Battery

Abstract

The utility model discloses a battery. The battery comprises: a housing having a storage cavity; the battery cell is arranged in the storage cavity; the flexible part is arranged in the storage cavity, and the flexible part is arranged between the battery cell and the wall of the storage cavity; and the flexible part is configured to extrude the battery cell and the shell between the battery cell and the shell when the flexible part is heated to expand. According to the battery disclosed by the utility model, the safety performance of the battery can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to battery. BACKGROUND

[0002] At present, with the rapid development of power battery, especially due to the surge in demand for clean energy, power battery has been widely used in electric vehicles and electric bicycles and other fields. These batteries mainly include electric core and steel shell body. However, due to the influence of road and weather conditions, power battery may suffer from falling or vibration in actual use, which is easy to cause the collision and bruise of electric core inside the shell, thereby reducing the service life of the battery. In addition, the electric core is installed in the steel shell body under interference fit, which is easy to cause short circuit, liquid leakage, smoke, fire and even explosion in the battery during falling.

[0003] In the related art, some ways are to increase the fixing process technology during the battery grouping packaging process to improve the stability of the battery, or to increase the protective layer between the electric core and the shell, and the electric core is interference fitted in the shell. These technologies can protect the electric core to some extent, but in the electric core falling process, due to the strong impact force, it is still easy to cause explosion and fire of the electric core, and cause fire safety problems. Therefore, developing a new type of battery to reduce the possibility of explosion and fire of the electric core when falling, and improving the safety and stability of the battery, has become a problem to be solved in the development of power battery technology. SUMMARY

[0004] The utility model aims at at least one of the technical problems existing in the prior art. To this end, the utility model provides a battery, which can improve the safety performance of the battery.

[0005] The battery according to the embodiment of the first aspect of the utility model comprises:

[0006] A shell, the shell has a storage cavity;

[0007] An electric core, the electric core is arranged in the storage cavity;

[0008] A flexible member, the flexible member is arranged in the storage cavity, and the flexible member is arranged between the electric core and the cavity wall of the storage cavity;

[0009] The flexible member is configured to be capable of expanding by heat to extrude the electric core and the shell.

[0010] The battery according to the embodiment of the first aspect of the utility model has at least the following beneficial effects: the safety performance of the battery can be improved.

[0011] In the application, the battery comprises a battery cell, a shell, and a flexible piece arranged between the shell and the battery cell, the flexible piece is connected with the shell, the flexible piece can protect the battery cell to a certain extent and improve the safety of the battery cell in slight collision. The flexible piece is configured to expand when the flexible piece is heated, so as to fill the gap between the flexible piece and the battery cell and generate a force pressing the battery cell and the shell between the battery cell and the shell, thereby accelerating the rupture of the shell to a certain extent, avoiding explosion and fire caused by continuous heating of the internal battery cell, and improving the safety performance of the battery.

[0012] According to some embodiments of the present application, one side of the flexible piece is close to the shell, and a gap exists between the other side of the flexible piece and the battery cell.

[0013] When the flexible piece is heated and expanded, the flexible piece can fill the gap.

[0014] According to some embodiments of the present application, the size of the gap is L, 0.4mm≥L≥0.3mm.

[0015] According to some embodiments of the present application, the outer surface of the shell is provided with a groove.

[0016] According to some embodiments of the present application, the flexible piece surrounds the entire circumference of the battery cell.

[0017] According to some embodiments of the present application, a plurality of flexible pieces are provided, and the plurality of flexible pieces are arranged at the corners of the shell.

[0018] According to some embodiments of the present application, the flexible piece has a first part and a second part, the first part and the second part are connected with each other, the first part extends along the width direction of the battery cell, and the second part extends along the length direction of the battery cell.

[0019] According to some embodiments of the present application, the maximum expansion size of the flexible piece is D, 0.5mm≥D>0.3mm.

[0020] According to some embodiments of the present application, the material of the flexible piece is polytetrafluoroethylene or polychloroprene.

[0021] According to some embodiments of the present application, the flexible piece has a pore for accommodating electrolyte.

[0022] Additional aspects and advantages of the present application will be given in part in the following description, will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The utility model is further described below in combination with the drawings and embodiments, in which

[0024] Figure 1 It is the schematic view of the first embodiment of the battery of the utility model.

[0025] Figure 2 It is the schematic view of the second embodiment of the battery.

[0026] Figure 3 It is the schematic view of setting recess in the shell.

[0027] Figure 4 It is the schematic view of setting recess in the shell.

[0028] Figure 5 It is the schematic view of the third embodiment of the battery.

[0029] Figure 6 It is the schematic view of the fourth embodiment of the battery.

[0030] Reference signs:

[0031] Shell 100, storage cavity 101, gap 102, recess 103, flexible piece 200, first part 210, second part 220, battery cell 300. DETAILED DESCRIPTION

[0032] The embodiments of the utility model are described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0033] In the description of the utility model, it is understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as limiting the utility model.

[0034] In the description of the utility model, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. is understood as not including the number, above, below, etc. is understood as including the number. If the first, the second is described, it is only used for distinguishing the technical features for the purpose, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0035] In the description of the utility model, unless otherwise expressly limited, the words such as setting, installing, connecting should be understood in a broad sense, and the skilled in the art can determine the specific meaning of the above words in the utility model in combination with the specific content of the technical scheme.

[0036] In the description of the utility model, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0037] The battery can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc. The present application embodiment is not limited thereto.

[0038] The battery generally includes a cell. The cell includes a positive electrode, a negative electrode and a separator. In the process of charging and discharging the battery, active ions (such as lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow the active ions to pass through.

[0039] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material arranged on at least one surface of the positive electrode current collector.

[0040] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0041] As an example, the positive electrode current collector can adopt a metal foil or a composite current collector. For example, as a metal foil, aluminum with silver plating treatment on the surface, stainless steel with silver plating treatment on the surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector can include a high polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a high polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0042] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to simply as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to simply as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to simply as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to simply as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be referred to simply as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), and modified compounds thereof, etc.

[0043] In some embodiments, the positive electrode can employ a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, etc. When the foam metal is used as the positive electrode, the surface of the foam metal can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the foam metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0044] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0045] As an example, the negative current collector can employ a metal foil, a foam metal, or a composite current collector. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, etc. can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0046] As an example, the negative electrode sheet can include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0047] As an example, the negative current collector has two surfaces opposite in a thickness direction thereof, and the negative active material is disposed on any one or both of the two opposite surfaces of the negative current collector.

[0048] As an example, the negative active material can employ a negative active material for a battery known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative active material for a battery can also be used. These negative active materials can be used alone or in combination of two or more.

[0049] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0050] In some embodiments, the battery cell further includes a separator disposed between the positive electrode and the negative electrode.

[0051] In some embodiments, the separator is a separator film. The separator film can be of various types, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0052] As an example, the material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0053] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the anode and the cathode, and functions to transport ions and to separate the anode and the cathode.

[0054] In some embodiments, the battery further includes an electrolyte that functions to conduct ions between the anode and the cathode. The electrolyte can be in a liquid state, a gel state, or a solid state. In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0055] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro oxalato borate, lithium bis-oxalato borate, lithium difluoro bis-oxalato phosphate, and lithium tetrafluoro oxalato phosphate.

[0056] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyrosulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and a crown ether.

[0057] In some embodiments, the gel-state electrolyte includes a polymer as a backbone network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0058] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0059] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0060] As an example, the inorganic solid-state electrolyte can include one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfide, argyrodite), amorphous sulfide), a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0061] As an example, the composite solid-state electrolyte is formed by adding inorganic solid-state electrolyte fillers in a polymer solid-state electrolyte.

[0062] In some embodiments, the battery cell is in a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound to form the jelly-roll structure.

[0063] In some embodiments, the battery cell is in a stack structure.

[0064] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided respectively and are alternately stacked.

[0065] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of folded segments which are stacked.

[0066] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments which are stacked.

[0067] As an example, a plurality of separators can be provided and are respectively arranged between any adjacent positive electrode sheets or negative electrode sheets.

[0068] As an example, the separators can be continuously provided and are arranged between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0069] In some embodiments, the battery cell can have a cylindrical shape, a flat shape, or a polygonal shape.

[0070] In some embodiments, the battery cell can be provided with tabs. The tabs can conduct current out of the battery cell. The tabs include positive tabs and negative tabs.

[0071] In some embodiments, the battery can include a housing. The housing is used to encapsulate the battery cell and other components such as electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0072] As an example, the battery can be a cylindrical battery, a prismatic battery, a pouch battery, or a battery of other shapes. The prismatic battery includes, but is not limited to, a square battery, a blade battery, and a polygonal battery such as a hexagonal battery, etc.

[0073] The battery referred to in the embodiments of the present application refers to a single physical module including one or more batteries to provide higher voltage and capacity.

[0074] In some embodiments, the battery can be a battery module. When there are multiple batteries, the multiple batteries are arranged and fixed to form a battery module.

[0075] In some embodiments, the battery can be a battery pack. The battery pack includes a box and a battery. The battery or the battery module is contained in the box.

[0076] In some embodiments, the box can be part of a chassis structure of a vehicle. For example, portions of the box can become at least part of a floor of the vehicle, or portions of the box can become at least part of cross members and longitudinal members of the vehicle.

[0077] Embodiments of the present application provide a power consuming device using a battery as a power source. The power consuming device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy can include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, an electric plane toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0078] With the increasing global demand for clean energy, power battery technology is experiencing rapid development and playing an increasingly important role in electric vehicles, electric bicycles, and other portable electronic devices. Such batteries are typically composed of core components, namely, the electric cells, and protective casings. However, in practical applications, these batteries can be at risk of falling or shaking due to poor road conditions or weather factors, which can cause collisions or frictional damage between the internal cells and the casing, thereby shortening the service life of the battery.

[0079] When the electric cells are tightly installed in the steel casing with an interference fit, such a design can lead to more serious consequences, such as internal short circuits, electrolyte leakage, smoking, fire, and even explosion, in the event of accidental falling. These problems not only threaten the safety of users, but also can cause environmental pollution.

[0080] To address the above challenges, the industry has explored various methods to enhance the stability of battery pack packaging, such as improving the fixing process or adding a buffer layer between the cells and the casing. Although these measures can to some extent reduce the impact of impact on the cells, there is still some risk in extreme cases, such as when subjected to a strong impact.

[0081] Therefore, it has become an urgent problem to develop a new type of power battery that can significantly reduce the risk of explosion and fire when subjected to impact.

[0082] Reference Figures 1 to 6 , mainly referring to Figure 1 , Figure 2According to an embodiment of the first aspect of the present invention, a battery includes a housing 100, a battery cell 300, and a flexible member 200. The housing 100 has a storage cavity 101, the battery cell 300 is disposed in the storage cavity 101, and the flexible member 200 is disposed in the storage cavity 101, and the flexible member 200 is disposed between the battery cell 300 and the cavity wall of the storage cavity 101. The flexible member 200 is configured such that it can thermally expand to compress the battery cell 300 and the housing 100.

[0083] The battery according to the first aspect of this utility model has at least the following beneficial effects: it can improve the safety performance of the battery. In this application, the battery includes a cell 300, a casing 100, and a flexible member 200 disposed between the casing 100 and the cell 300. The flexible member 200 is connected to the casing 100 and can protect the cell 300 to a certain extent, improving the safety of the cell 300 in the event of a minor impact. The flexible member 200 is configured to expand when heated to fill the gap 102 between the flexible member 200 and the cell 300, generating a force that compresses the cell 300 and the casing 100, thereby accelerating the rupture of the casing 100 to a certain extent, preventing the internal cell 300 from continuously heating up and exploding or catching fire, thus improving the safety performance of the battery.

[0084] Compared to the battery structures of related technologies that employ an interference fit to mount the cell 300 onto a housing 100 with a buffer, in this application, the flexible member 200 is disposed between the cell 300 and the housing 100, but the cell 300 and the flexible member 200 are not interference-fitted. Furthermore, the flexible member 200 is capable of thermal expansion. The flexible member 200 can protect the cell 300 from minor impacts to prevent internal short circuits, and can also prevent battery explosion and fire after severe impacts. Specifically, after a severe impact causes thermal runaway within the cell 300, the flexible member 200, located in the storage cavity 101 of the housing 100, expands due to heat, applying pressure between the housing 100 and the cell 300 to accelerate the rupture of the housing 100. This prevents the cell 300 from continuously heating up inside the housing 100, thus avoiding battery explosion and potential fire hazards. Therefore, since the battery of this application is provided with a flexible member 200 that can expand under heat, compared with the battery structure of the related technology where the cell 300 and the buffer member are squeezed together, the battery of this application can cause the flexible member 200 to expand under heat after the cell 300 thermally runs away, thereby applying outward pressure between the cell 300 and the casing 100, accelerating the rupture of the casing 100, and improving the safety performance of the battery.

[0085] According to some embodiments of the present application, one side of the flexible member 200 is close to the shell 100, and a gap 102 exists between the other side of the flexible member 200 and the battery cell 300. When the flexible member 200 is heated and expands, the flexible member 200 can fill the gap 102. Specifically, the flexible member 200 is heated and expands, one side of the flexible member 200 is close to the shell 100, the other side of the flexible member 200 abuts against the battery cell 300, and pressure is applied to the battery cell 300 and the shell 100 between the battery cell 300 and the shell 100, so as to accelerate the rupture of the shell.

[0086] The flexible member 200 can be arranged in a manner that one side abuts against the inner wall of the shell 100 and the other side abuts against the outer wall of the battery cell 300, or one side abuts against and is fixed to the inner wall of the shell 100 and the other side does not contact the battery cell 300, that is, a gap 102 exists between the other side and the battery cell 300. In this application, the gap 102 is provided between the flexible member 200 and the battery cell 300, so that the battery cell 300 can be protected by the flexible member 200 when it is slightly impacted. In addition, the gap 102 can provide space for the flexible member 200 to expand after being heated, so that the flexible member 200 expands between the battery cell 300 and the shell 100 and exerts pressure on the battery cell 300 and the shell 100, so as to extrude the shell 100, accelerate the rupture of the shell 100, avoid continuous heating of the battery cell 300 inside the shell 100 to cause explosion or even fire, and improve the safety performance of the battery.

[0087] According to some embodiments of the present application, the size of the gap 102 is L, and 0.4mm≥L≥0.3mm. Specifically, the gap 102 between the battery cell 300 and the flexible member 200 should not be too large or too small. If the gap 102 is too large, the internal space of the battery will be wasted, which is not conducive to improving the energy density of the battery. If the gap 102 is too small, it is not conducive to the thermal expansion of the flexible member 200, and thus not conducive to accelerating the rupture of the shell 100. Therefore, in this application, as an example, the size of the gap 102 can be 0.35mm, which can save the internal space of the battery, to a certain extent, to protect the battery cell 300 from being damaged when it is slightly impacted, and on the other hand, to reserve enough space for the flexible member 200 to expand, to exert pressure on the shell 100, to accelerate the rupture of the shell 100, and to avoid safety hazards such as explosion or fire. In addition, the size of the gap 102 can also be 0.32mm, 0.34mm, 0.36mm and 0.38mm, etc., as long as the flexible member 200 can protect the battery cell and have enough expansion space.

[0088] Referring to Figure 3 , Figure 4According to some embodiments of the present application, the outer surface of the shell 100 is provided with a groove 103. Specifically, the thickness of the groove 103 is less than the thickness of the body part of the shell 100. When the flexible member 200 expands after being heated, the flexible member 200 extrudes the shell 100, so that the shell 100 breaks along the groove 103. Further, the battery shell is generally made of steel material, and the hardness of the steel material is relatively high. Only under the action of the expansion force of the flexible member 200, it is often difficult to directly extrude and break the shell 100. Therefore, in the present application, the groove 103 is provided on the shell 100, and the thickness of the groove 103 is less than the thickness of other parts of the shell 100. Thus, when the shell 100 is extruded by the flexible member 200, the groove 103 can break the shell 100 along the groove 103 due to its thin thickness after the flexible member 200 expands, thereby breaking the shell 100, avoiding continuous heating of the battery cell 300 inside the shell 100 to cause explosion, even fire, and improving the safety performance of the battery. In addition, the flexible member can extrude the battery cell and the shell, and the expansion of the flexible member can also occupy more space in the storage cavity, thereby facilitating the high-temperature and high-pressure gas to break through the groove (the larger the space, the greater the gas pressure, and the easier it is to break the thinnest wall of the shell).

[0089] Further, the groove 103 can be provided on the surface of the cover part of the shell 100. It can be provided as one or more on the side of the cover part of the shell 100. The shape of the groove 103 can be arc-shaped or rectangular or other shapes, as long as the thickness of the shell 100 at the groove 103 is less than the thickness of other parts of the shell 100, so that the shell 100 can break along the groove 103 after the flexible member 200 expands, thereby breaking the shell 100, avoiding continuous heating of the battery cell 300 inside the shell 100 to cause explosion, even fire, and improving the safety performance of the battery.

[0090] Referring to Figure 5 According to some embodiments of the present application, the flexible member 200 surrounds the entire circumference of the battery cell 300. The flexible member 200 can be provided along the length and width of the entire circumference of the inner wall of the shell 100, and the flexible member 200 provided on the entire circumference of the inner wall of the shell 100 can surround the entire circumference of the battery cell 300, so as to fully surround the battery cell 300, avoiding short circuit inside the battery cell 300 when the battery cell 300 is impacted, thereby causing damage to the battery or fire.

[0091] Specifically, the flexible piece 200 can be arranged continuously along the full length and full width of the inner wall of the shell 100, forming a complete protective layer around the battery cell 300. This full-enclosure installation mode ensures that the battery cell 300 is effectively protected by the flexible piece 200 throughout its entire circumference. When the battery encounters external impact, the flexible piece 200 can act as a buffer barrier, significantly reducing the likelihood of impact force acting directly on the battery cell 300, thereby effectively preventing safety hazards such as internal short circuit, battery damage, or fire caused by impact. In this way, the overall safety performance of the battery is greatly improved.

[0092] With reference to the foregoing Figure 1 , Figure 2 According to some embodiments of the present application, the flexible piece 200 is provided in multiple numbers, and the multiple flexible pieces 200 are respectively arranged at the corners of the shell. In addition to arranging the flexible piece 200 along the entire circumference of the battery cell 300, the flexible piece 200 can also be provided in multiple numbers, and the multiple flexible pieces 200 are respectively arranged at the corners of the inner wall of the shell 100 in a spaced manner, so as to save internal space, save materials, and improve the energy density of the battery under the premise of protecting the battery cell 300.

[0093] With reference to the foregoing Figure 6 The arrangement of the flexible piece 200 of the present application is suitable for batteries of various shapes. When the shell 100 of the battery is a special-shaped shell 100, the flexible piece 200 can also be arranged at each corner of the shell 100 to protect the battery cell 300, and after the flexible piece 200 expands due to heat, the shell 100 can be squeezed to accelerate the rupture of the shell 100. The number of flexible pieces 200 can be arranged according to specific conditions, as long as the battery cell 300 can be protected and the shell 100 can be squeezed to accelerate its rupture after the flexible piece 200 expands due to heat.

[0094] According to some embodiments of the present application, the flexible piece 200 has a first portion 210 and a second portion 220, the first portion 210 and the second portion 220 are connected to each other, the first portion 210 extends in the width direction of the battery cell 300, and the second portion 220 extends in the length direction of the battery cell 300. Specifically, in the present application, the first portion 210 of the flexible piece 200 is arranged between the battery cell 300 and the wide side of the shell 100, the second portion 220 of the flexible piece 200 is arranged between the battery cell 300 and the long side of the shell 100, the first portion 210 and the second portion 220 are connected to each other, and the free end of the first portion 210 (i.e., the opposite end of the first portion 210 and the second portion 220 at the connection) and the free end of the second portion 220 have an inclined surface. The inclined surface can improve material utilization on the one hand, and also reserve space for the subsequent expansion of the flexible piece 200 on the other hand.

[0095] According to some embodiments of the present application, the maximum expansion size of the flexible member 200 is D, and 0.5mm≥D>0.3mm. In order to enable the flexible member 200 to exert pressure on the shell 100 after expansion to accelerate the rupture of the shell 100, the expansion size D of the flexible member 200 should be greater than the gap 102L between the battery cell 300 and the flexible member 200 before expansion. In this application, the expansion size of the flexible member 200 can be 0.4mm, which can ensure that the flexible member 200 can extrude the shell 100 after thermal expansion to accelerate the rupture of the shell 100, and can also prevent the flexible member 200 from excessively extruding the battery cell 300 after thermal expansion, thereby avoiding the explosion of the battery cell 300 due to excessive extrusion, and improving the safety performance of the battery. In addition, the expansion size of the flexible member 200 can also be 0.32mm, 0.35mm, 0.38mm, 0.42mm, 0.45mm, 0.48mm, etc.

[0096] According to some embodiments of the present application, the material of the flexible member 200 is polytetrafluoroethylene or polychloroprene. Specifically, the material of the flexible member 200 can have the characteristics of corrosion resistance, non-crystallization, thermal expansion, and the like, and the internal molecules after expansion have pores similar to those of a sponge. In this application, the required materials can be selected, such as polytetrafluoroethylene, rubber material or other modified composite materials.

[0097] According to some embodiments of the present application, the flexible member 200 has pores for accommodating electrolyte. As described above, the flexible member 200 is configured to form pores after thermal expansion, and these pores can absorb excess electrolyte. This helps to maintain the appropriate liquid environment required for the internal chemical reaction of the battery, avoids the explosion of the battery cell 300 due to the short circuit inside the battery cell 300 caused by excessive electrolyte, and thus improves the safety and reliability of the battery.

[0098] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A battery, characterized by, The application relates to a battery, comprising: a shell having a storage cavity; an electric core arranged in the storage cavity; a flexible piece arranged in the storage cavity and between the electric core and the cavity wall of the storage cavity; the flexible piece is configured to be expanded by heat to press the electric core and the shell.

2. The battery of claim 1, wherein, One side of the flexible piece is close to the shell, and a gap exists between the other side of the flexible piece and the electric core; when the flexible piece is expanded by heat, the flexible piece can fill the gap.

3. The battery of claim 2, wherein, The size of the gap is L, and 0.4mm>=L>=0.3mm.

4. The battery of claim 1, wherein, The outer surface of the shell is provided with a groove.

5. The battery of claim 1, wherein, The flexible piece surrounds the whole circumference of the electric core.

6. The battery of claim 1, wherein, A plurality of flexible pieces are arranged at the corners of the shell.

7. The battery of claim 6, wherein, The flexible piece has a first part and a second part, the first part and the second part are connected to each other, the first part extends along the width direction of the electric core, and the second part extends along the length direction of the electric core.

8. The battery of claim 1, wherein, The maximum expansion size of the flexible piece is D, and 0.5mm>=D>0.3mm.

9. The battery of claim 1, wherein, The material of the flexible piece is polytetrafluoroethylene or polychloroprene.

10. The battery of claim 1, wherein, The flexible piece has an aperture for accommodating electrolyte.

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