Cover plate structure for a cylindrical battery as well as a cylindrical battery

Abstract

Cover plate structure for a cylindrical battery, wherein the cover plate structure comprises a terminal clamp (200), wherein the terminal clamp (200) is connected at its base to a current collector disk (100) and a sealing ring (300) is placed on the terminal clamp (200), wherein a first insulating element (400) and a cover piece (500) are placed successively on the sealing ring (300) in a vertical direction, and wherein the current collector disk (100) is insulated from the cover piece (500) by the first insulating element (400).

Description

Technical FieldThe present application relates to the field of battery technology and, for example, to a cover plate structure for a cylindrical battery as well as a cylindrical battery.Prior ArtCylindrical batteries are widely used in fields such as electric tools and light electric vehicles because of their mature manufacturing process and high versatility. With the increasing demands on the performance of applications, the energy of conventional cylindrical batteries can no longer meet the demand. In addition to increasing the size of the battery and improving the capacity of the material system per gram, another modification of the structure of the positive and negative battery covers is required to increase the energy density of the battery, thus meeting the requirements for the high C-rate of the battery.The prior art battery cover pieces typically include a pole terminal, a current collector plate, a lower insulating plate, and a cover piece. In this case, the pole terminal is passed in sequence through the current collector plate, the lower insulating plate and the cover piece, wherein the cover piece is provided with a counterbore for the passage of the pole terminal and the counterbore is provided successively from the inside to the outside with an insulating plate and a sealing layer. The current collector disc is firmly connected to a winding cell and is also connected to the lower insulating disc by latching. The lower insulating disk and the sealing layer are each firmly connected to the cover piece. In the battery cover with the above structure, the current collector plate can be mounted on the pole terminal only when this current collector plate is provided with a larger through hole, resulting in a small contact area between the pole terminal and the current collector plate and thus a high overcurrent internal resistance of the battery. As more components are placed on the pole terminal, the pole terminal is made higher, so that material is wasted and manufacturing costs are increased. In addition, the surface of a welding region is uneven due to the weld impression in this welding region between the pole terminal and the current collector plate, so that the mounting location between the current collector plate and the lower insulating plate is leaky, which together with a poor seal leads to a risk of leakage.Therefore, there is an urgent need for a cover plate structure for a cylindrical battery to solve the above technical problem.Disclosure of the InventionThe embodiments of the present application provide a cover plate structure for a cylindrical battery. The cover plate structure for a cylindrical battery has a good seal and is therefore not prone to leaks. Moreover, it has a low overcurrent internal resistance due to a large contact area between a current collector plate and a pole terminal and low manufacturing costs due to a low height of the pole terminal.In a first aspect, the embodiments of the present application provide a cover plate structure for a cylindrical battery including a pole terminal, the pole terminal being connected at its bottom to a current collector plate, and a seal ring being placed on the pole terminal, a first insulating member and a cover piece being placed on the seal ring in sequence in a vertical direction, and the current collector plate being insulated from the cover piece by the first insulating member.In an embodiment, the pole terminal includes a base and a column connected to each other, the current collector plate is connected to a side of the base not connected to the column, and the seal ring is fitted on the column, and a bottom of the seal ring and a bottom of the first insulating member are each provided in contact with an end surface of the base.In one exemplary embodiment, it is provided that the bottom of the first insulating element is provided with a groove, wherein one end of the current collector plate is arranged in the groove.In an embodiment, it is provided that the first insulating member is provided with a mounting hole formed as a step hole having a step surface, the pillar extends through the mounting hole, and the end surface of the base is provided in contact with the step surface.In one exemplary embodiment, it is provided that the sealing ring comprises a large-diameter section and a small-diameter section, wherein the first insulating element is placed on the large-diameter section and the cover piece is placed on the small-diameter section.In one exemplary embodiment, it is provided that a connection between the current collector plate and the pole terminal is produced by welding.In one exemplary embodiment, it is provided that the cover piece is provided with a terminal, wherein the terminal is insulated from the cover piece by the second insulating element.In an embodiment, it is provided that the terminal is provided with a mounting hole formed as a step hole and an end surface of the pole terminal is provided with a flange, the pole terminal extends through the mounting hole, and the flange is snapped into the mounting hole.In one exemplary embodiment, it is provided that the second insulating element is provided with a first positioning projection and the clamp is provided with a first positioning groove, wherein the first positioning groove is formed with positive fit with the first positioning projection; or that the second insulating element is provided with the first positioning groove and the clamp is provided with the first positioning projection, wherein the first positioning groove is formed with positive fit with the first positioning projection.In one exemplary embodiment, it is provided that the cover piece is provided with a second positioning groove and the second insulating element is provided with a second positioning protrusion, wherein the second positioning groove is formed positively with the second positioning protrusion.In one exemplary embodiment, it is provided that the second positioning groove and the second positioning protrusion each have a cross-shaped profile; or that the second positioning groove and the second positioning protrusion each have a polygonal profile; or that the second positioning groove and the second positioning protrusion each have an elliptical profile.In one exemplary embodiment, the current collector plate is provided with a fuse.The embodiments of the present application provide a cylindrical battery. The cylindrical battery has a good seal and is therefore not prone to leaks. Moreover, it has a low overcurrent internal resistance due to a large contact area between a current collector plate and a pole terminal and low manufacturing costs due to a low height of the pole terminal. In addition, this battery is equipped with a structurally compact cover plate structure, so that a high energy density of the battery is achieved.In a second aspect, the embodiments of the present application provide a cylindrical battery comprising a housing and a cover plate structure for a cylindrical battery described above, wherein the housing is fixedly connected to the cover plate structure for a cylindrical battery.The present application has the following advantageous effects:As compared with the prior art, the difference is that in the cover plate structure for a cylindrical battery according to the embodiments of the present application, the current collector plate does not need to be passed through the pole terminal but is directly connected to the bottom of the pole terminal. As a result, the contact area between the pole terminal and the current collector plate is increased, so that the overcurrent internal resistance of the battery is reduced. Since the first insulating member is provided in contact with the pole terminal and thus no current collector plate separates the two, the connection between the first insulating member and the pole terminal is not affected by the weld imprint of the current collector plate and the pole terminal. Moreover, the sealing ring is in direct contact with the pole terminal, which allows a tighter connection and a better seal and thus reduces the risk of leakage. At the same time, the first insulating member may be arranged flat between the current collector plate and the cover piece to ensure insulation of the current collector plate from the cover piece and thus prevent a short circuit inside the battery. Since the current collector plate does not have to be placed on the pole terminal, the height of the pole terminal can be reduced accordingly, as a result of which raw material for the pole terminal is saved and the production costs are reduced.In the cylindrical battery according to the embodiments of the present application, the above-described cover plate structure for a cylindrical battery is used so as to be connected to the case. Through a reasonable structural design and arrangement of the cover plate structure, a compact construction of the cover plate structure and thus a high energy density of the battery is achieved. Moreover, the battery is well sealed, so that the risk of leakage caused by an leaky connection between the first insulating element and the pole terminal can be effectively avoided. By using less raw material for the pole terminal, the costs for the production of the battery are significantly lower.Brief Description of the FiguresFIG. 1 shows a sectional view of a battery according to the present application in a middle longitudinal section; FIG. 2 is an exploded view of a cover plate structure of a battery according to the present application; FIG. 3 is a schematic structural view of a first insulating member according to the present application; FIG. 4 is a schematic structural view of a clamp according to the present application; and FIG. 5 is a schematic structural view of a second insulating member according to the present application.List of reference numbers:100. Current collector plate; 200. Pole terminal; 210. Base; 220. Column; 230. Flange; 300. Sealing ring; 400. first insulating element; 410. Groove; 420. Step surface; 500. Cover piece; 510. second positioning groove; 600. second insulating member; 610. first positioning protrusion; 620. second positioning protrusion; 700. Clamp; 710. first positioning groove.DETAILED EMBODIMENTSIn the description of the present application, it is to be noted that the positional relationship indicated by the terms such as "center", "upper", "under", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the positional relationship shown in the drawings and is only for facilitating and simplifying the description of the present application, but does not imply that the designated device or member has a certain orientation or must be formed and operated in a certain orientation, and therefore the mentioned terms cannot be understood as limitations of the present application.Further, the terms "first" and "second" are only for description and cannot be understood to imply relative importance. Here, the terms "first position" and "second position" refer to two different positions. In addition, the expression that "a first feature is located above a second feature, on or above a second feature" includes that the first feature is located directly or obliquely above the second feature; alternatively, this expression only means that the first feature has a horizontal height that is higher than the horizontal height of the second feature. The term "that a first feature is below a second feature or below the second feature" is understood to mean that the first feature is directly or obliquely below the second feature; alternatively, this term only means that the first feature has a horizontal height that is lower than the horizontal height of the second feature.It should be noted that the terms "mounted," "coupled," and "connected" are intended to be broadly understood in the explanation of the present application unless there are any distinct rules and regulations. For example, it may be both a fixed connection and a removable connection, or it may be an integrated connection. It can be a mechanical connection or an electrical connection. It may be a direct connection or an indirect connection via a medium, it may also be a connection between the insides of two elements. One of ordinary skill in the art can be based on the subject to determine what meaning the terms mentioned according to the present application are intended to have.Hereinafter, embodiments of the present application will be described in detail.Examples of these embodiments are shown in the drawings, in which the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions. The exemplary embodiments described below with reference to the drawings are exemplary, serve merely for explaining the present application and are not to be understood as limitations of the present application.As shown in FIGS. 1 and 2, a cover plate structure for a cylindrical battery according to this embodiment includes a pole terminal 200. The pole terminal 200 is connected at its bottom to a current collector plate 100 and a sealing ring 300 is placed on the pole terminal 200. On the seal ring 300, a first insulating member 400 and a cover piece 500 are sequentially fitted in a vertical direction, and the current collector plate 100 is insulated from the cover piece 500 by the first insulating member 400.In the above-described cover plate structure for a cylindrical battery, the current collector plate 100 is connected to a bottom of the pole terminal 200. In comparison with the configuration according to the prior art, in which the current collector plate 100 is placed on the pole terminal 200, the current collector plate 100 does not have to be provided with a mounting hole dimensioned according to the diameter of the pole terminal 200. As a result, the contact area between the pole terminal 200 and the current collector plate 100 is increased, so that the overcurrent internal resistance of the battery is reduced. In addition, since the current collector plate 100 does not need to be placed on the pole terminal 200, the height of the pole terminal 200 can be reduced accordingly, thereby saving raw material therefor and reducing manufacturing costs. The first insulating element 400 is in direct contact with the pole terminal 200, so that no leakage arises due to an insufficiently tight connection between the first insulating element 400 and the pole terminal 200, which is caused by the weld impression between the pole terminal 200 and the current collector plate 100. The cover piece 500 is placed on the sealing ring 300 and the sealing ring 300 is in turn in direct contact with the pole terminal 200, as a result of which the sealing of the connection is ensured. The first insulating member 400 may be disposed flat between the current collector plate 100 and the cover piece 500 to ensure insulation of the current collector plate 100 from the cover piece 500 and thus prevent short circuit inside the battery.By way of example, the pole terminal 200 includes a base 210 and a column 220 connected together, wherein the current collector plate 100 is connected to a side of the base 210 that is not connected to the column 220. The connection may be made by welding, e.g. ultrasonic or laser welding. The seal ring 300 is fitted on the column 220 and is provided with its bottom in contact with an end surface of the base 210, while the first insulating member 400 is fitted on the seal ring 300 and a bottom of the first insulating member 400 is also provided in contact with the end surface of the base 210. By way of example, the pole terminal 200 can be a rivet, such that the sealing ring 300 is pressed by the rivet, which can ensure a good seal. By the current collector plate 100 not directly contacting and cooperating with the first insulating member 400, but contacting the end surface of the base 210 and the end surface of the base 210 being flat, a good insulating and sealing effect can be ensured and the risk of battery short circuit or leakage can be avoided.Referring to FIGS. 2 and 3, the bottom of the first insulating member 400 is provided with a groove 410 by way of example, and one end of the current collector plate 100 is disposed in the groove 410 to ensure the structural compactness of the cover plate structure. It is understood that the shape of the groove 410 should be designed according to the shape of the connection portion between the current collector plate 100 and the pole terminal 200.For example, the first insulating member 400 is provided with a mounting hole formed as a step hole having a step surface 420. The column 220 extends through the mounting hole, and the end surface of the base 210 is provided in contact with the step surface 420. Since the base 210 is formed in a circular disk shape, the step surface 420 has a shape of a circular ring. This structural configuration allows the position of the pole terminal 200 to be limited and also ensures a close arrangement between the individual components, as a result of which the interior space of the battery is space-saving and the battery has a high energy density.With further reference to FIG. 2, the seal ring 300 exemplarily includes a large diameter portion and a small diameter portion, wherein the first insulating member 400 is placed on the large diameter portion and the cover piece 500 is placed on the small diameter portion. It should be understood that the mounting hole in the first insulating member 400 should be formed corresponding to the outer diameter of the large diameter portion of the seal ring 300, and the dimension of the mounting hole of the first insulating member 400 may be larger than the outer diameter of the large diameter portion of the seal ring 300 to save raw material. Also, the mounting hole in the cover piece 500 should be formed corresponding to the outer diameter of the small diameter portion of the seal ring 300 so that the cover piece 500 can be passed through the pole terminal 200 and closely fitted on the seal ring 300. At the same time, an end surface of the large diameter portion of the seal ring 300 is in contact with the bottom surface of the cover piece 500 to ensure good sealing.By way of example, a terminal 700 and a second insulating element 600 are placed on the pole terminal 200, wherein the terminal 700 is insulated from the cover piece 500 by the second insulating element 600. The terminal 700 is provided with a mounting hole formed as a step hole, and an end surface of the pole terminal 200 is provided with a flange 230, the pole terminal 200 extends through the mounting hole, and the flange 230 is locked in the mounting hole to limit the terminal 700 and then prevent the terminal 700 from being detached from the pole terminal 200.By way of example, the second insulating element 600 is provided with a first positioning projection 610. Accordingly, the clamp 700 is provided with a first positioning groove 710 as shown in FIG. 4. The first positioning groove 710 is formed in a positive-locking manner with the first positioning protrusion 610 in order to then achieve a limiting effect between the second insulating element 600 and the terminal 700. Of course, it is possible that the second insulating member 600 is provided with the first positioning groove 710 and the terminal 700 is provided with the first positioning protrusion 610 to achieve a positioning effect. In this embodiment, the first positioning protrusion 610 is a cylindrical boss and the first positioning groove 710 is a cylindrical groove. Four first positioning projections 610 and four first positioning grooves 710 are provided, which are arranged centrally symmetrically with respect to the center of a component in which they are located. In other embodiments, the positioning member may have other structural shapes, and any structure capable of performing a positioning function falls within the scope of the present application.With reference to FIGS. 2 and 5, it is provided by way of example that the cover piece 500 is provided with a second positioning groove 510 and the second insulating element 600 is provided with a second positioning protrusion 620, wherein the second positioning groove 510 is formed positively with the second positioning protrusion 620. The second positioning groove 510 has a cross-shaped profile in this embodiment and is arranged concentrically with the mounting hole in the cover piece 500. In other embodiments, the second positioning groove 510 may also have a polygonal shape, an elliptical shape, and other shapes, and the shape of the second positioning protrusion 620 is configured according to the shape of the second positioning groove 510.By way of example, the current collector plate 100 is provided with a fuse. If the temperature of a circuit becomes too high due to an extreme situation such as a short circuit, the fuse may melt by its own heat and thus cut off the circuit rapidly, thus protecting the circuit and improving the safety of the battery. The fuse can be made by, for example, thinning the current collector plate 100 or coating a low melting point metal, etc.The present embodiments further provide a cylindrical battery including a case and a cover plate structure for a cylindrical battery described above which are fixedly connected to each other, wherein the case may be made of aluminum or another metal and may be joined to the cover piece 500 by welding.In the case of the cylindrical battery, a reasonable structural design and arrangement of the cover plate structure achieves a compact construction of the cover plate structure and thus a high energy density of the battery. Moreover, the battery is well sealed, so that the leakage risk caused by an leaky connection between the first insulating member 400 and the pole terminal 200 can be effectively avoided. By using less raw material for the pole terminal 200, the manufacturing costs are saved.As compared with the prior art, the difference is that in the cover plate structure for a cylindrical battery according to the present application, the current collector plate does not need to be passed through the pole terminal but is directly connected to the bottom of the pole terminal. As a result, the contact area between the pole terminal and the current collector plate is increased, so that the overcurrent internal resistance of the battery is reduced. Since the first insulating member is provided in contact with the pole terminal and thus no current collector plate separates the two, the connection between the first insulating member and the pole terminal is not affected by the weld imprint of the current collector plate and the pole terminal. Moreover, the sealing ring is in direct contact with the pole terminal, which enables a narrower connection. At the same time, the first insulating element and the covering piece are placed on the sealing ring, whereby a better sealing is achieved and thus the risk of leakage is reduced. At the same time, the first insulating member may be arranged flat between the current collector plate and the cover piece to ensure insulation of the current collector plate from the cover piece and thus prevent a short circuit inside the battery. Since the current collector plate does not have to be placed on the pole terminal, the height of the pole terminal can be reduced accordingly, as a result of which raw material for the pole terminal is saved and the production costs are reduced.

Claims

A cover plate structure for a cylindrical battery, the cover plate structure comprising a pole terminal (200), wherein the pole terminal (200) is connected at its bottom to a current collector plate (100), and a sealing ring (300) is placed on the pole terminal (200), wherein a first insulating member (400) and a cover piece (500) are placed on the sealing ring (300) one after another in a vertical direction, and wherein the current collector plate (100) is insulated from the cover piece (500) by the first insulating member (400).The cover plate structure for a cylindrical battery according to claim 1, wherein the pole terminal (200) comprises a base (210) and a column (220) connected to each other, wherein the current collector plate (100) is connected to a side of the base (210) opposite to the column (220), and the seal ring (300) is fitted on the column (220), and wherein a bottom of the seal ring (300) and a bottom of the first insulation member (400) are each provided in contact with an end surface of the base (210).The cover plate structure for a cylindrical battery according to claim 2, wherein the bottom of the first insulating member (400) is provided with a groove (410), one end of the current collector plate (100) being disposed in the groove (410).The cover plate structure for a cylindrical battery according to claim 2 or 3, wherein the first insulating member (400) is provided with a mounting hole formed as a step hole having a step surface (420), the pillar (220) extends through the mounting hole, and the end surface of the base (210) is provided in contact with the step surface (420).The cover plate structure for a cylindrical battery according to any one of claims 1 to 4, wherein the seal ring (300) includes a large diameter portion and a small diameter portion, the first insulating member (400) is fitted on the large diameter portion, and the cover piece (500) is fitted on the small diameter portion.The cover plate structure for a cylindrical battery according to any one of claims 1 to 5, wherein a connection between the current collector plate (100) and the pole terminal (200) is made by welding.The cover plate structure for a cylindrical battery according to any one of claims 1 to 6, wherein a terminal (700) and a second insulating member (600) are fitted on the pole terminal (200), the terminal (700) being insulated from the cover piece (500) by the second insulating member (600).The cover plate structure for a cylindrical battery according to claim 7, wherein the terminal (700) is provided with a mounting hole formed as a step hole, and an end surface of the pole terminal (200) is provided with a flange (230), the pole terminal (200) extends through the mounting hole, and the flange (230) is snapped into the mounting hole.The cover plate structure for a cylindrical battery according to claim 7 or 8, wherein the second insulating member (600) is provided with a first positioning protrusion (610) and the terminal (700) is provided with a first positioning groove (710), wherein the first positioning groove (710) is form-fitted with the first positioning protrusion (610); or wherein the second insulating member (600) is provided with the first positioning groove (710) and the terminal (700) is provided with the first positioning protrusion (610), wherein the first positioning groove (710) is form-fitted with the first positioning protrusion (610).The cover plate structure for a cylindrical battery according to any one of claims 7 to 9, wherein the cover piece (500) is provided with a second positioning groove (510), and the second insulating member (600) is provided with a second positioning protrusion (620), the second positioning groove (510) being formed positively with the second positioning protrusion (620).The cover plate structure for a cylindrical battery according to claim 10, wherein the second positioning groove (510) and the second positioning protrusion (620) each have a cross-shaped profile; or wherein the second positioning groove (510) and the second positioning protrusion (620) each have a polygonal profile; or wherein the second positioning groove (510) and the second positioning protrusion (620) each have an elliptical profile.The cover plate structure for a cylindrical battery according to any one of claims 1 to 11, wherein the power collector plate (100) is provided with a fuse.A cylindrical battery comprising a case and a cover plate structure for a cylindrical battery according to any one of claims 1 to 12, wherein the case is fixedly connected to the cover plate structure for a cylindrical battery.

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