Battery and battery pack

Abstract

The utility model provides a battery and a battery pack, relates to the technical field of batteries, and aims to solve the technical problem that thermal runaway of the battery is easy to occur in the prior art. The battery comprises a supporting tube, a shell, a roll core, a first connecting piece and a second connecting piece, the shell is located on the outer side of the supporting pipe and defines a mounting cavity together with the supporting pipe. The roll core is located in the installation cavity and arranged around the supporting pipe. The supporting pipe comprises a first end and a second end which are oppositely arranged, the first connecting piece is connected with the first end and the shell, the second connecting piece is connected between the second end and the shell, the first connecting piece and the second connecting piece seal the mounting cavity, at least one of the first connecting piece and the second connecting piece is a first stress weak part, and at least one of the first stress weak part and the second stress weak part is a second stress weak part. The first stress weak part is configured to be opened under the condition that the mounting cavity is under the first pressure; the shell is provided with a second stress weak part, the second stress weak part is configured to be opened under the condition that the mounting cavity is under the second pressure, and the first pressure is smaller than the second pressure.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery and a battery pack. Background Art

[0002] When the battery is in a state such as high temperature, overcharge or short circuit, a large amount of gas will be generated inside it, which will cause the air pressure inside the battery case to rise sharply. In order to prevent the battery from exploding, a stress-weakened part is usually provided on the battery case, so as to realize pressure relief and exhaust through the rupture of the stress-weakened part after the pressure inside the battery case reaches the set pressure.

[0003] In the related art, only the battery case is provided with a stress-weakened part. If the stress-weakened part cannot achieve good pressure relief after rupture, the pressure inside the battery case will continue to increase, which will lead to the risk of thermal runaway and violent explosion of the battery. Summary of the Utility Model

[0004] An embodiment of the utility model provides a battery and a battery pack, which can improve the technical problem that the battery in the related art is prone to thermal runaway and explosion.

[0005] In a first aspect, an embodiment of the utility model provides a battery, which includes: a support tube, a case, a wound core, a first connector and a second connector. The support tube is set to be hollow, and the support tube includes a first end and a second end which are oppositely arranged; the case is located outside the support tube and jointly defines an installation chamber with the support tube; the wound core is located in the installation chamber and is arranged around the support tube; the first connector connects the first end and the case; the second connector connects the second end and the case; wherein, the first connector and the second connector enclose the installation chamber, and at least one of the first connector and the second connector is a first stress-weakened part, and the first stress-weakened part is configured to: open when the installation chamber is under a first pressure; a second stress-weakened part is provided on the case, and the second stress-weakened part is configured to: open when the installation chamber is under a second pressure, and the first pressure is less than the second pressure.

[0006] In an embodiment, the case includes a first welding part, and the support tube includes a second welding part; the first welding part and the second welding part are welded through the first stress-weakened part.

[0007] In an embodiment, the thickness of the first welding part is greater than the thickness of the second welding part, and the first welding part is located on a side of the second welding part away from the axis of the support tube.

[0008] In one embodiment, the first stress-weakening portion includes a bent section, and two ends of the bent section are integrally connected to the support tube and the housing respectively.

[0009] In one embodiment, the ratio of the thickness of the housing to the thickness of the support tube is greater than or equal to 3 and less than or equal to 6.

[0010] In one embodiment, the second stress-weakening portion includes a first notch or an explosion-proof sheet provided on the housing.

[0011] In one embodiment, at least one of the first end and the second end is provided with an opening communicating with the outside.

[0012] In one embodiment, it further includes a first pole, a second pole, a first current collector, and a second current collector; the first pole, the second pole, and the first current collector are all located on the side where the first end is located, and the second current collector is located on the side where the second end is located; the winding core includes a first pole piece, a separator, and a second pole piece which are sequentially stacked, the first pole is electrically connected to the first pole piece through the first current collector, the second pole is electrically connected to the second current collector through the support tube, and the second current collector is electrically connected to the second pole piece.

[0013] In one embodiment, the second pole is also electrically connected to the second current collector through the housing.

[0014] In one embodiment, an insulating layer is further sleeved on the support tube on the side of the installation chamber.

[0015] In one embodiment, the outer wall of the insulating layer is provided with spaced convex portions, and the convex portions abut against the inner surface of the winding core.

[0016] In one embodiment, the support tube includes a main body portion, the first end and the second end are located at both ends of the main body portion, and the outer diameters of the first end and the second end are both smaller than the outer diameter of the main body portion.

[0017] In a second aspect, an embodiment of the present invention provides a battery pack, which includes the battery according to any one of the embodiments in the first aspect.

[0018] The beneficial effects of the embodiments of the present invention:

[0019] For the battery provided by the embodiment of the present utility model, the housing and the support tube jointly define a closed installation chamber, enabling the winding core to be installed in the installation chamber. When the battery is in a state such as high temperature, overcharge, or short circuit, a large amount of gas will be generated in the installation chamber and the air pressure will rise sharply. Since at least one of the first connecting member and the second connecting member is a first stress weak part, this air pressure will cause the first stress weak part to open (i.e., rupture) to achieve the communication between the installation chamber and the outside world, thereby realizing pressure relief and exhaust. In addition, since both the first stress weak part and the second stress weak part are provided on the housing, and the opening pressure of the second stress weak part is greater than that of the first stress weak part. In this way, when the battery undergoes thermal runaway, the first stress weak part can be opened first to achieve the preliminary pressure relief inside the housing, and the second stress weak part can be opened when the thermal runaway intensifies to achieve the further pressure relief inside the housing 10, thus effectively reducing the risk of the battery undergoing thermal runaway and explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present utility model. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 is a schematic structural diagram of the battery provided by the embodiment of the present utility model;

[0022] Figure 2 is Figure 1 a schematic structural diagram of area A in

[0023] Figure 3 is Figure 1 a schematic structural diagram of area B in

[0024] Figure 4 is a schematic diagram of the relative positional relationship between the bottom plate and the support tube according to the present utility model;

[0025] Figure 5 is a top view of the support tube according to the embodiment of the present utility model;

[0026] Figure 6 is a front view of the support tube according to the embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In the following, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0028] In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", or "some examples", etc. are intended to indicate that specific features, structures, materials, or characteristics related to the embodiment or example are included in at least one embodiment or example of the present application. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0029] Hereinafter, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0030] When describing some embodiments, the expression "connected" and its derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components have direct physical contact or electrical contact with each other. The embodiments disclosed herein are not necessarily limited to the content herein.

[0031] In the related art, only the battery case is provided with a stress weakening portion. If the stress weakening portion cannot achieve good pressure relief after rupture, the pressure inside the battery case will continue to increase, which may further lead to thermal runaway of the battery and the risk of violent explosion.

[0032] Based on this, the embodiments of the present application provide a battery, such as Figures 1 to 3As shown in the figure, the battery 100 includes a housing 10, a support tube 20, a wound core 30, a first connector 210, and a second connector 220. The housing 10 is located outside the support tube 20 and together with the support tube 20 defines an installation chamber 101. The wound core 30 is located within the installation chamber 101 and is arranged around the support tube 20. In this embodiment, the housing 10, the support tube 20, and the wound core 30 are coaxially arranged.

[0033] Among them, the support tube 20 is arranged in a hollow shape. The support tube 20 has a first end 21 and a second end 22 which are oppositely arranged. The first end 21 and the housing 10 are connected by the first connector 210, and the second end 22 and the housing 10 are connected by the second connector 220. The first connector 210 and the second connector 220 enclose the installation chamber 101, and at least one of the first connector 210 and the second connector 220 is a first stress-weakening part.

[0034] The first stress-weakening part is configured to open when the installation chamber 101 is under a first pressure; a second stress-weakening part is provided on the housing 10, and the second stress-weakening part is configured to open when the installation chamber 101 is under a second pressure, where the first pressure is less than the second pressure.

[0035] For the above battery 100, the housing 10 and the support tube 20 together define a closed installation chamber 101, so that the wound core 30 can be installed in the installation chamber 101. When the battery 100 is in a state such as high temperature, overcharge, or short circuit, a large amount of gas will be generated in the installation chamber 101 and the air pressure will rise sharply. Since at least one of the first connector 210 and the second connector 220 is a first stress-weakening part, the air pressure will cause the first stress-weakening part to open (i.e., rupture) to achieve the communication between the installation chamber 101 and the outside world, thereby achieving pressure relief and exhaust.

[0036] Moreover, since the first stress-weakening part is arranged at the connection part between the support tube 20 and the housing 10, and this connection part is far from the edge of the housing 10, this can effectively prevent the stress of the first stress-weakening part from changing after the housing 10 is collided by the outside world, thereby ensuring the opening stability of the first stress-weakening part. In addition, on the one hand, the support tube 20 can provide a certain degree of support for the wound core 30, thereby effectively preventing the collapse of the wound core due to the expansion of the electrode sheet during the charge and discharge process of the battery. On the other hand, the support tube 20 is in contact with the wound core 30, and the heat dissipated by the operation of the wound core 30 can also enter the hollow inner cavity of the support tube 20, thereby effectively reducing the temperature inside the wound core 30, and further ensuring its stable operation.

[0037] In addition, since the first stress weak part and the second stress weak part are provided on the shell 10, and the opening pressure of the second stress weak part is greater than the opening pressure of the first stress weak part, when the battery has thermal runaway, the first stress weak part can be opened first to achieve initial pressure relief inside the shell, and the second stress weak part can be opened when the thermal runaway intensifies to achieve further pressure relief inside the shell 10, which can effectively reduce the risk of thermal runaway and explosion of the battery.

[0038] It is worth noting that the installation chamber 101 being at the first pressure means that the internal pressure of the installation chamber 101 is the first pressure.

[0039] In some examples, the first pressure may be greater than or equal to 0.8 MPa and less than or equal to 1.2 MPa. That is, the first stress weak portion is opened when the installation chamber 101 is within the range of 0.8 MPa to 1.2 MPa, thereby achieving the first level of pressure relief.

[0040] In some examples, the second pressure may be greater than or equal to 1.3 MPa and less than or equal to 1.9 MPa. That is, the second stress weak portion is opened when the installation chamber 101 is within the range of 1.3 MPa to 1.9 MPa, thereby achieving the second level of pressure relief.

[0041] Therefore, when the first-stage pressure relief cannot fully meet the pressure release of the installation chamber 101, as the pressure in the installation chamber 101 continues to increase and reaches the second pressure, the second stress weak portion opens, thereby effectively meeting the further pressure relief requirements of the installation chamber 101.

[0042] It is worth noting that the stress-weak part mentioned in this article refers to the pressure increase in the installation chamber 101 when the battery 100 is in a high temperature, overcharged or short-circuited state. When the pressure increases to a certain extent, the stress-weak part can be stretched open to form an opening, and the opening can connect the installation chamber 101 with the external environment (i.e., the outside world) of the battery 100, thereby discharging the gas in the installation chamber 101, reducing the risk of expansion, deformation, or even explosion of the battery 100 caused by gas production inside the battery 100, thereby improving the safety of the battery 100.

[0043] In some examples, the stress-weakened portion (the first stress-weakened portion or the second stress-weakened portion) may include at least one of thickness (scores, grooves) and a solid portion having a strength lower than that of the material in the surrounding area. The solid portion having a strength lower than that of the material in the surrounding area means that the material of the stress-weakened portion has a strength lower than that of other areas on the housing 10 or the support tube 20, and when a certain pressure exists in the installation chamber 101, the material of the stress-weakened portion is easily deformed and ruptured, thereby forming an opening.

[0044] In some examples, the first stress-weakened portion and the second stress-weakened portion may be arranged in the same manner, for example, both of them only include grooves, but the depths of the grooves are different, so that the two can be opened at different pressures. In other examples, the first stress-weakened portion and the second stress-weakened portion may also be arranged in different manners, for example, one of them includes a groove, and the other includes a solid portion of a material with a strength lower than that of the surrounding area.

[0045] In some examples, the first connector 210 is a first stress-weakened portion. In other examples, the second connector 220 is a first stress-weakened portion. In yet other examples, both the first connector 210 and the second connector 220 are first stress-weakened portions.

[0046] For simplicity, some of the following embodiments only describe the case where the first connecting member 210 is the first stress weak portion. Of course, the specific setting when the second connecting member 220 is the first stress weak portion can refer to the setting when the first connecting member 210 is the first stress weak portion, and will not be repeated here.

[0047] In some embodiments, Figure 2 As shown, the housing 10 includes a first welding portion 1001, and the support tube 20 (for example, the first end 21) includes a second welding portion 2101, the first welding portion 1001 and the second welding portion 2101 are connected through a first stress-weakened portion, and the thickness of the first welding portion 1001 is greater than the thickness of the second welding portion 2101. The first welding portion 1001 is located on a side of the second welding portion 2101 away from the axis O of the support tube 20, that is, the first welding portion 1001 is farther away from the axis O of the support tube 20 than the second welding portion 2101.

[0048] The first stress-weakened portion (eg, the first connecting member 210 ) may be solder, through which the housing 10 and the support tube 20 may be connected by welding.

[0049] When the first connecting member 210 is the first stress weak part and the first stress weak part includes a solid part whose material strength is lower than that of the surrounding area, the following situations may exist. In the first situation, the material strength of the first connecting member 210 is lower than that of the housing 10 and the support pipe 20. Therefore, when there is a certain pressure in the installation chamber 101, the first connecting member 210 may rupture, thereby forming an opening and allowing the gas in the installation chamber 101 to escape. In the second situation, the material strength of the connection position between the first connecting member 210 and the housing 10 is lower than that of other surrounding areas. Therefore, when there is a certain pressure in the installation chamber 101, the connection position between the first connecting member 210 and the housing 10 may rupture, thereby forming an opening and allowing the gas in the installation chamber 101 to escape. In the third situation, the material strength of the connection position between the first connecting member 210 and the support pipe 20 is lower than that of other surrounding areas. Therefore, when there is a certain pressure in the installation chamber 101, the connection position between the first connecting member 210 and the support pipe 20 may rupture, thereby forming an opening and allowing the gas in the installation chamber 101 to escape.

[0050] In some examples, the first connecting member 210 and the pipe body 24 can be integrally formed, and the connection position between the first connecting member 210 and the housing 10 ruptures under the first pressure.

[0051] In some other examples, the first connecting member 210 and the housing 10 can be integrally formed, and the connection position between the first connecting member 210 and the pipe body 24 ruptures under the first pressure.

[0052] Since the thickness of the first welding part 1001 is greater than that of the second welding part 2101, and the first welding part 1001 is farther from the axis O of the support pipe 20 than the second welding part 2101. When the welding point between the first welding part 1001 and the second welding part 2101 ruptures, the gas in the installation chamber 101 will press the second welding part 2101 and cause it to deform towards the axis O of the support pipe 20, thereby increasing the opening formed after the first stress weak part is opened, which is more conducive to the pressure relief of the installation chamber 101.

[0053] In some embodiments, the ratio of the thickness of the housing 10 to the thickness of the support pipe 20 is greater than or equal to 3 and less than or equal to 6.

[0054] With this arrangement, when the pressure in the installation chamber 101 increases, it is easier to deform the support tube 20, so that the pressure in the installation chamber 101 can be relieved by damaging the support tube 20. In addition, the thickness of the support tube 20 is relatively small, which can avoid occupying a large area and affecting the installation area of ​​the winding core 30, thereby improving the unit energy density of the battery; on the other hand, it is also conducive to conducting the heat emitted from the inside of the winding core, thereby enhancing the heat dissipation effect of the winding core.

[0055] In some examples, the thickness of the first weld portion 1001 is the same as the thickness of the housing 10 , and the thickness of the second weld portion 2101 is the same as the thickness of the support tube 20 .

[0056] In some embodiments, the first stress-weakened portion includes a bent section, and both ends of the bent section are integrally connected to the support tube 20 and the housing 10, respectively. That is, the bent section, the support tube 20, and the housing 10 are integrally connected. Since the bent section is bent, the strength at the bent position is relatively weak. When the pressure inside the installation chamber 101 is relatively high, the bent section will be stretched open and ruptured, thereby achieving pressure relief inside the housing 10.

[0057] In some examples, the first connection member may be solder, and the second connection member may be a bent segment.

[0058] In some examples, a heat dissipation chamber 201 (i.e., a hollow inner chamber of the support tube 20) isolated from the installation chamber 101 is provided in the support tube 20, and the heat in the installation chamber 101 can be transferred to the heat dissipation chamber 201 through the support tube 20, so as to be discharged through the heat dissipation chamber 201. In this way, the heat dissipation efficiency of the battery 100 can be improved, thereby improving the performance of the battery 100.

[0059] In some embodiments, at least one of the first end 21 and the second end 22 is provided with an opening connected to the outside, so that the heat dissipation chamber 201 can be connected to the outside of the battery, thereby dissipating the heat in the heat dissipation chamber 201 to the outside of the battery, thereby improving the heat dissipation efficiency of the battery 100.

[0060] In some examples, the first end 21 or the second end 22 is provided with an opening communicating with the outside.

[0061] In some other examples, the first end 21 and the second end 22 are respectively provided with openings communicating with the outside.

[0062] In some examples, the heat dissipation chamber 201 may be filled with a heat dissipation medium to improve the heat dissipation efficiency of the heat dissipation chamber 201. Exemplarily, the heat dissipation medium may be a cooling liquid.

[0063] It should be noted that when the heat dissipation medium is a coolant, the coolant is an insulating medium, thus preventing short - circuiting between the two electrodes (i.e., the first electrode 41 and the second electrode 42) of the battery 100.

[0064] In some embodiments, such as Figure 1 and Figure 3 shown, the housing 10 includes a bottom plate 12, and the second connecting member 220 is located between the second end 22 and the bottom plate 12.

[0065] In some embodiments, such as Figure 1 and Figure 4 shown, the second stress - weakening portion includes a first notch 120 or an explosion - proof film provided on the housing 10. The first notch 120 or the explosion - proof film can be used to achieve secondary pressure relief of the installation chamber 101. Exemplarily, the second stress - weakening portion may include a first notch provided on the bottom plate 12, that is, the bottom plate 12 is provided with a first notch 120 to achieve secondary pressure relief of the installation chamber 101.

[0066] In some examples, such as Figure 4 shown, the first notch 120 can be arranged around the axis of the core 30, and the axis of the core 30 coincides with the axis O of the support tube 20.

[0067] In some embodiments, a third stress - weakening portion may also be provided on the housing 10. The third stress - weakening portion is configured to open when the installation chamber 101 is at a third pressure, where the third pressure is greater than the second pressure.

[0068] In this way, three - stage pressure relief of the installation chamber 101 can be achieved. That is, when the installation chamber 101 is at the first pressure, the first stress - weakening portion opens for primary pressure relief; when the pressure in the installation chamber 101 increases to the second pressure, the second stress - weakening portion opens for secondary pressure relief; and when the pressure in the installation chamber 101 continues to increase to the third pressure, the third stress - weakening portion opens for tertiary pressure relief.

[0069] In this way, through a multi - level pressure - relief design, better pressure relief of the installation chamber 101 can be further achieved, thus effectively avoiding violent explosion of the battery caused by battery thermal runaway.

[0070] In some examples, such as Figure 4 shown, the third stress - weakening portion may include a second notch 130 provided on the bottom plate 12.

[0071] Exemplarily, the second notch 130 is arranged around the axis of the core 30 and is located outside the first notch 120. In this way, after the second notch 130 ruptures, a larger opening area can be formed, thereby achieving better pressure relief of the installation chamber 101.

[0072] In some embodiments, as Figures 1 to 3 shown, the housing 10 further includes a top cover 11 and a surrounding plate 13. The top cover 11 and the bottom plate 12 are located at both ends of the surrounding plate 13 and are connected to the surrounding plate 13.

[0073] In some examples, the surrounding plate 13 and the bottom plate 12 can be integrally formed. The top cover 11 can be fixed to the surrounding plate 13 by welding.

[0074] In some embodiments, as Figures 1 to 3 shown, the battery 100 further includes a first pole 41, a second pole 42, a first current collector 51, and a second current collector 52. The first pole 41, the second pole 42, and the first current collector 51 are all located on the side where the first end 21 is located, and the second current collector 52 is located on the side where the second end 22 is located. The wound core 30 includes a first pole piece, a separator, and a second pole piece that are sequentially stacked or wound. The first pole 41 is electrically connected to the first pole piece through the first current collector 51. In this case, the current transmission direction corresponding to the first pole 41 is: first pole piece - first current collector 51 - first pole 41. The second pole 42 is electrically connected to the second current collector 52 through the support tube 20, and the second current collector 52 is electrically connected to the second pole piece. In this case, the current transmission direction corresponding to the second pole 42 is: second pole piece - second current collector 52 - support tube 20 - second pole 42.

[0075] With such an arrangement, the first pole 41 and the second pole 42 can be arranged on the same side, which is beneficial for subsequent welding of the electrodes (the first pole 41 and the second pole 42) of the battery 100. Connecting the first pole 41 and the second pole 42 to the battery pack can supply power to the battery pack. In addition, by using the support tube 20 for current transmission, the overcurrent path between the second pole 42 and the second pole piece can be shortened, so that the overcurrent capacity of the battery can be improved.

[0076] In some examples, the second current collector 52 can be directly in contact with and electrically connected to the support tube 20, or can be indirectly electrically connected to the support tube 20 through the housing 10 (such as the bottom plate 12). The present application does not limit this.

[0077] In some embodiments, the second pole 42 is also electrically connected to the second current collector 52 through the housing 10. In this case, the current transmission direction corresponding to the second pole 42 further includes: second pole piece - second current collector 52 - housing 10 - second pole 42. Therefore, there are two overcurrent paths between the second pole 42 and the second pole piece, so that the current collection capacity of the battery can be improved.

[0078] In some examples, an insulating member is provided between the first pole 41 and the second pole 42 to prevent a short circuit between the first pole 41 and the second pole 42.

[0079] In some examples, the first pole 41 can be the negative pole, the first pole piece is the negative pole piece, the second pole 42 is the positive pole, and the second pole piece is the positive pole piece.

[0080] In some embodiments, an opening is provided on the top cover 11, and the opening communicates with one end of the support tube 20, so that the heat dissipation chamber 201 of the support tube 20 can communicate with the outside.

[0081] The first welding part 1001 is located on the top cover 11, the second welding part 2101 is located at the first end 21 of the support tube 20, the first welding part 1001 and the second welding part 2101 are welded through the first connecting piece 210, and the top cover 11 can be directly used as the second pole 42 of the battery 100.

[0082] In some examples, the support tube 20 can be made of one of aluminum alloy, stainless steel or nickel-plated SPCC, so as to have good support performance and corrosion resistance.

[0083] In some embodiments, such as Figure 1 and Figure 5 As shown, an insulating layer 60 is further sleeved on one side of the support tube 20 in the installation chamber 101. On the one hand, the insulating layer can prevent the support tube 20 from being electrically connected to the positive and negative pole pieces, resulting in a short circuit problem. On the other hand, it can also form a good support for the core 30.

[0084] In some examples, the insulating layer 60 is made of an elastic material. By using the elastic deformation of the insulating layer 60, the extrusion force generated during the expansion of the negative pole piece during charging can be effectively relieved, which is beneficial to extending the long cycle life of the lithium battery.

[0085] It should be noted that the present application embodiment does not make specific requirements and special limitations on the material of the insulating layer 60, as long as it has high temperature resistance and chemical stability, and can still stably adhere to the surface of the support tube 20 when the internal temperature of the battery rises sharply, blocking the direct contact between the support tube 20 and the battery pole piece.

[0086] Exemplarily, the insulating layer 60 includes any one or a combination of at least two of polyether esters, propylene-based or vinyl-based.

[0087] For example, the insulating layer 60 can be made of TEPP material.

[0088] In some embodiments, the outer wall of the insulating layer 60 is provided with spaced-apart protrusions 61, and the protrusions 61 abut against the inner surface of the core 30. In this way, the protrusions 61 can provide stable support for the core 30, thus effectively avoiding the risk of the core 30 collapsing. In addition, one side of the protrusion 61 is recessed, which is beneficial to providing a buffer space for the interaction between the protrusion 61 and the core 30, and avoiding excessive extrusion between the protrusion 61 and the core 30, which may cause damage to both of them.

[0089] In some examples, as Figure 5 shown, a plurality of protrusions 61 may be provided, and the plurality of protrusions 61 are uniformly arranged along the circumferential direction of the support tube 20.

[0090] In some embodiments, as Figure 1 and Figure 6 shown, the support tube 20 includes a main body portion 23, a first end 21 and a second end 22 located at both ends of the main body portion 23, and the outer diameters of the first end 21 and the second end 22 are smaller than the outer diameter of the main body portion 23.

[0091] With this setting, the outer diameters of the first end 21 and the second end 22 are relatively small, which can reduce the welding area between the first end 21 and the second end 22 and the housing 10 respectively, thus being beneficial to reducing the first pressure corresponding to the opening of the first stress weak part. In addition, the relatively small diameters of the first end 21 and the second end 22 are also beneficial to smoothly inserting the support tube 20 into the middle cavity of the core.

[0092] In some examples, the thicknesses of the first end 21, the second end 22 and the main body portion 23 are all equal. In this case, the diameters of the openings corresponding to the first end 21 and the second end 22 (i.e., the inner diameters of the first end 21 and the second end 22) are both smaller than the inner diameter of the main body portion 23. In this way, when the heat dissipated in the main body portion 23 is discharged from the first end 21, the air flow velocity will increase due to the smaller inner diameter, thereby improving the heat dissipation efficiency of the support tube 20.

[0093] In some examples, along the axial direction of the support tube 20, the size of the insulating layer 60 is equal to the size of the main body portion 23. With this setting, the insulating layer 60 can form a good coverage of the main body portion 23.

[0094] Based on the above concept, some embodiments of the present application further provide a battery pack, which includes the battery 100 described in any of the above embodiments.

[0095] Since it includes the battery 100, this battery pack has the technical effects possessed by the above battery 100, and will not be elaborated here.

[0096] The above has introduced the embodiments of the present utility model in detail. Specific examples are used herein to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those skilled in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A battery, characterized in that: include: A support tube, arranged in a hollow shape, the support tube comprising a first end and a second end arranged opposite to each other; A housing, located outside the support tube and defining a mounting chamber together with the support tube; A winding core, located in the installation chamber and arranged around the support tube; a first connecting member, connecting the first end and the housing; as well as a second connecting member, connecting the second end and the housing; Wherein, the first connecting member and the second connecting member enclose the installation chamber, and at least one of the first connecting member and the second connecting member is a first stress-weakened portion, which is configured to be opened when the installation chamber is at a first pressure; a second stress-weakened portion is provided on the shell, which is configured to be opened when the installation chamber is at a second pressure, and the first pressure is less than the second pressure.

2. The battery according to claim 1, characterized in that The shell includes a first welding portion, and the support tube includes a second welding portion; the first welding portion and the second welding portion are welded through the first stress weak portion.

3. The battery according to claim 2, characterized in that The thickness of the first welding portion is greater than the thickness of the second welding portion, and the first welding portion is located on a side of the second welding portion away from the axis of the support tube.

4. The battery according to claim 1, characterized in that The first stress-weakened portion comprises a bending section, and two ends of the bending section are respectively integrally connected to the support tube and the shell.

5. The battery according to claim 1, characterized in that The ratio of the thickness of the shell to the thickness of the support tube is greater than or equal to 3 and less than or equal to 6.

6. The battery according to claim 1, characterized in that The second stress weakened portion includes a first notch or a bursting disc disposed on the housing.

7. The battery according to any one of claims 1 to 6, characterized in that At least one of the first end and the second end is provided with an opening communicating with the outside.

8. The battery according to any one of claims 1 to 6, characterized in that It also includes a first pole, a second pole, a first current collector and a second current collector; the first pole, the second pole and the first current collector are all located on the side where the first end is located, and the second current collector is located on the side where the second end is located; the winding core includes a first pole piece, a diaphragm and a second pole piece stacked in sequence, the first pole is electrically connected to the first pole piece through the first current collector, the second pole is electrically connected to the second current collector through the support tube, and the second current collector is electrically connected to the second pole piece.

9. The battery according to claim 8, characterized in that The second pole is also electrically connected to the second current collecting member through the shell.

10. The battery according to any one of claims 1 to 6, characterized in that The support tube is also sheathed with an insulating layer on one side of the installation chamber.

11. The battery according to claim 10, characterized in that The outer wall of the insulating layer is provided with spaced protrusions, and the protrusions abut against the inner surface of the winding core.

12. The battery according to any one of claims 1 to 6, characterized in that: The support tube further includes a main body, the first end and the second end are located at two ends of the main body, and the outer diameters of the first end and the second end are both smaller than the outer diameter of the main body.

13. A battery pack, characterized in that: include: A battery as claimed in any one of claims 1 to 12.

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