Single battery and battery pack

Abstract

The utility model provides a single battery and a battery pack, and relates to the technical field of batteries. The single battery comprises a shell, an anti-explosion valve, an electrode assembly and a supporting piece. An installation hole is formed in the bottom wall of the shell, the anti-explosion valve is connected with the bottom wall to seal the installation hole, the electrode assembly is located in the containing cavity of the shell, the supporting piece is located in the containing cavity and located between the electrode assembly and the bottom wall, the supporting piece comprises a first supporting part and a second supporting part, and the second supporting part is connected to the side, away from the electrode assembly, of the first supporting part. A positioning groove communicated with the containing cavity is formed in the bottom wall, a part of the second supporting part is located in the positioning groove, so that the first supporting part and the bottom wall jointly define an exhaust channel, and the exhaust channel is communicated with the containing cavity. According to the single battery provided by the invention, the exhaust channel is jointly defined by the first supporting part and the bottom wall, so that high-temperature and high-pressure gas can be conveniently evacuated when thermal runaway occurs; and through cooperation of the positioning groove and the second supporting part, the stability of the supporting piece is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell battery and a battery pack. Background Technology

[0002] Individual battery cells are a crucial component of the power battery pack in new energy vehicles. To mitigate the danger of thermal runaway in individual battery cells, a bottom-mounted explosion-proof valve design is typically employed. This involves placing the explosion-proof valve on the bottom wall of the individual battery cell's casing, with internal supports elevating the electrode assembly to create a venting channel. This allows high-temperature, high-pressure gases to dissipate to the bottom of the vehicle in the event of thermal runaway, preventing harm to occupants. However, when an individual battery cell is subjected to impact, the supports are prone to shifting, resulting in poor stability and compromising the safety of the individual battery cell. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a single battery cell and a battery pack, which aims to solve the technical problem that the poor stability of the support component affects the safety of the single battery cell.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] In a first aspect, embodiments of this application provide a single-cell battery having a height orientation, the single-cell battery comprising:

[0006] The outer shell has a receiving cavity. One end of the outer shell along the height direction is provided with an electrode post, and the other end of the outer shell opposite to the electrode post along the height direction is a bottom wall. The bottom wall is provided with a mounting hole through the height direction.

[0007] An explosion-proof valve is connected to the bottom wall to seal the mounting hole;

[0008] An electrode assembly is located within the receiving cavity and is electrically connected to the electrode post;

[0009] A support member is located within the receiving cavity and positioned between the electrode assembly and the bottom wall along the height direction. The support member includes a first support portion and a second support portion. The second support portion is connected along the height direction to the side of the first support portion away from the electrode assembly. A positioning groove communicating with the receiving cavity is formed on the bottom wall. A portion of the second support portion is located within the positioning groove, so that the first support portion and the bottom wall together define an exhaust channel, which communicates with the receiving cavity.

[0010] In one embodiment of the first aspect, in the height direction, the depth of the positioning groove is H1, and the height of the second support is H2, satisfying: 0.3mm≤H2-H1≤0.5mm.

[0011] In one embodiment of the first aspect, the explosion-proof valve is provided with an anti-corrosion layer on the side facing the electrode assembly along the height direction.

[0012] In one embodiment of the first aspect, the single battery cell further has a first direction and a second direction perpendicular to each other, the height direction being perpendicular to the first direction and the second direction respectively, and the explosion-proof valve having a groove.

[0013] In the first direction, the distance between the outer edges of the two sides of the groove is L1, the opening length of the mounting hole is L2, and the length of the anti-corrosion layer is L3, satisfying: L1+0.2mm≤L3≤L2-1mm.

[0014] In one embodiment of the first aspect, a plurality of second support portions are provided, the plurality of second support portions are arranged at intervals along the circumference of the first support portion, a plurality of positioning grooves are provided, the plurality of positioning grooves are arranged at intervals along the circumference of the bottom wall, the plurality of second support portions correspond one-to-one with the plurality of positioning grooves, and a portion of each second support portion is located in each corresponding positioning groove.

[0015] In one embodiment of the first aspect, the single battery cell further includes a base plate located within the receiving cavity. The base plate is positioned between the electrode assembly and the first support portion along the height direction and is connected to both the electrode assembly and the first support portion. A first vent hole communicating with the exhaust channel is provided through the base plate.

[0016] In one embodiment of the first aspect, a second vent hole is provided through the first support portion, and the second vent hole is connected to the first vent hole and the exhaust channel respectively.

[0017] In one embodiment of the first aspect, the first vent includes a plurality of sub-vents, the plurality of sub-vents being spaced apart circumferentially along the base plate, and the projection of the wall of each sub-vent on the support along the height direction is located within the second vent.

[0018] In one embodiment of the first aspect, the housing includes a shell and a top cover assembly, the shell having the receiving cavity and the bottom wall, the top cover assembly being connected to the shell, the top cover assembly and the bottom wall being disposed opposite each other along the height direction, and the pole being disposed on the top cover assembly.

[0019] Secondly, embodiments of this application also provide a battery pack, including the single battery cells described in any of the embodiments of the first aspect above.

[0020] The beneficial effects of this application are:

[0021] This application provides a single-cell battery, including a casing, an explosion-proof valve, an electrode assembly, and a support member. The casing has a receiving cavity and a bottom wall. A mounting hole is formed in the bottom wall. The explosion-proof valve is connected to the bottom wall to seal the mounting hole. The electrode assembly is located within the receiving cavity, and the support member is located within the receiving cavity, between the electrode assembly and the bottom wall. The support member includes a first support portion and a second support portion. The second support portion is connected to the side of the first support portion opposite to the electrode assembly. Furthermore, a positioning groove communicating with the receiving cavity is formed in the bottom wall, and a portion of the second support portion is located within the positioning groove. This not only allows the first support portion and the bottom wall to jointly define an exhaust channel, facilitating the evacuation of high-temperature, high-pressure gases in the event of thermal runaway in the single-cell battery, but also, through the cooperation of the positioning groove and the second support portion, restricts the movement of the support member, improving its stability and thus enhancing the safety of the single-cell battery.

[0022] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This application shows a schematic diagram of the structure of a single cell battery from one perspective in some embodiments;

[0025] Figure 2 It shows Figure 1 A schematic diagram of the decomposed structure;

[0026] Figure 3 This application shows a schematic diagram of the structure of a single cell battery from another perspective in some embodiments;

[0027] Figure 4 It shows Figure 3 A schematic diagram of the decomposed structure;

[0028] Figure 5 This paper shows another perspective structural schematic diagram of a single cell in some embodiments of this application;

[0029] Figure 6 It shows Figure 5 Schematic diagram of the cross-sectional structure at point AA;

[0030] Figure 7 It shows Figure 6 A magnified structural diagram of region B in the middle;

[0031] Figure 8 This illustration shows another perspective structural diagram of a single cell in some embodiments of this application;

[0032] Figure 9 It shows Figure 8 A schematic diagram of the cross-sectional structure at the CC section;

[0033] Figure 10 It shows Figure 9 A magnified structural diagram of region D in the middle;

[0034] Figure 11 This application shows a schematic diagram of the support structure from one perspective in some embodiments;

[0035] Figure 12 This application shows a schematic diagram of the support structure from another perspective in some embodiments;

[0036] Figure 13 This application shows a schematic diagram of the explosion-proof valve from one perspective in some embodiments;

[0037] Figure 14 This paper shows a schematic diagram of the explosion-proof valve from another perspective in some embodiments of this application.

[0038] Explanation of key component symbols:

[0039] 100 - Single cell; 110 - Electrode assembly; 120 - Outer casing; 121 - Housing; 1211 - Receiving cavity; 1212 - Exhaust channel; 1213 - Positioning groove; 1214 - Mounting hole; 1215 - Opening; 1216 - Bottom wall; 122 - Top cover assembly; 130 - Explosion-proof valve; 131 - Score groove; 140 - Support member; 141 - First support part; 1411 - Second vent hole; 142 - Second support part; 150 - Anti-corrosion layer; 160 - Bottom support plate; 161 - First vent hole; 1611 - Sub-vent hole; 170 - Protective sheet; 180 - Insulating film; 181 - Immersion hole; - First direction; y - Second direction; z - Height direction. Detailed Implementation

[0040] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0041] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and 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 this application.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0043] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 application according to the specific circumstances.

[0044] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] Individual batteries are a crucial component of the power battery pack in new energy vehicles. To mitigate the danger of thermal runaway in individual batteries, a bottom-outlet explosion-proof valve design is typically employed. This involves placing the explosion-proof valve on the bottom wall of the individual battery casing, with a support structure inside the casing to elevate the electrode assembly and create an exhaust channel. This allows high-temperature, high-pressure gases to be dispersed to the bottom of the vehicle in the event of thermal runaway, thus preventing harm to occupants.

[0046] However, when a single battery cell is subjected to impact, the support structure is prone to movement, resulting in poor stability. Furthermore, with the aforementioned bottom-mounted explosion-proof valve design, the electrode assembly inside the casing is susceptible to being compressed by gravity, potentially causing blockage of the explosion-proof valve or the venting passage between the valve and the electrode assembly. This could lead to the explosion-proof valve failing to open properly in the event of thermal runaway.

[0047] To solve the above technical problems, such as Figure 1 , Figure 3 , Figure 5 and Figure 8 As shown, in the first aspect, embodiments of this application provide a single battery cell 100, which relates to the field of battery technology and is mainly used in battery packs, so as to be used in electrical devices such as new energy vehicles, ships, and spacecraft in the form of battery packs. Of course, the single battery cell 100 can also be used directly in electrical devices without adopting the form of battery packs.

[0048] Combination Figure 6 , Figure 7 , Figure 9 and Figure 10 As shown, the single cell 100 provided in this embodiment has a height direction z and includes a housing 120, an explosion-proof valve 130, an electrode assembly 110, and a support member 140.

[0049] The outer casing 120 has a receiving cavity 1211. An electrode post is provided at one end of the outer casing 120 along the height direction z, and a bottom wall 1216 is provided at the other end opposite the electrode post along the height direction z. A mounting hole 1214 is provided through the bottom wall 1216 along the height direction z. An explosion-proof valve 130 is connected to the bottom wall 1216 to seal the mounting hole 1214. The electrode assembly 110 is located within the receiving cavity 1211 and is electrically connected to the electrode post. The support member 140 is located within the receiving cavity 1211 and is positioned between the electrode assembly 110 and the bottom wall 1216 along the height direction z. The support member 140 includes a first support portion 141 and a second support portion 142. The second support portion 142 is connected along the height direction z to the side of the first support portion 141 away from the electrode assembly 110. A positioning groove 1213 communicating with the receiving cavity 1211 is provided on the bottom wall 1216. A portion of the second support portion 142 is located within the positioning groove 1213, so that the first support portion 141 and the bottom wall 1216 together define an exhaust channel 1212, which communicates with the receiving cavity 1211.

[0050] It is understood that the single-cell battery 100 provided in this embodiment includes a first support portion 141 and a second support portion 142 in the support member 140. The second support portion 142 is connected to the side of the first support portion 141 away from the electrode assembly 110. Based on this, a positioning groove 1213 communicating with the receiving cavity 1211 is formed on the bottom wall 1216, and a part of the second support portion 142 is located in the positioning groove 1213. In this way, not only do the first support portion 141 and the bottom wall 1216 jointly define the exhaust channel 1212, which facilitates the evacuation of high-temperature and high-pressure gas when the single-cell battery 100 experiences thermal runaway (after the high-temperature and high-pressure gas passes through the exhaust channel 1212, the explosion-proof valve 130 opens under the impact of the high-temperature and high-pressure gas to exhaust it), but also, through the cooperation of the positioning groove 1213 and the second support portion 142, the movement of the support member 140 is restricted, thereby improving the stability of the support member 140 and enhancing the safety of the single-cell battery 100.

[0051] It should be noted that the support member 140 can be made of plastic. In this case, the support member 140 can provide electrical insulation between the electrode assembly 110 and the bottom wall 1216, thereby reducing the risk of short circuit in the single cell 100. In addition, the electrode assembly 110 includes at least one cell, which can be a wound cell or a stacked cell. No specific restrictions are placed on the structure of the electrode assembly 110 here.

[0052] like Figure 10 and Figure 12 As shown, in one embodiment, the depth of the positioning groove 1213 in the height direction z is H1, and the height of the second support 142 is H2, satisfying the relationship: 0.3mm≤H2-H1≤0.5mm.

[0053] For example, H2-H1 can be any value from 0.3mm, 0.31mm, 0.35mm, 0.38mm, 0.4mm, 0.42mm, 0.45mm, 0.46mm, 0.48mm, 0.49mm, 0.5mm, or any value from a range of any two of these values, without any specific limitation.

[0054] Understandably, by controlling H2-H1 within the range of 0.3mm to 0.5mm, the exhaust channel 1212 has sufficient space for exhaust, reducing the possibility of the exhaust channel 1212 being blocked by the electrode assembly 110, thereby enhancing the safety of the single cell 100.

[0055] like Figure 7 and Figure 10 As shown, the thickness of the bottom wall 1216 is T1, which satisfies: 1 / 3≤H1 / T1≤2 / 3.

[0056] For example, H1 / T1 can be any value from 1 / 3, 0.34, 0.35, 2 / 5, 0.41, 0.42, 0.45, 1 / 2, 2 / 3 or any value from a range of any two of these values, without any specific restrictions.

[0057] It is understandable that by controlling H1 / T1 within the range of 1 / 3 to 2 / 3, the bottom wall 1216 has sufficient remaining thickness at the positioning groove 1213, which reduces the risk of the bottom wall 1216 being too thin, thereby reducing the possibility of electrolyte corrosion penetrating the bottom wall 1216 in the receiving cavity 1211, and thus enhancing the safety of the single cell 100.

[0058] like Figure 7 and Figure 10 As shown, further, it satisfies: 0.5mm≤H1≤0.8mm, 1.2mm≤T1≤1.5mm.

[0059] For example, H1 can be any value from 0.5mm, 0.52mm, 0.53mm, 0.55mm, 0.6mm, 0.61mm, 0.62mm, 0.65mm, 0.69mm, 0.7mm, 0.73mm, 0.75mm, 0.78mm, 0.8mm, or any value within a range of any two of these values, without any specific limitation. T1 can be any value from 1.2mm, 1.22mm, 1.25mm, 1.3mm, 1.34mm, 1.38mm, 1.4mm, 1.42mm, 1.45mm, 1.46mm, 1.48mm, 1.5mm, or any value within a range of any two of these values, without any specific limitation.

[0060] It is understandable that by controlling H1 within the range of 0.5mm to 0.8mm and T1 within the range of 1.2mm to 1.5mm, to satisfy 1 / 3≤H1 / T1≤2 / 3, the risk of the bottom wall 1216 being too thin is reduced, thereby reducing the possibility of electrolyte corrosion penetrating the bottom wall 1216 in the cavity 1211, and thus enhancing the safety of the single cell 100.

[0061] like Figure 4 , Figure 7 and Figure 10 As shown, in one embodiment, the explosion-proof valve 130 is provided with an anti-corrosion layer 150 on the side facing the electrode assembly 110 along the height direction z, so as to improve the corrosion of the explosion-proof valve 130 by the electrolyte in the receiving cavity 1211 and reduce the risk of damage to the explosion-proof valve 130.

[0062] For example, the anti-corrosion layer 150 can be an anti-corrosion coating, an anti-corrosion adhesive layer, etc., without specific limitations.

[0063] like Figure 7 , Figure 13 and Figure 14 As shown, the single cell 100 further has a first direction x and a second direction y perpendicular to each other, and a height direction z perpendicular to the first direction x and the second direction y. The explosion-proof valve 130 has a groove 131. In the first direction x, the maximum distance between the outer edges of the two sides of the groove 131 is L1, the opening length of the mounting hole 1214 is L2, and the length of the anti-corrosion layer 150 is L3, satisfying: L1+0.2mm≤L3≤L2-1mm.

[0064] For example, L1 and L2 are measured using an electronic size testing microscope, and the computer can directly display the numerical values ​​of the sampling points.

[0065] Understandably, by controlling L3 within the range of L1+0.2mm to L2-1mm, the anti-corrosion layer 150 can completely cover the groove 131 of the explosion-proof valve 130, reducing the risk of the explosion-proof valve 130 becoming too thin due to corrosion of the groove 131 by the electrolyte in the receiving cavity 1211, thereby reducing the risk of damage to the explosion-proof valve 130. Furthermore, this prevents the anti-corrosion layer 150 from contacting the edge of the mounting hole 1214, thus reducing the possibility that the anti-corrosion layer 150 may be burned or deformed during the welding of the explosion-proof valve 130 to the mounting hole 1214, affecting its adhesion strength to the explosion-proof valve 130.

[0066] like Figure 7 and Figure 10 As shown, the thickness of the anti-corrosion layer 150 is T2, which satisfies the following condition: 0.05mm≤T2≤0.2mm.

[0067] For example, T2 can be any value from 0.05mm, 0.06mm, 0.08mm, 0.1mm, 0.12mm, 0.14mm, 0.15mm, 0.18mm, 0.19mm, 0.2mm or any value from a range of any two of these, without any specific limitation.

[0068] It is understandable that by controlling T2 within the range of 0.05mm to 0.2mm, sufficient adhesion is achieved between the anti-corrosion layer 150 and the explosion-proof valve 130, thereby enhancing the protective effect of the anti-corrosion layer 150 on the explosion-proof valve 130.

[0069] like Figure 10 and Figure 11As shown, in one embodiment, multiple second support portions 142 are provided, and the multiple second support portions 142 are arranged at intervals along the circumference of the first support portion 141. Multiple positioning grooves 1213 are provided, and the multiple positioning grooves 1213 are arranged at intervals along the circumference of the bottom wall 1216. The multiple second support portions 142 correspond one-to-one with the multiple positioning grooves 1213, and a portion of each second support portion 142 is located in each corresponding positioning groove 1213.

[0070] For example, the number of the second support portion 142 and the positioning groove 1213 can be two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, etc., without any specific limitation.

[0071] It is understandable that by providing multiple second support portions 142 at intervals along the circumference of the first support portion 141 on the side of the first support portion 141 away from the electrode assembly 110, and by providing multiple positioning grooves 1213 along the circumference of the bottom wall 1216, the multiple second support portions 142 and the multiple positioning grooves 1213 are matched one-to-one, which can better restrict the movement of the support member 140 and improve the stability of the support member 140.

[0072] like Figure 2 , Figure 4 and Figure 10 As shown, in one embodiment, the single cell 100 further includes a bottom support plate 160, which is located in the receiving cavity 1211. The bottom support plate 160 is located between the electrode assembly 110 and the first support portion 141 along the height direction z, and is connected to the electrode assembly 110 and the first support portion 141 respectively. A first vent hole 161 communicating with the exhaust channel 1212 is provided through the bottom support plate 160.

[0073] It is understood that by providing a base plate 160 between the electrode assembly 110 and the first support portion 141, the base plate 160 can support the electrode assembly 110, and the first vent hole 161 provided on the base plate 160 facilitates the dissipation of the gas generated by the electrode assembly 110 to the exhaust channel 1212.

[0074] like Figure 2 , Figure 10 and Figure 11 As shown, a second vent hole 1411 is further provided through the first support portion 141, and the second vent hole 1411 is connected to the first vent hole 161 and the exhaust channel 1212 respectively. In this way, the first vent hole 161 is connected to the exhaust channel 1212 through the second vent hole 1411, and the gas generated by the electrode assembly 110 can be dispersed to the exhaust channel 1212 in sequence through the first vent hole 161 and the second vent hole 1411.

[0075] like Figure 2 , Figure 4 and Figure 10 As shown, the first vent 161 further includes a plurality of sub-vents 1611, which are spaced apart circumferentially along the base plate 160. The projection of the hole wall of each sub-vent 1611 along the height direction z on the support member 140 is located within the second vent 1411, that is, the setting range of the second vent 1411 completely covers the plurality of sub-vents 1611. When the electrode assembly 110 generates gas, the gas is dispersed into the second vent 1411 through the plurality of sub-vents 1611, and then dispersed to the exhaust channel 1212 through the second vent 1411.

[0076] like Figure 1 and Figure 2 As shown, in one embodiment, the housing 120 includes a housing 121 and a top cover assembly 122. The housing 121 has a receiving cavity 1211 and a bottom wall 1216. The top cover assembly 122 is connected to the housing 121. The top cover assembly 122 and the bottom wall 1216 are arranged opposite each other along the height direction z. An electrode post is disposed on the top cover assembly 122. Typically, the electrode post passes through the top cover plate of the top cover assembly 122. The electrode post in the receiving cavity 1211 is electrically connected to the electrode assembly 110.

[0077] Understandably, when the single cell 100 experiences thermal runaway, the high-temperature and high-pressure gas generated by the electrode assembly 110 will be vented from the end of the housing 121 opposite to the top cover assembly 122, i.e. from the bottom wall 1216 of the housing 121, through the explosion-proof valve 130, thereby reducing the risk of heat spreading towards the top cover assembly 122 and providing higher safety.

[0078] like Figure 2 As shown, the housing 121 further includes an opening 1215 communicating with the receiving cavity 1211, and a top cover assembly 122 is connected to the end of the housing 121 with the opening 1215 to close the opening 1215. The opening 1215 facilitates the installation of the electrode assembly 110 into the receiving cavity 1211, thus making it convenient for the electrode assembly 110 to be inserted into the housing.

[0079] like Figures 2 to 4As shown, the single cell 100 further includes a protective sheet 170 and an insulating film 180. The protective sheet 170 is disposed on the side of the bottom wall 1216 away from the electrode assembly 110 and covers the explosion-proof valve 130 to protect the explosion-proof valve 130 from the influence of the external environment. The insulating film 180 is located in the receiving cavity 1211 and covers the electrode assembly 110, so that the electrode assembly 110 and the housing 121 are electrically insulated. A plurality of wetting holes 181 are spaced apart on the insulating film 180, and each wetting hole 181 communicates with the receiving cavity 1211 so that the electrolyte can wet the electrode assembly 110 through the wetting hole 181.

[0080] like Figures 10 to 12 As shown, in one embodiment, the second support 142 is a cylinder, the positioning groove 1213 is a circular hole, the diameter of the second support 142 is d, and the diameter of the positioning groove 1213 is D, satisfying: d+0.2mm≤D≤d+0.4mm.

[0081] For example, 2mm≤d≤3mm, in which case 2.2mm≤D≤3.4mm. Here, d can be any value from 2mm, 2.1mm, 2.2mm, 2.5mm, 2.6mm, 2.8mm, 2.9mm, 3mm, or any value from any combination of two of these values, without any specific restriction here.

[0082] Understandably, by ensuring that D ≥ d + 0.2 mm, it is easier to install the support 140 onto the bottom wall 1216, reducing assembly difficulty and the possibility of excessive friction between the second support 142 and the bottom wall 1216. By ensuring that D ≤ d + 0.4 mm, excessive gaps are prevented between the second support 142 and the hole wall of the positioning groove 1213, thereby reducing the risk of electrolyte in the receiving cavity 1211 entering the gaps and corroding the bottom wall 1216.

[0083] like Figure 6 and Figure 10 As shown, in one embodiment, the single cell 100 further has a first direction x and a second direction y that are perpendicular to each other, and a height direction z that is perpendicular to the first direction x and the second direction y. In the first direction x, the length of the electrode assembly 110 is L and the length of the first support portion 141 is L4. In the second direction y, the width of the electrode assembly 110 is W and the width of the first support portion 141 is L5, satisfying: L-4mm≤L4≤L, W-4mm≤L5≤W.

[0084] It should be noted that the units for W and L are both mm, and their specific values ​​can be set according to the design requirements of the 100 single cell, without any specific restrictions here.

[0085] It is understandable that by controlling L4 within the range of L-4mm to L and L5 within the range of W-4mm to W, the first support portion 141 can support most of the bottom area of ​​the electrode assembly 110, thereby achieving a higher support effect and enhancing the stability of the electrode assembly 110 within the receiving cavity 1211.

[0086] Secondly, embodiments of this application provide a battery pack including the single battery cell 100 in any of the embodiments of the first aspect described above.

[0087] It is understood that since the battery pack provided in this embodiment has the single cell 100 in any of the embodiments of the first aspect described above, it has all the beneficial effects of the single cell 100, which will not be described in detail here.

[0088] To better illustrate the beneficial effects of the embodiments of this application, the experimental test results of the single cell 100 are provided in Table 1.

[0089]

[0090] I. Testing Method:

[0091] After welding the explosion-proof valve 130 to the bottom wall 1216 of the housing 120, observe the adhesion between the anti-corrosion layer 150 and the explosion-proof valve 130, and then conduct a thermal runaway test: First, at room temperature (22±5℃), discharge the battery with a current of 0.33C to the lower limit voltage and let it rest for 30 minutes; then, charge the battery with a constant current of 1C to the upper limit voltage and switch to constant voltage charging until the charging current drops to 0.05C and stop charging and let it rest for 30 minutes; next, place the single cell 100 in an oven and heat it to 50℃ at a heating rate of 5℃ / min; then, use the same heating rate at 5℃ gradient intervals until the temperature reaches 200℃ or thermal runaway occurs, and maintain the temperature at each step of the ambient temperature for 30 minutes.

[0092] II. Test pass criteria:

[0093] 1. The anti-corrosion layer 150 is well attached to the explosion-proof valve 130.

[0094] 2. When the explosion-proof valve 130 is opened normally, the opening pressure value is within the design value range of 0.4Mpa to 0.8Mpa.

[0095] 3. Neither the bottom wall 1216 of the explosion-proof valve 130 nor the outer casing 120 showed signs of corrosion from the electrolyte.

[0096] III. Test results in Table 1:

[0097] 1. In Comparative Example 1, the explosion-proof valve 130 opened at 0.3 MPa, which is lower than the design opening pressure range. This indicates that the anti-corrosion layer 150 did not completely cover the groove 131 of the explosion-proof valve 130, causing corrosion at the groove 131 and resulting in insufficient residual thickness of the explosion-proof valve 130. The test failed. In Comparative Example 2, the anti-corrosion layer 150 showed signs of scalding and deformation, resulting in poor adhesion between it and the explosion-proof valve 130. The test failed. In Comparative Example 3, the explosion-proof valve 130 did not open normally, indicating that the space in the exhaust channel 1212 was too small, affecting the discharge of high-temperature and high-pressure gas. The test failed.

[0098] 2. In Examples 1 to 3, the anti-corrosion layer 150 and the explosion-proof valve 130 are well attached without any burns or deformation. The explosion-proof valve 130 opens normally with an opening pressure in the range of 0.4 MPa to 0.8 MPa. No corrosion is found on the bottom wall 1216 of the explosion-proof valve 130 and the outer shell 120. The test is passed.

[0099] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0100] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A single-cell battery, characterized in that, Having a height orientation (z), the single cell comprises: The outer shell (120) has a receiving cavity (1211). One end of the outer shell (120) along the height direction (z) is provided with a pole post, and the other end of the outer shell (120) opposite to the pole post along the height direction (z) is a bottom wall (1216). The bottom wall (1216) is provided with a mounting hole (1214) through it along the height direction (z). An explosion-proof valve (130) is connected to the bottom wall (1216) to seal the mounting hole (1214); An electrode assembly (110) is located within the receiving cavity (1211) and is electrically connected to the electrode post; A support member (140) is located within the receiving cavity (1211) and is positioned along the height direction (z) between the electrode assembly (110) and the bottom wall (1216). The support member (140) includes a first support portion (141) and a second support portion (142). The second support portion (142) is connected along the height direction (z) to the side of the first support portion (141) facing away from the electrode assembly (110). A positioning groove (1213) communicating with the receiving cavity (1211) is provided on the bottom wall (1216). A portion of the second support portion (142) is located within the positioning groove (1213) so that the first support portion (141) and the bottom wall (1216) together define an exhaust channel (1212), which communicates with the receiving cavity (1211).

2. The single-cell battery according to claim 1, characterized in that, In the height direction (z), the depth of the positioning groove (1213) is H1, and the height of the second support (142) is H2, satisfying: 0.3mm≤H2-H1≤0.5mm.

3. The single-cell battery according to claim 1, characterized in that, The explosion-proof valve (130) has an anti-corrosion layer (150) on the side facing the electrode assembly (110) along the height direction (z).

4. The single-cell battery according to claim 3, characterized in that, The single cell also has a first direction (x) and a second direction (y) that are perpendicular to each other, the height direction (z) is perpendicular to the first direction (x) and the second direction (y) respectively, and the explosion-proof valve (130) has a groove (131). In the first direction (x), the distance between the outer edges of the two sides of the groove (131) is L1, the opening length of the mounting hole (1214) is L2, and the length of the anti-corrosion layer (150) is L3, satisfying: L1+0.2mm≤L3≤L2-1mm.

5. The single-cell battery according to claim 1, characterized in that, The second support portion (142) is provided in multiple ways, and the multiple second support portions (142) are arranged at intervals along the circumference of the first support portion (141). The positioning groove (1213) is provided in multiple ways, and the multiple positioning grooves (1213) are arranged at intervals along the circumference of the bottom wall (1216). The multiple second support portions (142) correspond one-to-one with the multiple positioning grooves (1213), and a portion of each second support portion (142) is located in each corresponding positioning groove (1213).

6. The single-cell battery according to any one of claims 1 to 5, characterized in that, The single battery also includes a base plate (160), which is located inside the receiving cavity (1211). The base plate (160) is located between the electrode assembly (110) and the first support part (141) along the height direction (z), and is connected to the electrode assembly (110) and the first support part (141) respectively. A first vent hole (161) communicating with the exhaust channel (1212) is provided through the base plate (160).

7. The single-cell battery according to claim 6, characterized in that, A second vent hole (1411) is provided through the first support part (141), and the second vent hole (1411) is connected to the first vent hole (161) and the exhaust channel (1212) respectively.

8. The single-cell battery according to claim 7, characterized in that, The first vent (161) includes a plurality of sub-vents (1611), which are spaced apart along the circumference of the base plate (160). The projection of the hole wall of each sub-vent (1611) along the height direction (z) on the support (140) is located in the second vent (1411).

9. The single-cell battery according to claim 1, characterized in that, The outer casing (120) includes a housing (121) and a top cover assembly (122). The housing (121) has the receiving cavity (1211) and the bottom wall (1216). The top cover assembly (122) is connected to the housing (121). The top cover assembly (122) and the bottom wall (1216) are arranged opposite to each other along the height direction (z). The pole post is disposed on the top cover assembly (122).

10. A battery pack, characterized in that, The single-cell battery includes any one of claims 1 to 9.

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