Single battery and energy storage device

Abstract

The utility model belongs to the technical field of power batteries, and discloses a single battery and an energy storage device. The single battery comprises a shell, a fixed frame and a battery cell group, wherein the fixed frame is arranged in the shell; the fixed frame comprises a frame-shaped structure and at least one supporting piece, the at least one supporting piece is arranged in the frame-shaped structure at intervals in the first direction, and at least two containing cavities are formed by the at least one supporting piece and the frame-shaped structure; through grooves are formed in at least one side wall, in the first direction, of the frame-shaped structure and the supporting piece; the battery cell group comprises at least two pole groups, the at least two pole groups are arranged in the at least two accommodating cavities in a one-to-one correspondence manner, and the pole groups can be limited and propped against the cavity walls of the accommodating cavities; and the two adjacent tabs in the two adjacent pole groups are fixedly connected with each other. According to the single battery, the energy density and the structural strength of the single battery can be improved, the problems of deformation, movement and the like are avoided, and the yield of the single battery is improved; and the assembly is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a single battery and an energy storage device. Background Art

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, which has led to increasing requirements for the performance and safety of lithium-ion batteries.

[0003] Currently, lithium-ion batteries are gradually developing into longer batteries to increase their capacity and energy density. However, due to strength issues, the electrode assembly of longer cells often suffers from bending, deformation, and electrode assembly movement, resulting in reduced product yield. Furthermore, the molding process requirements for long and particularly long cells are more demanding, increasing manufacturing difficulty. During assembly and use, the tabs of long cells are prone to overlap when bent, resulting in inadequate protection. Furthermore, the tabs are bent in a C- or S-shape to achieve external electrical connection, making the connecting tabs longer and occupying more space.

[0004] Therefore, there is an urgent need for a new type of single cell battery and energy storage device to solve the above technical problems. Utility Model Content

[0005] One purpose of the present invention is to provide a single cell battery that can improve its energy density, is easy to assemble, improves its structural strength, avoids problems such as deformation and movement, and improves the yield rate of the single cell battery.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] Single battery, including:

[0008] shell;

[0009] A fixed frame, the fixed frame being disposed within the housing; the fixed frame comprising a frame structure and at least one support member, the at least one support member being spaced apart along a first direction within the frame structure and forming at least two accommodating cavities with the frame structure; at least one side wall of the frame structure along the first direction and the support member being provided with a through groove;

[0010] The battery cell group includes at least two electrode groups, and the at least two electrode groups are arranged in a one-to-one correspondence in at least two of the above-mentioned accommodating cavities, and the above-mentioned electrode groups can be limited and abutted by the cavity walls of the above-mentioned accommodating cavities; the two electrode ears close to each other in two adjacent above-mentioned electrode groups are fixedly connected.

[0011] Optionally, the through groove has a width L, 0.3 mm ≤ L ≤ 3 mm.

[0012] Optionally, the support member is provided with a protection hole along the first direction, and the connection between the pole tabs of two adjacent pole groups is arranged in the protection hole.

[0013] Optionally, the frame structure is provided with a plurality of first communication holes so that the periphery of the electrode group can be connected to the space between the fixed frame and the shell.

[0014] Optionally, the support member is provided with a hollow portion, the frame structure is provided with a second communicating hole, and the second communicating hole is connected to the hollow portion, so that the connection between the pole ear of the pole group and the space between the fixed frame and the shell are connected.

[0015] Optionally, a dimension of the frame structure along a second direction is smaller than a dimension of the pole group along the second direction to form an annular air channel, and the second direction is perpendicular to the first direction.

[0016] Optionally, the housing includes a shell and two cover structures, the shell is provided with openings at both ends along the first direction, and the cover structures are sealed and arranged at the openings in a one-to-one correspondence.

[0017] Optionally, a pole is provided on the cover structure, and the pole is electrically connected to a pole ear on either side of the battery cell group along the first direction.

[0018] Optionally, at least two explosion-proof valves are provided on the circumferential side wall of the housing at intervals along the first direction, and the at least two explosion-proof valves are provided in a one-to-one correspondence with the at least two electrode groups.

[0019] Another object of the present invention is to provide an energy storage device that can improve the structural strength and explosion-proof pressure relief capability of a single battery while increasing the battery capacity, thereby improving the safety of the energy storage device.

[0020] To achieve this purpose, the present invention adopts the following technical solutions:

[0021] An energy storage device includes the above-mentioned single battery.

[0022] Beneficial effects of the utility model:

[0023] The utility model provides a single cell and energy storage device. By sequentially connecting at least two electrode groups to form an elongated battery cell group, the energy density and space utilization rate of the single cell can be improved, and the manufacturing process is facilitated, thereby avoiding surface wrinkles, deformation, and other undesirable problems caused by an overly long battery cell group. A fixed frame is then used to fix the battery cell group, i.e., the connection between the electrode tabs of the electrode groups within the battery cell group, thereby strengthening the fixation of the battery cell group and improving the structural strength of the single cell. Even if the battery cell group is formed into an elongated battery cell, it still has good strength to improve its own deformation resistance, further avoiding surface wrinkles, deformation, layer crossover, fracture, and other undesirable problems caused by an overly long battery cell group, thereby improving the safety of the single cell. Furthermore, a portion of the fixed frame is provided with a through slot, which allows for a small range of adjustment of the width dimension of the fixed frame itself, thereby facilitating assembly between the fixed frame and the battery cell group. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an exploded view of a single battery provided in a specific embodiment of the present utility model;

[0025] Figure 2 It is a top view of a single cell provided in a specific embodiment of the utility model;

[0026] Figure 3 This is an axonometric diagram of a single battery provided by a specific embodiment of the utility model with part of the structure hidden;

[0027] Figure 4 yes Figure 3 A partial enlarged view of point A in the middle;

[0028] Figure 5 It is an axonometric view of a fixed frame provided by a specific embodiment of the utility model;

[0029] Figure 6 yes Figure 2 Cross-section at the middle BB;

[0030] Figure 7 yes Figure 6 A partial enlarged view of point C in the middle;

[0031] Figure 8 It is a front view of the protective patch provided by a specific embodiment of the utility model.

[0032] In the picture:

[0033] 10. Shell; 11. Housing; 12. Cover structure; 121. Pole; 122. Insulation board;

[0034] 20. Fixed frame; 21. Frame structure; 211. First communication hole; 212. Second communication hole; 213. First plate; 214. Second plate; 22. Support member; 221. Protective hole; 222. Hollow portion; 23. Through slot; 24. Accommodating cavity;

[0035] 30. Cell group; 31. Electrode group; 311. Tab;

[0036] 40. Explosion-proof valve; 50. Insulation film; 60. Protective sticker; 61. First incision. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0038] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0039] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper," "lower," "left," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0041] Please refer to the attached Figure 1To the attached Figure 8 The utility model introduces a single battery and an energy storage device.

[0042] It should be noted that the first direction is Figure 1 The X direction in the second direction is Figure 1 The Y direction in the third direction is Figure 1 In the Z direction, the X direction, Y direction and Z direction are perpendicular to each other.

[0043] Please refer to Figures 1 to 4 , this embodiment provides a single battery, which includes a shell 10, a fixed frame 20 and a battery cell group 30; wherein the fixed frame 20 is arranged in the shell 10; the fixed frame 20 includes a frame structure 21 and at least one support member 22, and the at least one support member 22 is arranged in the frame structure 21 at intervals along a first direction, and forms at least two accommodating cavities 24 with the frame structure 21; at least one side wall of the frame structure 21 and the support member 22 along the first direction are provided with a through groove 23, so that the fixed frame 20 can be opened and closed at least within a small range, thereby ensuring the supporting effect of the fixed frame 20; the battery cell group 30 includes at least two electrode groups 31, and the at least two electrode groups 31 are arranged in a one-to-one correspondence in at least two accommodating cavities 24, and the electrode groups 31 can be limited and abutted by the cavity wall of the accommodating cavity 24; two electrode ears 311 close to each other in two adjacent electrode groups 31 are fixedly connected.

[0044] The single cell battery of this embodiment, by sequentially connecting at least two electrode groups 31 to form an elongated cell group 30, can improve the energy density and space utilization of the single cell battery, facilitate manufacturing, and avoid surface wrinkles, deformation, and other undesirable issues caused by an overly long cell group 30. Then, the fixed frame 20 is used to fix the cell group 30, that is, the connection between the tabs 311 of the electrode groups 31 within the cell group 30, thereby strengthening the fixation of the cell group 30 and improving the structural strength of the single cell battery. Even though the cell group 30 is formed into an elongated cell, it still has good strength to improve its deformation resistance, further avoiding surface wrinkles, deformation, layer crossover, and fracture caused by an overly long cell group 30, thereby improving the safety of the single cell battery. Furthermore, a portion of the fixed frame 20 is provided with a through slot 23, which allows for a small range of adjustment of the width of the fixed frame 20 itself, thereby facilitating assembly between the fixed frame 20 and the cell group 30.

[0045] Optionally, the width of the through groove 23 is L, 0.3mm≤L≤3mm, which is a better range of the width of the through groove 23. It can not only adjust the width direction of the fixed frame 20 itself in a small range to facilitate the assembly of the fixed frame 20 and the battery cell group 30, but also ensure the insulation effect of the electrode group 31, avoid the problems of insulation failure and fixation failure caused by the through groove 23 being too large, and improve the safety of the single battery.

[0046] In some embodiments, the widths of the through slots 23 on at least one side wall of the frame structure 21 along the first direction and the through slots 23 on the support member 22 are the same or different, and can be adaptively set according to actual needs.

[0047] Please refer to Figure 5 In order to ensure the fixing effect of the fixed frame 20, in this embodiment, a through groove 23 is provided on one of the side walls of the frame structure 21 along the first direction and on the support member 22, while the through groove 23 is not provided on the other side wall of the frame structure 21 along the first direction. This ensures that the fixed frame 20 is an integral structure, thereby making it more firmly fixed to the battery cell group 30.

[0048] Optionally, the fixed frame 20 is integrally formed so as to have a certain degree of covering property, so as to better limit and fix the battery cell group 30. Specifically, the fixed frame 20 is injection molded, which has a mature process and high precision.

[0049] Please refer to Figure 4 and Figure 5 In some embodiments, the support member 22 is provided with a protection hole 221 along the first direction, and the connection between the pole ears 311 of two adjacent pole groups 31 is set in the protection hole 221. The protection hole 221 provides a penetration portion for the connection between the pole ears 311 of the two pole groups 31, so that they can be penetrated by the support member 22 and connected to each other, and at the same time can also be protected and supported by the hole wall of the protection hole 221 of the support member 22 to avoid external damage to the pole ears 311 and cause safety problems.

[0050] Specifically, the two adjacent pole groups 31 are connected in series by welding the pole ears 311. The pole ears 311 on the side of the pole group 31 facing the other pole group 31 are extended along the first direction. The support member 22 supports the connection between the pole ears 311 of the two pole groups 31, so that the pole ears 311 of the two pole groups 31 are connected by directly inserting and overlapping in a plane to avoid bending and fixing of the pole ears 311, shortening the length of the pole ears 311, improving space utilization, simplifying the processing technology, and also reducing internal resistance.

[0051] Optionally, the support member 22 is a square structure, so that the surface of the support member 22 in contact with the pole group 31 is a plane, thereby better playing the role of fixing and supporting.

[0052] However, because the fixed frame 20 partially covers the outer wall of the battery cell group 30, the electrolyte may not be able to fully contact the battery cell group 30. To address this issue, in some embodiments, the frame structure 21 is provided with a plurality of first communication holes 211, so that the outer periphery of the electrode group 31 can be connected to the space between the fixed frame 20 and the housing 10, allowing the electrolyte to fully contact the electrode group 31.

[0053] In order to better achieve sufficient contact between the electrode group 31 and the electrolyte, in some embodiments, the support member 22 is provided with a hollow portion 222, and the frame structure 21 is provided with a second connecting hole 212, and the second connecting hole 212 is connected to the hollow portion 222, so that the connection between the electrode ears 311 of two adjacent electrode groups 31 can be connected to the space between the fixed frame 20 and the shell 10, so that the connection between the adjacent electrode ears 311 can also be fully in contact with the electrolyte, thereby improving the reliability of charging and discharging of the single cell.

[0054] In some embodiments, the dimension of the frame structure 21 along the second direction is smaller than the dimension of the electrode assembly 31 along the second direction, thereby forming an annular airway. This allows for the formation of an annular airway between the frame structure 21 and the inner wall of the housing 10 to facilitate gas discharge. When thermal runaway occurs in the electrode assembly 31, gas can rapidly escape through the annular airway, releasing pressure within the cell and improving the safety of the cell. Furthermore, the first and second connecting holes 211, 212 also connect various locations of the electrode assembly 31 to the annular airway, ensuring that gas can be discharged from all locations of the electrode assembly 31, thereby preventing safety issues caused by excessive local pressure.

[0055] Specifically, the frame structure 21 includes a plurality of first plates 213 and a plurality of second plates 214, and the first plates 213 and the second plates 214 are alternately connected and arranged, and the size of the second plate 214 along the second direction is smaller than the size of the first plate 213 along the second direction, so that the gas storage area between the second plate 214 and the inner wall of the outer shell 10 is increased, and the volume of the annular air channel is increased, so that the gas on the other surfaces of the pole 121 can flow into the annular air channel through the gas storage space between the second plate 214 and the inner wall of the outer shell 10 and be discharged smoothly; and effectively increase the gas occupied space inside the outer shell 10 of the single cell, slow down the rising rate of the pressure inside the single cell, and further improve the safety of the single cell.

[0056] Please refer to Figure 1 and Figure 3In some embodiments, the housing 10 includes a shell 11 and two cover structures 12. The shell 11 has openings at both ends along the first direction, and the cover structures 12 are sealed and arranged at the openings one by one. After the battery cell group 30 and the fixed frame 20 are assembled, they can enter the shell 11 through the opening, and after post-processing, the cover structures 12 are sealed with the openings to complete the assembly of the single battery.

[0057] Specifically, a pole 121 is provided on the cover structure 12 , and the pole 121 is electrically connected to the tab 311 on either side of the battery cell group 30 along the first direction, so as to achieve external electrical connection of the single battery.

[0058] More specifically, the cover plate structure 12 on the side of the frame structure 21 where the through slot 23 is provided further includes an insulating plate 122 to further achieve insulation between the cover plate and the battery cell.

[0059] Furthermore, at least one cover plate structure 12 only retains the cover plate body and the pole 121 , without requiring other structures such as upper plastic, lower plastic, etc. This not only simplifies the structure but also reduces costs and improves space utilization.

[0060] Please refer to Figure 1 and Figure 2 In some embodiments, at least two explosion-proof valves 40 are spaced apart along the first direction on the circumferential sidewall of the housing 10. The at least two explosion-proof valves 40 are provided in a one-to-one correspondence with at least two electrode groups 31. Specifically, the explosion-proof valves 40, originally provided on the cover structure 12, are provided on the housing 11 to shorten the exhaust length of gas in the event of thermal runaway of the electrode group 31, thereby accelerating gas discharge, improving the explosion-proof and pressure-relieving effect of the single cell, and thus enhancing the safety of the single cell.

[0061] Specifically, the housing 11 is provided with a mounting hole, and the explosion-proof valve 40 is sealed and disposed on the mounting hole to achieve the installation of the explosion-proof valve 40 .

[0062] In some embodiments, the explosion-proof valve 40 is arranged on the two opposite side walls of the shell 11 along the third direction. The area of ​​the opposite side walls of the shell 11 along the third direction is smaller than the area of ​​the opposite side walls of the shell 11 along the second direction. Therefore, it occupies a smaller area and has better space utilization.

[0063] Please refer to Figures 6 to 8 Optionally, a protective sticker 60 is provided at the mounting hole to separate and protect the explosion-proof valve 40 and the battery cell group 30 to prevent the explosion-proof valve 40 from damaging the battery cell group 30 during installation.

[0064] Specifically, a first slit 61 is provided on the protective patch 60 to weaken the structural strength of the position corresponding to the protective patch 60 and the explosion-proof valve 40. When the pressure in the shell 10 is too high, the gas can directly break through the first slit 61 and spray out from the explosion-proof valve 40.

[0065] Please refer back to Figure 1 In some embodiments, the single battery further includes an insulating film 50 , which is coated on the periphery of the battery cell group 30 and the fixed frame 20 to provide insulation protection between the housing 11 and the battery cell group 30 .

[0066] Optionally, a second slit is provided at the position of the insulating film 50 corresponding to the explosion-proof valve 40. The function of the second slit is the same as that of the first slit 61, both of which avoid blocking the exhaust and opening of the explosion-proof valve 40, making the exhaust and opening of the explosion-proof valve 40 smoother.

[0067] This embodiment also provides an energy storage device comprising the single cell battery described in any of the above-mentioned solutions. The energy storage device is a structure, such as a battery module or battery pack, that incorporates the single cell battery and provides both power storage and external power supply. By utilizing the above-mentioned single cell battery, the energy storage device not only increases capacity and energy density but also improves structural strength and safety.

[0068] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A single cell battery, characterized in that: include: shell; a fixed frame, the fixed frame being disposed within the housing; the fixed frame comprising a frame-shaped structure and at least one supporting member, the at least one supporting member being spaced apart along a first direction within the frame-shaped structure and forming at least two accommodating cavities with the frame-shaped structure; at least one side wall of the frame-shaped structure along the first direction and the supporting member being provided with a through slot; A battery cell group, the battery cell group includes at least two electrode groups, the at least two electrode groups are arranged in a one-to-one correspondence in at least two of the accommodating cavities, and the electrode groups can be limited and abutted by the cavity walls of the accommodating cavities; the two electrode ears close to each other in two adjacent electrode groups are fixedly connected.

2. The single cell according to claim 1, characterized in that: The width of the through groove is L, 0.3mm≤L≤3mm.

3. The single cell according to claim 1, characterized in that: The support member is provided with a protection hole along the first direction, and the connection between the pole ears of two adjacent pole groups is arranged in the protection hole.

4. The single cell according to claim 1, characterized in that: The frame structure is provided with a plurality of first communication holes so that the periphery of the electrode group can be connected to the space between the fixed frame and the shell.

5. The single cell according to claim 4, characterized in that: The support member is provided with a hollow portion, and the frame structure is provided with a second communicating hole, which is connected to the hollow portion so that the connection between the tabs of two adjacent electrode groups can be connected to the space between the fixed frame and the shell.

6. The single cell according to claim 1, characterized in that: The size of the frame structure along the second direction is smaller than the size of the pole group along the second direction to form an annular air channel, and the second direction is perpendicular to the first direction.

7. The single cell according to claim 1, characterized in that: The housing includes a shell and two cover structures. The shell is provided with openings at both ends along the first direction. The cover structures are sealed and arranged at the openings in a one-to-one correspondence.

8. The single cell according to claim 7, characterized in that: The cover structure is provided with a pole, and the pole is electrically connected to the pole lugs on either side of the battery cell group along the first direction.

9. The single cell according to any one of claims 1 to 8, characterized in that: At least two explosion-proof valves are provided on the circumferential side wall of the housing at intervals along the first direction, and the at least two explosion-proof valves are provided in a one-to-one correspondence with the at least two electrode groups.

10. An energy storage device, characterized in that The invention comprises a single cell according to any one of claims 1 to 9.

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