Single battery and battery

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a single battery and a battery, the single battery comprises a shell, the shell comprises a bottom wall and a side wall, and the bottom wall and the side wall enclose a cavity with an opening at the upper end; the cover plate assembly is mounted on the shell and seals the opening; the naked battery cell is accommodated in the cavity; the anti-explosion valve is arranged on the bottom wall; the bottom wall is provided with a first area and a second area, the first area is closer to the naked battery cell than the second area, the projection of the second area is within the projection range of the first area along the height direction of the single battery, and the anti-explosion valve is arranged in the second area. According to the utility model, the first area and the second area which are different in height are arranged at the bottom of the shell, the naked battery cell is supported in the higher first area, and the anti-explosion valve is arranged in the lower second area, so that an extra exhaust space is formed between the naked battery cell and the anti-explosion valve, airflow and heat flow can be smoothly exhausted when the battery is in thermal runaway, and the safety of the battery is ensured. The anti-explosion valve is prevented from being blocked.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically relating to a single cell battery and a battery. Background Technology

[0002] Prismatic batteries ensure safety through the timely opening of an explosion-proof valve. When a cell experiences thermal runaway, a large amount of gas and heat is generated instantaneously, requiring immediate release through the explosion-proof valve. Otherwise, a significant amount of energy will accumulate inside the casing, potentially causing a battery explosion. To protect vehicle occupants, some batteries place the explosion-proof valve at the bottom of the casing, allowing air and heat to be ejected downwards during thermal runaway. However, in existing prismatic batteries, the bare cells are tightly fitted to the bottom casing, resulting in insufficient venting space and potential blockage of the explosion-proof valve, leading to the spread of heat within the battery. Utility Model Content

[0003] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a single cell battery and battery that can reduce the risk of explosion-proof valve blockage and improve safety.

[0004] To achieve the above and other related objectives, this utility model provides a single-cell battery, comprising:

[0005] A housing, the housing comprising a bottom wall and side walls, the bottom wall and side walls forming a cavity having an opening at the upper end;

[0006] A cover plate assembly is installed on the housing and closes the opening;

[0007] The bare battery cell is housed within the cavity;

[0008] An explosion-proof valve is installed on the bottom wall;

[0009] The bottom wall includes a first region and a second region. The first region is closer to the bare cell than the second region. Along the height direction of the single cell, the projection of the second region is within the projection range of the first region. The explosion-proof valve is disposed in the second region.

[0010] In an optional embodiment of the present invention, the first region includes an inclined surface extending from the bottom edge of the sidewall toward the second region.

[0011] In an optional embodiment of this utility model, a pad is provided between the bare battery cell and the first region, one side of the pad abuts against the bottom surface of the bare battery cell, and the bottom surface of the pad abuts against the inner surface of the first region.

[0012] In an optional embodiment of this utility model, the pad is disposed on both ends of the first region near the side wall, and the length of the pad on one side in the first direction is 1% to 5% of the length of the bottom wall in the first direction, wherein the first direction is the length direction of the single battery cell.

[0013] In an optional embodiment of this invention, the pad is made of an elastic material.

[0014] In an optional embodiment of this utility model, the second region is located in the middle of the bottom wall, and the first region is arranged around the second region.

[0015] In an optional embodiment of this utility model, the volume of the cavity between the bare cell and the bottom wall is V ml, and the capacity of the single battery cell is C amp-hours, wherein:

[0016] V = a × C;

[0017] The value of a is a constant, and the value of a ranges from 0.1 to 0.3.

[0018] In an optional embodiment of this utility model, the projected area of ​​the second region in the height direction of the single cell is 20% to 60% of the projected area of ​​the bottom wall in the height direction of the single cell.

[0019] In an optional embodiment of this utility model, the projected area of ​​the explosion-proof valve in the height direction of the single battery is 10% to 60% of the projected area of ​​the second region in the height direction of the single battery.

[0020] To achieve the above and other related objectives, this utility model also provides a battery, comprising:

[0021] The aforementioned single-cell battery; and

[0022] A base plate is provided to support the individual battery cell. The base plate is provided with a through hole corresponding to the individual battery cell. The projected area of ​​the through hole in the height direction of the individual battery cell is smaller than the projected area of ​​the bottom wall of the individual battery cell in the height direction of the individual battery cell. At least a second region of the bottom wall protrudes through the through hole to the bottom surface of the base plate.

[0023] The technical advantages of this invention are as follows: By setting a first region and a second region at different heights at the bottom of the casing, the bare battery cell is supported in the higher first region, and the explosion-proof valve is placed in the lower second region. This creates an additional venting space between the bare battery cell and the explosion-proof valve, ensuring smooth airflow and heat discharge during battery thermal runaway and preventing blockage of the explosion-proof valve. This invention can directly utilize the structure of the bottom wall itself to separate the bare battery cell from the explosion-proof valve, simplifying the internal battery structure, reducing assembly complexity, decreasing the number of parts, optimizing the manufacturing process, and improving production efficiency and battery reliability. Furthermore, the first region can serve not only as a structure supporting the bare battery cell but also as a structure supporting the entire single battery cell. When the single battery cell is mounted on the battery base plate, through holes can be provided on the base plate, and the first region can be supported at the edge of the through holes. This allows the second region to protrude below the top surface of the base plate, thereby avoiding the aforementioned additional venting space occupying internal battery volume and increasing battery energy density. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of a single battery provided in an embodiment of this utility model;

[0025] Figure 2 This is a bottom view of a single battery provided in an embodiment of this utility model;

[0026] Figure 3 yes Figure 2 AA section view;

[0027] Figure 4 yes Figure 2 BB section view;

[0028] Figure 5 This is a bottom wall annotation diagram provided in an embodiment of this utility model;

[0029] Figure 6 This is a partial cross-sectional view of the battery provided in an embodiment of this utility model;

[0030] Figure 7 This is a cross-sectional view of a single cell provided in an alternative embodiment of the present invention;

[0031] Figure 8 This is a cross-sectional view of a single cell provided in another alternative embodiment of this utility model. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0033] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0034] The single-cell battery described in this utility model specifically refers to a prismatic battery, which includes a casing 10, a bare cell 40, an electrolyte, and an explosion-proof valve 30. The casing 10 constitutes the outer shell of the battery, used to protect the internal structure and prevent leakage and the influence of the external environment. The bare cell 40 includes an anode, a cathode, and a separator, and is the core part of the battery. The electrolyte is used to conduct lithium ions and provide a medium for electrochemical reactions. The explosion-proof valve 30 is installed on the casing 10. When the internal pressure of the battery is too high, the explosion-proof valve 30 will automatically open to release the pressure and prevent the battery from exploding. To protect the safety of occupants, the explosion-proof valve 30 can be located at the bottom of the housing 10, allowing airflow and heat to be ejected downwards during thermal runaway. However, the bare cells 40 of the prismatic battery are in close contact with the bottom housing 10, resulting in insufficient venting space at the bottom, which can easily clog the explosion-proof valve 30 and cause thermal propagation. Therefore, this invention features a downwardly recessed cavity at the bottom of the housing 10, supporting the bare cells 40 above the cavity. The explosion-proof valve 30 is located at the bottom of the cavity, providing additional venting space between the bare cells 40 and the explosion-proof valve 30, ensuring that the explosion-proof valve 30 can open promptly in the event of thermal runaway. The technical solution of this invention will be described in detail below with reference to specific embodiments.

[0035] Please see Figure 1-6As shown, in the single-cell battery provided by this utility model, the housing 10 includes a bottom wall 11 and a side wall 12, which together form a cavity with an opening at the upper end. The housing 10 can be an integral structure made by deep hole stamping or welded from multiple metal plates. A cover plate assembly 20 is provided above the housing 10, which is installed on the housing 10 and closes the opening. Further, the cover plate assembly 20 may, for example, be provided with a positive terminal 21 and a negative terminal 22, which are electrically connected to the positive and negative tabs of the bare cell 40, respectively. The positive terminal 21 and the negative terminal 22 are provided in the single-cell battery. The top section prevents electrolyte deposition and corrosion of the terminals, thus preventing internal short circuits in the battery. A bare cell 40 is housed within the cavity, and an insulating film 41 is provided on the surface of the bare cell 40. An explosion-proof valve 30 is disposed on the bottom wall 11. The bottom wall 11 includes a first region 111 and a second region 112. The first region 111 is closer to the bare cell 40 than the second region 112. Along the height direction of the single battery cell, the projection of the second region 112 falls within the projection range of the first region 111. The bare cell 40 is supported in the first region 111, and the explosion-proof valve 30 is disposed in the second region 112.

[0036] This invention utilizes a first region 111 and a second region 112 at different heights at the bottom of the casing 10. The bare battery cell 40 is supported in the higher first region 111, while the explosion-proof valve 30 is positioned in the lower second region 112. This creates an additional venting space between the bare battery cell 40 and the explosion-proof valve 30, ensuring smooth airflow and heat discharge during battery thermal runaway and preventing blockage of the explosion-proof valve 30. This invention directly utilizes the structure of the bottom wall 11 itself to separate the bare battery cell 40 from the explosion-proof valve 30, simplifying the internal battery structure, reducing assembly complexity, decreasing the number of parts, optimizing the manufacturing process, and improving production efficiency and battery reliability. Furthermore, the first region 111 can serve not only as a structure supporting the bare battery cell 40 but also as a structure supporting the entire single battery cell, such as… Figure 6 As shown, when a single cell is mounted on the base plate 60 of the battery, a through hole 61 can be provided on the base plate 60 to support the first region 111 on the edge of the through hole 61. This allows the second region 112 to protrude below the top surface of the base plate 60, thereby avoiding the aforementioned additional venting space from occupying the internal volume of the battery and improving the energy density of the battery.

[0037] Please see Figure 2As shown, in an optional embodiment of this utility model, the first region 111 is disposed adjacent to the bottom edge of the sidewall 12. The first region 111 is directly adjacent to the sidewall 12, which can provide stable support for the bottom edge area of ​​the bare cell 40, enhancing the integrity and reliability of the battery structure; the first region 111 is disposed adjacent to the sidewall 12, further avoiding the second region 112 where the explosion-proof valve 30 is located, ensuring that the exhaust space is more unobstructed and avoiding obstruction of airflow and heat flow during thermal runaway; the first region 111 is disposed adjacent to the sidewall 12 to facilitate cooperation with the battery base plate 60. When the battery is installed on the battery base plate 60, the first region 111 can be stably supported on the edge of the through hole 61 of the base plate 60, so that the second region 112 protrudes below the base plate 60, avoiding additional exhaust space occupying the internal volume of the battery, thereby improving the energy density and space utilization of the battery.

[0038] Please see Figure 3 , 4 As shown, in an optional embodiment of this utility model, the first region 111 includes a slope extending from the bottom edge of the sidewall 12 toward the second region 112. This design facilitates the manufacture of the housing 10 by a one-piece stamping process because the transition structure of the slope reduces stress concentration during stamping, lowers the forming difficulty, and improves material utilization and production efficiency; furthermore, the slope design also enhances the structural strength of the housing 10. It should be understood that the structural form of the bottom wall 11 is not unique, for example in... Figure 7 , 8 In the embodiment shown, the first region 111 can also be set as a plane, and the transition between the first region 111 and the second region 112 can be achieved by a slope or a vertical surface.

[0039] Please see Figure 3 , 4 As shown, in an optional embodiment of this utility model, a pad 50 is provided between the bare cell 40 and the first region 111. One side of the pad 50 abuts against the bottom surface of the bare cell 40, and the bottom surface of the pad 50 abuts against the inner surface of the first region 111. This design further optimizes the support effect of the bare cell 40, ensuring that the position of the bare cell 40 within the housing 10 is more stable and avoiding displacement caused by vibration or impact. At the same time, the design of the pad 50 can evenly distribute the weight of the bare cell 40, reducing local pressure on the first region 111 and enhancing the durability of the battery structure. In addition, the adaptability design of the pad 50 facilitates assembly, improves production efficiency, and allows the thickness of the pad 50 to be adjusted according to requirements, flexibly adapting to bare cells 40 of different specifications, enhancing the versatility and practicality of the solution. It should be understood that in some other embodiments, for example when the first region 111 is... Figure 7 , 8 When the shape is planar as shown, the pad 50 may not be required.

[0040] Please see Figure 3 , 4 As shown, in an optional embodiment of this utility model, the pad 50 is disposed on both ends of the first region 111 near the side wall 12. This design can effectively avoid the pad 50 obstructing the airflow during thermal runaway, ensuring that airflow and heat flow can smoothly flow from the bottom of the bare cell 40 to the second region 112 where the explosion-proof valve 30 is located, thereby ensuring the unobstructed exhaust channel; at the same time, the placement of the pad 50 near the side wall 12 provides stable support for the bare cell 40 and minimizes the occupation of the pad 50 in the exhaust space, further optimizing the internal space utilization of the battery and improving the battery safety and exhaust efficiency during thermal runaway.

[0041] In an optional embodiment of this utility model, the pad 50 is made of an elastic material, including but not limited to styrene-butadiene rubber, silicone, fluororubber, etc. This design can effectively absorb the mechanical stress generated by external vibration and impact on the battery, reducing the direct impact on the bare cell 40 and the casing 10, thereby improving the structural stability and durability of the battery; at the same time, the flexibility of the elastic material allows the pad 50 to better fit the contact surface between the bare cell 40 and the first region 111, ensuring the uniformity and stability of the support; in addition, the buffering effect of the elastic material can also reduce the risk of damage to the internal components of the battery caused by mechanical stress, further improving the safety and service life of the battery.

[0042] Please see Figure 2 As shown, in an optional embodiment of this utility model, the second region 112 is located in the middle of the bottom wall 11, and the first region 111 is arranged around the second region 112. This design allows the explosion-proof valve 30 to be located in the center, ensuring that in the event of thermal runaway, airflow and heat flow are evenly diffused from the bottom of the bare cell 40 to the surrounding areas and concentrated for discharge through the explosion-proof valve 30, thereby improving exhaust efficiency. At the same time, the surrounding first region 111 provides more uniform and stable support for the bare cell 40, enhancing the overall integrity and impact resistance of the battery structure. In addition, this layout optimizes the spatial distribution at the bottom of the housing 10, facilitating cooperation with the through-hole 61 design of the battery base plate 60, avoiding additional exhaust space from occupying the internal volume of the battery, and further improving the energy density and space utilization of the battery.

[0043] In an optional embodiment of this utility model, the volume of the cavity between the bare cell 40 and the bottom wall 11 is V ml, and the capacity of the single battery cell is C amp-hours, wherein:

[0044] V = a × C;

[0045] The value of a is a constant, and the value of a ranges from 0.1 to 0.3.

[0046] This invention scientifically quantifies the relationship between venting space and battery capacity, ensuring sufficient venting space for different battery capacities and avoiding the risk of blockage of the explosion-proof valve 30 or thermal runaway due to insufficient venting space. At the same time, the reasonable range of α values ​​balances venting efficiency and battery energy density, ensuring battery safety while avoiding excessive occupation of internal battery space. This improves battery safety performance while optimizing the overall energy density and space utilization of the battery.

[0047] Please see Figure 4 , 5 As shown, in an optional embodiment of this invention, the projected area of ​​the second region 112 in the height direction of the single battery cell is 20% to 60% of the projected area of ​​the bottom wall 11 in the height direction of the single battery cell. This invention, by rationally allocating the area of ​​the second region 112, ensures that the area where the explosion-proof valve 30 is located has sufficient venting capacity, while avoiding the second region 112 being too large, which could lead to reduced structural strength or energy density loss at the bottom of the battery. Furthermore, the 20% to 60% ratio balances venting efficiency with the stability of the overall battery structure, ensuring efficient exhaust of airflow and heat during thermal runaway while maintaining the mechanical strength of the bottom of the casing 10 and the space utilization of the battery, thus achieving an optimized balance between safety and performance.

[0048] Please see Figure 4 , 5 As shown, in a specific embodiment, taking a flat square-shell battery as an example, when the length L1 of the bottom wall 11 is 300mm and the width L2 of the bottom wall 11 is 28mm, and the battery capacity is 100Ah, the dimensions of the bottom wall 11 are as follows: the bottom wall 11 can be set as a frustum shape, the lateral distance L3 from the edge of the second region 112 to the large surface of the cell is preferably 1-3mm, more preferably 1-2mm, the lateral distance L4 from the edge of the second region 112 to the narrow side of the cell is preferably 60-110mm, more preferably 90-110mm; the sinking height H1 of the second region 112 is preferably 3-5mm, more preferably 3-4mm.

[0049] It should be noted that the above-mentioned dimensions of the bottom wall 11 are not unique. For example, when the volume or aspect ratio of the battery cell changes, the above-mentioned dimensions can also be adjusted accordingly. As long as the numerical relationship between the cavity volume and the battery capacity can be satisfied, they should be applicable to this utility model.

[0050] Please see Figure 5As shown, in an optional embodiment of this invention, the projected area of ​​the explosion-proof valve 30 in the height direction of the single battery cell is 10% to 60% of the projected area of ​​the second region 112 in the height direction of the single battery cell. This invention, by reasonably controlling the size of the explosion-proof valve 30, ensures that it can quickly and effectively release pressure when the internal pressure of the battery is too high, while avoiding the reduction in structural strength of the bottom of the casing 10 or loss of battery energy density due to an excessively large area of ​​the explosion-proof valve 30. The 10% to 60% range balances venting efficiency and structural stability, ensuring smooth exhaust of airflow and heat flow during thermal runaway while maintaining the mechanical strength of the bottom of the casing 10 and the overall performance of the battery, thus achieving an optimized balance between safety, venting efficiency, and energy density.

[0051] exist Figure 5 In the illustrated embodiment, the explosion-proof valve 30 has the following dimensions: the pressure relief area of ​​the explosion-proof valve 30 is preferably 600–1000 mm². 2 More preferably 600-800mm 2 The distance L5 from the edge of the explosion-proof valve 30 to the second region 112 along its length is preferably 0-2 mm, more preferably 0-1 mm. The distance L6 from the edge of the explosion-proof valve 30 to the second region 112 along its width is preferably 5-15 mm, more preferably 10-15 mm. Similarly, the above dimensions of the explosion-proof valve 30 are not unique. When parameters such as the volume or aspect ratio of the battery cell change, the above dimensions can also be adjusted accordingly.

[0052] Please see Figure 3 As shown, in an optional embodiment of this utility model, the pads 50 are disposed at least at both ends of the bottom wall 11 along a first direction, where the first direction is the length direction of the housing 10. In a specific embodiment, the pads 50 may be, for example, an annular structure disposed along the edge of the bottom wall 11. This design provides more uniform and stable support for the bare cell 40, enhancing the overall integrity of the battery structure and its resistance to vibration and impact. Simultaneously, the arrangement of the pads 50 along the length direction or in an annular pattern avoids concentrated occupation in the exhaust space, ensuring that airflow and heat flow smoothly from the bottom of the bare cell 40 to the explosion-proof valve 30 during thermal runaway, thus ensuring unobstructed exhaust channels. Furthermore, this layout simplifies the installation process of the pads 50, improves production efficiency, and allows for flexible adjustment of the pad distribution according to requirements, further enhancing the versatility and practicality of the solution.

[0053] Please see Figure 3As shown, in an optional embodiment of this invention, the length of the pad 50 on one side in the first direction is 1% to 5% of the length of the bottom wall 11 in the first direction. This invention, by reasonably controlling the size of the pad 50, provides necessary support for the bare battery cell 40, ensuring its stability, while minimizing the space occupied by the pad 50, thus avoiding obstruction of airflow and heat flow during thermal runaway. Simultaneously, the 1% to 5% proportion balances support effectiveness and space utilization, ensuring the strength and durability of the battery structure while optimizing the internal spatial distribution of the battery, thereby achieving a good balance between support performance, venting efficiency, and energy density.

[0054] exist Figure 3 In the illustrated embodiment, the height H2 of the pad 50 is preferably 1-2 mm, more preferably 1-1.5 mm, and the length L7 of the pad 50 in the first direction is preferably 5-8 mm, more preferably 5-6 mm. Similarly, the dimensions of the pad 50 are not unique; when parameters such as the volume or aspect ratio of the battery cell change, the dimensions can be adjusted accordingly.

[0055] Please see Figure 6 As shown, this utility model also provides a battery, including the aforementioned single cell and a base plate 60. The base plate 60 supports the single cell, and has a through hole 61 corresponding to the single cell. The projected area of ​​the through hole 61 in the height direction of the single cell is smaller than the projected area of ​​the bottom wall 11 of the single cell in the height direction. At least a second region 112 of the bottom wall 11 protrudes below the top surface of the base plate 60 through the through hole 61. By protruding the second region 112 below the base plate 60, the additional venting space is avoided from occupying the internal volume of the battery, thereby improving the energy density and space utilization of the battery. Secondly, the design of the through hole 61 allows the first region 111 to be stably supported on the edge of the base plate 60, enhancing the overall structural stability and impact resistance of the battery. Finally, this layout ensures that airflow and heat flow can be smoothly discharged through the explosion-proof valve 30 during thermal runaway, while reducing the impact on other components inside the battery, thus improving the safety and reliability of the battery.

[0056] In summary, this invention provides a first region 111 and a second region 112 at different heights at the bottom of the casing 10. The bare battery cell 40 is supported in the higher first region 111, and the explosion-proof valve 30 is placed in the lower second region 112. This creates an additional venting space between the bare battery cell 40 and the explosion-proof valve 30, ensuring that airflow and heat can be smoothly discharged during battery thermal runaway and preventing blockage of the explosion-proof valve 30. This invention can directly utilize the structure of the bottom wall 11 itself to separate the bare battery cell 40 from the explosion-proof valve 30, simplifying the internal structure of the battery, reducing assembly complexity, reducing the number of parts, optimizing the manufacturing process, and improving production efficiency and battery reliability. In addition, the first region 111 can not only serve as a structure to support the bare cell 40, but also as a structure to support the entire single cell. When the single cell is installed on the base plate 60 of the battery, a through hole 61 can be provided on the base plate 60, and the first region 111 can be supported on the edge of the through hole 61. This allows the second region 112 to protrude below the top surface of the base plate 60, thereby avoiding the aforementioned additional venting space from occupying the internal volume of the battery and improving the energy density of the battery.

[0057] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

[0058] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

Claims

1. A single-cell battery, characterized in that, include: The housing (10) includes a bottom wall (11) and a side wall (12), which together form a cavity with an opening at the top. A cover assembly (20) is installed on the housing (10) and closes the opening; The bare battery cell (40) is housed within the cavity; An explosion-proof valve (30) is installed on the bottom wall (11); The bottom wall (11) includes a first region (111) and a second region (112). The first region (111) is closer to the bare cell (40) than the second region (112). Along the height direction of the single cell, the projection of the second region (112) is within the projection range of the first region (111). The explosion-proof valve (30) is disposed in the second region (112).

2. The single-cell battery according to claim 1, characterized in that, The first region (111) includes a slope extending from the bottom edge of the sidewall (12) toward the second region (112).

3. The single-cell battery according to claim 1, characterized in that, A pad (50) is provided between the bare cell (40) and the first region (111). One side of the pad (50) abuts against the bottom surface of the bare cell (40), and the bottom surface of the pad (50) abuts against the inner surface of the first region (111).

4. The single-cell battery according to claim 3, characterized in that, The pad (50) is disposed on the first region (111) near both ends of the side wall (12). The length of the pad (50) on one side in the first direction is 1% to 5% of the length of the bottom wall (11) in the first direction. The first direction is the length direction of the single cell.

5. The single-cell battery according to claim 4, characterized in that, The pad (50) is made of an elastic material.

6. The single-cell battery according to claim 2, characterized in that, The second region (112) is located in the middle of the bottom wall (11), and the first region (111) is arranged around the second region (112).

7. The single-cell battery according to claim 1, characterized in that, The volume of the cavity between the bare cell (40) and the bottom wall (11) is V ml, and the capacity of the single battery cell is C amp-hours, wherein: V = a × C; The value of a is a constant, and the value of a ranges from 0.1 to 0.

3.

8. The single-cell battery according to claim 1, characterized in that, The projected area of ​​the second region (112) in the height direction of the single cell is 20% to 60% of the projected area of ​​the bottom wall (11) in the height direction of the single cell.

9. The single-cell battery according to claim 1, characterized in that, The projected area of ​​the explosion-proof valve (30) in the height direction of the single cell is 10% to 60% of the projected area of ​​the second region (112) in the height direction of the single cell.

10. A battery, characterized in that, include: The single-cell battery according to any one of claims 1 to 9; as well as A base plate (60) is provided for supporting the single battery cell. The base plate (60) is provided with a through hole (61) corresponding to the single battery cell. The projected area of ​​the through hole (61) in the height direction of the single battery cell is smaller than the projected area of ​​the bottom wall (11) of the single battery cell in the height direction of the single battery cell. At least a second region (112) of the bottom wall (11) protrudes through the through hole (61) to the bottom surface of the base plate (60).

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