A single cell and a battery

Abstract

This invention provides a single-cell battery and a battery pack. The single-cell battery includes a housing, a motor assembly, and an insulating component. The housing includes an end wall with a pressure-sensitive weak point. An electrode assembly is sealed and housed within the housing. The insulating component is fixedly connected to the side of the end wall facing the electrode assembly to achieve insulation between the end wall and the electrode assembly. The insulating component includes a first insulating portion and a second insulating portion. The melting point of the first insulating portion is lower than that of the second insulating portion. The orthographic projection of the first insulating portion at least partially covers the pressure-sensitive weak point. The first insulating portion is configured to melt due to high temperature when the pressure-sensitive weak point ruptures, allowing it to be ejected from the rupture point to the outside of the housing under the internal pressure. The second insulating portion is configured not to melt when the pressure-sensitive weak point ruptures, maintaining a fixed connection with the end wall. This invention improves the problem that when the pressure-sensitive weak point ruptures and releases pressure, the insulating component easily obstructs the exhaust channel, affecting normal pressure release.

Description

Technical Field

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

[0002] In current technology, to improve the safety of individual battery cells, pressure-sensitive weak points are typically installed on the end walls of the battery cell casing. When the internal pressure of the battery cell reaches a set threshold, these pressure-sensitive weak points rupture and open venting channels to achieve rapid pressure relief, thereby preventing safety accidents such as rupture or explosion of the battery cell due to excessive internal pressure.

[0003] However, in practical applications, an insulating component is typically installed between the end wall of a single battery cell and its internal electrode assembly. The presence of this insulating component can easily obstruct the venting channel when a pressure-sensitive section ruptures and releases pressure, affecting the smooth progress of the pressure release process. This may result in the battery's internal pressure not being released in a timely manner, exacerbating heat accumulation, increasing the risk of thermal runaway, and even triggering more serious safety issues. Utility Model Content

[0004] This invention provides a single-cell battery and a battery pack to solve the technical problem that when a pressure-sensitive part on the casing ruptures and releases pressure, the insulating parts easily obstruct the unobstructed exhaust channel, thus affecting the normal pressure release of the single-cell battery.

[0005] This utility model provides a single-cell battery, comprising: a housing, a motor assembly, and an insulating component. The housing includes an end wall with a pressure-sensitive weak point for rupture when the internal pressure reaches a set threshold. An electrode assembly is sealed and housed within the housing. The insulating component is fixedly connected to the side of the end wall facing the electrode assembly to achieve insulation between the end wall and the electrode assembly. The insulating component includes a first insulating portion and a second insulating portion connected to the first insulating portion, wherein the melting point of the first insulating portion is lower than the melting point of the second insulating portion. The orthogonal projection of the first insulating portion onto the end wall at least partially covers the pressure-sensitive weak point. The first insulating portion is configured to melt due to high temperature when the pressure-sensitive weak point ruptures, and be ejected from the rupture point to the outside of the housing under the internal pressure of the housing. The second insulating portion is configured not to melt when the pressure-sensitive weak point ruptures, thereby maintaining a fixed connection with the end wall.

[0006] In one embodiment of the present invention, the orthographic projection contour of the first insulating portion on the end wall surrounds the outer periphery of the orthographic projection contour of the pressure-weak portion on the end wall.

[0007] In one embodiment of the present invention, the first insulating part is provided with at least one airflow channel, which penetrates the thickness of the first insulating part and is used to connect the spaces on both sides of the insulation part in the thickness direction before the pressure-weak part breaks.

[0008] In one embodiment of the present invention, the second insulating portion includes a first extension portion and a second extension portion, the first extension portion and the second extension portion being respectively connected to both sides of the first insulating portion along its length direction; along the direction from the end wall to the electrode assembly, the orthographic projection of the first extension portion and the orthographic projection of the first insulating portion at least partially overlap; and / or, the orthographic projection of the second extension portion and the orthographic projection of the first insulating portion at least partially overlap.

[0009] In one embodiment of the present invention, along the direction from the end wall to the electrode assembly, the two sides of the length direction of the first insulating portion abut against the side of the first extension portion away from the electrode assembly and the side of the second extension portion away from the electrode assembly, respectively.

[0010] In one embodiment of the present invention, the first insulating part and the second insulating part are connected by a snap-fit ​​structure. The snap-fit ​​structure includes a matching snap and a slot, one of which is disposed on the first insulating part and the other is disposed on the second insulating part. The snap-fit ​​structure is configured to lose its connection function when the first insulating part is heated and melted.

[0011] In one embodiment of the present invention, a pole mounting hole is further provided on the end wall, and a first clearance hole corresponding to the pole mounting hole is provided on the second insulating part.

[0012] In one embodiment of this utility model, the material of the first insulating part is polypropylene, and the material of the second insulating part is liquid crystal polymer.

[0013] In one embodiment of the present invention, the melting point of the first insulating part is 150-170°C, and the melting point of the second insulating part is 300-500°C.

[0014] This utility model also provides a battery pack, which includes the single battery cells in any of the above embodiments.

[0015] The beneficial effects of this utility model are as follows: The single-cell battery proposed in this utility model has an insulating component comprising a first insulating part and a second insulating part connected to the first insulating part, wherein the melting point of the first insulating part is lower than that of the second insulating part; wherein the orthographic projection of the first insulating part on the end wall at least partially covers the pressure-sensitive part; the first insulating part is configured to melt due to high temperature when the pressure-sensitive part ruptures, and to be ejected from the rupture point to the outside of the casing under the action of internal pressure; the second insulating part is configured not to melt when the pressure-sensitive part ruptures, so as to maintain a fixed connection with the end wall. This configuration, on the one hand, ensures that the pressure relief channel is unobstructed because the melting point of the first insulating part is relatively low, and it can melt rapidly when the pressure-sensitive part ruptures and be ejected from the rupture point to the outside of the casing under the action of internal pressure. Therefore, the smoothness of the pressure relief channel can be ensured, allowing the internal pressure of the single-cell battery to be released in a timely manner, effectively reducing the risk of thermal runaway. On the other hand, because the second insulating part has a relatively high melting point and does not melt when the pressure-sensitive part ruptures, it can always maintain the insulation between the end wall and the electrode assembly, avoiding internal short circuits due to insulation failure, thus reducing the risk of thermal runaway in a single cell. Furthermore, since the low-melting-point first insulating part is discharged outside the casing, the residue of low-melting-point materials from the insulating components inside the casing can be reduced. This further reduces the probability of spontaneous combustion of the residual low-melting-point materials upon contact with external oxygen, thereby further reducing the possibility of thermal runaway. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram:

[0018] Figure 1 This is a schematic diagram of the structure of a single battery provided in an embodiment of the present invention;

[0019] Figure 2 This is an exploded view of the end wall and the shell provided in one embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the overall structure of the insulating component provided in one embodiment of the present utility model;

[0021] Figure 4 This is an exploded view of the insulating component provided in one embodiment of the present invention;

[0022] Figure 5This is an exploded view of the component between the sidewall and the insulation provided in one embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of a battery according to one embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the structure of an embodiment of the electrical device of this utility model.

[0025] The attached figures are labeled as follows:

[0026] 100. Single cell; 110. Casing; 111. Side wall; 112. End wall; 1121. Terminal mounting hole; 1122. Liquid filling hole; 1123. Through hole; 113. Opening; 114. Pressure weak point; 1141. Explosion-proof valve; 121. Positive terminal; 122. Negative terminal; 130. Insulating component; 131. First insulating part; 1311. Airflow channel; 1312. First body part; 1313. First connecting part; 132. Second insulating part; 13 21. First extension; 13211. Second body part; 13212. Second connecting part; 1322. Second extension; 13221. Third body part; 13222. Third connecting part; 1323. First clearance hole; 1324. Second clearance hole; 140. Snap-fit ​​structure; 141. Snap-fit; 142. Snap-fit ​​groove; 200. Battery pack; 210. Housing; 211. First housing part; 212. Second housing part; 300. Electronic device; 310. Working part. Detailed Implementation

[0027] 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. 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. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. 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.

[0029] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0030] Please see Figures 1 to 7 This utility model provides a single cell battery 100 and a battery pack 200. The single cell battery 100 solves the technical problem that when the pressure weak part 114 ruptures to release pressure, the insulating part 130 can easily obstruct the smooth flow of the exhaust channel and affect the normal progress of the pressure release process by setting the insulating part 130 as a first insulating part 131 and a second insulating part 132 with different melting points, and making the melting point of the first insulating part 131 lower than that of the second insulating part 132.

[0031] In this invention, the single battery cell 100 may include lithium-ion batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this invention are not limited to this. The single battery cell 100 may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this invention are not limited to this. For example, in this embodiment, the single battery cell 100 is generally cuboid in shape.

[0032] Please see Figure 1 In one embodiment of the single cell battery 100 of this utility model, the single cell battery 100 includes: a housing 110, an electrode assembly and an insulating component 130.

[0033] Please see Figure 1 and Figure 2 The housing 110 includes an end wall 112 and a surrounding side wall 111, with openings 113 formed at both ends of the side wall 111. Two end walls 112 are provided, each corresponding to and sealing one of the openings 113. At least one end wall 112 has a pressure-weak portion 114 for rupturing when the internal pressure of the housing 110 reaches a set threshold. The end wall 112 can be integrally stamped and connected to the side wall 111, or it can be a separate part detachably mounted to the side wall 111. Optionally, in this embodiment, one of the two end walls 112 is integrally stamped and connected to the side wall 111, and the other is detachably connected to the side wall 111. The pressure-weak portion 114 is provided on the end wall 112 detachably connected to the side wall 111. Of course, in other embodiments, the pressure-weak portion 114 can also be provided on the end wall 112 integrally stamped and connected to the side wall 111.

[0034] It should be noted that the pressure weak point 114 refers to the area on the end wall 112 most prone to rupture due to structural thinning or the installation of a pressure valve. When the internal pressure of the housing 110 reaches a set threshold, the pressure weak point 114 will rupture, thereby forming a pressure relief channel on the end wall 112, achieving pressure relief inside the housing 110. The specific structure of the pressure weak point 114 can be varied, such as a grooved structure formed on the end wall 112, an explosion-proof valve plate, or an explosion-proof valve. Exemplarily, in this embodiment, the pressure weak point 114 is an explosion-proof valve 1141 installed on the end wall 112. Specifically, the end wall 112 is provided with a through hole 1123, and the explosion-proof valve 1141 is fixedly installed in the through hole 1123. When the internal pressure of the housing 110 reaches the set threshold, the explosion-proof valve 1141 opens, achieving pressure relief inside the housing 110.

[0035] The sidewall 111 can be cylindrical, cuboid, or polygonal. In this embodiment, the sidewall 111 is cuboid, and the end wall 112 and the sidewall 111 together form an approximately cuboid-shaped receiving cavity. The receiving cavity can be used to accommodate electrode components, electrolyte, and other necessary battery components. The housing 110 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. To prevent the housing 110 from rusting during long-term use, a rust-preventive material such as metallic nickel can be plated on the surface of the housing 110.

[0036] Please see Figure 1 The electrode assembly is sealed inside the housing 110, i.e., sealed within the receiving cavity. The electrode assembly is a key component in the single-cell battery 100 where the electrochemical reaction occurs. The housing 110 may contain one or more electrode assemblies. Each electrode assembly consists of an electrode sheet and a separator, which can be assembled together by stacking or winding. Specifically, in this embodiment, when the housing 110 has a cuboid structure, the electrode assembly is formed by stacking electrodes and separators.

[0037] The electrode assembly includes a positive electrode tab and a negative electrode tab. The positive and negative electrode tabs can be respectively disposed on opposite sides of the electrode assembly's height direction, or they can both be disposed on the same side of the electrode assembly's height direction. For example, in this embodiment, the positive and negative electrode tabs are disposed on the same side of the electrode assembly's height direction, and along the height direction of the housing 110 (e.g., ...). Figure 1 (As shown in the Z-axis direction), the positive and negative electrode tabs face the side of the end wall 112 where the pressure weak point 114 is provided. Of course, in other embodiments, the positive and negative electrode tabs may face the side of the end wall 112 where the pressure weak point 114 is not provided.

[0038] In this embodiment, a positive electrode post 121 and a negative electrode post 122 are provided on the end wall 112. The positive electrode post 121 is electrically connected to the positive electrode tab, and the negative electrode post 122 is electrically connected to the negative electrode tab.

[0039] Please see Figure 2 and Figure 5 The insulating member 130 is fixedly connected to the side of the end wall 112 facing the electrode assembly, serving to achieve insulation between the end wall 112 and the electrode assembly. It should be noted that the end wall 112 at this location refers to the end wall 112 with the pressure-weak portion 114. The method of fixing the insulating member 130 to the end wall 112 is not limited; for example, it can be fixed by adhesive bonding, or by using the positive electrode post 121 and the negative electrode post 122 to penetrate the insulating member 130, and using the riveting force between them and the end wall 112 to press and fix the insulating member 130 to the side of the end wall 112 facing the electrode assembly.

[0040] Please see Figure 3 and Figure 5 The insulating component 130 includes a first insulating part 131 and a second insulating part 132, with the second insulating part 132 connected to the first insulating part 131. The connection method can be various, such as adhesive bonding, snap-fit ​​bonding, or fusion bonding. The melting point of the first insulating part 131 is lower than that of the second insulating part 132.

[0041] Along the height direction of the housing 110, the orthographic projection of the first insulating portion 131 onto the end wall 112 at least partially covers the pressure-weak portion 114. The first insulating portion 131 is configured to melt due to high temperature when the pressure-weak portion 114 ruptures, and to be ejected from the rupture point to the outside of the housing 110 under the internal pressure of the housing 110. The second insulating portion 132 is configured not to melt when the pressure-weak portion 114 ruptures, thereby maintaining a fixed connection with the end wall 112.

[0042] It should be noted that during normal operation of the single cell 100, the pressure-weak portion 114 of the end wall 112 remains intact, and the internal pressure and temperature of the single cell 100 remain within the normal range. However, when abnormal conditions such as thermal runaway occur inside the single cell 100, the exothermic reaction of the internal active materials, the continuous heat generation at the short circuit point, or the direct impact of the high-temperature gas flow / material before eruption on the end wall 112 can cause the internal temperature of the casing 110 to rise sharply. This temperature can typically reach 200°C or even higher, depending on the materials of the single cell 100 and the severity of the thermal runaway. In this case, by setting the melting point of the first insulating portion 131 below the temperature at which thermal runaway occurs inside the casing 110 (e.g., 150°C), the first insulating portion 131 can be melted due to the high temperature before the pressure-weak portion 114 ruptures. As the internal temperature of the casing 110 continues to rise, the pressure inside the casing 110 gradually increases. Once a set threshold is reached, the pressure-weak portion 114 will rupture. At this time, the first insulating part 131, which is already in a molten state, will be ejected from the rupture point to the outside of the housing 110 under the action of the high-pressure airflow inside the housing 110, thereby achieving effective pressure relief and heat release, and mitigating the risk of thermal runaway.

[0043] By setting the melting point of the second insulating portion 132 to be higher than the maximum limit temperature at which thermal failure occurs inside the housing 110, thermal melting of the second insulating portion 132 can be avoided when the internal temperature of the housing 110 rises sharply. Therefore, when the pressure weak portion 114 ruptures, the second insulating portion 132 can remain solid and stably connected to the end wall 112, thereby maintaining the integrity of the structure. At the same time, since the arrangement of the second insulating portion 132 avoids the location of the pressure weak portion 114, the impact of high-pressure airflow generated when this part ruptures can be effectively avoided, maintaining the stability of the installation position between it and the end wall 112.

[0044] In this embodiment, the insulating member 130 includes a first insulating portion 131 and a second insulating portion 132 connected to the first insulating portion 131, and the melting point of the first insulating portion 131 is lower than the melting point of the second insulating portion 132; wherein, the orthographic projection of the first insulating portion 131 on the end wall 112 at least partially covers the pressure-weak portion 114; the first insulating portion 131 is configured to melt due to high temperature when the pressure-weak portion 114 breaks, so as to be ejected from the breakage point to the outside of the housing 110 under the action of the internal pressure of the housing 110; the second insulating portion 132 is configured not to melt when the pressure-weak portion 114 breaks, so as to maintain a fixed connection with the end wall 112. With this configuration, since the melting point of the first insulating part 131 is relatively low and it can melt when the pressure-weak part 114 breaks, and spray out from the break to the outside of the housing 110 under the action of internal pressure, it will not block the pressure relief channel. Therefore, it can ensure that the high-pressure gas inside the housing 110 can be discharged from the break in time, thereby ensuring the smoothness of the pressure relief channel and allowing the internal pressure of the single cell 100 to be released in time, effectively reducing the risk of thermal runaway.

[0045] Meanwhile, if all the insulating components 130 are made of low-melting-point materials, although it can ensure that the corresponding insulating components 130 can be discharged outside the housing 110 with the high-pressure gas flow when the pressure weak point 114 ruptures, the insulating components 130 at other locations on the end wall 112 will melt and become fluid at high temperatures, and may accumulate towards the pressure weak point 114 under the push of the high-pressure gas flow. When the pressure weak point 114 ruptures, this molten insulating material may remain at the rupture location, which may not only block the pressure relief channel and affect normal pressure relief, but may also pose a risk of spontaneous combustion due to the high-temperature residue coming into contact with oxygen in the outside air, thereby further aggravating thermal runaway.

[0046] Based on this, in this embodiment, the second insulating part 132 is made of a high melting point material, which can remain non-melting even when the pressure-weak part 114 ruptures, thereby maintaining its installation position stability on the end wall 112. This helps ensure the insulation reliability between the end wall 112 and the electrode assembly in the area outside the first insulating part 131, avoiding internal short circuits caused by large-area insulation failure on the end wall 112 side, and thus reducing the risk of escalating thermal runaway. In addition, since the low-melting-point first insulating part 131 can be effectively discharged outside the housing 110, reducing the residue of low-melting-point material inside the housing 110, the probability of spontaneous combustion after contact with oxygen in the air can be further reduced, thereby suppressing further escalation of thermal runaway.

[0047] Considering that the high temperature generated during thermal runaway inside the casing 110 is closely related to the capacity of the actual single-cell battery 100, the melting points of the first insulating part 131 and the second insulating part 132 need to be determined according to the specific capacity of the single-cell battery 100 in the actual product design. For example, in one embodiment of this utility model, the melting point of the first insulating part 131 is 150–170°C, for example, it can be 150°C, 160°C, or 170°C, etc. The melting point of the second insulating part 132 is 300–500°C, for example, it can be 300°C, 400°C, or 500°C, etc. Such a melting point setting can meet the capacity requirements of most conventional single-cell batteries 100, ensuring that when a single-cell battery 100 experiences thermal runaway, the first insulating part 131 can melt due to the high temperature inside the casing 110, while the second insulating part 132 can remain stable under high temperature, without melting or minimizing the degree of melting.

[0048] As long as the melting point requirements of the first insulating part 131 and the second insulating part 132 are met, the specific materials used in the embodiments of this utility model are not limited. In one specific embodiment of this utility model, the first insulating part 131 is made of polypropylene (PP), and the second insulating part 132 is made of liquid crystal polymer (LCP). Since the melting point range of polypropylene is 164-170℃, it can well meet the requirement of a low melting point when thermal runaway occurs inside the shell 110. At the same time, polypropylene also has good comprehensive properties, including excellent electrical insulation, acid and alkali corrosion resistance (stable to electrolyte), low density, and relatively low cost. Liquid crystal polymer can be modified to increase its heat distortion temperature to 300-500℃, so that it is not easy to melt due to high temperature when thermal runaway occurs inside the shell 110. In addition, when its flame retardant temperature is controlled below 350℃, the cost increase of liquid crystal polymer is also smaller compared with polypropylene.

[0049] Please see Figure 5 In one embodiment of the present invention, the orthographic projection outline of the first insulating portion 131 on the end wall 112 surrounds the outer periphery of the orthographic projection outline of the pressure-weak portion 114 on the end wall 112. That is, the orthographic projection of the first insulating portion 131 on the end wall 112 completely surrounds and includes the orthographic projection of the pressure-weak portion 114 on the end wall 112.

[0050] With this configuration, when the internal temperature of the single cell 100 rises to the point where the first insulating part 131 (made of a low-melting-point material) melts, since the coverage area of ​​the first insulating part 131 completely includes the area of ​​the pressure-weak part 114, the insulating material in the corresponding area can be completely melted and removed at the same time as the pressure-weak part 114 ruptures. This avoids molten material remaining at the rupture site, which not only further ensures the unobstructed flow of the pressure relief channel but also reduces the amount of molten material remaining at the pressure relief channel location, thus reducing the probability of spontaneous combustion when the residue comes into contact with oxygen in the air. At the same time, the first insulating part 131 has a surrounding layout relative to the pressure-weak part 114, which can guide the molten insulating material located on the outer periphery of the pressure-weak part 114 to contract towards the central area of ​​the pressure-weak part 114 so that it can be discharged outside the casing 110 when ruptured, thereby further reducing the possibility of the first insulating part 131 being partially retained at the rupture site or inside the casing 110.

[0051] In one embodiment of this utility model, the first insulating part 131 is provided with at least one airflow channel 1311, which penetrates the thickness of the first insulating part 131 and is used to connect the spaces on both sides of the insulation member 130 in the thickness direction before the pressure weak part 114 ruptures. The airflow channel 1311 can be a strip-shaped through-hole structure, a through-hole structure, etc. Optionally, in this embodiment, the airflow channel 1311 is a strip-shaped through-hole structure. There can be one or more strip-shaped through-hole structures, depending on whether the pressure relief requirements of the single cell 100 are met.

[0052] By providing an airflow channel 1311 on the first insulating part 131, in the event of thermal runaway inside the single cell 100 before the pressure weak part 114 ruptures and the first insulating part 131 has not yet completely melted, the high-pressure gas inside the casing 110 can flow through the airflow channel 1311 to the space between the pressure weak part 114 and the first insulating part 131, and accumulate there. This arrangement ensures that once the pressure weak part 114 ruptures, the high-pressure gas can be quickly discharged, thereby improving the timeliness of the pressure relief response.

[0053] Please see Figure 3 and Figure 4 In one embodiment of the present invention, the second insulating portion 132 includes a first extension 1321 and a second extension 1322, the first extension 1321 and the second extension 1322 being respectively connected to the first insulating portion 131 along its length direction (e.g., ...). Figure 3(As shown in the X-axis direction). The length direction of the first insulating portion 131 is consistent with the length direction of the housing 110. The first extension portion 1321 and the second extension portion 1322 can be symmetrically arranged on both sides of the length direction of the first insulating portion 131, or they can be asymmetrically arranged on both sides of the length direction of the first insulating portion 131. Along the direction from the end wall 112 to the electrode assembly, the orthographic projection of the first extension portion 1321 and the orthographic projection of the first insulating portion 131 at least partially overlap, and the orthographic projection of the second extension portion 1322 and the orthographic projection of the first insulating portion 131 also at least partially overlap.

[0054] Please see Figure 3 and Figure 4 Specifically, the first insulating portion 131 includes a first body portion 1312 and two first connecting portions 1313, which are respectively connected to both ends of the first body portion 1312 along its length. An airflow channel 1311 is disposed on the first body portion 1312. The first extension portion 1321 includes a second body portion 13211 and a second connecting portion 13212 connected to the second body portion 13211 near the first insulating portion 131. The second extension portion 1322 includes a third body portion 13221 and a third connecting portion 13222 connected to the third body portion 13221 near the first insulating portion 131. The two first connecting portions 1313 are respectively connected to the second connecting portion 13212 and the third connecting portion 13222. This achieves at least partial overlap between the orthographic projection of the first extension portion 1321 and the orthographic projection of the first insulating portion 131, and at least partial overlap between the orthographic projection of the second extension portion 1322 and the orthographic projection of the first insulating portion 131.

[0055] It should be noted that in this embodiment, the two first connecting parts 1313 are respectively overlapped with the second connecting part 13212 and the third connecting part 13222. This can mean that the two first connecting parts 1313 overlap with the first connecting part 1313 and the second connecting part 13212, or that the second connecting part 13212 and the third connecting part 13222 overlap with the two first connecting parts 1313. The fixed connection between the two first connecting parts 1313 and the second connecting part 13212 and the third connecting part 13222 can be achieved solely through overlap, or, in addition to overlap, a snap-fit ​​structure or adhesive method can be used to further enhance the strength of the connection.

[0056] In this embodiment, the orthographic projection of the first extension 1321 at least partially overlaps with the orthographic projection of the first insulating portion 131, and / or the orthographic projection of the second extension 1322 at least partially overlaps with the orthographic projection of the first insulating portion 131. This overlapping design can effectively reduce the possibility of a connection gap occurring at the connection position between the first insulating portion 131 and the second insulating portion 132. Therefore, the insulation performance between the end wall 112 and the electrode assembly can be ensured, avoiding a decrease in insulation performance due to the presence of a connection gap.

[0057] It should be noted that, in another embodiment, only the orthographic projections of the first extension 1321 and the first insulating portion 131 may at least partially overlap. In other embodiments, only the orthographic projections of the second extension 1322 and the first insulating portion 131 may at least partially overlap. This arrangement can also reduce the connection gap to some extent.

[0058] Based on the above embodiments, please further refer to... Figure 3 and Figure 4 The thickness of the first connecting portion 1313 is less than the thickness of the first body portion 1312, the thickness of the second connecting portion 13212 is less than the thickness of the second body portion 13211, and the thickness of the third connecting portion 13222 is also less than the thickness of the third body portion 13221. Through this thickness difference design, when the first connecting portion 1313 is connected to the second connecting portion 13212, and when the first connecting portion 1313 is connected to the third connecting portion 13222, a smaller stacking thickness can be formed in the overlapping connection area. This not only helps to reduce the height space occupied by the insulating component 130 inside the housing 110, but also provides conditions for the lightweight design of the insulating component 130, thereby avoiding a significant increase in the overall weight of the insulating component 130.

[0059] Based on the above embodiment where the two first connecting portions 1313 are respectively connected to the second connecting portion 13212 and the third connecting portion 13222 by overlapping, please refer to [further details omitted]. Figure 3 and Figure 4 In one embodiment of this utility model, along the direction from the end wall 112 to the electrode assembly, the two sides of the first insulating portion 131 in the length direction respectively abut against the side of the first extension portion 1321 opposite to the electrode assembly and the side of the second extension portion 1322 opposite to the electrode assembly. That is, the two first connecting portions 1313 abut against the side of the second connecting portion 13212 opposite to the electrode assembly and the side of the third connecting portion 13222 opposite to the electrode assembly, respectively. This arrangement allows the two first connecting portions 1313 to overlap with the second connecting portion 13212 and the third connecting portion 13222, respectively.

[0060] In this embodiment, due to the internal pressure of the housing 110, the first insulating portion 131 is subjected to a thrust toward the side away from the electrode assembly. Especially when the pressure-weak portion 114 ruptures, this thrust can effectively push the first insulating portion 131 away from the electrode assembly. By adopting the overlapping method of this embodiment, it is beneficial to break the connection between the first insulating portion 131 and the second insulating portion 132 under the action of this thrust, thereby achieving their separation. This design can ensure that when the pressure-weak portion 114 ruptures, the first insulating portion 131 can detach quickly and completely, avoiding the residue of insulating material or blockage of the rupture location of the pressure-weak portion 114 due to connection structure failure, thereby ensuring the smoothness and reliability of the pressure relief process.

[0061] Please see Figure 3 and Figure 4 In one embodiment of this utility model, the first insulating part 131 and the second insulating part 132 are connected by a snap-fit ​​structure 140. The snap-fit ​​structure 140 includes a matching snap 141 and a slot 142. The snap 141 is disposed on the second insulating part 132, and the slot 142 is disposed on the first insulating part 131. The snap-fit ​​structure 140 is configured to lose its connecting function when the first insulating part 131 is heated and melted. The specific structure of the snap 141 is not limited and can be a conical snap 141, a long strip snap 141, or a T-shaped snap 142. The slot 142 can be designed to match the shape of the snap 141, such as a conical slot, a long strip slot, or a T-shaped slot. The snap 141 can be integrally injection molded with the first insulating part 130 or connected through other detachable structures. The snap-fit ​​structure 140 can be provided in one set, or in two or more sets.

[0062] In one embodiment, two sets of snap-fit ​​structures 140 are provided. One set of snap-fit ​​structures 140 connects the first connecting portion 1313 and the second connecting portion 13212, while the other set of snap-fit ​​structures 140 connects the first connecting portion 1313 and the third connecting portion 13222. Specifically, at the connection point between the first connecting portion 1313 and the second connecting portion 13212, the snap-fit ​​141 is integrally injection molded onto the second connecting portion 13212, and the corresponding slot 142 is provided on the first connecting portion 1313. Similarly, at the connection point between the first connecting portion 1313 and the third connecting portion 13222, the snap-fit ​​141 is also integrally injection molded onto the third connecting portion 13222, and the matching slot 142 is provided on the corresponding first connecting portion 1313.

[0063] When the first insulating member 130 and the second insulating member 130 need to be combined, the snap-fit ​​141 and the snap-fit ​​slot 142 engage with each other to achieve a snap-fit ​​and fixed connection between the first insulating part 131 and the first extension part 1321, and between the first insulating part 131 and the second extension part 1322. This snap-fit ​​method ensures that a stable connection can be maintained between the first insulating member 130 and the second insulating member 130 under normal operating conditions.

[0064] As the internal temperature of the housing 110 rises, especially in the event of thermal runaway or other abnormal conditions, the first insulating element 130 will melt at high temperatures. Since the slot 142 is located on the first insulating element 130, when the first insulating element 130 melts, the slot 142 will also melt. This causes the connection between the slot 142 and the latch 141 to fail, thereby releasing the fixed connection between the first and second insulating elements 130. Therefore, when the pressure weak point 114 ruptures, the first insulating element 130 can more easily detach from the second insulating element 130 under the pressure inside the housing 110 and be discharged to the outside of the housing 110. This design reduces the residue of the low-melting-point first insulating element 130 inside the housing 110, thereby reducing the risk of spontaneous combustion caused by residual low-melting-point molten material, and further improving the safety and reliability of the single-cell battery 100 under abnormal conditions.

[0065] Please see Figure 5 In one embodiment of this utility model, the end wall 112 is further provided with a terminal mounting hole 1121, and the second insulating part 132 is provided with a first clearance hole 1323 corresponding to the terminal mounting hole 1121. The terminal mounting hole 1121 is used to install the terminal. For a single cell 100, a positive terminal 121 and a negative terminal 122 are usually provided, and both the positive terminal 121 and the negative terminal 122 are electrically connected to the electrode assembly inside the single cell 100. Therefore, there can be two terminal mounting holes 1121 on the end wall 112, one terminal mounting hole 1121 is used to install the positive terminal 121, and the other terminal mounting hole 1121 is used to install the negative terminal 122.

[0066] By providing a first clearance hole 1323 on the second insulating portion 132 corresponding to the terminal mounting hole 1121, the terminal can pass through the first clearance hole 1323 to make an electrical connection with the electrode assembly inside the housing 110. Furthermore, since the second insulating portion 132 inevitably comes into contact with the terminal, and the terminal temperature of the single-cell battery 100 is high during operation, the second insulating portion 132 has a higher melting point than the first insulating portion 131, thus providing superior high-temperature resistance. Therefore, this arrangement helps prevent the area where the second insulating portion 132 contacts the terminal from melting due to high temperature, thereby ensuring the insulation performance at this location is maintained and reducing the risk of short circuits inside the housing 110 due to positive and negative electrode contact.

[0067] Please see Figure 5 In one embodiment of this utility model, an injection hole 1122 may also be provided on the end wall 112, and a second insulating part 132 is provided with a second clearance hole 1324 corresponding to the injection hole 1122. With this arrangement, the injection hole 1122 and the second clearance hole 1324 together form an electrolyte injection channel, so that the electrolyte can be smoothly injected into the electrode assembly inside the housing 110.

[0068] Please see Figure 6 In one embodiment of the battery pack 200 of this utility model, the battery pack 200 includes a housing 210 and at least one individual battery cell 100; the housing 210 includes a first housing portion 211 and a second housing portion 212, which cover each other to form an accommodating space, in which multiple individual batteries cell 100 are accommodated, and the multiple individual batteries cell 100 can be connected in series and / or in parallel. The battery pack 200 can be, for example, a battery module, a battery pack, etc.

[0069] Please see Figure 7In one example of the electronic device 300 of this utility model, the electronic device 300 includes a working part 310 and a battery pack 200. The working part 310 is electrically connected to the battery pack 200 to obtain electrical power. The working part 310 can be a unit component capable of obtaining electrical power from the battery pack 200 and performing corresponding work, such as a fan blade rotation unit, a vacuum cleaner suction unit, or a wheel drive unit in an electric vehicle. The electronic device 300 can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This utility model embodiment does not impose special limitations on the above-mentioned electronic device 300. In one embodiment of the electronic device 300 of this utility model, the electronic device 300 is a vehicle, the working part 310 is the vehicle body, and the battery pack 200 is fixedly installed on the vehicle body, thereby providing driving force for the vehicle to operate.

[0070] 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.

Claims

1. A single-cell battery, characterized in that, include: A housing, the housing including an end wall, the end wall having a pressure-weak portion for rupturing when the internal pressure of the housing reaches a set threshold; The electrode assembly is sealed and housed within the housing; An insulating component is fixedly connected to the side of the end wall facing the electrode assembly to achieve insulation between the end wall and the electrode assembly; the insulating component includes a first insulating portion and a second insulating portion connected to the first insulating portion, and the melting point of the first insulating portion is lower than the melting point of the second insulating portion; Wherein, the first insulating portion, when projected onto the end wall, at least partially covers the pressure-weak portion; the first insulating portion is configured to melt due to high temperature when the pressure-weak portion ruptures, and be ejected from the rupture point to the outside of the housing under the internal pressure of the housing; the second insulating portion is configured not to melt when the pressure-weak portion ruptures, so as to maintain a fixed connection with the end wall.

2. The single-cell battery according to claim 1, characterized in that, The orthographic projection outline of the first insulating portion on the end wall surrounds the outer periphery of the orthographic projection outline of the pressure-weak portion on the end wall.

3. The single-cell battery according to claim 1, characterized in that, The first insulating part is provided with at least one airflow channel, which penetrates the thickness of the first insulating part and is used to connect the spaces on both sides of the insulation part in the thickness direction before the pressure-weak part breaks.

4. The single-cell battery according to claim 1, characterized in that, The second insulating portion includes a first extension and a second extension, which are respectively connected to both sides of the first insulating portion along its length; along the direction from the end wall to the electrode assembly, the orthographic projection of the first extension and the orthographic projection of the first insulating portion at least partially overlap. And / or, the orthographic projection of the second extension at least partially overlaps with the orthographic projection of the first insulating portion.

5. The single-cell battery according to claim 4, characterized in that, Along the direction from the end wall to the electrode assembly, the two sides of the first insulating portion in the length direction respectively abut against the side of the first extension portion away from the electrode assembly and the side of the second extension portion away from the electrode assembly.

6. The single-cell battery according to claim 1, characterized in that, The first insulating part and the second insulating part are connected by a snap-fit ​​structure, which includes a matching snap and a slot. One of the snap and the slot is disposed on the first insulating part, and the other is disposed on the second insulating part. The snap-fit ​​structure is configured to lose its connection function when the first insulating part is heated and melted.

7. The single-cell battery according to claim 1, characterized in that, The end wall is also provided with a pole mounting hole, and the second insulating part is provided with a first clearance hole corresponding to the pole mounting hole.

8. The single-cell battery according to claim 1, characterized in that, The first insulating part is made of polypropylene, and the second insulating part is made of liquid crystal polymer.

9. The single-cell battery according to claim 1, characterized in that, The melting point of the first insulating part is 150-170°C, and the melting point of the second insulating part is 300-500°C.

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

Images