Battery and electrical apparatus

Abstract

A battery (100) and an electrical apparatus. The battery (100) comprises a bare cell (1), a housing (2) and a top cover (3), wherein the housing (2) is formed with an accommodating cavity (2a), the accommodating cavity (2a) penetrates through one side surface of the housing (2) along a first direction to form a mounting port (2b), the bare cell (1) is arranged in the accommodating cavity (2a), a housing wall of the housing (2) is formed with a heated softening area (2c) and a body area (2d), the hardness of the heated softening area (2c) is lower than the hardness of the body area (2d), the bare cell (1) and the heated softening area (2c) are arranged at an interval along the first direction, and the top cover (3) covers the mounting port (2b).

Description

Battery and power device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on Chinese patent application number 202420363641.2, application date February 27, 2024, and invention name “A battery and electrical device”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into the present disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a battery and an electrical device. Background Art

[0004] New energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems like hydropower, thermal power, wind power, and solar power stations, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars.

[0005] In the related art, a bare cell is disposed in the battery shell. During the charge and discharge process of the battery, the bare cell will expand, which may easily cause the shell to deform and crack.

[0006] Summary of the Invention

[0007] In view of this, embodiments of the present disclosure aim to provide a battery and an electrical device that can reduce the probability of shell cracking.

[0008] In order to achieve the above-mentioned purpose, the technical solution of the embodiment of the present disclosure is implemented as follows:

[0009] In one aspect, an embodiment of the present disclosure discloses a battery comprising a bare cell, a housing, and a top cover. The housing defines a receiving cavity, which extends along a first direction through a side surface of the housing to form a mounting opening. The bare cell is disposed in the receiving cavity. The housing wall defines a heat-softening zone and a body zone, wherein the heat-softening zone has a lower hardness than the body zone. The bare cell and the heat-softening zone are spaced apart along the first direction. The top cover is disposed over the mounting opening.

[0010] In the above technical solution, by providing a accommodating cavity and an installation port connected to the accommodating cavity in the shell, the bare cell can be placed into the accommodating cavity from the installation port, so as to protect the bare cell to a certain extent and improve the service life of the bare cell. Here, during the charging and discharging process of the battery, the bare cell will cyclically expand, so that the stress at the installation port where the top cover is connected to the shell is relatively concentrated, which is easy to cause cracking. Therefore, the present disclosure forms a heating and softening zone and a body zone on the shell wall of the shell. The hardness of the heating and softening zone is lower than that of the body zone. In this way, after the bare cell expands, the heating and softening zone with lower hardness can absorb and disperse the force of the bare cell on the shell wall, thereby reducing the risk of cracking of the shell, and then reducing the probability of leakage of the electrolyte in the shell, and having high safety. By arranging the bare cell and the heating and softening zone at intervals along the first direction, the damage to the bare cell caused by the temperature of the heating and softening zone can be reduced, thereby improving the service life of the bare cell.

[0011] In one embodiment, the distance between the bare battery core and the heated softening zone along the first direction is between 0.3 mm and 7 mm.

[0012] In the above technical solution, by setting a suitable spacing, the toughness of the shell can be improved while reducing damage to the bare battery cell and increasing the service life of the bare battery cell.

[0013] In one embodiment, the distance between the bare battery core and the heated softening zone along the first direction is between 1 mm and 3 mm.

[0014] In the above technical solution, by setting a suitable spacing, damage to the bare battery cells can be reduced.

[0015] In one embodiment, the battery includes a lower plastic, which is arranged on the side of the top cover facing the bare cell, and the distance between the lower plastic and the heated softening zone along the inner-outer direction is greater than 1 mm, wherein the inner-outer direction is perpendicular to the first direction.

[0016] In this technical solution, by placing the lower plastic on the side of the top cover facing the bare cells, it can insulate and separate the top cover and the bare cells, preventing direct contact between the top cover and the bare cells, thereby reducing the risk of short circuits and battery damage. By setting an appropriate spacing, the temperature of the heated softening zone can be reduced to reduce damage to the lower plastic, extending the service life of the lower plastic and improving operational stability.

[0017] In one embodiment, the distance between the lower plastic and the heated softening zone along the inner and outer directions is between 1.2 mm and 5 mm.

[0018] In the above technical solution, by setting a suitable spacing, damage to the lower plastic can be reduced.

[0019] In one embodiment, the ratio of the hardness of the heated softened zone to the hardness of the main zone is between 0.3 and 0.8.

[0020] In one embodiment, the ratio of the hardness of the heated softened zone to the hardness of the main zone is between 0.5 and 0.8.

[0021] In the above technical solution, by setting a suitable hardness ratio, on the one hand, it can provide sufficient structural strength for the shell to protect the bare battery cell and increase the service life of the bare battery cell; on the other hand, the heated softening zone with lower hardness after the bare battery cell expands can reduce the force exerted by the bare battery cell on the shell, reduce the risk of cracking of the shell, and have high safety.

[0022] In one embodiment, the heated and softened zone is formed at least on a target shell wall of the shell, where the target shell wall is a shell wall with the largest area of ​​the shell, and the target shell wall is arranged adjacent to the installation opening.

[0023] In the above technical solution, after the bare battery cell expands, the target shell wall is the largest force-exerting object after the bare battery cell expands. Therefore, the hardness of the heated and softened zone is set to be lower than the hardness of the main body zone. In this way, after the bare battery cell expands, the heated and softened zone with lower hardness can absorb and disperse the force of the bare battery cell on the target shell wall, thereby reducing the risk of cracking of the shell, and then reducing the chance of leakage of electrolyte in the shell, with high safety.

[0024] In one embodiment, the top cover and the shell are connected by welding, the hardness of the molten pool zone formed by the shell welding is not less than the hardness of the heated softening zone, and the size of the heated softening zone along the first direction is not less than 0.2 mm.

[0025] In the above technical solution, by welding the top cover to the shell, the hardness of the molten pool area is no less than that of the heated softening zone, thereby improving the connection strength between the top cover and the shell. By setting a suitably sized heated softening zone, the shell can be given sufficient structural strength while also possessing strong toughness to absorb and disperse the forces exerted on the shell by the expansion of the bare battery cells, reducing stress concentration and cracking at the mounting opening, and improving the shell's cyclic expansion life under charge and discharge cycles.

[0026] In one embodiment, the size of the heated softening zone along the first direction is not less than 1 mm.

[0027] In the above technical solution, by providing a heating and softening zone of appropriate size, cracking at the installation opening can be reduced.

[0028] In one embodiment, the molten pool area is located on a side of the heated and softened area along the corresponding first direction toward the corresponding installation opening.

[0029] In the above technical solution, the molten pool area is arranged between the mounting port and the heating and softening area along the first direction, which facilitates stable welding of the top cover and the shell and high connection strength. The heating and softening area is close to the molten pool area, which can reduce the stress concentration in the molten pool area and thus reduce the occurrence of cracks in the molten pool area.

[0030] Another embodiment of the present disclosure discloses an electrical device, comprising the battery of any one of the above embodiments, wherein the battery is used to provide electrical energy. As the safety of the battery is improved, the safety of the corresponding electrical device is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a schematic structural diagram of a battery provided by an embodiment of the present disclosure;

[0032] FIG2 is a schematic cross-sectional view of FIG1 ;

[0033] FIG3 is an enlarged schematic diagram of point A in FIG2 ;

[0034] Figure 4 is a metallographic image of the bulk region;

[0035] FIG5 is a metallographic image of the heated softening zone;

[0036] Figure 6 is a Vickers hardness spectrum of a portion of the shell;

[0037] Figure 7 shows the Brinell hardness spectrum of part of the shell.

[0038] Explanation of the reference numerals: battery 100; bare cell 1; shell 2; accommodating cavity 2a; mounting port 2b; heating and softening zone 2c; body zone 2d; molten pool zone 2e; first shell wall 21; second shell wall 22; third shell wall 23; top cover 3; pressure relief port 3a; liquid injection port 3b; electrode port 3c; lower plastic 4. DETAILED DESCRIPTION

[0039] The following embodiments of the technical solution of the present disclosure are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present disclosure and are therefore only examples and are not intended to limit the scope of protection of the present disclosure.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the terms "including" and "having" and any variations thereof in the specification of the present disclosure and the above-mentioned drawings are intended to cover non-exclusive inclusions.

[0041] In the description of the embodiments of the present disclosure, technical terms such as "first," "second," and "third" are used solely to distinguish different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0042] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installation" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0044] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0045] Currently, new energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars. As the application of power batteries continues to expand, market demand is also growing.

[0046] As part of the creative concept of the present disclosure, before describing the embodiments of the present disclosure, it is necessary to analyze the reasons why the battery shell is prone to cracking in the related art, and obtain the technical solution of the embodiments of the present disclosure through reasonable analysis.

[0047] In the related art, the bare battery cell is located in the accommodating cavity of the shell. During the charging and discharging process of the battery, taking the charging of lithium-ion batteries as an example, during the charging process of the lithium-ion battery, lithium ions will be released from the positive electrode and embedded in the negative electrode. This will cause the distance between the negative electrode layers to increase, thereby causing the bare battery cell to expand. The expanded bare battery cell will squeeze the shell, causing it to deform and crack.

[0048] If a heating and softening zone is set on the shell wall, and the hardness of the heating and softening zone is less than that of the main body zone, after the bare battery cell expands, the heating and softening zone with lower hardness can absorb and disperse the force exerted by the bare battery cell on the preset shell wall, thereby reducing the risk of cracking of the shell, and then reducing the chance of leakage of electrolyte in the shell, and having high safety.

[0049] The solutions of the embodiments of the present disclosure may be, but are not limited to, hard-pack battery cells, battery modules including multiple hard-pack battery cells, or battery packs including hard-pack battery cells or battery modules, and may also be applied to soft-pack battery cells, battery modules including multiple soft-pack battery cells, or battery packs including soft-pack battery cells or battery modules.

[0050] A battery cell is a unit that can convert chemical energy into electrical energy.

[0051] In the embodiment of the present disclosure, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0052] In the embodiments of the present disclosure, the battery cells may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., but the embodiments of the present disclosure are not limited to this.

[0053] The bare cell 1 refers to the electrochemical core in the battery, i.e., the battery cell. The bare cell 1 includes a positive electrode and a negative electrode and is capable of storing and releasing electrical energy.

[0054] The bare cell 1 can be formed by winding or stacking electrode sheets.

[0055] In one aspect, an embodiment of the present disclosure provides a battery. Referring to Figures 1 to 3 , battery 100 includes a bare cell 1, a housing 2, and a top cover 3. Housing 2 defines a housing cavity 2a, which extends through a side surface of housing 2 along a first direction to form a mounting opening 2b. Bare cell 1 is disposed within housing cavity 2a. The housing wall of housing 2 defines a heat-softening zone 2c and a body zone 2d. The heat-softening zone 2c has a lower hardness than the body zone 2d. Bare cell 1 and heat-softening zone 2c are spaced apart along the first direction. Top cover 3 is disposed over mounting opening 2b.

[0056] The shell 2 refers to a structure with a certain wall thickness. The shell 2 is mainly used to accommodate the bare battery cell 1, provide a certain degree of protection for the bare battery cell 1, and reduce the risk of the bare battery cell 1 being exposed to the outside and damaged.

[0057] For example, the shape of the housing 2 can be a cuboid or a cylinder. When the shape of the housing 2 is a cuboid, the corresponding battery 100 is a square battery. When the shape of the housing 2 is a cylinder, the corresponding battery 100 is a cylindrical battery.

[0058] The accommodating cavity 2a refers to the accommodating space inside the shell 2, which is used to accommodate the bare battery cell 1.

[0059] The installation opening 2 b is in communication with the accommodating cavity 2 a , and the bare cell 1 can be placed into the accommodating cavity 2 a of the housing 2 through the installation opening 2 b .

[0060] The heated softening zone 2c and the main body zone 2d both refer to the shell wall of the shell 2, which can be the inner wall of the shell 2 or the outer wall of the shell 2. The difference is that the hardness of the heated softening zone 2c is less than the hardness of the main body zone 2d. For example, the main body zone 2d can specifically be the area of ​​the shell wall of the shell 2 that has not been heated and softened, and the heated softening zone 2c can specifically be formed by the main body zone 2d being heated and softened.

[0061] The battery 100 provided in the embodiment of the present disclosure is provided with a accommodating cavity 2a and an installation port 2b connected to the accommodating cavity 2a in the shell 2, so that the bare cell 1 can be placed into the accommodating cavity 2a from the installation port 2b, so as to protect the bare cell 1 to a certain extent and improve the service life of the bare cell 1. Here, during the charging and discharging process of the battery 100, the bare cell 1 will cyclically expand, so that the stress at the installation port 2b where the top cover 3 is connected to the shell 2 is relatively concentrated, which is easy to cause cracking. Therefore, the present disclosure forms a heating softening zone 2c and a main body zone 2d on the shell wall of the shell 2, and the hardness of the heating softening zone 2c is lower than the hardness of the main body zone 2d. In this way, after the bare cell 1 expands, the heating softening zone 2c with lower hardness can absorb and disperse the force of the bare cell 1 on the shell wall of the shell 2, thereby reducing the risk of cracking of the shell 2, and then reducing the probability of leakage of the electrolyte in the shell 2, and having high safety. By arranging the bare battery cell 1 and the heated and softened zone 2 c at intervals along the first direction, the damage to the bare battery cell 1 caused by the temperature of the heated and softened zone 2 c can be reduced, thereby increasing the service life of the bare battery cell 1 .

[0062] In one embodiment, referring to FIG. 3 , the distance between the bare battery cell 1 and the heated softening area 2 c along the first direction is between 0.3 mm and 7 mm.

[0063] For example, the distance between the heated softening zone 2c and the bare battery core 1 along the first direction can be represented by H1, and H1 can be 0.3 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm or 7 mm, etc.

[0064] In this way, by setting a suitable spacing, the toughness of the shell 2 can be improved while reducing damage to the bare battery cell 1 and increasing the service life of the bare battery cell 1.

[0065] In one embodiment, the distance between the bare battery core 1 and the heated softening zone 2 c along the first direction is between 1 mm and 3 mm.

[0066] For example, the distance H1 between the bare cell 1 and the heated softening zone 2c along the first direction may be 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm or 3 mm, etc.

[0067] In this way, by setting a suitable spacing, damage to the bare battery cell 1 can be reduced.

[0068] In one embodiment, referring to FIG. 1 and FIG. 3 , the battery 100 includes a lower plastic 4 , which is disposed on the side of the top cover 3 facing the bare cell 1 , and a distance between the lower plastic 4 and the heated softening zone 2 c along the inner-outer direction is greater than 1 mm, wherein the inner-outer direction is perpendicular to the first direction.

[0069] For example, the distance between the lower plastic 4 and the heated softening zone 2c in the inner and outer directions can be represented by H2, and H2 can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc.

[0070] Thus, by placing the lower plastic 4 on the side of the top cover 3 facing the bare cell 1, it can insulate and separate the top cover 3 and the bare cell 1, preventing direct contact between the top cover 3 and the bare cell 1, thereby reducing the risk of short circuits and damage to the battery 100. By setting an appropriate spacing, the damage caused by the temperature of the heated softening zone 2c to the lower plastic 4 can be reduced, thereby increasing the service life of the lower plastic 4 and improving operational stability.

[0071] For example, the inward-outward direction may be a second direction, and the second direction is perpendicular to the first direction. For example, R1 in FIG1 may be the first direction, R2 may be the second direction, and R3 may be the third direction.

[0072] In one embodiment, the distance between the lower plastic 4 and the heated softening zone 2 c along the inner and outer directions is between 1.2 mm and 5 mm.

[0073] For example, the distance H2 between the lower plastic 4 and the heated softening zone 2c along the inner and outer directions may be 1.2 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc.

[0074] In this way, by setting a suitable spacing, damage to the lower plastic 4 can be reduced.

[0075] In one embodiment, the ratio of the hardness of the heated softened zone 2 c to the hardness of the main zone 2 d is between 0.3 and 0.8.

[0076] For example, the ratio of the hardness of the heated softened zone 2c to the hardness of the main body zone 2d can be 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8, etc.

[0077] In this way, by setting a suitable hardness ratio, on the one hand, the shell 2 can be provided with sufficient structural strength to protect the bare battery cell 1 and improve the service life of the bare battery cell 1; on the other hand, after the bare battery cell 1 expands, the heated softening zone 2c with lower hardness can reduce the force exerted by the bare battery cell 1 on the shell 2, reduce the risk of cracking of the shell 2, and have high safety.

[0078] In one embodiment, the ratio of the hardness of the heated softened zone 2 c to the hardness of the main zone 2 d is between 0.5 and 0.8.

[0079] For example, the ratio of the hardness of the heated softened zone 2 c to the hardness of the main body zone 2 d may be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8, etc.

[0080] It should be noted that the hardness of the heated softening zone 2c and the hardness of the main body zone 2d are both Brinell hardness, that is, the above hardness ratio is a layout hardness ratio.

[0081] It should be noted that HB is the unit of Brinell hardness.

[0082] In one embodiment, please refer to Figures 6 and 7. Figure 6 is a Vickers hardness spectrum of a portion of the shell, and Figure 7 is a Brinell hardness spectrum of a portion of the shell. The shell 2 is made of aluminum, the hardness of the main body area 2d is between 35HB and 65HB, and the hardness of the heated softening area 2c is between 25HB and 40HB.

[0083] For example, the hardness of the main body zone 2d can be 35HB, 40HB, 45HB, 50HB, 55HB, 60HB or 65HB, etc., and the hardness of the heated softening zone 2c can be 25HB, 30HB, 35HB or 40HB, etc.

[0084] Here, by providing the heat-softened zone 2 c with a suitable hardness and the body zone 2 d with a suitable hardness, not only can sufficient structural strength be provided for the shell 2 , but also the risk of cracking of the shell 2 can be reduced.

[0085] It should be noted that HV is a unit of Vickers hardness.

[0086] For example, in one embodiment, the reason why point E in FIG6 has a lower hardness is due to the hole position.

[0087] For example, in one embodiment, the hardness of the heated softened zone 2 c may be 30 HB, and the hardness of the main body zone 2 d may be 60 HB.

[0088] For example, in one embodiment, please refer to Table 1, which shows the mechanical properties of 3003 alloy. O, H12, H14, H16, or H18 are material designations. The hardness column in the table indicates the hardness before processing. For example, H14, before being processed into the shell 2, has a hardness of 40 HB. After being processed into the shell 2, its hardness will be greater than 40 HB; after softening to the heated softening zone 2c, its hardness will be less than 40 HB. For another example, H18, before being processed into the shell 2, has a hardness of 55 HB. After being processed into the shell 2, its hardness will be greater than 55 HB; after softening to the heated softening zone 2c, its hardness will be less than 55 HB.

[0089] Table 1 Mechanical properties of 3003 alloy

[0090] It should be noted that 3003 is an aluminum-manganese alloy.

[0091] It should be noted that the “O” state in the above table refers to the data of the annealed state of the corresponding aluminum alloy.

[0092] In one embodiment, please refer to Figures 4 and 5. Figure 4 is a metallographic image of the main area 2d, and Figure 5 is a metallographic image of the heated and softened area 2c. The grain type of the main area 2d is strip crystals and / or ribbon crystals, and the grain type of the heated and softened area 2c is columnar crystals and / or equiaxed crystals.

[0093] For example, the grain type of the bulk region 2d may be a lamellar crystal, or the grain type of the bulk region 2d may be a ribbon crystal, or the grain type of the bulk region 2d may be a lamellar crystal and a ribbon crystal. The grain type of the heat-softened region 2c may be a columnar crystal, or the grain type of the heat-softened region 2c may be an equiaxed crystal, or the grain type of the heat-softened region 2c may be a columnar crystal and an equiaxed crystal.

[0094] Banded crystals refer to a type of grain in which the grains are arranged in a band-like pattern along a certain direction.

[0095] Lath crystals refer to grains that grow along a specific direction to form a strip-like or fibrous grain type.

[0096] Columnar crystal is a crystal form characterized by a longitudinally extending, columnar shape.

[0097] Equiaxed crystals are crystals with small differences in size in all directions and a high degree of symmetry. In an equiaxed crystal system, the three crystal axes are equal in length and form 90° angles with each other.

[0098] In this way, by setting the grain type of the main body area 2d to strip crystals and / or ribbon crystals, and setting the grain type of the heat-softening zone 2c to columnar crystals and / or equiaxed crystals, it is shown that the hardness of the heat-softening zone 2c is lower than that of the main body area 2d. This is because during the crystallization process of the metal, the formation of columnar crystals and equiaxed crystals will be hindered, resulting in blurred boundaries between grains and a relatively disordered lattice structure, while ribbon crystals and strip crystals are relatively easy to form, and their lattice structures are relatively ordered. The crystal structure will affect the mechanical properties of the metal. For example, a disordered crystal structure will lead to reduced hardness and strength, while increased toughness. An ordered lattice structure will increase the hardness and strength of the device, but reduce toughness. That is to say, when the shell 2 is subjected to the force exerted on it by the expansion of the bare battery cell 1, the disordered crystal structure can better absorb and disperse the force due to its higher toughness, so as to reduce the expansion of cracks and the occurrence of fractures.

[0099] For example, in one embodiment, the reason why the hardness of point E in FIG. 6 is relatively low is due to the pores in the shell wall of the shell 21 , but the grain type at this point is still strip crystals and / or ribbon crystals.

[0100] For example, in one embodiment, the heated softened zone 2c may be formed by heating and annealing the body zone 2d.

[0101] For example, in one embodiment, the body region 2d does not need to be completely annealed, as long as its hardness meets the hardness requirement of the heated softened region 2c.

[0102] For example, in one embodiment, the heated softened zone 2c can be formed by laser softening the main body zone 2d. Laser softening offers high precision and controllability, allowing precise heating of a specific area without affecting surrounding areas. Laser softening is also non-contact, making it safer to use. Furthermore, laser heating is rapid, completing the softening process in a short time and achieving high efficiency.

[0103] In one embodiment, the heated softening zone 2 c is formed at least on the target shell wall of the shell 2 . The target shell wall is the shell wall with the largest area of ​​the shell 2 . The target shell wall is arranged adjacent to the installation opening 2 b .

[0104] The target housing wall refers to the housing wall of the housing 2 that has the largest area and is adjacent to the mounting opening 2 b.

[0105] Exemplarily, the shell 2 has five shell walls, two of the five shell walls are first shell walls 21, and the areas of the two first shell walls 21 are equal. Two of the five shell walls are second shell walls 22, and the areas of the two second shell walls 22 are equal. The last of the five shell walls is a third shell wall 23, and the areas of the second shell wall 22 and the third shell wall 23 are both smaller than the area of ​​the first shell wall 21. The two first shell walls 21 are arranged at intervals along the second direction, and the two second shell walls 22 are arranged at intervals along the third direction. The third shell wall 23 is connected to the two first shell walls 21 and the two second shell walls 22 along the first direction to jointly define the accommodating cavity 2a and the installation port 2b. The first shell wall 21 can be the target shell wall.

[0106] Here, after the bare battery cell 1 expands, the target shell wall is the largest force-exerting object after the bare battery cell 1 expands. Therefore, the hardness of the heated softening zone 2c is set to be lower than the hardness of the main body zone 2d. In this way, after the bare battery cell 1 expands, the heated softening zone 2c with lower hardness can absorb and disperse the force of the bare battery cell 1 on the target shell wall, thereby reducing the risk of cracking of the shell 2, and then reducing the probability of leakage of the electrolyte in the shell 2, with high safety.

[0107] Exemplarily, in one embodiment, please refer to Figure 1, a pressure relief port 3a, a liquid injection port 3b and an electrode port 3c are formed on the top cover 3. The pressure relief port 3a, the liquid injection port 3b and the electrode port 3c all penetrate the top cover 3 along the first direction. The top cover 3 is provided at the mounting port 2b. The pressure relief port 3a, the liquid injection port 3b and the electrode port 3c are all connected to the accommodating cavity 2a. The pressure relief port 3a is used to relieve pressure in the accommodating cavity 2a after the bare cell 1 has a thermal runaway to avoid an explosion. The liquid injection port 3b is used to inject electrolyte into the accommodating cavity 2a. The electrode port 3c facilitates electrical connection to the tabs of the bare cell 1.

[0108] In one embodiment, referring to Figures 1 and 3, the top cover 3 is connected to the shell 2 by welding, the hardness of the molten pool area 2e formed by welding the shell 2 is not less than the hardness of the heated softening area 2c, and the size of the heated softening area 2c along the first direction is not less than 0.2 mm.

[0109] The molten pool area 2e refers to the part of the base material that is melted into a pool shape by the heat of the welding arc, and is the liquid metal part with a certain geometric shape formed on the weldment during fusion welding.

[0110] For example, the top cover 3 and the housing 2 are welded at the mounting opening 2b. The hardness of the molten pool areas 2e-21e formed by the welding of the housing 2 is not less than the hardness of the heated softened area 2c. The dimension of the heated softened area 2c along the first direction can be represented by H3, which can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, or 12 mm, etc.

[0111] Thus, by welding the top cover 3 to the housing 2, the hardness of the molten pool area 2e is no less than that of the heated softened area 2c, thereby improving the connection strength between the top cover 3 and the housing 2. By providing a heated softened area 2c of appropriate size, the housing 2 can be given sufficient structural strength while also having greater toughness to absorb and disperse the force exerted on the housing 2 by the expansion of the bare battery cell 1, thereby reducing stress concentration at the mounting opening 2b, reducing cracking at the mounting opening 2b, and improving the cyclic expansion life of the housing 2 under charge and discharge.

[0112] In one embodiment, the size of the heated softening zone 2c along the first direction is not less than 1 mm.

[0113] Exemplarily, the dimension H3 of the heated softening zone 2c along the first direction may be 1 mm, 2 mm, 3 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm or 12 mm, etc.

[0114] In this way, by providing the heating softening zone 2c with a suitable size, the cracking at the installation opening 2b can be reduced.

[0115] In one embodiment, the molten pool area 2e is located on a side of the heated and softened area 2c along the corresponding first direction toward the corresponding mounting opening 2b.

[0116] That is to say, the molten pool area 2e is arranged between the installation port 2b and the heating and softening area 2c along the first direction, which facilitates stable welding of the top cover 3 and the shell 2 and high connection strength. The heating and softening area 2c is close to the molten pool area 2e, which can reduce the stress concentration in the molten pool area 2e, and thus reduce the occurrence of cracks in the molten pool area 2e.

[0117] Another embodiment of the present disclosure provides an electrical device, which includes the battery 100 in any one of the above embodiments, and is used to provide electrical energy. Due to the improved safety of the battery 100, the safety of the corresponding electrical device is also improved.

[0118] An electrical device is a device that uses electricity as an energy source and consumes it to achieve its corresponding function. For example, an electrical device may include, but is not limited to, a mobile phone, tablet computer, laptop computer, electric toy, power tool, battery-powered vehicle, electric vehicle, ship, spacecraft, etc. Electric toys may include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0119] The electric device of the embodiment of the present disclosure may include a device body and a power supply device, the power supply device is used to supply power to the device body, and the power supply device may include a battery 100.

[0120] The device body refers to the main structure that consumes electrical energy to perform its corresponding functions. For example, the power-consuming device may be a mobile phone, where the device body is the portion that performs functions such as communication, and battery 100 supplies power to this portion. For example, the power-consuming device may be a car, where the device body is the portion that provides passengers with a seat and is capable of traveling on the road, and battery 100 supplies power to this portion.

[0121] The power supply device refers to a device that can output electric energy. For example, the electric energy can be output through the battery 100.

[0122] The electric device according to an embodiment of the present disclosure is described as a vehicle as an example.

[0123] The vehicle provided in one embodiment of the present disclosure may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle, and the battery 100 may be provided at the bottom, head or tail of the vehicle. The battery 100 may be used to power the vehicle, for example, the battery 100 may serve as an operating power source for the vehicle. The vehicle may further include a controller and a motor, and the controller may be used to control the battery to power the motor. For example, the battery unit may be used for starting, navigating and operating power requirements of the vehicle during driving.

[0124] The battery 100 provided in the embodiment of the present disclosure, please refer to Figures 1 to 7. The battery 100 includes a bare cell 1, a shell 2 and a top cover 3. The shell 2 is formed with a receiving cavity 2a. The receiving cavity 2a passes through a side surface of the shell 2 along a first direction to form an installation opening 2b. The bare cell 1 is arranged in the receiving cavity 2a, and the top cover 3 is arranged on the installation opening 2b. The shell wall of the shell 2 is formed with a heat-softening zone 2c and a body zone 2d. The heat-softening zone 2c is formed at least on the target shell wall of the shell 2. The target shell wall is the shell wall with the largest area of ​​the shell 2, and the target shell wall is arranged adjacent to the installation opening 2b. The hardness of the heat-softening zone 2c is lower than the hardness of the body zone 2d. Specifically, the ratio of the hardness of the heat-softening zone 2c to the hardness of the body zone 2d is between 0.5 and 0.8. The grain type of the heat-softening zone 2c is strip crystal and / or ribbon crystal, and the grain type of the body zone 2d is columnar crystal and / or equiaxed crystal. The spacing between the bare cell 1 and the heated softening zone 2c along the first direction is between 1mm and 3mm. The battery 100 includes a lower plastic 4, which is disposed on the side of the top cover 3 facing the bare cell 1. The spacing between the lower plastic 4 and the heated softening zone 2c along the inner-outer direction is between 1.2mm and 5mm, wherein the inner-outer direction is perpendicular to the first direction. The top cover 3 is connected to the shell 2 by welding. The hardness of the molten pool zone 2e formed by welding the shell 2 is not less than that of the heated softening zone 2c. The molten pool zone 2e is located on the side of the heated softening zone 2c along the corresponding first direction toward the corresponding mounting opening 2b. The dimension of the heated softening zone 2c along the first direction is not less than 1mm.

[0125] The above description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that the present disclosure is susceptible to various modifications and variations. Any modifications, equivalent substitutions, and improvements that fall within the spirit and principles of the present disclosure are intended to be within the scope of protection of the present disclosure.

Claims

1. A battery comprising: Bare battery cells; The housing is formed with a housing cavity, the housing cavity penetrates a side surface of the housing along a first direction to form a mounting opening, the bare battery cell is arranged in the housing cavity, the shell wall of the housing is formed with a heating softening zone and a body zone, the hardness of the heating softening zone is lower than the hardness of the body zone, and the bare battery cell and the heating softening zone are spaced apart along the first direction; A top cover is provided on the installation opening.

2. The battery according to claim 1, wherein The distance between the bare battery core and the heated softening zone along the first direction is between 0.3 mm and 7 mm.

3. The battery according to claim 2, wherein The distance between the bare battery core and the heated softening zone along the first direction is between 1 mm and 3 mm.

4. The battery according to any one of claims 1 to 3, wherein The battery includes a lower plastic, which is arranged on the side of the top cover facing the bare cell. The distance between the lower plastic and the heated softening zone along the inner and outer directions is greater than 1 mm, wherein the inner and outer directions are perpendicular to the first direction.

5. The battery according to claim 4, wherein The distance between the lower plastic and the heated softening zone along the inner and outer directions is between 1.2 mm and 5 mm.

6. The battery according to any one of claims 1 to 5, wherein The ratio of the hardness of the heated softening zone to the hardness of the main body zone is between 0.3 and 0.

8.

7. The battery according to claim 6, wherein The ratio of the hardness of the heated softening zone to the hardness of the main body zone is between 0.5 and 0.

8.

8. The battery according to any one of claims 1 to 7, wherein The heating and softening zone is formed at least on a target shell wall of the shell, where the target shell wall is a shell wall with the largest area of ​​the shell, and the target shell wall is arranged adjacent to the installation opening.

9. The battery according to any one of claims 1 to 8, wherein The top cover is connected to the shell by welding. The hardness of the molten pool zone formed by welding of the shell is not less than the hardness of the heated softening zone. The size of the heated softening zone along the first direction is not less than 0.2 mm.

10. The battery according to claim 9, wherein The size of the heated softening zone along the first direction is not less than 1 mm.

11. The battery according to claim 9 or 10, wherein The molten pool area is located on a side of the heated and softened area along the first direction toward the mounting opening.

12. An electrical device comprising the battery according to any one of claims 1 to 11, for providing electrical energy.

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