A square battery, battery module and battery pack

Abstract

The present invention proposes a square battery, a battery module and a battery pack. The square battery includes a first shell, a winding core, a first pole, a second pole and a second shell. The winding core is arranged in the first shell. The first shell has two sets of first surfaces and two sets of second surfaces arranged opposite to each other. The area of ​​the first surface is larger than the area of ​​the second surface. The first pole and the second pole are respectively arranged on the two first surfaces; the first shell is arranged in the second shell, and the outer end surfaces of the electrical connection end of the first pole and the electrical connection end of the second pole are both flush with the outer side surface of the second shell; a liquid cooling chamber for the flow of cooling liquid is formed between the first shell and the second shell, and a liquid inlet and a liquid outlet connected to the liquid cooling chamber are respectively provided at both ends in the length direction of the second shell. After the square batteries disclosed in the present invention are grouped, they can avoid the pole electrical connection structure and the liquid cooling structure from occupying a large space in the battery module, thereby ensuring that the energy density of the battery module is maximized.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a square battery, a battery module and a battery pack. Background Art

[0002] The electric vehicle industry is currently developing rapidly and will gradually replace fuel-powered vehicles in the future. To increase the energy density of electric vehicle power batteries, optimizing the structural design of power battery cells, reducing weight, and conserving space have become key areas of technological development. In existing technologies, the series and parallel connections of single cells in power battery modules are mostly achieved by laser welding external busbars to the battery terminals. However, these external busbars occupy a significant amount of space within the battery module, making assembly difficult and increasing the overall weight of the battery module, which negatively impacts the improvement of the module's energy density.

[0003] In the prior art, the patent with publication number CN209544504U discloses a single battery, which includes a shell, a battery cell accommodated in the shell, a positive electrode post and a negative electrode post. The shell includes a top cover, and the positive electrode post and the negative electrode post are respectively arranged on the top cover of the shell and are electrically connected to the battery cell of the single battery; the positive electrode post can be directly connected to the negative electrode post or the positive electrode post of the adjacent single battery, and the negative electrode post can be directly connected to the positive electrode post or the negative electrode post of the adjacent single battery; the electrical connection end of the positive electrode post and / or the electrical connection end of the negative electrode post protrudes from the side of the single battery body. When the single batteries are composed of a battery module, the total weight of the battery module is reduced and the energy density of the battery module is improved by directly connecting the electrodes.

[0004] Although the above technical solution eliminates the need for an external busbar during the battery cell grouping process, which improves the battery module energy density to a certain extent, the positive and negative electrodes of the above-mentioned battery cells have Z-shaped cross-sections. The positive and negative electrodes of the Z-shaped structure are overlapped and welded together. After the group welding is completed, the connected structure between the positive and negative electrodes will be higher than the top surface of the top cover, which will also occupy a certain amount of space in the battery module, thus failing to maximize the battery module energy density.

[0005] In addition, traditional power battery thermal management structures often use liquid cooling plates installed on the bottom and sides of the battery module to cool and dissipate heat from the bottom and two sides of the individual battery cells. This liquid cooling method has the problem that the liquid cooling plate and the individual battery cells are in contact on only three surfaces, and the large surfaces of the individual battery cells cannot be cooled. This can easily lead to excessive temperatures between the large surfaces of the individual battery cells, causing thermal runaway. Although some battery modules use a serpentine liquid cooling plate structure to dissipate heat from the large surfaces of the individual battery cells, thereby improving heat dissipation efficiency, during the battery module assembly process, the liquid cooling plate needs to be assembled and fixed to each individual battery cell, requiring the participation of more parts, which will occupy a larger space in the battery module, thereby increasing the total weight of the battery module and reducing the energy density of the battery module.

[0006] Therefore, at the current stage, during the grouping process of square batteries, the pole electrical connection structure and liquid cooling structure are important factors affecting the energy density of the battery module, and they need to be urgently resolved. Summary of the Invention

[0007] In view of this, the present invention proposes a square battery, a battery module and a battery pack to solve the problem that after the existing square batteries are grouped, the electrical connection structure and liquid cooling structure between the poles will occupy a large battery module space, and the energy density of the battery module cannot be maximized.

[0008] The technical solution of the present invention is achieved as follows:

[0009] In one aspect, the present invention provides a square battery, comprising a first shell, a winding core, a first pole, and a second pole, wherein the winding core is disposed in the first shell, and the first pole and the second pole are disposed on the first shell;

[0010] The first shell is square in shape and has two sets of first surfaces and two sets of second surfaces arranged opposite to each other. The area of ​​the first surface is larger than the area of ​​the second surface. The first pole and the second pole are respectively arranged on the two first surfaces. The first pole is used to connect to the first tab of the winding core, and the second pole is used to connect to the second tab of the winding core.

[0011] The square battery further includes a second shell, the first shell is disposed within the second shell, the first pole and the second pole both extend outside the second shell, and the outer end surfaces of the electrical connection ends of the first pole and the second pole are both flush with the outer side surface of the second shell, the first pole can be directly connected to the second pole or the first pole of the adjacent square battery, and the second pole can be directly connected to the first pole or the second pole of the adjacent square battery;

[0012] A liquid cooling chamber for cooling liquid to flow is formed between the first shell and the second shell. A liquid inlet and a liquid outlet are respectively provided at both ends of the length direction of the second shell. The liquid inlet and the liquid outlet are respectively connected to the liquid cooling chamber.

[0013] Based on the above technical solution, preferably, the first pole and the second pole are both arranged on the first surface corresponding to the same end in the length direction of the first shell, and the edges of the first pole and the second pole are close to the outer end surface in the length direction of the first shell;

[0014] A first mounting groove is provided on the outer surface of the second shell corresponding to the first pole, and the first pole is located in the first mounting groove. A second mounting groove is provided on the outer surface of the second shell corresponding to the second pole, and the second pole is located in the second mounting groove. The first mounting groove and the second mounting groove both extend beyond the outer end surface of the second shell on one side close to the outer end surface in the length direction of the second shell.

[0015] On the basis of the above technical solution, preferably, the outer surfaces of the second shell corresponding to the two first surfaces are provided with ridges and grooves along the length direction of the second shell, and two groups of the ridges and the grooves are provided. The ridges and the grooves correspond to each other in the thickness direction of the second shell, and the two adjacent square batteries are connected by the cooperation of the ridges and the grooves.

[0016] On the basis of the above technical solution, preferably, a liquid inlet chamber is provided between one end of the first shell in the length direction and the second shell, and a liquid outlet chamber is provided between the other end of the first shell in the length direction and the second shell, the liquid inlet chamber, the liquid cooling chamber and the liquid outlet chamber are connected in sequence, the liquid inlet is connected to the liquid inlet chamber, and the liquid outlet is connected to the liquid outlet chamber.

[0017] Further, preferably, a plurality of connecting ribs are connected between the second surface and the inner wall of the second shell, and the plurality of connecting ribs are arranged at intervals along the thickness direction of the second shell, and the length of the connecting ribs is the same as that of the first shell.

[0018] On the basis of the above technical solution, preferably, a plurality of buffer ribs are arranged between the first surface and the inner wall of the second shell, and the plurality of buffer ribs are arranged at intervals along the width direction of the second shell. The buffer ribs are equal in length to the first shell, one side of the buffer rib is fixedly connected to the inner wall of the second shell, and there is a certain gap between the other side of the buffer rib and the first surface.

[0019] Furthermore, preferably, the first surface is provided with a barrier rib that fits with the side of the buffer rib, the barrier rib is of the same length as the buffer rib, and there is a certain gap between the side of the barrier rib away from the first surface and the inner wall of the second shell.

[0020] On the other hand, the present invention also discloses a battery module, comprising a plurality of square batteries, wherein the plurality of square batteries are stacked and arranged, the square batteries are arranged sideways, and the length direction of the square batteries is horizontally arranged, the first pole and the second pole or the first pole in two adjacent square batteries are connected, and the second pole and the first pole or the second pole in two adjacent square batteries are connected.

[0021] On the basis of the above technical solution, the battery module further includes a liquid inlet pipe and a liquid outlet pipe; wherein,

[0022] The liquid inlet pipe is located at one end of the square battery in the length direction, and a liquid inlet channel is provided in the liquid inlet pipe. The liquid inlet channel is connected in parallel with the liquid inlet port on each square battery. A liquid inlet connector connected to the liquid inlet channel is provided at one end of the liquid inlet pipe;

[0023] The liquid outlet pipe is located at the other end of the square battery in the length direction. A liquid outlet channel is provided in the liquid outlet pipe. The liquid outlet channel is connected in parallel with the liquid outlet on each of the square batteries. A liquid outlet connector connected to the liquid outlet channel is provided at one end of the liquid outlet pipe.

[0024] The present invention also discloses a battery pack, comprising a lower box, an upper box and a battery module, wherein the battery module is arranged between the upper box and the lower box.

[0025] The present invention has the following beneficial effects compared to the prior art:

[0026] (1) The square battery disclosed in the present invention arranges the first pole and the second pole on two groups of first surfaces of the first shell respectively, and arranges the second shell outside the first shell, so that the first pole and the second pole both extend outside the second shell, and at the same time ensures that the outer end faces of the electrical connection end of the first pole and the electrical connection end of the second pole are flush with the outer side face of the second shell. As a result, when multiple square batteries are grouped, the first pole and the second pole between the square batteries can be directly connected without welding the bus bar, and the battery module space is not occupied, which can greatly improve the battery module space utilization. In addition, a liquid cooling chamber is formed between the first shell and the second shell, and coolant can be circulated into the liquid cooling chamber through the liquid inlet and liquid outlet at both ends of the second shell in the length direction, thereby realizing liquid cooling of the core wrapping, greatly improving the heat dissipation efficiency of the square battery. At the same time, the liquid cooling structure is integrated into the shell of the square battery, and there is no need to arrange a liquid cooling plate in the battery module to connect with the outside of the square battery, avoiding the assembly of more liquid cooling components, reducing the weight of the battery module, and further improving the space utilization rate after the square battery is grouped, thereby maximizing the energy density of the battery module.

[0027] (2) By arranging the first mounting groove and the second mounting groove on the outer surface of the second shell, it is convenient to assemble the first pole to the outer surface of the second shell through the first mounting groove, and it is also convenient to assemble the second pole to the outer surface of the second shell through the second mounting groove, thereby facilitating the electrical connection of two adjacent square batteries. The first pole can be directly connected to the second pole, and the outer end surface of the second shell is extended by the first mounting groove and the second mounting groove on one side close to the outer end surface of the second shell in the longitudinal direction. It is convenient to detect the connection status of the first pole and the second pole at the openings of the first mounting groove and the second mounting groove, and it is also convenient to weld the first pole and the second pole at the openings of the first mounting groove and the second mounting groove, thereby ensuring that the electrical connection reliability of the first pole and the second pole is stronger;

[0028] (3) The outer surface of the second shell corresponding to the two first surfaces is provided with ridges and grooves along the length direction of the second shell, and the ridges and grooves are provided in two groups, while ensuring that the ridges and grooves correspond to each other in the thickness direction of the second shell. In this way, after two adjacent square batteries are stacked, they can be connected by the ridges and grooves on the outer surfaces of the two second shells cooperating with each other, and then a plurality of square batteries are connected to each other to form a battery module with strong structural strength. The module box does not need to be involved in the assembly process of the battery module, which further reduces the weight of the battery module and improves the space utilization rate of the battery module;

[0029] (4) By connecting a plurality of connecting ribs between the second surface and the inner wall of the second shell, on the one hand, the first shell can be fixedly connected to the second shell through the connecting ribs, so that the position of the first shell is fixed in the second shell, which facilitates the formation of a liquid cooling chamber between the first shell and the second shell. On the other hand, the setting of the connecting ribs can separate the liquid cooling chamber between the second surface and the second shell to form a plurality of liquid cooling channels, so that the cooling liquid can enter different liquid cooling channels respectively during the flow process, thereby achieving uniform heat dissipation of the winding core in the first shell;

[0030] (5) A plurality of buffer ribs are provided between the first surface and the inner wall of the second shell, and the plurality of buffer ribs are arranged at intervals along the width direction of the second shell. One side of the buffer rib is fixedly connected to the inner wall of the second shell, and a certain gap is formed between the other side of the buffer rib and the first surface. On the one hand, the winding core squeezes the first surface on the first shell during the charge and discharge expansion process, and the gap between the first surface and the buffer rib can accommodate the expansion and deformation displacement of the first surface. On the other hand, the buffer rib can also limit the expansion displacement of the first surface, thereby avoiding a large displacement change of the first shell in the second shell, which leads to an unstable internal structure of the square battery. Thirdly, the buffer ribs are arranged at intervals, which can separate the liquid cooling chamber between the first surface and the second shell to form a plurality of liquid cooling channels, so that the coolant can enter different liquid cooling channels respectively during the flow process, thereby achieving uniform heat dissipation of the winding core in the first shell.

[0031] (6) By setting a barrier rib on the first surface that fits with the side of the buffer rib, the barrier rib and the buffer rib are of equal length, and there is a certain gap between the side of the barrier rib away from the first surface and the inner wall of the second shell. In this way, the barrier rib and the buffer rib fit together, and the liquid cooling chamber between the first surface and the second shell can be separated to form a plurality of liquid cooling channels that are not connected to each other, thereby avoiding the coolant from flowing in the gap between the buffer rib and the first surface, ensuring the coolant is cooled in different areas, and improving the uniformity of the cooling and heat exchange of the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 This is a schematic diagram of the three-dimensional structure of the square battery disclosed in the present invention;

[0034] Figure 2 This is a schematic diagram of the internal structure of the square battery disclosed in the present invention;

[0035] Figure 3 This is a schematic diagram of the planar structure of the square battery disclosed in the present invention;

[0036] Figure 4 for Figure 3 Cross-sectional view at AA in the middle;

[0037] Figure 5 for Figure 3 Cross-sectional view at the middle BB;

[0038] Figure 6 for Figure 5 A partial enlarged view of point C in the middle;

[0039] Figure 7 This is a schematic plan view of the square battery assembly structure disclosed in the present invention;

[0040] Figure 8 for Figure 7 A partial enlarged view of point D in the middle;

[0041] Figure 9 A schematic diagram of the three-dimensional structure of the battery module disclosed in the present invention;

[0042] Figure 10 It is a schematic diagram of the three-dimensional structure of the liquid inlet pipe and the liquid outlet pipe disclosed in the present invention;

[0043] Figure 11 A schematic diagram of the three-dimensional structure of the battery pack disclosed in the present invention;

[0044] Reference numerals:

[0045] 100. Square battery; 1. First shell; 2. Winding core; 3. First pole; 4. Second pole; 11. First surface; 12. Second surface; 5. Second shell; L1. Liquid cooling chamber; 51. Liquid inlet; 52. Liquid outlet; 50. End cover; 53. First mounting groove; 54. Second mounting groove; 55. Rib; 56. Groove; L2. Liquid inlet chamber; L3. Liquid outlet chamber; 57. Connecting rib; 58. Buffer rib; 59. Barrier rib; 200. Battery module; 6. Liquid inlet pipe; 7. Liquid outlet pipe; 61. Liquid inlet channel; 62. Liquid inlet connector; 71. Liquid outlet channel; 72. Liquid outlet connector; 300. Battery pack; 8. Lower case; 9. Upper case; 10. Pressing strip. DETAILED DESCRIPTION

[0046] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] As for the existing technology, the positive and negative poles of the square battery are usually installed on the top cover, and the top cover is installed at the top opening of the shell. Therefore, after the square batteries are connected in series, they need to be connected to the battery poles through a bus bar on the top of the battery module through laser welding to form an electrical connection. Among them, the external bus bar occupies a larger space of the battery module, the assembly operation is not easy, and the overall weight of the battery module is increased, which has an adverse effect on the improvement of the energy density of the battery module.

[0048] At the same time, after the square batteries are assembled into battery modules, liquid cooling plates are often installed on the bottom and sides of the battery modules to cool and dissipate heat from the bottom and two sides of the square batteries. The above-mentioned liquid cooling method has the problem that the liquid cooling plate and the square battery are in contact with only three surfaces, and the large surfaces of the square battery cannot be cooled. This can easily lead to excessive temperatures between the large surfaces of the square battery, causing thermal runaway. Although some battery modules use a serpentine liquid cooling plate structure to dissipate heat from the large surfaces of the square battery, thereby improving heat dissipation efficiency, during the battery module assembly process, the above-mentioned liquid cooling plate needs to be assembled and fixed to each square battery, requiring more components to participate, which will occupy a larger space in the battery module, thereby increasing the total weight of the battery module and reducing the energy density of the battery module.

[0049] To this end, in order to solve the above technical problems, the present invention discloses a square battery 100, such as Figure 1 As shown, combined Figure 2-4 The square battery 100 includes a first shell 1 , a winding core 2 , a first pole 3 and a second pole 4 . The winding core 2 is disposed in the first shell 1 , and the first pole 3 and the second pole 4 are disposed on the first shell 1 .

[0050] The first housing 1 is square in shape, with four side faces and two end faces. It has two sets of opposing first surfaces 11 and two sets of second surfaces 12. The first surfaces 11 and second surfaces 12 are alternately arranged around the periphery of the first housing 1. The area of ​​the first surfaces 11 is larger than that of the second surfaces 12. The first surfaces 11 can be referred to as "large surfaces." In this embodiment, the first housing 1 extends longitudinally. The distance between the two first surfaces 11 is defined as the thickness of the first housing 1, and the distance between the two second surfaces 12 is defined as the width of the first housing 1.

[0051] The first pole 3 and the second pole 4 are respectively arranged on the two first surfaces 11, and the first pole 3 is used to connect to the first pole ear of the core 2, and the second pole 4 is used to connect to the second pole ear of the core 2. In this embodiment, the first pole 3 is defined as the positive pole and the second pole 4 is defined as the negative pole, which is for the convenience of distinction. The first pole 3 and the second pole 4 are located at the same end in the length direction of the first shell 1, and the first pole 3 and the second pole 4 are both close to the outer end surface in the length direction of the first shell 1. This is to achieve the connection of the first pole 3 with the positive pole ear of the core 2 and the connection of the second pole 4 with the negative pole ear of the core 2 without affecting the length of the core 2.

[0052] In this embodiment, the first pole 3 and the second pole 4 may correspond to each other in the thickness direction of the first shell 1 , or the first pole 3 and the second pole 4 may be staggered in the thickness direction of the first shell 1 .

[0053] In this embodiment, the winding core 2 can be of a winding type or a laminated type.

[0054] In the above technical solution, the square battery 100 is formed by the first shell 1, the winding core 2, the first pole 3 and the second pole 4, and the first pole 3 and the second pole 4 are arranged on the large surface of the first shell 1. Such a structural setting can make the large surfaces of the square batteries 100 connected to each other during the group connection process, thereby making it possible for the first pole 3 and the second pole 4 between adjacent square batteries 100 to be directly electrically connected, thereby eliminating the need for the setting of a bus. To a certain extent, the space utilization rate of the battery module 200 can be improved, thereby improving the energy density of the battery module 200.

[0055] Although the above solution can solve the problem of space occupied by the electrical connection structure between the poles in the battery module 200, except for the change in the position of the poles, the other structures of the above-mentioned square battery 100 are consistent with the square shell batteries on the market. After the square batteries 100 are grouped, it is still necessary to set a liquid cooling structure on the battery module 200 to connect with the square batteries 100. In this case, the liquid cooling structure will occupy the space of the battery module 200, resulting in the inability to improve the energy density of the battery module 200.

[0056] To this end, based on the above technical solution, the present application further improves the structure of the square battery 100 to solve the above two problems at the same time.

[0057] For details, please refer to the attached Figure 2-4 As shown, the square battery 100 also includes a second shell 5. The first shell 1 is arranged in the second shell 5. The volume of the second shell 5 is larger than that of the first shell 1. The second shell 5 is also square. At the same time, the second shell 5 extends along the length direction. The length of the second shell 5 is greater than the length of the first shell 1.

[0058] Both the first pole 3 and the second pole 4 extend out of the outside of the second shell 5, and the outer end surfaces of the electrical connection end of the first pole 3 and the electrical connection end of the second pole 4 are flush with the outer side surface of the second shell 5. The first pole 3 can be directly connected to the second pole 4 or the first pole 3 of the adjacent square battery 100, and the second pole 4 can be directly connected to the first pole 3 or the second pole 4 of the adjacent square battery 100.

[0059] By adopting the above technical solution, the first pole 3 and the second pole 4 are respectively arranged on the two groups of first surfaces 11 of the first shell 1, and the second shell 5 is arranged on the outside of the first shell 1, so that the first pole 3 and the second pole 4 both extend outside the second shell 5, and at the same time, the outer end surfaces of the electrical connection ends of the first pole 3 and the second pole 4 are ensured to be flush with the outer side surface of the second shell 5. As a result, when multiple square batteries 100 are grouped, the first pole 3 and the second pole 4 between the square batteries 100 can be directly connected without the need for welding busbars, and do not occupy the space of the battery module 200, which can greatly improve the space utilization of the battery module 200.

[0060] In this embodiment, a liquid cooling chamber L1 for cooling liquid to flow is formed between the first shell 1 and the second shell 5. A liquid inlet 51 and a liquid outlet 52 are respectively provided at both ends of the length direction of the second shell 5. The liquid inlet 51 and the liquid outlet 52 are respectively connected to the liquid cooling chamber L1.

[0061] By adopting the above technical solution, the coolant is circulated into the liquid cooling chamber L1 through the liquid inlet 51 and the liquid outlet 52 at both ends of the second shell 5 in the longitudinal direction, thereby realizing liquid cooling of the six sides of the core 2, fully realizing immersion liquid cooling, and greatly improving the heat dissipation efficiency of the square battery 100. At the same time, the liquid cooling structure is integrated into the shell of the square battery 100, and there is no need to arrange a liquid cooling plate in the battery module 200 to connect with the outside of the square battery 100, avoiding the assembly of more liquid cooling components, reducing the weight of the battery module, and further improving the space utilization after the square battery 100 is grouped, thereby maximizing the energy density of the battery module 200.

[0062] In this embodiment, in order to facilitate the placement of the first shell 1 in the second shell 5, an opening is provided at one end of the second shell 5 in the longitudinal direction, and an end cover 50 is provided for sealing. At the same time, a liquid inlet 51 is arranged on the end cover 50, so that the coolant can be directly introduced into the liquid cooling chamber L1 through the liquid inlet 51.

[0063] It is worth noting that the first shell 1 in this embodiment also has an open end, and the open end of the first shell 1 is sealed with a cover plate. This is to facilitate the assembly of the core 2 in the first shell 1, and then the core 2 is sealed in the first shell 1 through the cover plate.

[0064] In this embodiment, since the first shell 1 is placed inside the second shell 5, in order to make it possible to more clearly observe the connection between the first pole 3 and the second pole 4 when the square battery 100 is electrically connected, in this embodiment, the first pole 3 and the second pole 4 are both arranged on the first surface 11 corresponding to the same end in the length direction of the first shell 1, and the edges of the first pole 3 and the second pole 4 are close to the outer end face in the length direction of the first shell 1. In this way, the first pole 3 and the second pole 4 are both located at the same end edge in the length direction of the second shell 5, which is convenient for docking during assembly. If the first pole 3 and the second pole 4 are away from the end in the length direction of the second shell 5 and tend to the middle, on the one hand, it will cause the energy density of the core 2 to be low, and on the other hand, when the square batteries 100 are connected to each other, when the surfaces of the second shell 5 contact each other, it is inconvenient to align the first pole 3 and the second pole 4.

[0065] Since there is a certain gap between the first shell 1 and the second shell 5, the gap is used to provide the liquid cooling chamber L1. The first pole 3 and the second pole 4 are fixed to the first surface 11 of the first shell 1. The first pole 3 and the second pole 4 need to pass through the second shell 5, and the electrical connection end surface of the first pole 3 and the electrical connection end surface of the second pole 4 are flush with the outer surface of the second shell 5. In this case, due to the thin wall thickness of the second shell 5, the first pole 3 and the second pole 4 are structurally unstable when installed on the second shell 5, and it is also inconvenient to assemble and fix.

[0066] For this purpose, refer to the attached Figure 2 、 7 As shown in Figure 8, in this embodiment, a first mounting groove 53 is provided on the outer surface of the second housing 5 corresponding to the first pole 3, and the first pole 3 is located in the first mounting groove 53. A second mounting groove 54 is provided on the outer surface of the second housing 5 corresponding to the second pole 4, and the second pole 4 is located in the second mounting groove 54. As a result, the first mounting groove 53 and the second mounting groove 54 are both recessed into the second housing 5. This facilitates the assembly of the first pole 3 to the outer surface of the second housing 5 through the first mounting groove 53, and also facilitates the assembly of the second pole 4 to the outer surface of the second housing 5 through the second mounting groove 54. This further facilitates the direct connection of the first pole 3 to the second pole 4 when two adjacent square batteries 100 are electrically connected. At the same time, the first pole 3 is hidden in the first mounting groove 53, which can protect the first pole 3 from damage caused by external force. Similarly, the second pole 4 is hidden in the second mounting groove 54, which can protect the second pole 4 from damage caused by external force.

[0067] In some preferred embodiments, when connecting the first pole 3 and the second pole 4, the electrically connected outer end surface of the first pole 3 can be directly brought into contact with the electrically connected outer end surface of the second pole 4. However, this approach may result in inaccurate positioning and poor contact. To this end, a recessed portion can be provided on the electrically connected outer end surface of the first pole 3, and a raised portion can be provided on the electrically connected outer end surface of the second pole 4 to match the recessed portion. This facilitates the positioning and connection of the first pole 3 and the second pole 4, and also ensures a more secure contact after the first pole 3 and the second pole 4 are connected.

[0068] Since the first mounting groove 53 and the second mounting groove 54 are both formed by being recessed inward along the outer surface of the second shell 5, after the square battery 100 is electrically connected, the first mounting groove 53 and the second mounting groove 54 are butted against each other and closed. Although the first pole 3 and the second pole 4 can be electrically connected by contacting each other, or by the cooperation of the recessed portion and the raised portion, there may be a situation where the contact between the first pole 3 and the second pole 4 is not firm. During the assembly process, due to the problem of material accuracy, there is a contact gap problem between the first pole 3 and the second pole 4, which will result in a small contact area between the first pole 3 and the second pole 4, poor contact, and excessive contact internal resistance, which is not suitable for high-power charging and discharging.

[0069] To this end, the first mounting groove 53 and the second mounting groove 54 extend from the outer end surface of the second shell 5 on one side close to the outer end surface in the length direction of the second shell 5, so that the connection status of the first pole 3 and the second pole 4 can be easily detected at the openings of the first mounting groove 53 and the second mounting groove 54. At the same time, it is also convenient to weld the first pole 3 and the second pole 4 at the openings of the first mounting groove 53 and the second mounting groove 54, thereby ensuring that the electrical connection reliability of the first pole 3 and the second pole 4 is stronger.

[0070] In order to achieve stacking and arranging multiple square batteries 100 to form a battery module 200, in the prior art, end plates and side plates are usually used to form a module box to enclose and fix the multiple square batteries 100. This method will add more components, occupy the space of the battery module 200, increase the total weight of the battery module 200, and cause the energy density of the battery module 200 to decrease.

[0071] For this purpose, refer to the attached Figure 6-8 As shown, in this embodiment, ridges 55 and grooves 56 are provided on the outer surface of the second shell 5 corresponding to the two first surfaces 11 along the length direction of the second shell 5. Two groups of ridges 55 and grooves 56 are provided. The ridges 55 and grooves 56 correspond to each other in the thickness direction of the second shell 5. The adjacent two square batteries 100 are connected by the ridges 55 and grooves 56 cooperating with each other.

[0072] With this arrangement, after two adjacent square batteries 100 are stacked, they can be connected by cooperating with each other through the ridges 55 and grooves 56 on the outer surfaces of the two second shells 5, so that after multiple square batteries 100 are connected to each other, a battery module 200 with strong structural strength is formed. The assembly process of the battery module 200 does not require the participation of the module box, which further reduces the weight of the battery module 200 and improves the space utilization of the battery module 200.

[0073] In the above embodiment, the structure of the ridge 55 is a dovetail protrusion, and the groove 56 is configured as a dovetail groove that matches the dovetail protrusion. Of course, it can also be configured as other mortise and tenon structures.

[0074] As an embodiment, the two ridges 55 can be provided on the same outer surface of the second shell 5 , and the corresponding two grooves 56 can be provided on the other opposite outer surface of the second shell 5 .

[0075] As another embodiment, one outer surface of the second shell 5 is provided with a ridge 55 and a groove 56, and the opposite outer surface of the second shell 5 is provided with a ridge 55 and a groove 56. The ridges 55 and the grooves 56 correspond to each other in the thickness direction of the second shell 5. In this way, when two prismatic batteries 100 are connected, the two sets of ridges 55 and the two sets of grooves 56 are connected separately, achieving a stable and secure connection.

[0076] In this embodiment, the ridges 55 and the grooves 56 are provided with a certain fitting gap, which can maintain a gap of 0 to 3 mm between the square batteries 100. According to the different functional uses of the square batteries 100, the expansion degree of the square batteries 100 is different, and different gaps can be set to meet the expansion requirements of the square batteries 100 and ensure the connection and fixing strength between the square batteries 100 and the square batteries 100.

[0077] In this embodiment, a liquid cooling chamber L1 is formed between the first shell 1 and the second shell 5. In order to facilitate the flow of coolant into the liquid cooling chamber L1 through the liquid inlet 51, and to discharge the coolant in the liquid cooling chamber L1 through the liquid outlet 52 after heat exchange, a certain gap is set between one end of the first shell 1 in the longitudinal direction and the second shell 5 to form a liquid inlet chamber L2, and a certain gap is set between the other end of the first shell 1 in the longitudinal direction and the second shell 5 to form a liquid outlet chamber L3. Figure 4 As shown, the liquid inlet chamber L2, the liquid cooling chamber L1 and the liquid outlet chamber L3 are connected in sequence, the liquid inlet 51 is connected to the liquid inlet chamber L2, and the liquid outlet 52 is connected to the liquid outlet chamber L3.

[0078] It is worth noting that the first pole 3 and the second pole 4 are located at one end of the liquid inlet chamber L2. In this way, the heat generated by the first pole 3 and the second pole 4 during charging and discharging can be quickly cooled down.

[0079] In order to fix the first shell 1 in the second shell 5, in this embodiment, multiple connecting ribs 57 are connected between the second surface 12 and the inner wall of the second shell 5. The multiple connecting ribs 57 are arranged at intervals along the thickness direction of the second shell 5, and the connecting ribs 57 are the same length as the first shell 1.

[0080] With this arrangement, on the one hand, the first shell 1 can be fixedly connected to the second shell 5 through the connecting rib 57, so that the position of the first shell 1 in the second shell 5 is fixed, which facilitates the formation of a liquid cooling chamber L1 between the first shell 1 and the second shell 5. On the other hand, the arrangement of the connecting rib 57 can separate the liquid cooling chamber L1 between the second surface 12 and the second shell 5 to form multiple liquid cooling channels, so that the cooling liquid can enter different liquid cooling channels respectively during the flow process, thereby achieving uniform heat dissipation of the core 2 in the first shell 1.

[0081] Since the area between the two first surfaces 11 is defined as the thickness direction of the first shell 1 , the winding core 2 will expand and squeeze the first shell 1 in the thickness direction during charging, thereby causing the first surface 11 to expand and displace.

[0082] If a connecting rib 57 is also provided between the first surface 11 and the second shell 5 , this will prevent the first shell 1 from expanding in the thickness direction.

[0083] For this purpose, refer to the attached Figure 5-6 As shown, in this embodiment, a plurality of buffer ribs 58 are provided between the first surface 11 and the inner wall of the second shell 5. The plurality of buffer ribs 58 are arranged at intervals along the width direction of the second shell 5. One side of the buffer rib 58 is fixedly connected to the inner wall of the second shell 5, and a certain gap is formed between the other side of the buffer rib 58 and the first surface 11. On the one hand, the core 2 squeezes the first surface 11 on the first shell 1 during the charge and discharge expansion process. The gap between the first surface 11 and the buffer rib 58 can accommodate the expansion and deformation displacement of the first surface 11. On the other hand, the buffer rib 58 can also limit the expansion and displacement of the first surface 11, thereby avoiding a large displacement change of the first shell 1 in the second shell 5, which would cause instability in the internal structure of the square battery 100. Thirdly, the buffer ribs 58 are arranged at intervals, which can separate the liquid cooling chamber L1 between the first surface 11 and the second shell 5 to form a plurality of liquid cooling channels, so that the coolant can enter different liquid cooling channels respectively during the flow process, thereby achieving uniform heat dissipation of the core 2 in the first shell 1.

[0084] Since there is a gap between the buffer rib 58 and the first surface 11 , the coolant in the plurality of liquid cooling channels between the first surface 11 and the second housing 5 will flow through the gap, thereby causing uneven cooling.

[0085] To this end, this embodiment provides a barrier rib 59 on the first surface 11 that is in contact with the side of the buffer rib 58. The barrier rib 59 is of the same length as the buffer rib 58. Thus, the barrier rib 59 and the buffer rib 58 are in contact with each other, and the liquid cooling chamber L1 between the first surface 11 and the second shell 5 can be separated to form a plurality of liquid cooling channels that are not connected to each other, thereby preventing the coolant from flowing in the gap between the buffer rib 58 and the first surface 11, ensuring regional liquid cooling of the coolant, and improving the cooling and heat exchange uniformity of the core 2.

[0086] By ensuring a certain gap between the side of the barrier rib 59 away from the first surface 11 and the inner wall of the second shell 5, the barrier rib 59 can move toward the inner wall of the second shell 5 when the first shell 1 expands. In this way, there can be a certain amount of expansion displacement. When the expansion displacement reaches a certain value, the buffer rib 58 is used to limit the position to avoid excessive expansion force displacement, which would cause a large position change of the first shell 1 in the second shell 5.

[0087] The present invention also discloses a battery module 200. Figure 9 As shown, it includes a plurality of square batteries 100, which are stacked and arranged. The square batteries 100 are arranged sideways, and the length direction of the square batteries 100 is in a horizontal arrangement. The first pole 3 and the second pole 4 or the first pole 3 in two adjacent square batteries 100 are connected, and the second pole 4 and the first pole 3 or the second pole 4 in two adjacent square batteries 100 are connected.

[0088] In this embodiment, the square batteries 100 can be connected through ridges 55 and grooves 56, so that after multiple square batteries 100 are connected to each other, a battery module 200 with strong structural strength is formed. The assembly process of the battery module 200 does not require the participation of the module box, which further reduces the weight of the battery module 200 and improves the space utilization of the battery module 200.

[0089] When multiple square batteries 100 are grouped, the first pole 3 and the second pole 4 between the square batteries 100 can be directly connected without welding the busbar and taking up the space of the battery module 200, which can greatly improve the space utilization of the battery module 200. At the same time, the liquid cooling chamber L1 is integrated inside the shell of the square battery 100, and there is no need to arrange a liquid cooling plate in the battery module 200 to connect with the outside of the square battery 100, avoiding the assembly of more liquid cooling components, reducing the weight of the battery module, and further improving the space utilization after the square batteries 100 are grouped, thereby maximizing the energy density of the battery module 200.

[0090] In the above embodiment, in order to synchronously circulate coolant through the plurality of square batteries 100 in the battery module 200 , the battery module 200 of this embodiment further includes a liquid inlet pipe 6 and a liquid outlet pipe 7 .

[0091] Refer to the attached Figure 10 As shown, the liquid inlet pipe 6 is located at one end of the square battery 100 in the length direction, and a liquid inlet channel 61 is provided in the liquid inlet pipe 6. The liquid inlet channel 61 is connected in parallel with the liquid inlet port 51 on each square battery 100. A liquid inlet connector 62 connected to the liquid inlet channel 61 is provided at one end of the liquid inlet pipe 6.

[0092] The liquid outlet pipe 7 is located at the other end of the square battery 100 in the length direction. A liquid outlet channel 71 is provided in the liquid outlet pipe 7. The liquid outlet channel 71 is connected in parallel with the liquid outlet 52 on each square battery 100. A liquid outlet connector 72 connected to the liquid outlet channel 71 is provided at one end of the liquid outlet pipe 7.

[0093] According to this arrangement, the coolant is introduced into the liquid inlet channel 61 through the liquid inlet joint 62, and the coolant passes through the liquid inlet 51 of each square battery 100 respectively. After cooling and heat exchange of the winding core 2 is realized in the coolant liquid cooling chamber L1, it is merged into the liquid outlet channel 71 through the liquid outlet 52 and discharged through the liquid inlet and outlet joint 72. The liquid inlet joint 62 and the liquid outlet joint 72 are connected to the coolant refrigeration cycle equipment.

[0094] The above structural arrangement can ensure that each square battery 100 in the battery module 200 can dissipate heat synchronously, thereby improving the heat dissipation efficiency while ensuring stable uniformity.

[0095] In this embodiment, in the battery module 200, multiple square batteries 100 can be connected in series or in parallel. As an embodiment, the first pole 3 and the second pole 4 of two adjacent square batteries 100 are connected, and the second pole 4 and the first pole 3 of two adjacent square batteries 100 are connected. This arrangement enables the multiple square batteries 100 to be connected in series. The first pole 3 and the first pole 3 of two adjacent square batteries 100 are connected, and the second pole 4 and the second pole 4 of two adjacent square batteries 100 are connected. This arrangement enables the multiple square batteries 100 to be connected in parallel.

[0096] The present invention also discloses a battery pack 300, Figure 11 As shown, the battery module 200 includes a lower case 8, an upper case 9, and a battery module 200, which is disposed between the upper case 9 and the lower case 8. In this embodiment, after a plurality of prismatic batteries 100 are assembled into the battery module 200, they can be directly placed inside the lower case 8. Since the prismatic batteries 100 are connected by ridges 55 and grooves 56, the overall horizontal structural strength of the battery module 200 is more stable. In this case, the battery module 200 only needs to be positioned at the two ends of the prismatic batteries 100 in the longitudinal direction.

[0097] Of course, in order to prevent the entire battery module 200 from moving between the upper box body 9 and the lower box body 8, a pressure strip 10 can be set on the battery module 200, and the length direction of the pressure strip 10 is perpendicular to the length direction of the square battery 100, and the pressure strip 10 is fixed to the lower box body 8 at the same time, so that the battery module 200 can be firmly fixed in the lower box body 8, and the upper box body 9 and the lower box body 8 are connected to achieve protection of the battery module 200.

[0098] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A square battery, the square battery (100) comprising a first shell (1), a winding core (2), a first pole (3) and a second pole (4), wherein the winding core (2) is arranged in the first shell (1), and the first pole (3) and the second pole (4) are arranged on the first shell (1); Its characteristics are: The first shell (1) is square in shape and has two sets of first surfaces (11) and two sets of second surfaces (12) arranged opposite to each other, the area of ​​the first surface (11) is larger than the area of ​​the second surface (12), the first pole (3) and the second pole (4) are respectively arranged on the two first surfaces (11), the first pole (3) is used to connect to the first pole lug of the winding core (2), and the second pole (4) is used to connect to the second pole lug of the winding core (2); The square battery (100) further includes a second shell (5), the first shell (1) is arranged in the second shell (5), the first pole (3) and the second pole (4) both extend outside the second shell (5), and the outer end surfaces of the electrical connection end of the first pole (3) and the electrical connection end of the second pole (4) are both flush with the outer side surface of the second shell (5), the first pole (3) can be directly connected to the second pole (4) or the first pole (3) of the adjacent square battery (100), and the second pole (4) can be directly connected to the first pole (3) or the second pole (4) of the adjacent square battery (100); A liquid cooling chamber (L1) for cooling liquid to flow is formed between the first shell (1) and the second shell (5); a liquid inlet (51) and a liquid outlet (52) are respectively provided at both ends of the length direction of the second shell (5); the liquid inlet (51) and the liquid outlet (52) are respectively connected to the liquid cooling chamber (L1).

2. The square battery according to claim 1, wherein: The first pole (3) and the second pole (4) are both arranged on the first surface (11) corresponding to the same end in the length direction of the first shell (1), and the edges of the first pole (3) and the second pole (4) are both close to the outer end surface in the length direction of the first shell (1); A first mounting groove (53) is provided on the outer surface of the second shell (5) corresponding to the first pole (3), and the first pole (3) is located in the first mounting groove (53). A second mounting groove (54) is provided on the outer surface of the second shell (5) corresponding to the second pole (4), and the second pole (4) is located in the second mounting groove (54). The first mounting groove (53) and the second mounting groove (54) extend out of the outer end surface of the second shell (5) on one side close to the outer end surface of the second shell (5) in the longitudinal direction.

3. The square battery according to claim 1 or 2, wherein: The outer surfaces of the second shell (5) corresponding to the two first surfaces (11) are both provided with ridges (55) and grooves (56) along the length direction of the second shell (5), and two groups of the ridges (55) and the grooves (56) are provided. The ridges (55) and the grooves (56) correspond to each other in the thickness direction of the second shell (5), and two adjacent square batteries (100) are connected by the ridges (55) and the grooves (56) cooperating with each other.

4. The square battery according to claim 1, wherein: A liquid inlet chamber (L2) is provided between one end of the first shell (1) in the longitudinal direction and the second shell (5), and a liquid outlet chamber (L3) is provided between the other end of the first shell (1) in the longitudinal direction and the second shell (5). The liquid inlet chamber (L2), the liquid cooling chamber (L1) and the liquid outlet chamber (L3) are connected in sequence, the liquid inlet (51) is connected to the liquid inlet chamber (L2), and the liquid outlet (52) is connected to the liquid outlet chamber (L3).

5. The square battery according to claim 1 or 4, characterized in that: A plurality of connecting ribs (57) are connected between the second surface (12) and the inner wall of the second shell (5), and the plurality of connecting ribs (57) are arranged at intervals along the thickness direction of the second shell (5), and the length of the connecting ribs (57) is the same as that of the first shell (1).

6. The square battery according to claim 5, wherein: A plurality of buffer ribs (58) are provided between the first surface (11) and the inner wall of the second shell (5), and the plurality of buffer ribs (58) are arranged at intervals along the width direction of the second shell (5). The buffer ribs (58) are equal in length to the first shell (1), one side of the buffer rib (58) is fixedly connected to the inner wall of the second shell (5), and a certain gap is formed between the other side of the buffer rib (58) and the first surface (11).

7. The square battery according to claim 6, wherein: The first surface (11) is provided with a barrier rib (59) that fits in contact with the side of the buffer rib (58); the barrier rib (59) is of the same length as the buffer rib (58); and a certain gap exists between the side of the barrier rib (59) away from the first surface (11) and the inner wall of the second shell (5).

8. A battery module comprising a plurality of the square batteries according to any one of claims 2 to 7, characterized in that: A plurality of the square batteries (100) are stacked and arranged, the square batteries (100) are arranged sideways, and the length direction of the square batteries (100) is arranged horizontally, the first pole (3) and the second pole (4) or the first pole (3) in two adjacent square batteries (100) are connected, and the second pole (4) and the first pole (3) or the second pole (4) in two adjacent square batteries (100) are connected.

9. The battery module according to claim 8, wherein: It also includes a liquid inlet pipe (6) and a liquid outlet pipe (7); wherein, The liquid inlet pipe (6) is located at one end of the square battery (100) in the longitudinal direction. A liquid inlet channel (61) is provided in the liquid inlet pipe (6). The liquid inlet channel (61) is connected in parallel with the liquid inlet port (51) on each square battery (100). One end of the liquid inlet pipe (6) is provided with a liquid inlet connector (62) connected to the liquid inlet channel (61). The liquid outlet pipe (7) is located at the other end of the square battery (100) in the longitudinal direction. A liquid outlet channel (71) is provided in the liquid outlet pipe (7). The liquid outlet channel (71) is connected in parallel with the liquid outlet (52) on each square battery (100). One end of the liquid outlet pipe (7) is provided with a liquid outlet connector (72) connected to the liquid outlet channel (71).

10. A battery pack comprising a lower box (8), an upper box (9) and the battery module (200) according to claim 9, characterized in that: The battery module (200) is arranged between the upper box (9) and the lower box (8).

Images