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

A battery and an electrical device

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202420363641.2, filed on February 27, 2024, entitled “A Battery and an Electric Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery technology, and more particularly to a battery and an electrical device. Background Technology

[0004] New energy batteries are being used more and more widely in daily life and industry. They are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars.

[0005] In related technologies, bare cells are installed inside the battery casing. During the charging and discharging process of the battery, the bare cells will expand, which can easily lead to deformation and cracking of the casing.

[0006] Summary of the Invention

[0007] In view of this, the present disclosure aims to provide a battery and power supply device that can reduce the probability of casing cracking.

[0008] To achieve the above objectives, the technical solution of this disclosure embodiment is implemented as follows:

[0009] This disclosure provides an embodiment of a battery, including a bare cell, a casing, and a top cover. The casing has a receiving cavity extending through one side of the casing along a first direction to form a mounting opening. The bare cell is disposed within the receiving cavity. The casing wall has a heating softening zone and a body zone, the hardness of which is lower than that of the body zone. The bare cell and the heating 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 receiving cavity and an installation port communicating with the receiving cavity within the casing, the bare battery cell can be inserted into the receiving cavity through the installation port, thus protecting the bare battery cell to a certain extent and improving its service life. During charging and discharging, the bare battery cell undergoes cyclic expansion, causing stress concentration at the installation port where the top cover connects to the casing, which can easily lead to cracking. Therefore, this disclosure forms a heating softening zone and a body zone on the casing wall. The hardness of the heating softening zone is lower than that of the body zone. Thus, after the bare battery cell expands, the lower-hardness heating softening zone can absorb and disperse the force exerted by the bare battery cell on the casing wall, thereby reducing the risk of casing cracking and consequently reducing the probability of electrolyte leakage, resulting in high safety. By spacing the bare battery cell and the heating softening zone along a first direction, the temperature of the heating softening zone can be reduced to minimize damage to the bare battery cell, thereby improving its service life.

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

[0012] In the above technical solution, by setting an appropriate spacing, the toughness of the casing can be improved, while damage to the bare battery cell can be reduced, thereby increasing the service life of the bare battery cell.

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

[0014] In the above technical solution, by setting an appropriate spacing, damage to the bare battery cell can be reduced.

[0015] In one embodiment, the battery includes a lower plastic layer disposed on the side of the top cover facing the bare battery cell. The distance between the lower plastic layer and the heating 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.

[0016] In the above technical solution, by placing the lower plastic layer on the side of the top cover facing the bare battery cell, it can serve to insulate and separate the top cover from the bare battery cell, preventing direct contact between the top cover and the bare battery cell, thereby avoiding the risk of short circuits and battery damage. By setting an appropriate spacing distance, the damage to the lower plastic layer caused by the temperature of the heating and softening zone can be reduced, improving the service life of the lower plastic layer and ensuring good operational stability.

[0017] In one embodiment, the distance between the lower plastic and the heated softening zone along the inside-out direction is between 1.2 mm and 5 mm.

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

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

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

[0021] In the above technical solution, by setting an appropriate hardness ratio, on the one hand, sufficient structural strength can be provided to the casing to protect the bare battery cell and improve its service life; on the other hand, the heating softening zone with lower hardness after the bare battery cell expands can reduce the force exerted by the bare battery cell on the casing, reduce the risk of the casing cracking, and ensure high safety.

[0022] In one embodiment, the heating softening zone is formed at least on the target shell wall of the housing, which is the shell wall with the largest area of ​​the housing, and the target shell wall is arranged adjacent to the mounting port.

[0023] In the above technical solution, after the bare cell expands, the target shell wall is the object of the greatest force exerted by the bare cell after expansion. Therefore, the hardness of the heating softening zone is set to be lower than that of the body zone. In this way, after the bare cell expands, the heating softening zone with lower hardness can absorb and disperse the force exerted by the bare cell on the target shell wall, thereby reducing the risk of shell cracking and thus reducing the probability of electrolyte leakage inside the shell, resulting in high safety.

[0024] In one embodiment, the top cover and the shell are connected by welding, and the hardness of the molten pool area formed by the welding of the shell is not less than the hardness of the heat softening area, and the size of the heat softening area 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 zone is not less than the hardness of the heat-softening zone, which can improve the connection strength between the top cover and the shell. By setting a heat-softening zone of appropriate size, while ensuring that the shell has sufficient structural strength, it can also have strong toughness to absorb and disperse the force exerted on the shell by the expansion of the bare cell, reduce stress concentration at the mounting port, reduce cracking at the mounting port, and improve the cyclic expansion life of the shell under charge and discharge.

[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 setting a heating softening zone of appropriate size, it is easier to reduce cracking at the installation opening.

[0028] In one embodiment, the molten pool region is located on the side of the heating and softening region facing the corresponding mounting port along the corresponding first direction.

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

[0030] Another aspect of this disclosure provides an electrical device including the battery described in any of the foregoing embodiments, the battery being used to provide electrical energy. Due to the improved safety of the battery, the safety of the corresponding electrical device is also improved. Attached Figure Description

[0031] Figure 1 is a schematic diagram of the structure of a battery provided in an embodiment of this disclosure;

[0032] Figure 2 is a cross-sectional view of Figure 1;

[0033] Figure 3 is an enlarged view of point A in Figure 2;

[0034] Figure 4 shows the metallographic diagram of the body region;

[0035] Figure 5 shows the metallographic image of the heated softened zone;

[0036] Figure 6 shows the Vickers hardness spectrum of part of the shell;

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

[0038] The attached diagram shows the following reference numerals: Battery 100; Bare cell 1; Casing 2; Receiving cavity 2a; Mounting port 2b; Heating 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 Implementation

[0039] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0041] In the description of the embodiments of this disclosure, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

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

[0043] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0044] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0045] Currently, new energy batteries are being used more and more widely in daily life and industry. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars. As the application areas of power batteries continue to expand, the market demand for them is also constantly increasing.

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

[0047] In related technologies, the bare cell is located in the housing cavity of the casing. During the charging and discharging process of the battery, taking the charging of a lithium-ion battery as an example, lithium ions will be extracted from the positive electrode and embedded in the negative electrode during the charging process. This will cause the negative electrode layer spacing to increase, thereby causing the bare cell to expand. The expanded bare cell will squeeze the casing, causing it to deform and crack.

[0048] If a heating softening zone is set on the shell wall, and the hardness of the heating softening zone is less than that of the body area, after the bare cell expands, the heating softening zone with lower hardness can absorb and disperse the force of the bare cell on the pre-set shell wall, thereby reducing the risk of shell cracking and thus reducing the probability of electrolyte leakage inside the shell, resulting in high safety.

[0049] The solutions in the embodiments of this disclosure can be applied to, 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. They can 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 this embodiment of the disclosure, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0052] In this embodiment of the disclosure, the battery cell 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-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and this embodiment of the disclosure is not limited to this.

[0053] Bare cell 1 refers to the electrochemical core of a battery, i.e., the cell itself. Bare cell 1 contains a positive electrode and a negative electrode, and is capable of storing and releasing electrical energy.

[0054] Bare cells 1 can be formed by winding or stacking electrode sheets.

[0055] This disclosure provides a battery, as shown in Figures 1 to 3. The battery 100 includes a bare cell 1, a housing 2, and a top cover 3. The housing 2 has a receiving cavity 2a, which extends through one side of the housing 2 along a first direction to form a mounting opening 2b. The bare cell 1 is disposed in the receiving cavity 2a. The housing wall of the housing 2 has a heating softening region 2c and a body region 2d. The hardness of the heating softening region 2c is lower than that of the body region 2d. The bare cell 1 and the heating softening region 2c are spaced apart along the first direction. The top cover 3 covers the mounting opening 2b.

[0056] The casing 2 refers to a structure with a certain wall thickness. The casing 2 is mainly used to house the bare battery cell 1, providing a certain degree of protection for the bare battery cell 1 and reducing the risk of the bare battery cell 1 being exposed 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 cuboid, the corresponding battery 100 is a square battery; when the shape of the housing 2 is cylindrical, the corresponding battery 100 is a cylindrical battery.

[0058] The receiving cavity 2a refers to the receiving space inside the housing 2, which is used to receive the bare battery cell 1.

[0059] The mounting port 2b is connected to the receiving cavity 2a, and the bare battery cell 1 can be placed into the receiving cavity 2a of the housing 2 through the mounting port 2b.

[0060] Both the heat-softened zone 2c and the body zone 2d refer to the shell wall of the shell 2, which can be the inner wall or the outer wall of the shell 2. The difference is that the hardness of the heat-softened zone 2c is less than that of the body zone 2d. For example, the body zone 2d can be the area of ​​the shell wall of the shell 2 that has not been heat-softened, while the heat-softened zone 2c can be the body zone 2d that has been heat-softened.

[0061] The battery 100 provided in this embodiment of the present disclosure provides a receiving cavity 2a and an installation port 2b communicating with the receiving cavity 2a within the housing 2. This allows the bare battery cell 1 to be inserted into the receiving cavity 2a through the installation port 2b, thus protecting the bare battery cell 1 to a certain extent and improving its service life. During charging and discharging, the bare battery cell 1 undergoes cyclic expansion, causing stress concentration at the installation port 2b where the top cover 3 connects to the housing 2, which can easily lead to cracking. Therefore, this disclosure forms a heating softening zone 2c and a body zone 2d on the shell wall of the housing 2. The hardness of the heating softening zone 2c is lower than that of the body zone 2d. This allows the lower-hardness heating softening zone 2c to absorb and disperse the force exerted by the bare battery cell 1 on the shell wall of the housing 2 after expansion, thereby reducing the risk of cracking of the housing 2 and consequently reducing the probability of electrolyte leakage within the housing 2, resulting in high safety. By spacing the bare cell 1 and the heating softening zone 2c along the first direction, the damage caused by the temperature of the heating softening zone 2c to the bare cell 1 can be reduced, thereby improving the service life of the bare cell 1.

[0062] In one embodiment, referring to FIG3, the distance between the bare cell 1 and the heating softening zone 2c 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 cell 1 along the first direction can be represented by H1, which can be 0.3mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm or 7mm, etc.

[0064] In this way, by setting an appropriate spacing, the toughness of the casing 2 can be improved, while damage to the bare cell 1 can be reduced, thereby increasing the service life of the bare cell 1.

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

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

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

[0068] In one embodiment, referring to Figures 1 and 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. The distance between the lower plastic 4 and the heating softening zone 2c in the inward and outward directions is greater than 1 mm, wherein the inward and outward directions are perpendicular to the first direction.

[0069] For example, the distance between the lower plastic 4 and the heated softening zone 2c along the inside and outside direction can be represented by H2, which can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc.

[0070] In this way, by placing the lower plastic 4 on the side of the top cover 3 facing the bare battery cell 1, it can serve to insulate and separate the top cover 3 from the bare battery cell 1, avoiding direct contact between the top cover 3 and the bare battery cell 1, thereby avoiding the risk of short circuit and damage to the battery 100. By setting an appropriate spacing distance, the damage caused by the temperature of the heating softening zone 2c to the lower plastic 4 can be reduced, improving the service life of the lower plastic 4 and ensuring good operational stability.

[0071] For example, the inside / outside direction can be a second direction, which is perpendicular to the first direction. For instance, in Figure 1, R1 can be the first direction, R2 can be the second direction, and R3 can be the third direction.

[0072] In one embodiment, the distance between the lower plastic 4 and the heated softening zone 2c along the inside-out direction 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 in the inward and outward directions can be 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0074] By setting appropriate spacing, damage to the lower plastic 4 can be reduced.

[0075] In one embodiment, the ratio of the hardness of the heat-softened region 2c to the hardness of the body region 2d is between 0.3 and 0.8.

[0076] For example, the ratio of the hardness of the heat-softened region 2c to the hardness of the body region 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 an appropriate hardness ratio, on the one hand, the shell 2 can provide sufficient structural strength to protect the bare cell 1 and improve the service life of the bare cell 1; on the other hand, the heating softening zone 2c with lower hardness after the bare cell 1 expands can reduce the force of the bare cell 1 on the shell 2, reduce the risk of the shell 2 cracking, and ensure high safety.

[0078] In one embodiment, the ratio of the hardness of the heat-softened region 2c to the hardness of the body region 2d is between 0.5 and 0.8.

[0079] For example, the ratio of the hardness of the heat-softened region 2c to the hardness of the body region 2d can 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 heat-softened zone 2c and the hardness of the body zone 2d are both Brinell hardness, that is, the above hardness ratio is the arrangement 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 shows the Vickers hardness spectrum of a portion of the shell, and Figure 7 shows the Brinell hardness spectrum of a portion of the shell. The shell 2 is made of aluminum. The hardness of the body region 2d is between 35 HB and 65 HB, and the hardness of the heat-softened region 2c is between 25 HB and 40 HB.

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

[0084] Here, by setting a heating softening zone 2c with appropriate hardness and a body zone 2d with appropriate hardness, not only can sufficient structural strength be provided for the shell 2, but the risk of cracking of the shell 2 can also be reduced.

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

[0086] For example, in one embodiment, the reason why point E in Figure 6 has a lower hardness is due to the presence of holes.

[0087] For example, in one embodiment, the hardness of the heat-softening region 2c can be 30HB, and the hardness of the body region 2d can be 60HB.

[0088] For example, in one embodiment, please refer to Table 1, which shows the mechanical properties of alloy 3003. O, H12, H14, H16, or H18 are material grades. The hardness column in the table represents the hardness before processing. Taking H14 as an example, its hardness is 40 HB before being processed into shell 2. After processing into shell 2, its hardness will be greater than 40 HB; after softening into the heat-softened zone 2c, its hardness will be less than 40 HB. Similarly, taking H18 as an example, its hardness is 55 HB before being processed into shell 2. After processing into shell 2, its hardness will be greater than 55 HB; after softening into the heat-softened 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 table above refers to the data of the corresponding annealed state of the aluminum alloy.

[0092] In one embodiment, please refer to Figures 4 and 5. Figure 4 is a metallographic image of the body region 2d and Figure 5 is a metallographic image of the heat softening region 2c. The grain type of the body region 2d is strip-shaped and / or banded, and the grain type of the heat softening region 2c is columnar and / or equiaxed.

[0093] For example, the grain type of the body region 2d can be strip-shaped grains, or the grain type of the body region 2d can be banded grains, or the grain type of the body region 2d can be both strip-shaped and banded grains. The grain type of the heat-softening region 2c can be columnar grains, or the grain type of the heat-softening region 2c can be equiaxed grains, or the grain type of the heat-softening region 2c can be both columnar and equiaxed grains.

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

[0095] Strip-shaped crystals refer to a type of crystal that grows along a specific direction, forming strip-shaped or fibrous grains.

[0096] Columnar crystals are a type of crystal characterized by their longitudinal extension and columnar shape.

[0097] Isometric crystals are characterized by grains with relatively small differences in size across all directions, exhibiting a high degree of symmetry. In the isometric crystal system, the three crystal axes are of equal length and are at 90° angles to each other.

[0098] Thus, by setting the grain type of the body region 2d to strip-shaped and / or banded crystals, and setting the grain type of the heat-softening region 2c to columnar and / or equiaxed crystals, it is shown that the hardness of the heat-softening region 2c is lower than that of the body region 2d. This is because during the crystallization process of metal, the formation of columnar and equiaxed crystals is hindered, resulting in blurred boundaries between grains and a relatively disordered lattice structure. In contrast, banded and striped crystals are relatively easy to form, and their lattice structure is relatively ordered. Crystal structure affects the mechanical properties of metals. For example, a disordered crystal structure leads to a decrease in hardness and strength, but an increase in toughness. An ordered lattice structure increases hardness and strength, but reduces toughness. In other words, when the shell 2 is subjected to the force exerted by the expansion of the bare cell 1, the disordered crystal structure, due to its higher toughness, can better absorb and disperse the force, thereby reducing crack propagation and fracture.

[0099] For example, in one embodiment, the reason why point E in Figure 6 has a lower hardness is due to the pores in the shell wall of the shell 21, but the grain type at this point is still strip-shaped and / or banded crystals.

[0100] In one exemplary embodiment, the heat-softening region 2c can be formed by heat-annealing the body region 2d.

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

[0102] For example, in one embodiment, the heated softening region 2c can be formed by laser softening of the body region 2d. On the one hand, laser softening has high precision and controllability, allowing for precise heating of a specific area without affecting the surrounding area; on the other hand, laser softening is non-contact, making it safer during processing; furthermore, laser heating is fast, completing the softening process in a short time, resulting in high efficiency.

[0103] In one embodiment, the heating softening zone 2c is formed at least on the target shell wall of the housing 2, which is the shell wall with the largest area of ​​the housing 2, and the target shell wall is arranged adjacent to the mounting port 2b.

[0104] The target shell wall refers to the shell wall of shell 2 with the largest area that is adjacent to the mounting port 2b.

[0105] For example, the housing 2 has five shell walls. Two of the shell walls are first shell walls 21 with equal areas. Two of the shell walls are second shell walls 22 with equal areas. The last of the five shell walls is a third shell wall 23. The areas of both the second shell walls 22 and the third shell wall 23 are smaller than the area of ​​the first shell walls 21. The two first shell walls 21 are spaced apart along a second direction. The two second shell walls 22 are spaced apart along a third direction. The third shell wall 23 is connected to the two first shell walls 21 and the two second shell walls 22 along a first direction to jointly define the receiving cavity 2a and the mounting port 2b. The first shell walls 21 can be the target shell walls.

[0106] Here, after the bare cell 1 expands, the target shell wall is the object of the greatest force exerted by the bare cell 1 after expansion. Therefore, the hardness of the heating softening zone 2c is set to be lower than that of the 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 exerted by the bare cell 1 on the target shell wall, thereby reducing the risk of the shell 2 cracking and thus reducing the probability of electrolyte leakage inside the shell 2, resulting in high safety.

[0107] In one exemplary embodiment, referring 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, liquid injection port 3b, and electrode port 3c all penetrate the top cover 3 along a first direction, covering the mounting port 2b. The pressure relief port 3a, liquid injection port 3b, and electrode port 3c are all connected to the receiving cavity 2a. The pressure relief port 3a is used to relieve pressure in the receiving cavity 2a after thermal runaway of the bare cell 1, preventing an explosion. The liquid injection port 3b is used to inject electrolyte into the receiving cavity 2a. The electrode port 3c facilitates electrical connection to the tabs of the bare cell 1.

[0108] In one embodiment, please refer to Figures 1 and 3. The top cover 3 and the shell 2 are connected by welding. The hardness of the molten pool region 2e formed by welding the shell 2 is not less than the hardness of the heat softening region 2c. The dimension of the heat softening region 2c along the first direction is not less than 0.2 mm.

[0109] The molten pool zone 2e refers to the portion of the base material that melts into a pool shape due to the heat of the welding arc, which is the liquid metal portion 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 port 2b, and the hardness of the molten pool region 2e21e formed by the welding of the housing 2 is not less than the hardness of the heat-softened region 2c. The dimension of the heat-softened region 2c along the first direction can be represented by H3, and H3 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 3mm, 5mm, 8mm, 10mm or 12mm, etc.

[0111] In this way, by welding the top cover 3 to the shell 2, the hardness of the molten pool region 2e is not less than the hardness of the heat-softening region 2c, which can improve the connection strength between the top cover 3 and the shell 2. By setting a heat-softening region 2c of appropriate size, while ensuring that the shell 2 has sufficient structural strength, it can also have strong toughness to absorb and disperse the force exerted on the shell 2 by the expansion of the bare cell 1, reduce stress concentration at the mounting port 2b, reduce cracking at the mounting port 2b, and improve the cycle expansion life of the shell 2 under charge and discharge.

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

[0113] For example, the dimension H3 of the heating and softening zone 2c along the first direction can be 1mm, 2mm, 3mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm or 12mm, etc.

[0114] In this way, by setting a heating softening zone 2c of appropriate size, it is easier to reduce cracking at the installation port 2b.

[0115] In one embodiment, the molten pool region 2e is located on the side of the heating and softening region 2c facing the corresponding mounting port 2b along the corresponding first direction.

[0116] In other words, the molten pool zone 2e is positioned between the mounting port 2b and the heating and softening zone 2c along the first direction, which facilitates stable welding of the top cover 3 and the shell 2 and results in high connection strength. The heating and softening zone 2c being close to the molten pool zone 2e can reduce stress concentration in the molten pool zone 2e, thereby reducing the occurrence of cracks in the molten pool zone 2e.

[0117] Another aspect of this disclosure provides an electrical device that includes the battery 100 from any of the above embodiments, the battery 100 being 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] Electrical devices are devices that use electrical energy as their energy source to perform corresponding functions by consuming electrical energy. For example, electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

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

[0120] The main body of a device refers to the main structure that consumes electrical energy to perform the corresponding function. For example, an electrical device can be a mobile phone, where the main body is the part that enables communication and other functions, and the battery 100 supplies power to this part. Similarly, an electrical device can be a car, where the main body is the part that provides seating and allows the vehicle to travel on roads, and the battery 100 supplies power to this part.

[0121] A power supply device is a device that can output electrical energy. For example, electrical energy can be output through a battery 100.

[0122] The following description will use a vehicle as an example of an electrical device according to one embodiment of the present disclosure.

[0123] One embodiment of this disclosure provides a vehicle that can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is installed inside the vehicle, and the battery 100 can be located at the bottom, front, or rear of the vehicle. The battery 100 can be used to power the vehicle; for example, the battery 100 can serve as the vehicle's operating power source. The vehicle may also include a controller and a motor, and the controller can be used to control the battery to power the motor. For example, the battery unit can be used to meet the vehicle's power needs during starting, navigation, and driving.

[0124] The battery 100 provided in this embodiment, as shown in Figures 1 to 7, includes a bare cell 1, a casing 2, and a top cover 3. The casing 2 has a receiving cavity 2a that extends through one side of the casing 2 along a first direction to form a mounting opening 2b. The bare cell 1 is disposed in the receiving cavity 2a, and the top cover 3 covers the mounting opening 2b. The casing wall of the casing 2 has a heat-softening region 2c and a body region 2d. The heat-softening region 2c is formed at least on a target casing wall of the casing 2, which is the casing wall with the largest area. The target casing wall is arranged adjacent to the mounting opening 2b. The hardness of the heat-softening region 2c is lower than that of the body region 2d. Specifically, the ratio of the hardness of the heat-softening region 2c to the hardness of the body region 2d is between 0.5 and 0.8. The grain type of the heat-softening region 2c is strip-shaped and / or banded, and the grain type of the body region 2d is columnar and / or equiaxed. The distance between the bare cell 1 and the heating softening zone 2c along the first direction is between 1 mm and 3 mm. 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 distance between the lower plastic 4 and the heating softening zone 2c along the inner and outer directions is between 1.2 mm and 5 mm, wherein the inner and outer directions are perpendicular to the first direction. The top cover 3 and the shell 2 are connected by welding. The hardness of the molten pool region 2e formed by welding the shell 2 is not less than the hardness of the heating softening zone 2c. The molten pool region 2e is located on the side of the heating softening zone 2c facing the corresponding mounting port 2b along the corresponding first direction. The dimension of the heating softening zone 2c along the first direction is not less than 1 mm.

[0125] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. All modifications, equivalent substitutions, improvements, etc., within the spirit and principles of this disclosure are included within the scope of protection of this disclosure.

Claims

1. A battery, comprising: Bare battery cells; The housing has a receiving cavity, which extends through one side of the housing along a first direction to form an installation port. The bare battery cell is disposed in the receiving cavity. The housing wall has a heating softening zone and a body zone. The hardness of the heating softening zone is lower than that of the body zone. The bare battery cell and the heating softening zone are spaced apart along the first direction. A top cover is provided over the mounting port.

2. The battery according to claim 1, wherein, The distance between the bare battery cell and the heated softening area 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 cell and the heated softening area 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 layer disposed on the side of the top cover facing the bare battery cell. The distance between the lower plastic layer and the heating softening zone in the inward and outward directions is greater than 1 mm, wherein the inward and outward 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 inside-out direction 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 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 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 the target shell wall of the housing, the target shell wall being the shell wall with the largest area of ​​the housing, and the target shell wall being arranged adjacent to the mounting port.

9. The battery according to any one of claims 1 to 8, wherein, The top cover and the shell are connected by welding. The hardness of the molten pool area formed by welding the shell is not less than the hardness of the heat-softened area. The size of the heat-softened area 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 the side of the heating and softening zone facing the corresponding mounting port along the first direction.

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

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