Single battery and electric device

Abstract

The application belongs to the technical field of batteries, and discloses a single battery and an electric device. The single battery comprises a battery shell, at least one battery cover plate, a battery pole group and a first explosion-proof valve. The battery shell is provided with a mounting port at at least one end in a first direction. The battery cover plate is correspondingly mounted on the mounting port. The battery pole group is mounted in the battery shell. The first explosion-proof valve is arranged on the outer wall of any end of the battery shell in a third direction. The end of the battery cover plate away from the battery pole group in the first direction is provided with a mounting groove, and a pole assembly of the battery cover plate is arranged in the mounting groove. At least one end of the battery pole group in the first direction is provided with a groove part, the groove part is provided with a pole group tab, and the pole assembly is correspondingly welded with the pole group tab. The single battery can improve the space utilization rate of the single battery after being assembled into a group, has higher mechanical strength, improved safety and reliability, is more stable during assembly, and can improve the assembly reliability.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a single-cell battery and an electrical device thereof. Background Technology

[0002] As the core power source for electric vehicles and energy storage systems, lithium-ion batteries face increasingly stringent requirements regarding safety, energy density, and fast-charging performance. The structural design of lithium-ion cells, as key safety components of battery packs, directly impacts overall battery performance.

[0003] Current mainstream battery cell structures have several technical limitations:

[0004] The cover plates generally adopt a flat plate structure. The protruding rivet blocks and upper plastic components occupy external space during module assembly, significantly reducing the pack volume assembly rate. Moreover, they are prone to structural damage due to bumps during transportation and assembly, leading to poor appearance and safety risks. The ends of the electrode groups are all designed with a planar structure, which cannot adapt to the internal space of irregularly shaped cell shells, restricting the optimization of effective capacity and volume assembly ratio. The unbalanced support structure between the cover plate and the electrode group can easily cause electrode damage or displacement due to uneven force during the assembly of the negative electrode group into the shell, creating a short circuit hazard. The loose layout of the space under the cover plate results in low internal space utilization, limiting the improvement of energy density per unit volume. In addition, the existing cover plate thickness is too thin, making it easy to deform under external force, leading to sealing failure or structural damage, and failing to meet mechanical strength requirements.

[0005] Of particular note is that the above structural design reveals significant defects in high-capacity and high-rate fast charging scenarios: the planar electrode assembly and cover plate obstruct the design of low-resistivity current path, exacerbate the problem of uneven heat distribution, and seriously restrict the thermal safety and cycle life during high-current charging and discharging.

[0006] In summary, existing cell structures suffer from systemic bottlenecks in terms of space utilization, assembly reliability, mechanical strength, and high-power performance. Therefore, there is an urgent need to provide a new type of single-cell battery and electrical device to solve the aforementioned technical problems in the existing technology. Summary of the Invention

[0007] One objective of this invention is to provide a single-cell battery that can improve the space utilization rate after the single-cell batteries are assembled into a group, while having higher mechanical strength, improved safety and reliability, and greater stability during assembly, thereby improving assembly reliability.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] The single battery includes a battery casing, at least one battery cover, a battery electrode assembly, and a first explosion-proof valve. The battery casing has a mounting opening at at least one end along a first direction; the battery cover is correspondingly mounted to the mounting opening; the battery electrode assembly is fitted inside the battery casing; the first explosion-proof valve is located on the outer wall of any end of the battery casing along a third direction; wherein, the battery cover has a mounting groove at the end along the first direction away from the battery electrode assembly, and a terminal post assembly of the battery cover is disposed in the mounting groove; the battery electrode assembly has a groove at at least one end along the first direction, and a terminal tab of the battery electrode assembly is disposed in the groove, with the terminal post assembly welded to the terminal tab.

[0010] Optionally, one of the outer walls at both ends of the battery electrode assembly along the second direction is provided with a first protrusion, and the other is provided with two second protrusions spaced apart along the third direction. The first protrusion can be sandwiched between the two second protrusions of an adjacent single cell. The size of the first protrusion along the second direction is not greater than the size of the second protrusion along the second direction.

[0011] Optionally, the first protrusion protrudes from the groove along the first direction.

[0012] Optionally, the projection of the mounting groove along the first direction onto the battery electrode assembly at least covers the groove portion and the first protrusion portion.

[0013] Optionally, the dimension of the groove portion along the first direction is F1, and the dimension of the portion of the first protrusion portion protruding from the groove portion along the first direction is F2, where 5mm≤F2≤10mm and 8mm≤F1-F2≤30mm.

[0014] Optionally, the above-mentioned mounting groove is provided with a second explosion-proof valve, which is positioned opposite the above-mentioned first protrusion.

[0015] Optionally, the dimension of the battery electrode assembly along the third direction is A, the dimension of the groove portion along the third direction is L1, the dimension of the first protrusion portion along the third direction is L2, the dimension of the second protrusion portion along the third direction is L3, 0.6≤L1 / A≤0.85, 0.55≤L2 / L3≤1.

[0016] Optionally, the portion of the battery electrode assembly having the second protrusion has a dimension of E1 along the second direction, the groove has a dimension of E2 along the second direction, the second protrusion has a dimension of H1 along the second direction, and the first protrusion has a dimension of H2 along the second direction, where 0.6≤E2 / E1≤0.8 and 0.2mm≤H1-H2≤0.5mm.

[0017] Optionally, the maximum dimension of the battery electrode assembly along the second direction is B, and the minimum dimension of the battery electrode assembly along the second direction is W, where 45mm≤B≤118mm and 18mm≤W≤80mm.

[0018] Another object of the present invention is to provide an electrical device comprising a single battery as described in any of the above embodiments.

[0019] Beneficial effects:

[0020] In this invention, the battery casing of a single battery cell has a battery cover plate at one end of the mounting opening along a first direction. The terminal post assembly of the battery cover plate is welded to the battery electrode group inside the battery casing. The battery cover plate also has a mounting groove, and the battery electrode group has a corresponding groove. The electrode tabs are located in the grooves, and the terminal post assembly is located in the mounting groove. This allows the terminal post assembly to sink into the battery cover plate, becoming concealed within the mounting groove, forming a three-dimensional protective barrier and completely eliminating the risk of damage to the welding points during transportation and assembly. Furthermore, the sinking layout of the mounting groove and the terminal post assembly significantly reduces the overall thickness of the battery cover plate, further compressing the space occupied by the single battery cell in a third direction, directly increasing the volumetric packing ratio. It can also match irregularly shaped electrode groups obtained through winding / stacking processes, maximizing the use of the internal space of the single battery cell and overcoming the limitations of a flat cover plate on the shape of the battery electrode group, creating physical conditions for increasing battery capacity and energy density. Additionally, the explosion-proof valve is located on one side wall of the battery casing along a third direction, i.e., on a small surface of the battery casing, with a shorter venting and depressurization path, improving the safety performance of the single battery cell. This single cell can improve the space utilization rate after the single cells are assembled into a group. At the same time, it has higher mechanical strength, improved safety and reliability, and is more stable during the assembly process, which can improve the assembly reliability. Attached Figure Description

[0021] Figure 1 This is an isometric view of a single battery cell provided in a specific embodiment of the present invention;

[0022] Figure 2 This is an exploded view of a single battery cell provided in a specific embodiment of the present invention;

[0023] Figure 3 This is a side view of a single battery cell assembled into a group according to a specific embodiment of the present invention;

[0024] Figure 4 This is a partial enlarged view of the longitudinal section of a single battery cell located at the battery cover plate, provided in a specific embodiment of the present invention;

[0025] Figure 5 This is a front view of the battery electrode assembly located at any end along the second direction, according to a specific embodiment of the present invention.

[0026] Figure 6 This is a side view of the battery electrode assembly provided in a specific embodiment of the present invention.

[0027] In the picture:

[0028] 100. Battery casing; 110. Mounting port; 120. First boss; 130. Second boss;

[0029] 200. Battery cover; 210. Mounting groove; 211. Terminal assembly;

[0030] 300. Battery electrode assembly; 310. Recessed portion; 311. Electrode assembly tab; 321. First protrusion; 322. Second protrusion;

[0031] 400, First explosion-proof valve; 410, Second explosion-proof valve. Detailed Implementation

[0032] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0033] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. In the description of this embodiment, unless otherwise specified, "multiple" specifically refers to two or more.

[0037] In the description of this embodiment, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are based on the orientation or positional relationships shown in the accompanying drawings and are only for ease of description and simplification of operation. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are merely used for distinction in description and have no special meaning. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an element in between.

[0038] In this embodiment, the first direction is the X direction shown in the figure, which is the length direction of the single cell; the second direction is the Y direction shown in the figure, which is the thickness direction of the single cell; and the third direction is the Z direction shown in the figure, which is the width direction of the single cell. The first direction, the second direction, and the third direction are all perpendicular to each other.

[0039] like Figure 1 and Figure 2As shown, the single battery includes a battery casing 100, at least one battery cover plate 200, a battery electrode assembly 300, and a first explosion-proof valve 400. The battery casing 100 has a mounting opening 110 at at least one end along a first direction; the battery cover plate 200 is correspondingly mounted in the mounting opening 110; the battery electrode assembly 300 is fitted inside the battery casing 100; the first explosion-proof valve 400 is disposed on the outer wall of any end of the battery casing 100 along a third direction; wherein, the battery cover plate 200 has a mounting groove 210 at one end along the first direction away from the battery electrode assembly 300, and a terminal post assembly 211 of the battery cover plate 200 is disposed in the mounting groove 210; the battery electrode assembly 300 has a groove portion 310 at at least one end along the first direction, and a terminal tab 311 of the battery electrode assembly 300 is disposed in the groove portion 310, with the terminal post assembly 211 welded to the terminal tab 311.

[0040] In this embodiment, the battery casing 100 of the single battery is provided with a battery cover plate 200 at one end of the mounting port 110 along the first direction. The terminal assembly 211 of the battery cover plate 200 is welded to the battery electrode group 300 inside the battery casing 100. At the same time, the battery cover plate 200 is provided with a mounting groove 210, and the battery electrode group 300 is provided with a groove portion 310 corresponding to the mounting groove 210. The electrode tab 311 is provided in the groove portion 310, and the terminal assembly 211 is provided in the mounting groove 210. This allows the terminal assembly 211 to sink on the battery cover plate 200 and be hidden inside the mounting groove 210, forming a three-dimensional protective barrier and completely eliminating the risk of damage to the welding points during transportation and assembly. Meanwhile, the recessed layout of the mounting groove 210 and the terminal assembly 211 significantly reduces the overall thickness of the battery cover 200, further compressing the space occupied by the individual battery cells in the third direction, directly improving the volumetric assembly rate. It also allows for the matching of irregularly shaped terminal assemblies obtained through winding / stacking processes, maximizing the utilization of the internal space of the individual battery cells. This overcomes the limitations imposed by the flat cover on the shape of the battery terminal assembly 300, creating physical conditions for increasing battery capacity and energy density. Furthermore, the explosion-proof valve is located on one end of the battery housing 100 along the third direction, i.e., on a small surface of the battery housing 100, resulting in a shorter venting and depressurization path and improved safety performance of the individual battery cells. This individual battery cell improves the space utilization rate after assembly, while also exhibiting higher mechanical strength, enhanced safety and reliability, and greater stability during assembly, thus improving assembly reliability.

[0041] Optionally, one of the outer walls at both ends of the battery electrode assembly 300 along the second direction is provided with a first protrusion 321, and the other is provided with two second protrusions 322 spaced apart along the third direction. The first protrusion 321 can be sandwiched between the two second protrusions 322 of an adjacent single battery cell, and the size of the first protrusion 321 along the second direction is not greater than the size of the second protrusions 322 along the second direction. Correspondingly, the battery casing 100 also has a similar irregular structure, that is, one of the outer walls at both ends of the battery casing 100 along the second direction is provided with a first boss 120, and the other is provided with two second bosses 130 spaced apart along the third direction. The first boss 120 can be sandwiched between the two second bosses 130 of an adjacent battery casing 100, and the size of the first boss 120 along the second direction is not greater than the size of the second boss 130 along the second direction. The irregular structure formed by the first protrusion 321 and the second protrusion 322, combined with the irregular electrode assembly obtained by the winding / stacking process, can provide asymmetric space inside the battery casing 100, maximize the use of the internal space of the single cell, break through the limitation of the flat cover plate on the shape of the battery electrode assembly 300, and create physical conditions for improving battery capacity and energy density.

[0042] Meanwhile, when the two second protrusions 130 are inserted and assembled with the first protrusion 120, there is a certain gap between the three in the third direction, which facilitates the assembly and insertion of the two individual cells in the second direction. At the same time, the size of the first protrusion 120 and the second protrusion 130 should not be too large or too small, so as to ensure that the structural strength and capacity of the individual cells meet the requirements.

[0043] Furthermore, a second explosion-proof valve 410 is provided in the aforementioned mounting groove 210, and the second explosion-proof valve 410 is positioned directly opposite the aforementioned first protrusion 321. The second explosion-proof valve 410 works in conjunction with the first explosion-proof valve 400 on the small surface of the battery casing 100 to jointly provide explosion-proof and pressure relief, further improving the safety of the individual battery. Moreover, the fact that the second explosion-proof valve 410 is positioned directly opposite the first protrusion 321 provides installation space for the second explosion-proof valve 410, improving the reliability of the structure, which will not be elaborated further here.

[0044] like Figure 2 and 3 As shown, when the individual cells are assembled into a group, they are stacked along the second direction. The first protrusion 120 can be sandwiched between the two second protrusions 130 of another individual cell, forming a reinforced support for the side wall of the battery casing 100, significantly improving the overall mechanical strength and resisting the risk of deformation from external impact. Furthermore, the two second protrusions 130 accommodate the first protrusion 120, reducing the space occupied by the first protrusion 120 and the second protrusion 130 in the second direction during stacking, allowing for a tight fit in the second direction and improving the space utilization rate when assembling the group.

[0045] Furthermore, the dimension of the first protrusion 321 along the second direction is larger than the dimension of the second protrusion 322 along the second direction. This arrangement allows for a certain gap in the second direction between the bottom wall of the recess formed between the first protrusion 321 and the two second protrusions 322 when the two second protrusions 322 are inserted and assembled with the first protrusion 321. This facilitates the assembly and insertion of the two individual batteries in the second direction and reduces the space occupied by the two individual batteries in the second direction when assembled.

[0046] Optionally, the first protrusion 321 protrudes from the groove 310 along the first direction. This arrangement allows the first protrusion 321 to be as large as possible along the first direction, thereby making full use of the internal space of the battery casing 100, saving assembly space for individual batteries, thereby increasing the capacity and energy density of individual batteries, and improving the space utilization rate after assembly into a group.

[0047] In this embodiment, the outer wall of the second protrusion 322 at one end away from the center of the battery electrode group 300 along the third direction is flush with the outer wall of any end of the battery electrode group 300 along the third direction, forming a continuous plane. Correspondingly, the second protrusion 130 of the battery housing 100 is flush with the outer wall of any end of the battery housing 100 along the third direction. When individual batteries are stacked into modules, it can eliminate the stepped misalignment, and the battery housings 100 can be seamlessly fitted after stacking. Secondly, the end of the second protrusion 130 is coplanar with the end face of the battery housing 100, forming a natural stacking positioning reference in the third direction. Finally, the design of the second protrusion 130 being flush with the battery housing 100 means that the height of the second protrusion 130 is precisely controlled, and it will not protrude excessively beyond the battery housing 100 or form a stepped structure with the battery housing 100. This will not cause the second protrusion 130 to affect the assembly of individual batteries, and it also increases the space utilization rate.

[0048] Specifically, the outer walls at both ends of the first protrusion 120 along the third direction, and the outer walls at one end of the two second protrusions 130 near the center of the battery casing 100 along the third direction, are all set at a preset angle. If the slope of the outer walls is insufficient, interference and friction may easily occur between individual cells during assembly, reducing the overall assembly efficiency and yield. If the slope is too large, it will affect the size of the battery electrode group 300 at the corresponding position, reducing the lifting range of the individual cells and hindering the improvement of the energy density of the individual cells.

[0049] like Figure 3 and Figure 4As shown, the projection of the mounting groove 210 along the first direction onto the battery electrode assembly 300 at least covers the groove portion 310 and the first protrusion 321. The fact that the projection of the mounting groove 210 along the first direction onto the battery electrode assembly 300 at least covers the first protrusion 321 prevents the bottom wall of the mounting groove 210 from being affected by the first protrusion 321 protruding from the groove portion 310, making the bottom wall of the mounting groove 210 planar. This facilitates the assembly and installation of the mounting groove 210, improves the module assembly rate and structural strength, and ultimately improves the battery performance indicators.

[0050] In this embodiment, the circumferential sidewalls of the mounting groove 210 and the groove portion 310 are both inclined at a preset angle to the first direction. That is, the longitudinal section of the mounting groove 210 and the groove portion 310 is inverted trapezoidal, which provides the necessary clearance space for the installation of the pole assembly 211 and the second explosion-proof valve 410, improves the convenience of installing the pole assembly 211 and welding the pole assembly 211 to the pole lug 311, and improves assembly efficiency.

[0051] like Figure 5 As shown, the dimension of the groove portion 310 along the first direction is F1, and the dimension of the portion of the first protrusion 321 protruding from the groove portion 310 along the first direction is F2, where 5mm≤F2≤10mm and 8mm≤F1-F2≤30mm. Insufficient height difference between the first protrusion 321 and the port of the groove portion 310 will lead to a reduction in the capacity of the single battery cell and a decrease in the performance indicators of the single battery cell; while excessive height difference will lead to a reduction in the strength of the supporting surface of the battery electrode assembly 300 itself, and increase the stamping difficulty and production cost of the corresponding battery cover 200.

[0052] Optionally, the dimension of the battery electrode assembly 300 along the third direction is A, the dimension of the groove portion 310 along the third direction is L1, the dimension of the first protrusion portion 321 along the third direction is L2, and the dimension of the second protrusion portion 322 along the third direction is L3, where 0.6≤L1 / A≤0.85 and 0.55≤L2 / L3≤1. If the dimension of the groove portion 310 along the third direction is insufficient, the overcurrent capacity of the battery electrode assembly 300 will not meet the fast charging requirements, and the temperature rise during charging and discharging will be too high, reducing the performance of the individual battery. Conversely, if the dimension of the groove portion 310 along the third direction is too large, the dimensions of the first protrusion portion 321 and the second protrusion portion 322 on both end faces will be insufficient, affecting the capacity increase of the individual battery and reducing the end support area of ​​the individual battery along the first direction, making the battery electrode assembly 300 prone to deformation and damage.

[0053] Furthermore, in the battery electrode assembly 300, the portion of the second protrusion 322 has a dimension of E1 along the second direction, the recessed portion 310 has a dimension of E2 along the second direction, the second protrusion 322 has a dimension of H1 along the second direction, and the first protrusion 321 has a dimension of H2 along the second direction, where 0.6 ≤ E2 / E1 ≤ 0.8 and 0.2 mm ≤ H1 - H2 ≤ 0.5 mm. If the recessed portion 310's dimension along the second direction is insufficient, the battery electrode assembly 300's overcurrent capacity will not meet fast charging requirements, and the temperature rise during charging and discharging will be too high, reducing the performance of individual cells. Conversely, if the recessed portion 310's dimension along the second direction is too large, the dimensions of the first protrusion 321 and the second protrusion 322 on both end faces will be insufficient, affecting the capacity increase of individual cells and reducing the end support area of ​​individual cells along the first direction, making the battery electrode assembly 300 prone to deformation and damage.

[0054] In this embodiment, the maximum dimension of the battery electrode assembly 300 along the second direction is B, and the minimum dimension of the battery electrode assembly 300 along the second direction is W, where 45mm≤B≤118mm and 18mm≤W≤80mm. This setting limits the dimensions of the first protrusion 321 and the second protrusion 322 in the second direction. If the dimensions are too small, the height of the first protrusion 321 or the second protrusion 322 on both sides of the battery electrode assembly 300 will be insufficient, limiting the size of the increased battery electrode assembly 300 and thus reducing the capacity of the single battery. Conversely, if the height of the first protrusion 321 or the second protrusion 322 on both sides is too large, the middle part of the battery electrode assembly 300 will be relatively weak, resulting in insufficient overall strength of the single battery. Consequently, the middle part of the corresponding battery electrode assembly 300 is prone to deformation and damage, which will not be elaborated further here.

[0055] It should be noted that the wall thickness of the outer wall of the battery housing 100 where the first explosion-proof valve 400 is installed is greater than the wall thickness of the outer wall of any other side of the battery housing 100. That is, the wall thickness of the battery housing 100 where the first explosion-proof valve 400 is installed is greater than the wall thickness of the battery housing 100 where the first explosion-proof valve 400 is not installed. The side with the first explosion-proof valve 400 has a thicker wall, resulting in a battery housing 100 with unequal wall thicknesses. This reduces the weight and cost of the housing while meeting structural strength requirements, and also standardizes design parameters, reducing design defects.

[0056] The specific type of single battery can be a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid (or lead-acid) battery, a lithium-ion battery, a polymer lithium-ion battery, etc. A single battery can also be a primary lithium-ion battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc., which will not be elaborated further here.

[0057] The following section details the impact of the aforementioned size parameters on a single cell, using specific comparative examples and embodiments. The table below provides six specific embodiments and six comparative examples:

[0058]

[0059] In Example 1, the yield rate of individual cells is >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of individual cells was normal.

[0060] In Example 2, the single cell pass rate was >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of single cells was normal.

[0061] In Example 3, the single cell qualification rate was >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of single cells was normal.

[0062] In Example 4, the single cell pass rate was >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of single cells was normal.

[0063] In Example 5, the single cell qualification rate was >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of single cells was normal.

[0064] In Example 6, the single cell pass rate was >98%; no abnormalities were found in the matching, positioning, or strength of the battery cover 200, battery casing 100, and battery electrode group 300; and the battery casing 100, battery electrode group 300, and electrode group tabs 311 were all undamaged and undeformed; at the same time, the assembly of the entire pack of single cells was normal.

[0065] In Comparative Example 1, its L1 / A is less than the calibrated value, and the pass rate of the single cell is <98%; the size ratio of the groove portion 310 along the third direction is insufficient, which will cause the overcurrent capacity of the battery electrode group 300 to fail to meet the fast charging requirements, and the temperature rise during charging and discharging is too high, which reduces the performance of the single cell.

[0066] In Comparative Example 2, L1 / A is greater than the calibrated value, and the pass rate of the single cell is <98%; the size ratio of the groove portion 310 along the third direction is too large, resulting in insufficient size of the first protrusion portion 321 and the second protrusion portion 322 on both sides, which affects the capacity increase of the single cell and also reduces the end support area of ​​the single cell along the first direction, making it easy for the battery electrode group 300 to deform or be damaged.

[0067] In Comparative Example 3, the E2 / E1 ratio is less than the calibrated value, and the pass rate of the single cell is less than 98%. The insufficient size ratio of the groove portion 310 along the second direction will cause the overcurrent capacity of the battery electrode group 300 to fail to meet the fast charging requirements. At the same time, the temperature rise during charging and discharging is too high, which reduces the performance of the single cell.

[0068] In Comparative Example 4, E2 / E1 is greater than the calibrated value, and the pass rate of the single cell is <98%; the size of the groove portion 310 along the second direction is too large, resulting in insufficient size of the first protrusion portion 321 and the second protrusion portion 322 on both sides of the end face, which affects the capacity increase of the single cell and also reduces the end support area of ​​the single cell along the first direction, making it easy for the battery electrode group 300 to deform or be damaged.

[0069] In Comparative Example 5, the F1-F2 values ​​are too small, and the pass rate of the single cell is <98%; the height difference between the port of the first protrusion 321 and the groove 310 is insufficient, which will lead to a reduction in the capacity of the single cell and reduce the performance index of the single cell.

[0070] In Comparative Example 6, the F1-F2 values ​​are too large, and the pass rate of the single cell is <98%; the excessive distance between the port of the first protrusion 321 and the groove 310 will reduce the strength of the supporting surface of the battery electrode assembly 300 itself, and increase the stamping difficulty and production cost of the corresponding battery cover 200.

[0071] This embodiment also provides an electrical device comprising a single battery cell as described in any of the above embodiments. Specifically, this electrical device can be an electric bicycle, electric vehicle, hybrid vehicle, ship, energy storage device, etc., as long as it uses electrical energy as its energy source; further details are omitted here. This electrical device possesses the beneficial effects of the single battery cell described in any of the above embodiments; further details are omitted here.

[0072] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A single-cell battery, characterized in that, include: A battery housing, wherein at least one end of the battery housing along a first direction is provided with a mounting port; At least one battery cover, which is installed correspondingly to the mounting port; A battery electrode assembly, which is fitted and installed inside the battery casing; The first explosion-proof valve is disposed on the outer wall of any end of the battery housing along a third direction; Wherein, the battery cover plate is provided with a mounting groove at one end away from the battery electrode group along the first direction, and the terminal post assembly of the battery cover plate is disposed in the mounting groove; the battery electrode group is provided with a groove portion at at least one end along the first direction, and the groove portion is provided with the electrode group tab of the battery electrode group, and the terminal post assembly is welded to the electrode group tab accordingly. One of the outer walls at both ends of the battery electrode assembly along the second direction is provided with a first protrusion, and the other is provided with two second protrusions at intervals along the third direction. The first protrusion can be sandwiched between the two second protrusions of another adjacent single battery cell. The size of the first protrusion along the second direction is not greater than the size of the second protrusion along the second direction. The first protrusion protrudes from the groove along the first direction; The projection of the mounting groove onto the battery electrode assembly along the first direction at least covers the groove portion and the first protrusion portion; The second protrusion protrudes from the groove along the first direction; The first direction is the length direction of the single battery cell, the second direction is the thickness direction of the single battery cell, and the third direction is the width direction of the single battery cell. The first direction, the second direction, and the third direction are all perpendicular to each other. The dimension of the groove portion along the first direction is F1, and the dimension of the portion of the first protrusion portion protruding from the groove portion along the first direction is F2, where 5mm≤F2≤10mm and 8mm≤F1-F2≤30mm. The dimension of the battery electrode assembly along the third direction is A, and the dimension of the groove portion along the third direction is L1, where 0.6 ≤ L1 / A ≤ 0.85; The portion of the battery electrode assembly with the second protrusion has a dimension of E1 along the second direction, and the portion with the groove has a dimension of E2 along the second direction, where 0.6 ≤ E2 / E1 ≤ 0.

8.

2. The single-cell battery according to claim 1, characterized in that, The mounting groove is provided with a second explosion-proof valve, which is positioned directly opposite the first protrusion.

3. The single-cell battery according to claim 1, characterized in that, The first protrusion has a dimension of L2 along the third direction, and the second protrusion has a dimension of L3 along the third direction, where 0.55 ≤ L2 / L3 ≤ 1.

4. The single-cell battery according to claim 1, characterized in that, The second protrusion has a dimension of H1 along the second direction, and the first protrusion has a dimension of H2 along the second direction, with 0.2mm ≤ H1 - H2 ≤ 0.5mm.

5. The single-cell battery according to claim 1, characterized in that, The maximum dimension of the battery electrode assembly along the second direction is B, and the minimum dimension of the battery electrode assembly along the second direction is W, where 45mm≤B≤118mm and 18mm≤W≤80mm.

6. Electrical equipment, characterized in that, Includes the single-cell battery as described in any one of claims 1-5.

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