the battery pack 10.

[0029] Therefore, the positioning and installation of the battery pack 10 are facilitated, and the difficulty of assembling and disassembling the battery pack 10 is reduced. After the battery pack 10 is installed, the pulley 131 is sunk into the corresponding installation slot, the bottom surface 111 of the battery pack 10 and the bearing surface of the battery pack containing space are in surface contact, and the transportation safety of the energy storage device 100 is ensured.

[0030] Please refer to Figures 5 to 7 The application provides an energy storage device 100, which comprises a cabinet 20 and a plurality of battery packs 10. The battery pack 10 is installed in the cabinet 20.

[0031] The cabinet 20 comprises a support 21 and a support member 22. The support 21 and the support member 22 are cross-connected to form a plurality of battery pack containing spaces 23.

[0032] For example, the support 21 is a vertical reinforcing rib, and the support member 22 is horizontally arranged. The support member 22 and the reinforcing rib are cross-connected to form a plurality of battery pack containing spaces 23. For example, the support member 22 is used to bear the battery pack 10 and is arranged in a plurality of rows along the vertical direction (for example, the z direction shown in the figure). Any two rows of support members 22 form a battery pack containing space 23. Figure 5 The extension direction of the support member 22 is the installation direction of the battery pack 10. The battery pack 10 is pushed into the battery pack containing space 23 along the support member 22, so as to be installed in the battery pack containing space 23.

[0033] The battery pack containing space 23 comprises at least two oppositely arranged support members 22 (for example, a first support member and a second support member). The two sides of the battery pack 10 are respectively borne on the track surfaces of the two support members 22. In this way, the two oppositely arranged support members 22 can stably bear the battery pack 10 and reduce the cost, and the middle region of the battery pack 10 is not blocked, so that the heat dissipation performance of the battery pack 10 is improved.

[0034] Optionally, the track surface 221 of the support member 22 is provided with an installation slot 222. When the battery pack 10 is installed in the battery pack containing space 23 along the installation direction (that is, the battery pack 10 is completely pushed into the battery pack containing space 23), the pulley 131 arranged on the bottom surface 111 of the battery pack 10 falls into the corresponding installation slot 222.

[0035] In this way, during the installation process, the pulley 131 realizes the line-surface contact between the battery pack 10 and the battery pack containing space 23, and reduces the wear of the battery pack 10. After the installation of the battery pack 10 is completed, the pulley 131 of the battery pack 10 is sunk into the corresponding installation slot 222, so that the battery pack 10 is limited, and the battery pack 10 is prevented from sliding out of the battery pack containing space 23.

[0036] Optionally, the mounting grooves 222 and the pulleys 131 of the pulley assembly 13 are in one-to-one correspondence and are matched in size. In this way, when the battery pack 10 is installed into the battery pack containing space 23, the pulleys 131 are located in the corresponding mounting grooves 222 and are closely combined, which can improve the limiting effect of the mounting grooves 222 on the battery pack 10 and improve the installation stability of the battery pack 10.

[0037] Optionally, when the battery pack 10 is installed into the battery pack containing space 23, the bottom surface 111 of the battery pack 10 is in contact with the track surface 221 of the support 22.

[0038] In this way, when the pulleys 131 are sunk into the corresponding mounting grooves 222, the bottom surface 111 of the battery pack 10 is in contact with the track surface 221 of the support 22, achieving face-to-face contact between the battery pack 10 and the track surface 221. Not only can the limiting of the battery pack 10 be achieved, but the installation stability of the battery pack 10 can also be ensured. During the transportation of the energy storage device 100, the battery pack 10 is always in stable contact with the battery pack containing space 23, ensuring the stability of the energy storage device 100 during transportation and thus ensuring the safety of transportation.

[0039] Optionally, the support 22 includes opposite first and second ends, which are sequentially arranged along the installation direction of the battery pack 10, and the second end is provided with a limiting block 223.

[0040] In this way, the limiting block 223 limits the battery pack 10 in the installation direction, avoiding the battery pack 10 from being pushed too far and damaging the cabinet 20 during installation. When the battery pack 10 is installed into the battery pack containing space 23, the battery pack 10 and the limiting block 223 are sequentially arranged along the installation direction.

[0041] Optionally, the first end of the support 22 is provided with a flange 224, and the cabinet 20 further includes a fixing block 24 and a bolt 25, which are sequentially arranged through the fixing block 24 and the flange 224 to install the fixing block 24 on the flange 224, and the battery pack 10 is located between the limiting block 223 and the fixing block 24.

[0042] In this way, the fixing block 24 is fixed to the flange 224 of the first end of the support 22 by the bolt 25, so that the battery pack 10 is located between the fixing block 24 and the limiting block 223, and the fixing block 24 cooperates with the limiting block 223 to limit the battery pack 10 in the installation direction, avoiding the battery pack 10 from sliding out of the battery pack containing space 23 while improving the installation stability of the battery pack 10.

[0043] Optionally, the first support and the second support of the battery pack accommodating space 23 are respectively located at two sides of the battery pack 10, and the support 22 further comprises a limiting member 225, the limiting member 225 is arranged on the track surface 221, and the battery pack 10 is located between the limiting members 225 of the first support and the second support.

[0044] The height of the limiting member 225 is higher than the ground height of the battery pack 10. For example, the limiting member 225 can be a limiting surface extending away from the edge of the track surface 221.

[0045] In this way, the battery pack 10 is limited in the width direction (for example, the x direction shown in the figure, the width direction is perpendicular to the installation direction of the battery pack 10, or in other words, perpendicular to the length direction of the battery pack 10) by the limiting member 225 of the first support and the limiting member 225 of the second support at two sides of the battery pack 10, and the installation stability of the battery pack 10 is further improved. Figure 5

[0046] Please refer again to Figures 1 to 4 The battery pack 10 of the embodiment of the present application comprises a box body 11, a battery module 12 and a plurality of pulley assemblies 13.

[0047] The box body 11 forms an accommodating space for accommodating the battery module 12. The box body 11 comprises a bottom surface 111, a side surface 112 and a top surface 113, the bottom surface 111 and the top surface 113 are opposite, and the side surface 112 connects the top surface 113 and the bottom surface 111.

[0048] The battery module 12 comprises a plurality of battery monomers, the plurality of battery monomers are combined into the battery module 12 in a series connection, parallel connection or series-parallel connection hybrid manner, and the battery module 12 comprises one or more, and the one or more battery modules 12 are further packaged and integrated to form the battery pack 10.

[0049] The battery monomer is modularly designed, so that the battery monomer can be replaced or maintained when any battery monomer fails (for example, hardware failure, thermal runaway, etc.). The battery module 1230 forms a power supply circuit with an external load through a total positive and a total negative, so as to supply power. The battery module 1230 is a core component of the energy storage device 100, and is used for energy storage and power supply.

[0050] Optionally, the battery monomer is a rectangular body, and the plurality of battery monomers are arranged in a rectangular array. In this way, the plurality of battery monomers are arranged compactly, which is beneficial to miniaturization of the energy storage device 100.

[0051] Optionally, the battery monomer comprises a battery shell, a battery core and an explosion-proof valve. The battery core is arranged in the battery shell, and the explosion-proof valve is arranged in the battery shell. When the battery core has thermal runaway, overcharging or the like, reaction gas will be generated, and the pressure in the battery shell will continuously rise. The explosion-proof valve is used for pressure relief to avoid explosion of the battery monomer.​

[0052] Optionally, a plurality of battery packs 10 are installed into the battery pack containing space 23 of the cabinet body 20 respectively, forming a battery cluster. The energy storage device 100 can include one or more battery clusters.

[0053] In some embodiments, the energy storage device 100 can be an energy storage cabinet, and the cabinet body 20 is provided with one or more battery clusters, and the cabinet body 20 is also equipped with a complete power conversion, monitoring, management and other systems.

[0054] Among them, the pulley assembly 13 is arranged on the bottom surface 111 of the box body 11. The battery pack 10 is in contact with the supporting part 22 of the battery pack containing space 23 through the pulley assembly 13 arranged on the bottom surface 111 of the box body 11 during installation, thereby reducing the wear of the battery pack 10 during installation.

[0055] Optionally, the pulley assembly 13 includes a plurality of pulley assemblies 13, and the plurality of pulley assemblies 13 are arranged in sequence along the installation direction of the battery pack 10. In this way, through the plurality of pulley assemblies 13 arranged along the installation direction of the battery pack 10, the installation of the battery pack 10 is facilitated, and the plurality of pulley assemblies 13 can provide stable support when the battery is placed.

[0056] Optionally, along the installation direction of the battery pack 10, the sizes of the pulleys 131 of the plurality of pulley assemblies 13 increase in sequence.

[0057] It can be understood that since the track surface 221 of the supporting part 22 is provided with an installation groove 222 corresponding to the pulley 131 of each pulley assembly 13, when the battery pack 10 is pushed into the battery pack containing space 23, among the plurality of pulley assemblies 13 arranged in sequence along the installation direction, the pulley 131 of the last pulley assembly 13 enters the battery pack containing space 23 first, and then the pulley 131 passes through the installation groove 222 corresponding to the first pulley assembly 13. If the size of the pulley 131 is less than or equal to the size of the installation groove 222, the pulley 131 of the last pulley assembly 13 will be trapped in the installation groove 222 corresponding to the first pulley assembly 13, thereby blocking the battery pack 10. If the user continues to push the battery pack, a greater pushing force needs to be applied, causing difficulty in installing the battery pack 10, and even if the force is too strong, the pulley assembly 13 or even the battery pack 10 will be damaged.

[0058] Therefore, along the installation direction of the battery pack 10, the pulleys 131 of the plurality of pulley assemblies 13 are sized to increase in turn, and due to the size matching between the installation grooves 222 and the pulleys 131 of the corresponding pulley assemblies 13, when the pulley 131 of the last pulley assembly 13 reaches the installation groove 222 corresponding to the first pulley assembly 13, the pulley 131 of the last pulley assembly 13 is larger in size than the pulley 131 of the first pulley assembly 13, and thus is also larger in size than the installation groove 222 corresponding to the first pulley assembly 13, which prevents the pulley 131 of the last pulley assembly 13 from being trapped in the installation groove 222 corresponding to the first pulley assembly 13. Similarly, before the pulley 131 of the last pulley assembly 13 slides into the corresponding installation groove 222, it will not be trapped in any other installation groove 222, and before the pulleys 131 of the other pulley assemblies 13 slide into the corresponding installation grooves 222, they will not be trapped in any other installation groove 222.

[0059] In this way, the problem of the battery pack 10 being trapped by the installation grooves 222 when the battery pack 10 is not fully pushed into the battery pack accommodating space 23 is avoided, and the battery pack 10 can be smoothly and completely pushed into the battery pack accommodating space 23.

[0060] Alternatively, the sizes of the pulleys 131 of the plurality of pulley assemblies 13 can increase in turn in the following manners: along the width direction of the battery pack 10, the widths of the pulleys 131 of the plurality of pulley assemblies 13 increase in turn; or the outer diameters of the pulleys 131 of the plurality of pulley assemblies 13 increase in turn; or in the plurality of pulley assemblies 13, the widths of the pulleys 131 of a part of the pulley assemblies 13 increase in turn, and the outer diameters of the pulleys 131 of another part of the pulley assemblies 13 increase in turn.

[0061] Alternatively, the centers of the pulleys 131 of the plurality of pulley assemblies 13 are arranged in a line. In this way, the width of the installation area for installing the pulley assemblies 13 in the bottom surface 111 of the box body 11 is narrow, and this area is generally located in the bottom surface 111 of the box body 11 and is not opposite to the battery cell (or is located outside the projection area of the battery cell on the bottom surface 111 of the box body 11), thereby avoiding the problem of the pulley assemblies 13 being pressed when bearing weight, which causes the bottom surface 111 of the box body 11 to press the battery cell and affect the safety of the battery cell.

[0062] In one example, the pulley assemblies 13 include a first pulley assembly A, a second pulley assembly B, and a third pulley assembly C, which are arranged in turn along the installation direction of the battery pack 10, and the pulleys 131 of the first pulley assembly A, the second pulley assembly B, and the third pulley assembly C are different in size, and the installation direction of the battery pack 10 is parallel to the length direction of the battery pack 10.

[0063] Considering that the weight of the battery pack 10 is generally large and the size of the pulley assembly 13 is generally small (reducing the size of the battery pack 10), if the number of pulley assemblies 13 is too small, it will cause the pulley assembly 13 to be insufficiently supported and thus damaged. Therefore, based on the specific load-bearing requirements, a plurality of pulley assemblies 13 can be provided, such as three pulley assemblies 13 (i.e., the first pulley assembly A, the second pulley assembly B, and the third pulley assembly C), which can achieve the load-bearing of the battery pack 10 and the installation of the battery pack 10.

[0064] Optionally, each pulley assembly 13 can include a plurality of pulley assemblies 13 arranged in the width direction of the battery pack 10 to distribute the load of the battery pack 10 to different positions in the width direction, avoiding damage to a single pulley assembly 13 due to excessive force.

[0065] For example, the first pulley assembly A, the second pulley assembly B, and the third pulley assembly C each include two, and in the width direction of the battery pack 10, two first pulley assemblies A (such as the first pulley assemblies A1 and A2) are arranged at both ends of the box body 11, two second pulley assemblies B (such as the second pulley assemblies B1 and B2) are arranged at both ends of the box body 11, and two third pulley assemblies C (such as the third pulley assemblies C1 and C2) are arranged at both ends of the box body 11.

[0066] In this way, each pulley assembly 13 includes two pulley assemblies 13 arranged at both ends of the box body 11, so that the two pulley assemblies 13 are in contact with the two support pieces 22, achieving stable load-bearing of the battery pack 10 and linear surface contact installation of the battery pack 10 and the support pieces 22.

[0067] Similarly, since the mounting grooves 222 correspond one-to-one and match the sizes of the pulley assemblies 13, the mounting grooves 222 also include a first mounting groove D, a second mounting groove E, and a third mounting groove F, which are arranged in the installation direction of the battery pack 10 in sequence, and the sizes of the first mounting groove D, the second mounting groove E, and the third mounting groove F increase in sequence. The installation direction of the battery pack 10 is parallel to the length direction of the battery pack 10.

[0068] The first mounting groove D is arranged opposite to the pulley 131 of the first pulley assembly A, the second mounting groove E is arranged opposite to the pulley 131 of the second pulley assembly B, and the third mounting groove F is arranged opposite to the pulley 131 of the third pulley assembly C.

[0069] Similarly, the first installation slot D, the second installation slot E and the third installation slot F each include two, two first installation slots D (such as first installation slots D1 and D2) are respectively arranged opposite to the pulleys 131 of the two first pulley assemblies A, two second installation slots E (such as second installation slots E1 and E2) are respectively arranged opposite to the pulleys 131 of the two second pulley assemblies B, and two third installation slots F (such as first installation slots F1 and F2) are respectively arranged opposite to the pulleys 131 of the two third pulley assemblies C.

[0070] In the installation process of the battery pack 10, along the installation direction of the battery pack 10, the size of the installation slot 222 and the pulley 131 of the corresponding pulley assembly 13 are matched, when the pulley 131 of the third pulley assembly C reaches the first installation slot D, since the size of the pulley 131 of the third pulley assembly C is larger than the size of the pulley 131 of the first pulley assembly A, the size of the pulley 131 of the third pulley assembly C is also larger than the size of the first installation slot D, which makes the pulley 131 of the third pulley assembly C not sink into the first installation slot D. Similarly, before the pulley 131 of the third pulley assembly C slides to the third installation slot F, it also will not sink into the second installation slot E; and before the pulley 131 of the second pulley assembly B slides to the second installation slot E, it also will not sink into the first installation slot D.

[0071] In this way, the problem that the battery pack 10 is stuck by the installation slot 222 when the battery pack 10 is not completely pushed into the battery pack containing space 23 (such as the first pulley assembly A is not sunk into the first installation slot D) is avoided, and it is ensured that the battery pack 10 can be smoothly and completely pushed into the battery pack containing space 23.

[0072] Please refer again to Figure 3 Optionally, the pulley assembly 13 includes a fixed plate 132 and a pulley 131, the fixed plate 132 is arranged on the bottom surface of the battery pack 10, the fixed plate 132 is provided with a through hole 1321, the bottom surface 111 of the box body 11 is provided with a pulley groove 114, the pulley groove 114 and the through hole 1321 are arranged opposite to each other, and the pulley 131 is arranged in the pulley groove 114 by penetrating the through hole 1321.

[0073] In order to reduce the volume of the battery pack 10, the pulley assembly 13 can use an embedded design, the pulley groove 114 is arranged on the bottom surface 111 of the box body 11, then the pulley assembly 13 is fixed on the bottom surface 111 of the box body 11 through the fixed plate 132, and the pulley 131 is at least partially embedded in the pulley groove 114, so that the pulley assembly 13 only partially protrudes from the pulley groove 114.

[0074] In the description of the specification, the description of the terms "certain embodiments", "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific feature, structure, material or characteristic being described is included in at least one embodiment or example of the application. The illustrative description of the above terms does not necessarily indicate that a description is referring to the same or a similar embodiment or example. Moreover, the specific features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0075] Furthermore, the terms "first", "second" or the like are used merely to describe corresponding features, and do not imply or connote relative importance or a quantity of the specified technical features. Thus, a feature defined with "first", "second" can include at least one feature explicitly or implicitly. In the description of the application, the meaning of "plurality" is at least two, for example two, three, unless otherwise explicitly and specifically limited.

[0076] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be interpreted as limiting the present application, and the ordinary skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery pack, characterized by, The battery pack comprises: a box body; a battery module arranged in the box body; and a plurality of pulley assemblies arranged in the bottom surface of the box body in sequence along the installation direction of the battery pack, wherein the sizes of the pulleys of the plurality of pulley assemblies increase in sequence along the installation direction of the battery pack.

2. The battery pack of claim 1, wherein, The pulley assemblies comprise a first pulley assembly, a second pulley assembly and a third pulley assembly arranged in sequence along the installation direction of the battery pack, wherein the sizes of the pulleys of the first, second and third pulley assemblies are different, and the installation direction of the battery pack is parallel to the length direction of the battery pack.

3. The battery pack of claim 2, wherein, The first, second and third pulley assemblies each comprise a plurality of pulley assemblies, wherein the first, second and third pulley assemblies are arranged in sequence along the width direction of the battery pack.

4. The battery pack of claim 3, wherein, The first, second and third pulley assemblies each comprise two pulley assemblies, wherein the two first pulley assemblies are arranged at the two ends of the box body of the battery pack in the width direction of the battery pack, the two second pulley assemblies are arranged at the two ends of the box body of the battery pack in the width direction of the battery pack, and the two third pulley assemblies are arranged at the two ends of the box body of the battery pack in the width direction of the battery pack.

5. The battery pack of any one of claims 1-4, wherein, The pulley assembly comprises a fixing plate and a pulley, wherein the fixing plate is fixed to the bottom surface of the box body, the fixing plate is provided with a through hole, the bottom surface of the box body is provided with a pulley groove, the pulley groove and the through hole are arranged opposite to each other, the pulley is arranged in the through hole and in the pulley groove.

6. The battery pack of claim 1, wherein, The centers of the pulleys of the plurality of pulley assemblies are arranged in a line.

7. An energy storage device, characterized by, It comprises: a cabinet body comprising a plurality of battery pack accommodation spaces; a plurality of battery packs according to any one of claims 1-6 arranged in the battery pack accommodation spaces.

8. The energy storage device of claim 7, wherein, The cabinet body comprises a support and a support member, wherein the support member and the support are cross-connected to form the battery pack accommodation space, the support member extends along the installation direction of the battery pack, the track surface of the support member is provided with an installation groove, in the case that the battery pack is installed into the battery pack accommodation space along the installation direction, the pulley is located in the corresponding installation groove, and the installation groove and the pulley of the pulley assembly are one-to-one corresponding and size-matched.

9. The energy storage device of claim 8, wherein, The track surface of the support member is further provided with a limiting block, and the battery pack and the limiting block are arranged in sequence along the installation direction of the battery pack.

10. The energy storage device of claim 9, wherein, An edge is arranged at the end of the support member away from the limiting block, and the cabinet body further comprises a fixing block and a bolt, wherein the bolt is arranged in sequence in the fixing block and the edge to install the fixing block on the edge, and the battery pack is located between the limiting block and the fixing block.

11. The energy storage device of claim 8, wherein, The support member comprises a first support member and a second support member, wherein the first support member and the second support member are respectively located at the two sides of the battery pack, and the support member further comprises a limiting member arranged on the track surface, and the battery pack is located between the limiting members of the first support member and the second support member.

12. The energy storage device of claim 8, wherein, In a case where the battery pack is installed into the battery pack accommodation space, a bottom surface of the battery pack is in contact with a rail surface of the support.

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