Battery and electrical device

Abstract

The present application discloses a battery and an electrical device, which can reduce slip-off. The battery includes a battery cell assembly, a first housing, a second housing, and a third housing. The first housing and the second housing both include a bottom wall and a side wall connecting the bottom wall. The third housing includes a side wall. The side walls of the first housing and the second housing are respectively in interference fit with the side walls at both ends of the third housing. The battery cell assembly is located in the cavity formed by the first housing, the second housing, and the third housing. When the internal pressure of the battery cell increases, the probability of slip-off between the first housing, the second housing, and the third housing can be reduced.

Description

Technical Field

[0001] This application relates to the field of electrochemistry, and particularly to a battery and an electrical device using the same. Background Art

[0002] In current batteries, such as those used in TWS (True Wireless Stereo) earphones, the battery housing and the cover form a battery through clearance assembly. When the battery is in use, if the internal pressure of the battery cell increases, the housing and the cover will slip and separate, causing splashing. Summary of the Invention

[0003] In view of this, in order to solve or improve the problems of the prior art, this application provides a battery, its preparation method, and an electrical device using the same, which can reduce slip-off.

[0004] One aspect of this application provides a battery, including a battery cell assembly, a first housing, a second housing, and a third housing. Both the first housing and the second housing include a bottom wall and a side wall connecting the bottom wall. The third housing includes a side wall. The side walls of the first housing and the second housing are respectively in interference fit with the side walls at both ends of the third housing. The battery cell assembly is located in the cavity formed by the first housing, the second housing, and the third housing. When the internal pressure of the battery cell increases, the probability of slip-off between the first housing, the second housing, and the third housing can be reduced.

[0005] In one embodiment, the side wall surfaces of the third housing in contact with the first housing and the second housing are provided with a first limiting groove and a second limiting groove. Both the first housing and the second housing are provided with a necking. The first limiting groove is interlocked and limited with the necking of the first housing, and the second limiting groove is interlocked and limited with the necking of the second housing. This can further reduce slip-off.

[0006] In one embodiment, the first limiting groove includes a limiting groove or at least two sub-limiting grooves smaller than it; the necking of the first housing includes a full-circle necking or at least two sub-neckings smaller than a full circle.

[0007] In one embodiment, the second limiting groove includes a limiting groove or at least two sub-limiting grooves smaller than it; the necking of the second housing includes a full-circle necking or at least two sub-neckings smaller than a full circle.

[0008] In one embodiment, the side wall of the first housing includes a first side wall. The first end of the first side wall is connected to the bottom wall of the first housing. The second end of the first side wall away from the bottom wall shrinks towards the third housing and extends into the first limiting groove. The side wall at the shrinking part is the necking of the first housing.

[0009] In one embodiment, the side wall of the second housing includes a second side wall. The first end of the second side wall is connected to the bottom wall of the second housing. The second end of the second side wall away from the bottom wall of the second housing shrinks towards the third housing and extends into the second limiting groove. The side wall at the shrinking portion is the necking of the second housing.

[0010] In one embodiment, the second end of the first side wall of the first housing away from the bottom wall of the first housing shrinks towards the third housing, and the shrinking angle is greater than zero degree and less than a preset angle. The influence of the pressure generated when the necking is too large on the side wall of the third housing can be reduced.

[0011] In one embodiment, the second end of the second side wall of the second housing away from the bottom wall of the second housing shrinks towards the third housing, and the shrinking angle is greater than zero degree and less than a preset angle. The influence of the pressure generated when the necking is too large on the side wall of the third housing can be reduced.

[0012] In one embodiment, the preset angle is 45° to 90°.

[0013] In one embodiment, when the sealing structure includes a coating, the material of the coating is sealant, adhesive, silicone or polyurethane.

[0014] In one embodiment, the thickness of the coating is 5μm - 100μm. It can not only meet the roughness specification but also have no impact on the space utilization rate of the battery cell.

[0015] In one embodiment, the burr size of the end face of the first housing and / or the end face of the second housing is less than or equal to 0.01mm. It can prevent the burrs from scraping off the coating and avoid forming a liquid leakage channel.

[0016] In one embodiment, the side wall width of at least one of the first housing, the second housing and the third housing is greater than or equal to 0.5mm. The width direction is perpendicular to the first direction, and the first direction is the buckling direction when the first housing and the second housing are respectively assembled with the third housing. It is beneficial to isolate external water vapor and can also prevent electrolyte leakage.

[0017] In one embodiment, both the first housing and the second housing are conductive metal housings.

[0018] In one embodiment, the battery cell assembly includes a positive electrode tab and a negative electrode tab. The positive electrode tab of the battery cell assembly is electrically connected to the first housing, and the negative electrode tab of the battery cell assembly is electrically connected to the second housing.

[0019] In one embodiment, the third housing is an insulating housing.

[0020] In one embodiment, the third housing is a plastic housing.

[0021] In one embodiment, the side wall surface of the third housing in contact with the first housing and the second housing is provided with a boss. On the one hand, it can reduce the electrical contact between the first housing and the second housing, and on the other hand, it can also enhance the strength of the third housing.

[0022] In one embodiment, the height of the side wall of the third housing is greater than the sum of the heights of the side walls of the first housing and the second housing. The height direction is the first direction, and the first direction is the buckling direction when the first housing and the second housing are respectively assembled with the third housing. After the first housing, the second housing and the third housing are assembled, there is a gap between the first housing and the second housing, which can reduce the electrical contact between the first housing and the second housing.

[0023] One aspect of the present application provides an electrical device including the above-mentioned battery.

[0024] One aspect of the present application provides a method for preparing a battery, including the following steps:

[0025] Provide a first housing, a second housing, a third housing and an electrode core assembly. Both the first housing and the second housing include a bottom wall and a side wall connecting the bottom wall, and the third housing includes a side wall;

[0026] Bucklingly assemble the first housing and the second housing with the third housing respectively, place the electrode core assembly in the cavity formed by buckling the first housing, the second housing and the third housing, and perform interference fit between the side wall of the first housing, the side wall of the second housing and the side walls at both ends of the third housing.

[0027] In one embodiment, it further includes: forming a first limiting groove and a second limiting groove on the side wall surface of the third housing to form a necking for both the first housing and the second housing; and when the first housing is assembled with the third housing, interlock and limit the first limiting groove with the necking of the first housing, and when the second housing is assembled with the third housing, interlock and limit the second limiting groove with the necking of the second housing.

[0028] In one embodiment, it further includes providing a sealing structure on the surfaces where the first housing contacts the third housing and the second housing contacts the third housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application, and those skilled in the art can also obtain other drawings based on these drawings.

[0030] Figure 1 It is a schematic top view structure diagram of the battery in one embodiment of the present application;

[0031] Figure 2is a schematic cross-sectional structure diagram of a battery in the A-A direction in an embodiment of the present application; Figure 1 Schematic top view structure diagram of the circular first housing;

[0032] Figure 3 Schematic top view structure diagram of the circular first housing;

[0033] Figure 4 Schematic top view structure diagram of the first housing in a polygonal shape;

[0034] Figure 5 Schematic top view structure diagram of the first housing in an irregular shape;

[0035] Figure 6 is a partial enlarged structure diagram of the structure at the circle in an embodiment of the present application; Figure 2 Schematic partial enlarged structure diagram of the structure at the circle;

[0036] Figure 7 is a schematic cross-sectional structure diagram of a battery in another embodiment of the present application;

[0037] Figure 8 is a partial enlarged structure diagram of the structure at the circle in an embodiment of the present application; Figure 7 Schematic partial enlarged structure diagram of the structure at the circle;

[0038] Figure 9 is a schematic structure diagram of the first housing with a full-circle necking in an embodiment of the present application;

[0039] Figure 10 is a schematic structure diagram of the first housing with two sub-neckings in an embodiment of the present application;

[0040] Figure 11 is a schematic structure diagram of the first housing with 4 sub-neckings in an embodiment of the present application;

[0041] Figure 12 is a schematic structure diagram of the first housing with a chamfer-shaped necking in an embodiment of the present application;

[0042] Figure 13 is a schematic structure diagram of the first housing with a right-angle-shaped necking in an embodiment of the present application;

[0043] Figure 14 is a schematic structure diagram of the first housing with an arc-shaped necking in an embodiment of the present application. Detailed implementation manners

[0044] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. Without conflict, the technical features of the following various embodiments can be combined with each other.

[0046] As described in the background art, for current batteries, when the internal pressure of the battery cell increases during use, the housing and the cover will slip and disengage, causing splashing.

[0047] The present application proposes a battery that can reduce the slip and disengagement of the housing and the cover. The battery of the present application can be, but is not limited to, a lithium-ion battery.

[0048] For convenience of description, the first direction and the second direction mentioned in the present application are defined as follows. The first direction is the fastening direction when the first housing and the second housing are respectively assembled with the third housing; the second direction is perpendicular to the first direction. Please refer to Figure 2 or Figure 7 , the first direction is the direction shown by T, and the second direction is the direction shown by L.

[0049] Please refer to Figure 1 , which is a top view structural schematic diagram of the battery in an embodiment of the present application. Please refer to Figure 2 , which is a cross-sectional structural schematic diagram of the battery in an embodiment of the present application along the Figure 1 A-A direction in. As Figure 2 shown, the battery includes: a battery cell assembly 21, a first housing 22, a second housing 23, and a third housing 24. The first housing 22 and the second housing 23 both include a bottom wall and a side wall connecting the bottom wall. The third housing 24 includes a side wall. The side walls of the first housing 22 and the second housing 23 are respectively in interference fit with both ends of the side wall of the third housing 24. The battery cell assembly 21 is located in the cavity formed by the first housing 22, the second housing 23, and the third housing 24.

[0050] In this embodiment, since the side walls of the first housing 22 and the second housing 23 are both in interference fit with the side wall of the third housing 24, the sealing performance of the battery is improved. Therefore, when the internal pressure of the battery cell increases, the probability of the first housing 22 and the second housing 23 slipping and disengaging from the third housing 24 respectively can be reduced. In addition, a battery with better sealing performance can also play a role in restricting the increase in thickness when the battery cell expands cyclically.

[0051] It can be understood that an interference fit means that the tolerance zone of the hole is below that of the shaft, that is, the algebraic difference obtained by subtracting the dimensions of the shaft in all directions from the dimensions of the hole in all directions. When this difference is negative, it is an interference fit. In this embodiment, as Figure 2 shown, the first housing 22 is used as the hole, and the third housing 24 is used as the shaft. The difference obtained by subtracting the cross-sectional diameter of a certain point on the side wall of the third housing 22 corresponding to this point from the cross-sectional diameter of a certain point on the side wall of the first housing 22 is negative.

[0052] For the first housing 22 and the second housing 23, in some embodiments, both the first housing 22 and the second housing 23 can be conductive metal housings. In some examples, the conductive metal can be, but is not limited to, stainless steel, alloy, composite metal, silver, copper, gold, aluminum, tungsten, nickel, iron, etc. These conductive metals have good processing and forming properties, excellent electrical conductivity, and electrolyte resistance, which are beneficial to improving the performance of the battery.

[0053] In some embodiments, the side walls of the first housing 22, the second housing 23, and the third housing 24 can all be full-circle side walls. In this way, the risk of the core component being exposed can be reduced. In other embodiments, the side walls of the first housing 22, the second housing 23, and the third housing 24 can also all be side walls less than a full circle. Further, the battery can also include a sealing sleeve structure for sealing the part of the core component not covered by the first housing 22, the second housing, and the third housing 24, reducing the risk of the core component being exposed.

[0054] In some embodiments, the burr size of the end face of the first housing 22 and the burr size of the end face of the second housing 23 can both be less than or equal to 0.01 mm. The inventor's research found that when designed with this burr size, it can prevent the burr from scraping off the coating and avoid forming a liquid leakage channel.

[0055] In some embodiments, the surface of the bottom wall of the first housing 22 for connecting the tab and the surface of the bottom wall of the second housing 23 for connecting the tab can both be flat. By electrically connecting with the tab through a relatively flat plane, the connection reliability can be improved.

[0056] In some embodiments, the cross-section of the side wall and the bottom wall of the first housing 22, and the cross-section of the side wall and the bottom wall of the second housing 23 can all be circular, arc-shaped, elliptical, polygonal (such as square or triangular), or irregular, etc. Taking the first housing 22 as an example, please refer to Figures 3 to 5 , which are respectively the top view structural schematic diagrams of the first housing 22 when the side walls are circular, polygonal, and irregular.

[0057] In some embodiments, the cross-sectional shapes of the portions of the side walls of the third housing 24 that are respectively assembled with the side walls of the first housing 22 and the second housing 23 are the same as the side walls of the first housing 22 and the second housing 23, respectively. For example, the first end of the side wall of the third housing 24 is assembled with the side wall of the first housing 22. If the side wall of the first housing 22 is circular, then the first end of the side wall of the third housing 24 is also circular.

[0058] In some embodiments, the thicknesses of the side walls of the first housing 22 and the second housing 23 can both be 0.02 mm - 5 mm. For example, 0.02 mm, 5 mm, or 2.51 mm can be taken, but it is not limited thereto.

[0059] In some examples, in the second direction, the widths of the side walls of the first housing 22 and the second housing 23 are both greater than or equal to 0.5 mm, but it is not limited thereto. The inventors have found through research that this width condition is beneficial for isolating external water vapor and can also prevent electrolyte leakage. For example, the widths of the side walls of the first housing 22 and the second housing 23 are both 5 mm - 100 mm. For example, 5 mm, 52.5 mm, or 100 mm can be taken.

[0060] In some embodiments, in the first direction, the heights of the side walls of the first housing 22 and the second housing 23 can both be 1 mm - 10 mm. For example, 1 mm, 5.5 mm, or 10 mm can be taken. However, it is not limited thereto, and it can be specifically determined according to the size of the battery cell assembly 21.

[0061] For the third housing 24, in some embodiments, the third housing 24 is an insulating housing. This helps reduce the probability of forming an electronic conduction channel between the first housing 22 and the second housing 23. Further, in some examples, the third housing 24 can be a plastic housing, such as LCP (Liquid Crystal Polymer), PPS (Polyphenyl sulfidegranula), PEEK (poly ether ether ketone), PSF (polysulfone), PET (Polyethylene terephthalate), PTFE (Polyte trafluoroethene), PVDF (Poly vinylidene fluoride), PCTFE (polychloro trifluoro ethylene), PFA (Polyfluoroalkoxy, copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene), PP (Polypropylene), ABS (AcrylonitrileButadiene Styrene), etc. The inventors have found that when the third housing 24 uses the above-mentioned plastic housing as the insulating housing, it not only has good insulation performance, but also has good hardness, processing and forming performance, electrolyte resistance performance and water isolation performance.

[0062] In some embodiments, the transition between the side wall and the end face of the third housing 24 adopts an R-angle transition structure. In this way, it is beneficial to the assembly guiding function of the third housing 24 and can also reduce the probability of scratching the battery cell assembly 21 when the third housing 24 is assembled with the battery cell assembly 21.

[0063] In some embodiments, the width of the side wall of the third housing 24 is greater than or equal to 0.5 mm. This width condition is beneficial to isolating external moisture and can also prevent electrolyte leakage.

[0064] In some embodiments, the height of the side wall of the third housing 24 is greater than the sum of the heights of the side walls of the first housing 22 and the second housing 23. In this way, there is a gap between the first housing 22 and the second housing 23. When the first housing 22 and the second housing 23 are conductive housings, the electrical contact between the first housing 22 and the second housing 23 can be reduced.

[0065] In other embodiments, the sidewall height of the third housing 24 may also be less than or equal to the sum of the sidewall heights of the first housing 22 and the second housing 23, that is, there may be no gap between the first housing 22 and the second housing 23. In this case, the partial sidewalls at the contact between the first housing 22 and the second housing 23 may all be made of insulating material, and the bottom walls of the first housing 22 and the second housing 23 are both conductive metals, and the partial sidewalls connected to the bottom walls may also be conductive metals. Thus, the first housing 22 and the second housing 23 can be used as conductive housings and direct electrical contact can be avoided.

[0066] It can be understood that in order to provide a gap between the first housing 22 and the second housing 23, in some other embodiments, the sidewall height of the third housing 24 is less than or equal to the sum of the sidewall heights of the first housing 22 and the second housing 23, and the sidewall of the third housing 24 does not extend to the bottom wall of the first housing and / or the bottom wall of the second housing.

[0067] In some embodiments, referring to Figure 2 or Figure 7 , there are bosses 243 provided on the sidewall surface of the third housing 24. The bosses 243 are used to separate the first housing 22 and the second housing 23. Specifically, as shown in Figure 2 or 7, the bosses 243 are provided on the outer surface of the sidewall of the third housing 24 in contact with the first housing 22 and the second housing 23. In these embodiments, by providing the bosses 243 to separate the first housing 22 and the second housing 23, on the one hand, the electrical contact between the first housing 22 and the second housing 23 can be reduced, especially when combined with embodiments where there are gaps between the third housing 24 and the first housing 22 and the second housing 23 respectively. On the other hand, the strength of the third housing 24 can be enhanced by providing the bosses 243.

[0068] For the battery cell assembly 21, in some embodiments, as shown in Figure 2 , the battery cell assembly 21 includes a positive electrode tab 211 and a negative electrode tab 212. Further, in some examples, the positive electrode tab 211 of the battery cell assembly 21 is electrically connected to the first housing 22, and the negative electrode tab 212 of the battery cell assembly 21 is electrically connected to the second housing 23. When both the first housing 22 and the second housing 23 are conductive metal housings, the first housing 22 can be used as the positive electrode housing of the battery, and the second housing 23 can be used as the negative electrode housing. The aforementioned electrical connection can be by welding, but is not limited thereto. In some embodiments, in addition to the positive electrode tab 211 and the negative electrode tab 212, the battery cell assembly 21 further includes an anode plate, a cathode plate, a separator, a sealing glue (not shown), etc.

[0069] In some examples, the battery cell assembly 21 can be a wound structure or a stacked structure.

[0070] In some embodiments, the battery further includes a sealing structure ( Figure 2 not shown in the figure). The sealing structure is disposed on the surfaces where the first housing 22 contacts the third housing 24 and on the surfaces where the second housing 23 contacts the third housing 24. In this embodiment, on the basis of using an interference fit, a sealing structure is further added, which can further improve the sealing performance of the battery. Therefore, when the internal pressure of the battery cell increases, it is more conducive to reducing the probability that the first housing 22 and the second housing 23 slip away from the third housing 24 respectively.

[0071] For the sealing structure, in some embodiments, the sealing structure includes a coating, and the coating is formed on any one or more surfaces where the third housing 24 contacts the first housing 22 and on any one or more surfaces where the third housing 24 contacts the second housing 23. The coating not only plays a sealing role, but also helps to isolate external water vapor and prevent electrolyte leakage.

[0072] In some examples, it may be that the outer surface of the side wall of the third housing 24 contacts the inner surfaces of the side walls of the first housing 22 and the second housing 23. Then, the outer surfaces of the first housing 22 and the second housing 23 are both exposed, which can increase the contact area between the first housing 22 and the second housing 23 as conductive housings and external electrical receiving devices. In this case, the coating can be formed on any one or more surfaces of the outer surface of the side wall of the third housing 24 and the inner surface of the side wall of the first housing 22, and on any one or more surfaces of the outer surface of the side wall of the third housing 24 and the inner surface of the side wall of the second housing 23.

[0073] Furthermore, the coating can be formed only on the outer surface of the side wall of the third housing 24. Because when the third housing 24 is in interference fit with the first housing 22 and the second housing 23, due to the extrusion effect, the coating molecules will move and fill the micropores on the inner surface of the first housing 22 and the micropores on the inner surface of the second housing 23 to form a seal. Therefore, when only coated on the third housing 24, both sealing can be achieved and cost can be saved.

[0074] In some examples, the coating can be a single layer or multiple layers. It is specifically determined according to the actual situation.

[0075] The coating needs to have good adhesion to prevent it from falling off when the first housing 22, the second housing 23 and the third housing 24 are snap-fitted and assembled. Therefore, in some examples, the material of the coating can be at least one of sealant, glue, silica gel or polyurethane. The coatings of these materials have good adhesion, low surface viscosity, are not sticky, do not shed powder, and at the same time have good sealing performance, compressibility, electrolyte resistance and water isolation performance. Specifically in implementation, the coating with corresponding components can be selected according to different actual requirements.

[0076] In some examples, the thickness of the coating is 5 μm - 100 μm, and for example, 5 μm, 52.5 μm or 100 μm can be taken. The coating is mainly used to fill the roughness gaps existing between the third housing 24 and the first housing 22, and the roughness gaps existing between the third housing 24 and the second housing 23. The inventors have found through research that a coating with a thickness of 5 μm - 100 μm can meet the roughness specifications, and this thickness is relatively small and will not affect the space utilization rate of the battery cell.

[0077] In some other embodiments, the sealing structure may include a sealing component, which is inserted between the surfaces where the third housing 24 contacts the first housing 22 and between the surfaces where the third housing 24 contacts the second housing 23. The sealing component can be an O-ring or the like, but is not limited thereto.

[0078] In some embodiments, the sealing structure may include both a coating and a sealing component, which is more conducive to enhancing the sealing performance.

[0079] In some embodiments, such as Figure 2 、 Figure 6 、 Figure 7 、 Figure 8 As shown, on the side wall surface where the third housing 24 contacts the first housing 22, a first limiting groove 241 is provided, and on the side wall surface where the third housing 24 contacts the second housing 23, a second limiting groove 242 is provided. Both the first housing 22 and the second housing 23 are provided with neckings. The first limiting groove 241 and the necking 221 of the first housing 22 are interlocked and limited, and the second limiting groove 242 and the necking 231 of the second housing 23 are interlocked and limited. In this way, on the basis of using an interference fit, with the interlocking and limiting of the limiting groove and the necking, the slip-off can be further reduced.

[0080] Please refer to Figure 2 or Figure 7 , both the first limiting groove 241 and the second limiting groove 242 are square grooves, but are not limited thereto.

[0081] In one embodiment, please refer to Figure 2 or Figure 7 , the side wall of the first housing 22 includes a first side wall. The first end of the first side wall is connected to the bottom wall of the first housing. The second end of the first side wall away from the bottom wall of the first housing 22 shrinks towards the third housing 24 and extends into the first limiting groove 241, and the side wall at the shrinking part is the necking of the first housing 22. In some examples, the second end of the first side wall may further extend to the bottom of the first limiting groove 241.

[0082] In one embodiment, please refer to Figure 2 or Figure 7, the side wall of the second housing 23 includes a second side wall. To avoid conflict with the definition of the first side wall of the first housing 22, in this embodiment, it is defined as the second side wall. The first end of the second side wall is connected to the bottom wall of the second housing 23, and the second end of the second side wall away from the bottom wall of the second housing 23 shrinks towards the third housing 24 and extends into the second limiting groove 242. The side wall at the shrinking part is the necking of the second housing 23. In some examples, the second end of the second side wall can further extend to the bottom of the second limiting groove 242.

[0083] In some embodiments, both the first limiting groove 241 and the second limiting groove 242 can include a full-circle limiting groove, or both include at least two sub-limiting grooves less than a full circle. Correspondingly, in some embodiments, the neckings 221 of the first housing 22 and the necking 231 of the second housing 23 can also be full-circle neckings or at least two sub-neckings less than a full circle. In some examples, when both the first limiting groove 241 and the second limiting groove 242 include at least two sub-limiting grooves less than a full circle, the lengths of the respective sub-limiting grooves can be equal or unequal. Correspondingly, the lengths of the respective neckings can be equal or unequal.

[0084] For example, taking the first housing 22 with a circular cross-section of the side wall as an example, Figure 9 , 10 , 11 are schematic diagrams of the first housing 22 in different embodiments, where Figure 9 , 10 , the diagram b in 11 is a cross-sectional structure diagram of the A-A plane of the diagram a. As Figure 9 shown, the necking 221 of the first housing 22 is a full-circle necking. As Figure 10 shown, the first housing 22 is provided with two sub-neckings, and the arc lengths of the respective sub-neckings are equal, and the arc length is greater than one-third of the circumference and less than one-half of the circumference. As Figure 11 shown, the first housing 22 is provided with 4 sub-neckings, and the arc lengths of the respective sub-neckings are equal, and the arc length is greater than one-fifth of the circumference and less than one-fourth of the circumference.

[0085] In some examples, the shapes of the necking 221 of the first housing 22 and the necking 231 of the second housing 23 can both be chamfers, right angles or arcs, but are not limited thereto. As Figure 12 , 13 , 14 shown, are schematic diagrams of the first housing 22 in different embodiments, where, Figure 12 , 13 , the diagram b in 14 is a cross-sectional structure diagram of the A-A plane of the diagram a. As Figure 12 b shown, the shape of the necking is a chamfer. As Figure 13 b shown, the shape of the necking is a right angle. As Figure 14 b shown, the shape of the necking is an arc.

[0086] In some embodiments, on the basis of an interference fit, the battery may further adopt both the sealing structure in the foregoing embodiments and the necking interlocking limiting structure in the foregoing embodiments. In this way, it is not only more conducive to reducing slip-off, but the sealing structure can also improve the problem of sealing liquid leakage caused by an overly small necking. When specifically implemented, it is preferable to use a coating as the sealing structure for sealing, because in the case of a large necking, overpressure is likely to occur. If a sealing ring is used, it is prone to breakage under overpressure, while using a coating can reduce the risk of breakage.

[0087] The size of the necking in this application is determined according to the contraction angle of the side wall at the necking. The larger the angle, the larger the necking, which is more conducive to sealing, and at the same time, the greater the pressure on the side wall of the third housing 24. For example, Figure 6 the necking size of [X] is about 15°, Figure 8 the necking size of [Y] is about 30°, and the necking size of the former is smaller than that of the latter.

[0088] In some embodiments, the contraction angle of the side wall at the necking of the first housing 22 and the contraction angle of the side wall at the necking of the second housing 23 can both be greater than 0 degrees and less than a preset angle. The preset angle can be 45° to 90°, for example, 45°, 62.5°, or 90° can be taken. In this way, the influence of the pressure generated when the necking is too large on the side wall of the third housing 24 and the sealing structure thereon can be reduced. Especially when the sealing structure is a plug-in sealing component, using a smaller necking can reduce the risk of overpressure breakage of the sealing component. When specifically implemented, the preset angle is not limited to the foregoing limitations and can be determined according to the requirements for sealing performance and the rigidity conditions of the sealing structure.

[0089] This application also proposes an electrical device, including the battery in any of the foregoing embodiments. The electrical device may include, but is not limited to, consumer electronics, drones, power tools, energy storage devices, electric bicycles, electric vehicles, etc. Consumer electronics may specifically be a mobile communication device, a laptop computer, a tablet computer, a wearable device (such as TWS earphones), etc.

[0090] This application also proposes a method for manufacturing a battery.

[0091] The method for manufacturing a battery in an embodiment of this application includes the following steps:

[0092] Step S1, providing a first housing, a second housing, and a third housing. The first housing and the second housing both include a bottom wall and a side wall connected to the bottom wall, and the third housing includes a side wall.

[0093] In some embodiments, the draft angles of the side wall and the bottom wall of the first housing and the draft angles of the side wall and the bottom wall of the second housing during incoming material can both be greater than or equal to 90°. Herein, it is beneficial for the stamping demolding of the first housing and the second housing, and is beneficial for the guiding and sealing during the snap - fitting assembly of the first housing and the second housing with the third housing.

[0094] In some examples, both the first housing and the second housing can be formed into a circular cup - shaped structure with a bottom wall and a side wall by mechanical stamping.

[0095] In some examples, a circular barrel - shaped structure with a side wall can be formed by processes such as injection molding, transfer molding, machining, etc. as the third housing. The draft angle between the side wall and the end face of the third housing during incoming material can also be greater than 90°, which is beneficial for the assembly guiding of the third housing with the first housing and the second housing.

[0096] Step S2: Place the battery cell assembly in the cavity formed by the snap - fitting of the first housing, the second housing, and the third housing, and perform interference fitting between the side wall of the first housing and the side wall at one end of the third housing, and perform interference fitting between the side wall of the second housing and the side wall at the other end of the third housing.

[0097] In some embodiments, it further includes the step of providing a sealing structure on the surfaces where the first housing contacts the third housing and where the second housing contacts the third housing. In some examples, a coating can be formed on any one or more surfaces where the third housing contacts the first housing, and a coating can be formed on any one or more surfaces where the third housing contacts the second housing. In some examples, when the outer surface of the side wall of the third housing is in interference fit with the inner surfaces of the side walls of the first housing and the second housing, a coating can be formed only on the outer surface of the side wall of the third housing. In some examples, a single - layer coating or a multi - layer coating can be formed.

[0098] In some examples, the coating can be formed by processes such as spraying, roll - spraying, dipping, coating, gluing, etc., so that the coating adheres to the surface of the housing side wall. In some examples, the coating material can be gaseous, liquid, or solid, and the state of the coating material can be specifically determined according to the substrate to be sprayed. In some examples, the coating material can be at least one of sealant, glue, silicone, or polyurethane.

[0099] Taking the coating formed on the outer surface of the third housing as an example, the preparation method of the battery in a specific embodiment of the present application is described as follows. The specific steps are as follows:

[0100] Before the incoming materials, spray a good coating on the outer surface of the third housing, and place the third housing on a platform fixture for fixation. Then place one end of the second housing along the axial direction of the third housing, and apply an external pressure on the second housing to make the second housing move towards the third housing until an interference fit is formed between the side wall of the second housing and the side wall of the third housing. And under the pressing action, the coating on the outer surface of the third housing forms a seal with the side wall of the second housing. Then place the battery cell assembly in the cavity formed by the assembled second housing and third housing, use an external pressing block to press-fit the negative electrode tab of the battery cell assembly with the inner surface of the bottom wall of the second housing, and form an electrical connection between the negative electrode tab of the battery cell assembly and the inner surface of the bottom wall of the second housing by means of laser or resistance welding, etc.

[0101] Then place the first housing on a fixed fixture, bend the positive electrode tab of the battery cell assembly to the inner surface of the bottom wall of the first housing, press-fit the positive electrode tab of the battery cell assembly with the inner surface of the bottom wall of the first housing by means of a mechanical pressing block, and then form an electrical connection between the positive electrode tab of the battery cell assembly and the inner surface of the bottom wall of the second housing by means of laser or resistance welding, etc. Then place the first housing at the other end along the axial direction of the third housing, and apply an external pressure on the first housing to make the first housing move towards the third housing until an interference fit is formed between the side wall of the first housing and the side wall of the third housing. And under the pressing action, the coating on the outer surface of the third housing forms a seal with the side wall of the first housing.

[0102] Therefore, through the above preparation method, the first housing and the second housing are respectively snap-fitted with the third housing to form an interference fit. At the same time, the coating on the outer surface of the third housing fills the micropores on the surfaces of the first housing and the second housing under the pressing action to form a seal, thereby preparing a battery. For the above preparation method, the way of leading out the electrode tabs is also relatively simple.

[0103] In some embodiments, it further includes the steps of forming a first limiting groove and a second limiting groove on the side wall surface of the third housing, and forming a necking on the side walls of both the first housing and the second housing. And when the first housing is assembled with the third housing, interlock and limit the first limiting groove with the necking of the first housing, and when the second housing is assembled with the third housing, interlock and limit the second limiting groove with the necking of the second housing.

[0104] In some embodiments, the width of the open end of the side wall of the first housing and the width of the open end of the side wall of the second housing during the incoming materials can both be greater than or equal to 0.1 mm. The inventor has found through research that this width condition requires the first housing and the second housing to have good processing and forming performance.

[0105] Although the present application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on a reading and understanding of this specification and the drawings. The present application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above-described components, the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (i.e., it is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementations of this specification shown herein.

[0106] That is, the above are only embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made using the content of the specification and drawings of the present application, such as the mutual combination of technical features between various embodiments, or direct or indirect application in other related technical fields, is similarly included within the patent protection scope of the present application.

[0107] In addition, in the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present application. In addition, for structural elements with the same or similar characteristics, the present application may use the same or different reference numerals for identification. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0108] In this application, the term "exemplary" is used to mean "serving as an example, instance, or illustration". Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or better than other embodiments. The foregoing description is presented to enable any person skilled in the art to make and use this application. In the foregoing description, various details are set forth for purposes of explanation. It will be apparent to those skilled in the art that the application may be practiced without these specific details. In other instances, well-known structures and processes are not set forth in detail to avoid obscuring the description of the application with unnecessary detail. Accordingly, the application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. A battery, characterized in that, Comprising: a battery cell assembly, a first housing, a second housing and a third housing, wherein the first housing and the second housing each include a bottom wall and a side wall connecting the bottom wall, the third housing includes a side wall, and the third housing is a circular barrel-shaped structure with the side wall, the side walls of the first housing and the second housing are respectively in interference fit with the side walls at both ends of the third housing, and the battery cell assembly is located in the cavity formed by the first housing, the second housing and the third housing; a first limiting groove is provided on the side wall surface of the third housing in contact with the first housing, a second limiting groove is provided on the side wall surface of the third housing in contact with the second housing, the first housing and the second housing are both provided with a necking, the first limiting groove is interlocked and limited with the necking of the first housing, and the second limiting groove is interlocked and limited with the necking of the second housing; the battery further includes a sealing structure, and the sealing structure is provided on the surface where the first housing is in contact with the third housing and the surface where the second housing is in contact with the third housing; the first housing and the second housing are both conductive metal housings; the third housing is an insulating housing, the insulating housing is a plastic housing, and a boss is provided on the side wall surface of the third housing in contact with the first housing and the second housing for separating the first housing and the second housing; a part of the side wall of the third housing in contact with the first housing and the boss jointly enclose the first limiting groove, and a part of the side wall of the third housing in contact with the second housing and the boss jointly enclose the second limiting groove; both the first limiting groove and the second limiting groove include at least two sub-limiting grooves less than a full circle; the neckings of the first housing and the second housing include at least two sub-neckings less than a full circle.

2. The battery according to claim 1, wherein the side wall of the first housing includes a first side wall, the first end of the first side wall is connected to the bottom wall of the first housing, the second end of the first side wall away from the bottom wall shrinks towards the third housing and extends into the first limiting groove, and the side wall at the shrinking part is the necking of the first housing; the side wall of the second housing includes a second side wall, the first end of the second side wall is connected to the bottom wall of the second housing, the second end of the second side wall away from the bottom wall shrinks towards the third housing and extends into the second limiting groove, and the side wall at the shrinking part is the necking of the second housing.

3. The battery according to claim 2, wherein the second end of the first side wall of the first housing away from the bottom wall of the first housing shrinks towards the third housing, and the shrinking angle is greater than zero degree and less than a preset angle, the preset angle is 45° to 90°, and / or the second end of the second side wall of the second housing away from the bottom wall of the second housing shrinks towards the third housing, and the shrinking angle is greater than zero degree and less than a preset angle, the preset angle is 45° to 90°.

4. The battery according to claim 1, wherein The sealing structure includes a sealing component, which is inserted between the surfaces where the third housing contacts the first housing and between the surfaces where the third housing contacts the second housing; and / or the sealing structure includes a coating, which is formed on one or more surfaces where the third housing contacts the first housing and on one or more surfaces where the third housing contacts the second housing; the coating has compressibility.

5. The battery according to claim 4, characterized in that, When the sealing structure includes a coating, the material of the coating is at least one of sealant, glue, silica gel or polyurethane.

6. The battery according to claim 4, wherein When the sealing structure includes a coating, the thickness of the coating is 5μm - 100μm.

7. The battery according to claim 4, characterized in that, The burr size of the end face of the first housing and / or the end face of the second housing is less than or equal to 0.01mm.

8. The battery according to claim 1, characterized in that, The side wall width of at least one of the first housing, the second housing and the third housing is greater than or equal to 0.5mm, and the width direction is perpendicular to the first direction, where the first direction is the fastening direction when the first housing and the second housing are respectively assembled with the third housing.

9. The battery according to claim 1, characterized in that, The battery cell assembly includes a positive electrode tab and a negative electrode tab, the positive electrode tab is electrically connected to the first housing, and the negative electrode tab is electrically connected to the second housing.

10. An electrical device, characterized in that, A battery comprising any one of claims 1 to 9.

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