A large capacity battery

Abstract

The application provides a large-capacity battery, which mainly solves the problem that there is a gap between the upper cover assembly and the shell of the single battery of the existing large-capacity battery, which may cause virtual welding between the shell and the upper cover assembly during laser fusion welding, and even cause the problem of welding failure. The large-capacity battery comprises a shell and a plurality of single batteries in the shell, the shell is provided with a shared chamber communicating with the inner cavities of the single batteries, and a plurality of first through holes are formed in the top of the shell for the pole columns of the single batteries to extend out of the shell; the upper cover assembly of each single battery comprises a cover plate body, two pole columns and two hollow members; the two ends of the hollow member are both open, and one open end is connected with the pole column hole of the cover plate body; the two pole columns are correspondingly arranged in the two hollow members; an insulating sleeve is arranged between the pole column and the hollow member to realize the insulation between the hollow member and the pole column; and a fixing part is arranged on the insulating sleeve to realize the sealed connection of the hollow member and the pole column through the insulating sleeve.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of batteries, and particularly relates to a large-capacity battery. BACKGROUND

[0002] In existing battery modules, due to the differences between individual batteries, the uniformity of individual batteries in the battery module is poor, which directly leads to the limited cycle life of the battery module, and therefore how to improve the uniformity of individual batteries in the battery module has become the focus and difficulty in the field.

[0003] In order to solve the above problems, a large-capacity battery structure is provided, as shown in Figure 1 The large-capacity battery comprises a shell 6 and a plurality of individual batteries 1; the plurality of individual batteries 1 are placed in parallel in the shell 6, and the shell 6 is provided with at least one shared chamber 68 in communication with the inner cavities of the individual batteries 1. If the shared chamber is in communication with the electrolyte zones of the inner cavities of the individual batteries, a large-capacity battery with a shared electrolyte system can be formed; if the shared chamber is in communication with the gas zones of the inner cavities of the individual batteries, a large-capacity battery with a gas balance system can be formed; if the shared chamber is a plurality of chambers, and is in communication with the electrolyte zones and the gas zones of the inner cavities of the individual batteries, respectively, a large-capacity battery with both a shared electrolyte system and a gas balance system can be formed.

[0004] When the above individual batteries are assembled with the shell to form a large-capacity battery, a plurality of first through holes 67 are formed in the top of the shell for the pole posts of the individual batteries to extend out of the shell, and after the plurality of individual batteries are grouped, the upper cover assembly of each individual battery corresponding to each first through hole of the shell needs to be sealed and welded to ensure the sealing at this position. The current method is to use laser fusion welding to weld the shell and the upper cover assembly of the individual battery in the peripheral area corresponding to each first through hole (the welding track is circled at A in Figure 1 ).

[0005] However, when large-capacity batteries are mass-produced, due to the existence of processing errors and assembly errors, if it is necessary to ensure that the bottoms of the individual batteries are at the same level, the tops (i.e. the upper cover assemblies) of the individual batteries will have uneven height differences, which causes gaps between the upper cover assemblies of some individual batteries and the shell in some large-capacity batteries, leading to the possibility of false welding between the shell and the upper cover assembly during laser fusion welding, or even the problem of being unable to weld, which affects the yield of the large-capacity batteries. SUMMARY

[0006] In order to solve the problem of gaps between the upper cover assemblies of the individual batteries and the shell of the existing large-capacity batteries, which leads to the possibility of false welding between the shell and the upper cover assembly during laser fusion welding, or even the problem of being unable to weld, the application provides a large-capacity battery.

[0007] To solve the above problems, the technical scheme provided by the present application is as follows:

[0008] A large-capacity battery comprises a shell and a plurality of single batteries located in the shell, the shell is provided with a shared chamber in communication with the inner cavities of the single batteries, and a plurality of first through holes are formed in the top of the shell for the pole columns of the single batteries to extend out of the shell; the upper cover assembly of each single battery comprises a cover plate body and two pole columns, and is characterized in that it further comprises two hollow members; both ends of the hollow member are open, one open end is connected with the pole column hole of the cover plate body, and the other open end is used for being connected with the shell of the large-capacity battery; the two pole columns are correspondingly arranged in the two hollow members, and the pole column of the single battery extends out of the shell through the first through hole; an insulating sleeve is arranged between the pole column and the hollow member to realize the insulation between the hollow member and the pole column; and a fixing portion is arranged on the insulating sleeve to realize the sealed connection of the hollow member and the pole column through the insulating sleeve.

[0009] Further, the insulating sleeve and the fixing portion are integrally formed by injection molding.

[0010] Further, at least one second through hole is arranged on the side wall of the hollow member, the fixing portion is a fixing sleeve arranged outside the hollow member and an insulating connecting column embedded in the second through hole, and the two ends of the insulating connecting column are respectively connected with the fixing sleeve and the insulating sleeve.

[0011] Further, at least one second through hole is arranged on the side wall of the hollow member, and the fixing portion is a columnar protrusion arranged on the outer wall of the insulating sleeve and embedded in the second through hole.

[0012] Further, a first annular groove protruding outward is arranged on the side wall of the hollow member, and the fixing portion is a first annular protrusion arranged on the outer wall of the insulating sleeve and embedded in the first annular groove.

[0013] Further, a second annular groove is arranged on the outer wall of the pole column, and the fixing portion further comprises a second annular protrusion arranged on the inner wall of the insulating sleeve and embedded in the second annular groove.

[0014] Further, a gas hole is arranged on the cover plate body, the gas hole is sealed by a sealing mechanism formed by injection molding, or a gas hole is arranged on the gas hole.

[0015] Further, the hollow member is integrally formed on the cover plate body.

[0016] Further, the part of the hollow member away from the cover plate body can be bent, and the bent area is used for welding and sealing with the peripheral area of the first through hole on the shell of the large-capacity battery.

[0017] Further, a buffer deformation groove is arranged on the side wall of the hollow member, and a through groove for clamping a heat pipe is arranged on the pole column of the pole column.

[0018] The application also provides a single battery, comprising an outer cylinder, an upper cover assembly, a lower cover assembly and an electrode assembly, characterized in that the upper cover assembly is any one of the above-mentioned upper cover assemblies.

[0019] Compared with the prior art, the application has the following advantages:

[0020] 1. In the upper cover assembly provided by the application, two hollow members are arranged on the cover plate body. When a plurality of single batteries are placed in a large-capacity battery shell in groups, whether there is a gap between the shell and the upper cover assembly of each single battery or the gap size is different, only the part of the hollow member of each single battery away from the cover plate body and the area corresponding to the first through hole on the shell need to be sealed and connected during operation, thereby ensuring the sealing of the large-capacity battery shell and solving the problem of virtual welding or even the problem of being unable to weld when the shell and the upper cover assembly of the single battery are directly laser fusion welded in the prior art.

[0021] 2. In the upper cover assembly provided by the application, reliable insulation is achieved between the pole and the hollow member through the insulating sleeve, and the hollow member and the pole can also be sealed and connected through the insulating sleeve, so that the upper cover assembly is a whole structure, facilitating subsequent assembly and disassembly.

[0022] 3. In the upper cover assembly provided by the application, the insulating sleeve formed by the injection molding process can completely fill the gap between the hollow member and the pole, so that the sealing of the pole hole on the cover plate body is better, and the insulating sleeve formed by the injection molding process is not easy to fall out, and the insulation reliability is higher.

[0023] 4. In the upper cover assembly provided by the application, the fixing part is a fixing sleeve sleeved outside the hollow member and an insulating connecting column embedded in the second through hole, and the two ends of the insulating connecting column are connected with the fixing sleeve and the insulating sleeve respectively. The fixing part of this structure can reliably install the insulating sleeve on the hollow member, and can also protect the hollow member, avoiding damage or deformation of the hollow member during the handling of the single battery, so as to affect the subsequent sealing connection with the large-capacity battery shell.

[0024] 5. In the upper cover assembly provided by the application, the fixing part is a columnar protrusion arranged on the outer wall of the insulating sleeve and embedded in the second through hole. The fixing part of this structure is simple in structure and convenient to process and manufacture.

[0025] 6. In the upper cover assembly provided by the application, the fixing part is a first annular protrusion arranged on the outer wall of the insulating sleeve and embedded in the first annular groove. The fixing part of this structure is simple in structure, and its installation is convenient, which can be very conveniently installed in the hollow member.

[0026] 7. The upper cover assembly provided by the present application, the second annular boss of the insulating sleeve is embedded into the second annular groove of the pole, further avoiding the insulation failure problem caused by the falling of the insulating sleeve.

[0027] 8. The upper cover assembly provided by the present application, the gas hole on the cover plate body is sealed by the sealing mechanism of injection molding, or the gas hole is provided with a blast venting part, so that the upper cover assembly meets the multifunctional use requirements.

[0028] 9. The upper cover assembly provided by the present application, the hollow member is integrally formed on the cover plate body, which not only facilitates the processing and manufacturing, but also makes the sealing of the single battery better.

[0029] 10. The upper cover assembly provided by the present application, a part of the hollow member away from the cover plate body is provided with a bending area welded and sealed with the peripheral area of the first through hole on the large-capacity battery shell, which improves the operability and adaptability of the sealing and fixation between the hollow member on each single battery and the shell.

[0030] 11. The upper cover assembly provided by the present application, the side wall of the hollow member is provided with a buffer deformation groove. The buffer deformation groove not only provides a certain deformation allowance for sealing and fixation, which can be used to compensate for the problem of too large or too small gap between the shell and the single battery, and also can compensate for the coaxiality deviation of the pole of the single battery and the corresponding first through hole; at the same time, when the large-capacity battery is subjected to external force or its own vibration, the buffer deformation groove itself has a certain buffering effect, ensuring the reliability of the sealing and fixation. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the prior art large-capacity battery;

[0032] Figure 2 It is a structural schematic diagram of the upper cover assembly in Example 1;

[0033] Figure 3 It is an exploded view of the upper cover assembly in Example 1;

[0034] Figure 4 It is a sectional view of the upper cover assembly (the fixed part is a fixed sleeve + an insulating connecting column) in Example 1;

[0035] Figure 5 It is a sectional view of the upper cover assembly (the fixed part is a first annular boss) in Example 1;

[0036] Figure 6 It is a structural schematic diagram of the upper cover assembly (the fixed part is a columnar boss) in Example 1;

[0037] Figure 7 It is a sectional view of the hollow member provided with a buffer deformation groove in Example 1;

[0038] Figure 8 Structure diagram of single battery in Example 2 Figure 1 ;

[0039] Figure 9 Structure diagram of single battery in Example 2 Figure 2 ;

[0040] Figure 10 Structure diagram of large capacity battery in Example 2 Figure 1 ;

[0041] Figure 11 Structure diagram of large capacity battery in Example 2 Figure 2 ;

[0042] Figure 12 Structure diagram of large capacity battery in Example 2 Figure 3 ;

[0043] Figure 13 Structure diagram of large capacity battery in Example 2.

[0044] Label: 1-single battery; 2-upper cover assembly; 3-outer cylinder; 4-lower cover assembly; 5-sealing mechanism; 6-outer shell; 21-cover plate body; 22-pole; 23-hollow member; 24-insulating sleeve; 25-fixing part; 26-insulating plate; 27-retaining ring; 28-liquid injection port; 211-gas hole; 221-second annular groove; 222-through groove; 231-second through hole; 232-first annular groove; 233-buffer deformation groove; 241-second annular boss; 251-fixing sleeve; 252-insulating connecting column; 253-columnar protrusion; 254-first annular protrusion; 61-cylinder body; 62-first cover plate; 63-second cover plate; 64-U-shaped shell; 65-third cover plate; 66-fourth cover plate; 67-first through hole; 68-shared chamber. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments but not all of the embodiments. Based on the embodiments below, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present application.

[0046] Meanwhile, it should be noted that the terms "top, bottom, inner and outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the technical solutions. In addition, the terms "first, second or third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0047] Unless otherwise explicitly specified and limited, the terms "mounting, connecting, connecting" in the present application should be understood broadly, for example: it can be fixed connection, detachable connection or integral connection; it can also be mechanical connection, electrical connection or direct connection, it can also be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] The present application provides an upper cover assembly, which is different from the existing single battery upper cover assembly: two hollow members are added to the existing upper cover assembly to solve the problem that the gap between the shell and the upper cover assembly of each single battery in some large capacity batteries is too large due to processing errors and assembly errors during batch production of large capacity batteries, resulting in virtual welding or welding failure when the two are welded by laser. At the same time of solving the above problems, it is also necessary to ensure the insulation between the hollow member and the pole. Therefore, an insulating sleeve is arranged between the hollow member and the pole, and the insulating sleeve is reliably mounted on the hollow member, so that the large capacity battery can be used safely and reliably.

[0049] Example 1

[0050] As Figures 2 to 7 shown, the upper cover assembly 2 in the present embodiment includes a cover plate body 21, two pole columns 22 and two hollow members 23. The cover plate body 21 is generally a rectangular flat plate structure, and two pole column holes are provided on the cover plate body 21. Both ends of the hollow member 23 are open, and one end of the hollow member 23 is sealingly connected with the pole column hole of the cover plate body 21, so that the open end of the hollow member 23 is in communication with the pole column hole of the cover plate body 21; the other end of the hollow member 23 is sealingly connected with the area corresponding to the first through hole on the large capacity battery shell 6. The area corresponding to the first through hole is the peripheral area of the large capacity battery shell corresponding to any one of the first through holes; or the area corresponding to the first through hole is the first through hole wall.

[0051] In the embodiment, the hollow member 23 is a thin-walled tubular structure, and the cross section of the hollow member 23 can be circular or rectangular, and the cross section of the hollow member 23 is usually circular to better match the shape of the first through hole and the pole 22. The hollow member 23 can be connected to the cover plate body 21 by bonding, riveting or welding. However, the above methods have the defects of complicated processing and low efficiency. Therefore, in the preferred embodiment, the hollow member 23 is integrally formed on the cover plate body 21. The integrally formed structure is not only convenient for processing, but also has better sealing performance of the entire upper cover assembly 2. At the same time, the hollow member 23 can also be connected to the shell of the large-capacity battery by bonding, riveting or welding. However, compared with welding, the bonding has poor reliability, and the riveting is not convenient for assembly, so the welding is usually used to connect the hollow member 23 to the shell of the large-capacity battery.

[0052] When the hollow member 23 is connected to the shell of the large-capacity battery, the part of the hollow member 23 away from the cover plate body 21 can be bent outward to form a bent area, and the bent area is connected to the peripheral area corresponding to the first through hole 67 on the shell. The bent area can improve the operability and adaptability of the sealing and fixation between the hollow member 23 and the shell on each single battery 1. In other embodiments, if the part of the hollow member 23 away from the cover plate body 21 is not bent, but the end of the hollow member 23 away from the cover plate body 21 is directly welded to the shell, then the laser welding method cannot be used, which may result in relatively weak reliability and sealing performance of the welding part. In addition, if the part of the hollow member 23 away from the cover plate body 21 is not bent, a ring plate can be added to the end of the hollow member 23 away from the cover plate body 21. During installation, the hollow member 23 is arranged in the first through hole, the ring plate is welded to the top of the hollow member 23, and the ring plate is connected to the peripheral area corresponding to the first through hole 67 on the shell. The above connection method is relatively complex, so the hollow member 23 is bent to form a bent area, and the bent area is connected to the shell.

[0053] In the embodiment, the two poles 22 are arranged in the two hollow members 23, and the one end of each pole 22 extends to the outside of the open end of the hollow member 23, so that the pole 22 can extend out of the shell of the large-capacity battery during assembly of the large-capacity battery. The other end of each pole 22 (positive pole or negative pole) is connected to the electrode assembly of the single battery through the positive connection piece or the negative connection piece.

[0054] In order to ensure the safe use of the single battery 1, the upper cover assembly 2 needs to be insulated. First, an insulating plate 26 is arranged on the side of the cover plate body 21 facing the electrode assembly. The insulating plate 26 not only insulates the cover plate body 21 from the electrode assembly, but also insulates the pole 22 from the cover plate body 21. The structure and function of the insulating plate 26 are the same as those of the existing insulating plate 26 of the upper cover assembly 2 of the single battery 1, and will not be described in detail here. In this embodiment, attention should be paid to the insulation between the pole 22 and the hollow member 23. In this embodiment, an insulating sleeve 24 is arranged between the pole 22 and the hollow member 23 to ensure reliable insulation between the pole 22 and the hollow member 23. At the same time, the insulating sleeve 24 is provided with a fixing portion 25 to reliably connect the insulating sleeve 24 with the hollow member 23 and the pole 22, preventing the insulating sleeve 24 from falling off and causing insulation failure. The fixing portion 25 can be implemented in the following multiple structures:

[0055] First, as shown in Figures 4 to 6 , a second annular groove 221 is arranged on the outer wall of the pole 22, and the fixing portion 25 is a second annular protrusion 241 arranged on the inner wall of the insulating sleeve 24, and the second annular protrusion 241 of the insulating sleeve 24 is embedded in the second annular groove 221 of the pole 22;

[0056] Second, as shown in Figure 5 , a first annular groove 232 protruding outward is arranged on the side wall of the hollow member 23, and the fixing portion 25 is a first annular protrusion 254 arranged on the outer wall of the insulating sleeve 24 and embedded in the first annular groove 232;

[0057] Third, as shown in Figure 6 , at least one second through hole 231 is arranged on the side wall of the hollow member 23, and the fixing portion 25 is a columnar protrusion 253 arranged on the outer wall of the insulating sleeve 24 and embedded in the second through hole 231;

[0058] Fourth, as shown in Figure 3 and Figure 4 , at least one second through hole 231 is arranged on the side wall of the hollow member 23, and the fixing portion 25 is a fixing sleeve 251 arranged outside the hollow member 23 and an insulating connecting column 252 embedded in the second through hole 231, and the two ends of the insulating connecting column 252 are connected with the fixing sleeve 251 and the insulating sleeve 24, respectively;

[0059] Fifth, as shown in Figure 3 and Figure 4As shown, the fixing part 25 includes a second annular boss 241 on the inner wall of the insulating sleeve 24, a fixing sleeve 251 sleeved outside the hollow member 23, and an insulating connecting column 252 embedded in the second through hole 231. The outer wall of the pole 22 is provided with a second annular groove 221, and the second annular boss 241 of the insulating sleeve 24 is embedded in the second annular groove 221 of the pole 22. The side wall of the hollow member 23 is provided with at least one second through hole 231, and the two ends of the insulating connecting column 252 pass through the second through hole 231 and are connected with the fixing sleeve 251 and the insulating sleeve 24, respectively.

[0060] Sixth, as Figure 5 As shown, the fixing part 25 includes a second annular boss 241 on the inner wall of the insulating sleeve 24 and a first annular protrusion 254 on the outer wall of the insulating sleeve 24. The outer wall of the pole 22 is provided with a second annular groove 221, and the second annular boss 241 of the insulating sleeve 24 is embedded in the second annular groove 221 of the pole 22. At the same time, the side wall of the hollow member 23 is provided with a first annular groove 232 protruding outward, and the first annular protrusion 254 is embedded in the first annular groove 232.

[0061] Among the six kinds of structures of the fixing part, the fixing part 25 of the first structure, the second structure and the third structure is simple in structure and convenient to process and manufacture, but the stability of the insulating sleeve 24 after connection is relatively weak. The fixing part 25 of the fourth structure can reliably install the insulating sleeve 24 to the hollow member 23, and can also protect the hollow member 23, avoiding damage or deformation of the hollow member 23 during the carrying process of the single battery 1, so as to affect the subsequent connection with the large-capacity battery shell 6. Among them, the fixing part 25 of the fifth structure and the sixth structure is a preferred structure. The fixing part 25 of this structure not only protects the hollow member 23 and avoids damage or deformation of the hollow member 23 during the carrying process of the single battery 1, but also reliably connects the insulating sleeve 24 with the pole 22 and the hollow member 23, further avoiding the insulation failure problem caused by the falling of the insulating sleeve 24.

[0062] In this embodiment, the insulating sleeve 24 and the fixing portion 25 are integrally formed via an injection molding process. The insulating sleeve 24 formed via the injection molding process can completely fill the gap between the hollow member 23 and the pole 22, resulting in a better seal at the pole hole on the cover body 21. During injection molding, the insulating sleeve 24 and the fixing portion 25 are made of a material similar to that of the insulating plate 26, typically PPS (polyphenylene sulfide), although materials similar to PPS can also be used. Furthermore, during injection molding of the insulating sleeve 24 and the fixing portion 25, a retaining ring 27 can be placed on top of the insulating plate 26. This retaining ring 27 blocks the molten raw material during the injection molding of the insulating sleeve 24 and the fixing portion 25, preventing leakage of the molten raw material and ensuring the proper injection molding of the insulating sleeve 24 and the fixing portion 25.

[0063] In other embodiments, the above-mentioned insulating sleeve 24 and the fixing portion 25 are manufactured and then embedded between the hollow member 23 and the pole 22 by extrusion or the like. However, this method may damage the insulating sleeve 24 and the fixing portion 25 during the installation process, making the sealing performance of the insulating sleeve 2 worse than that of the injection molding method. Therefore, it is recommended to use the injection molding process to manufacture the insulating sleeve 24 and the fixing portion 25 in one piece.

[0064] In addition, the upper cover assembly 2 of this embodiment can also be optimized as follows:

[0065] 1. As Figure 6 As shown, to prevent thermal runaway of each battery cell 1 caused by localized overheating of the terminal 22, a through slot 222 for receiving a heat transfer tube is provided in the portion of the terminal 22 extending from the housing 6. The cross-section of the through slot 222 can be designed as a U-shape or a C-shape. Because the C-shaped through slot 222 has natural tension at the opening, it facilitates installation of the heat transfer tube and helps to more tightly clamp the heat transfer tube within the through slot 222, thereby improving the heat transfer effect between the heat transfer connector and the heat transfer tube. Therefore, in this embodiment, the C-shape is selected as the cross-section of the through slot 222.

[0066] 2. If Figure 7 As shown, in this embodiment, a buffer deformation groove 233 is further provided on the side wall of the hollow member 23. The buffer deformation groove 233 is located above the first annular groove 232. This buffer deformation groove 233 not only provides a certain deformation margin for sealing and fixing, which can be used to compensate for the problem of welding difficulties caused by the excessive gap between the shell 6 and the single battery 1, but also compensates for the coaxial deviation between the single battery 1 terminal 22 and the corresponding first through hole 67. At the same time, when the large-capacity battery is subjected to external forces or self-vibration, the buffer deformation groove 233 itself has a certain buffering effect, ensuring the reliability of the sealing and fixing.

[0067] like Figure 2 and Figure 3As shown, in this embodiment, the cover plate body 21 can also be provided with a liquid injection port 28 for injecting liquid into the single battery 1, and the liquid injection port 28 is sealed after the liquid injection is completed. At the same time, the cover plate body 21 can also be provided with a gas hole 211 between the two hollow members 23, and a sealing mechanism 5 can be provided on the gas hole 211. The sealing mechanism 5 can be opened under the action of electrolyte or external force, so that the gas area in the single battery 1 cavity and the shared chamber 68 are communicated, so that each single battery 1 is in a gas balance state. The sealing mechanism 5 is generally covered on the gas hole 211 by welding, bonding or injection molding, and the preferred way is to use polypropylene or other non-metal materials for injection molding. The sealing mechanism 5 of this material will not cause short circuit of the battery even if the flying debris flies out and adheres between the positive and negative electrodes during the opening process. At the same time, the process is simple and easy to process by one-time injection molding, and the yield is high.

[0068] In addition, the gas hole 211 can also be installed with a pressure relief part (such as a pressure relief film) to ensure that the single battery 1 thermal runaway flue gas breaks through the pressure relief part and is discharged. If the upper cover assembly 2 is not provided with a pressure relief part, the pressure relief part of the single battery 1 can be provided on the lower cover assembly 4.

[0069] Embodiment 2

[0070] As shown in Figure 8 and Figure 9 The single battery provided in this embodiment comprises an outer cylinder 3, an upper cover assembly 2, a lower cover assembly 4 and an electrode assembly. The upper and lower ends of the outer cylinder 3 are both open, and the upper cover assembly 2 and the lower cover assembly 4 are sealed and fixed to the upper and lower open ends of the outer cylinder 3, thereby forming a sealed battery shell, and the electrode assembly is installed in the battery shell and connected with the pole 22 in the upper cover assembly 2. The single battery 1 cavity is provided with electrolyte. In this embodiment, the upper cover assembly 2 adopts the upper cover assembly 2 in embodiment 1, and the purpose of using the upper cover assembly 2 is to ensure good sealing between the single battery 1 in the shell 6 and the external environment when assembling a large-capacity battery with a shared chamber through the hollow member of the upper cover assembly 2 in each single battery 1.

[0071] At the same time, at least one of the upper cover assembly 2 and the lower cover assembly 4 in this embodiment is provided with a sealing mechanism 5. The sealing mechanism 5 is opened under the action of electrolyte or external force to form an opening on the battery shell. The form of the sealing mechanism 5 can be referred to patent CN218525645U.

[0072] As shown in Figures 10 to 11As shown, the N single batteries 1 are arranged side by side and are arranged inside the shell 6 to form a large-capacity battery. The top of the shell 6 has 2N first through holes 67, and the part of the hollow member 23 of the upper cover assembly 2 of the single battery 1 away from the cover plate body 21 can be bent outward and sealingly welded with the corresponding peripheral area of one of the first through holes 67 on the shell 6; the pole 22 of the single battery 1 extends out of the shell 6, and the pole 22 and the hollow member 23 are kept insulated.

[0073] At least one of the top and bottom of the shell 6 is provided with a shared chamber 68, and the 2N first through holes 67 are arranged on both sides of the shared chamber 68 on the top of the shell 6; the shared chamber 68 in the large-capacity battery allows each single battery 1 to be in a uniform electrolyte environment or a gas balance environment, ensuring the uniformity of each single battery 1 and improving the performance and cycle life of the large-capacity battery.

[0074] When the gas hole 211 of the upper cover assembly 2 is provided with the sealing mechanism 5, the sealing mechanism 5 can be opened under the action of the electrolyte or external force, thereby making the gas area in the cavity of the single battery 1 and the shared chamber 68 communicate.

[0075] When the gas hole 211 on the upper cover assembly 2 is provided with a pressure relief part, the shared chamber 68 covers the pressure relief part of each single battery 1 to ensure that the smoke gas of the single battery 1 after thermal runaway breaks through the pressure relief part is discharged through the shared chamber 68.

[0076] When the sealing mechanism 5 is arranged on the lower cover assembly 4, the sealing mechanism 5 can be opened under the action of the electrolyte or external force, thereby making the electrolyte area in the cavity of the single battery 1 and the shared chamber 68 communicate, thereby making each single battery 1 in a common electrolyte system, improving the performance and cycle life of the large-capacity battery.

[0077] It should be noted that in order to ensure the operability and reliability of the welding between the shell 6 and the hollow member 23 of the large-capacity battery, since the shell 6 of the single battery 1 is made of aluminum material, the hollow member 23 and the shell 6 of the large-capacity battery are also made of aluminum material.

[0078] The shell 6 of the large-capacity battery can be formed in the following three forms:

[0079] I. As shown in FIG. 1, the shell 6 of the large-capacity battery is formed by a plurality of shells 6 arranged side by side. Figure 10As shown, the shell 6 includes a cylinder 61, a first cover plate 62 and a second cover plate 63; the top and bottom of the cylinder 61 are open, the first cover plate 62 is sealingly fixed (welded) to the top of the cylinder 61, and the second cover plate 63 is sealingly fixed (welded) to the bottom of the cylinder 61; the first cover plate 62 is provided with 2N first through holes 67; at the same time, at least one of the first cover plate 62 and the second cover plate 63 has a shared chamber 68, which can be integrally formed with the first cover plate 62 and the second cover plate 63;

[0080] II. As shown in Figure 11 , the shell 6 includes a cylinder 61, a third cover plate 65 and a fourth cover plate 66; the front and rear of the cylinder 61 are open, the third cover plate 65 is sealingly fixed (welded) to the front of the cylinder 61, and the fourth cover plate 66 is sealingly fixed (welded) to the rear of the cylinder 61; at least one of the top of the cylinder 61 and the bottom of the cylinder 61 has an integrally formed shared chamber 68;

[0081] III. As shown in Figure 12 and Figure 13 , the shell 6 includes a U-shaped shell 64, a first cover plate 62, a third cover plate 65 and a fourth cover plate 66; the top, front and rear of the U-shaped shell 64 are open, the first cover plate 62 is sealingly fixed (welded) to the top of the U-shaped shell 64, and the third cover plate 65 and the fourth cover plate 66 are sealingly fixed (welded) to the front and rear of the U-shaped shell 64, respectively. The first cover plate 62 is provided with 2N first through holes 67; at least one of the first cover plate 62 and the bottom of the U-shaped shell 64 has a shared chamber 68, which can be integrally formed with the first cover plate 62 and the U-shaped shell 64;

[0082] In the above three ways of the shell 6, the cylinder 61 and the U-shaped shell 64 can be spliced by welding, or can be integrally formed by casting or stamping, etc. In order to facilitate processing while ensuring sealing, the embodiment chooses the integrally formed mode.

[0083] Finally, in order to reduce the problem of thermal runaway caused by the local high temperature of the pole 22 of each single battery 1 on the large capacity battery, in the embodiment, the pole 22 of the same polarity on each single battery 1 of the large capacity battery is clamped with a heat transfer pipe.

Claims

1. A large capacity battery, characterized by comprising: The shell is provided with a shared chamber in communication with the inner cavities of the single batteries, and a plurality of first through holes are formed in the top of the shell for the pole columns of the single batteries to extend out of the shell; The upper cover assembly of each single battery comprises a cover plate body, two pole columns and two hollow members; The hollow members are both open at both ends, one open end is connected with the pole column hole of the cover plate body, and the other open end is connected with the shell of the large capacity battery; The two pole columns are correspondingly arranged in the two hollow members, and the pole columns of the single battery extend out of the shell through the first through holes; An insulating sleeve is arranged between the pole column and the hollow member to realize insulation between the hollow member and the pole column; A fixing portion is arranged on the insulating sleeve to realize sealed connection of the hollow member and the pole column through the insulating sleeve.

2. The high capacity battery of claim 1, wherein, The insulating sleeve and the fixing portion are integrally formed by injection molding.

3. The high capacity battery of claim 2, wherein, At least one second through hole is arranged on the side wall of the hollow member, the fixing portion is a fixing sleeve arranged outside the hollow member and an insulating connecting column embedded in the second through hole, and the two ends of the insulating connecting column are respectively connected with the fixing sleeve and the insulating sleeve.

4. The high capacity battery of claim 2, wherein, At least one second through hole is arranged on the side wall of the hollow member, the fixing portion is a columnar protrusion arranged on the outer wall of the insulating sleeve and embedded in the second through hole.

5. The high capacity battery of claim 2, wherein, A first annular groove protruding outward is arranged on the side wall of the hollow member, and the fixing portion is a first annular protrusion arranged on the outer wall of the insulating sleeve and embedded in the first annular groove.

6. The high capacity battery of any one of claims 2 to 5, wherein, A second annular groove is arranged on the outer wall of the pole column, and the fixing portion further comprises a second annular protrusion arranged on the inner wall of the insulating sleeve and embedded in the second annular groove.

7. The high capacity battery of claim 6, wherein, A gas hole is arranged on the cover plate body, the gas hole is sealed by a sealing mechanism formed by injection molding, or a gas hole is arranged on the gas hole.

8. The high capacity battery of any one of claims 1 to 5, wherein, The hollow member is integrally formed on the cover plate body.

9. The battery of claim 8, wherein, The part of the hollow member away from the cover plate body can be bent, and the bent area is used for welding and sealing with the peripheral area of the first through hole on the shell of the large capacity battery.

10. The high capacity battery of claim 8, wherein, A buffer deformation groove is arranged on the side wall of the hollow member, and a through groove for clamping a heat pipe is arranged on the pole column of the pole column.

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