Patent Application
20230395956
This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0024411 filed with the Korean Intellectual Property Office on Feb. 23, 2021, the entire contents of which are incorporated herein by reference.
The present invention relates to a secondary battery, a secondary battery manufacturing method, a battery pack, and a vehicle.
A secondary battery is easy to apply to product groups and has electrical characteristics such as high energy density. Therefore, the secondary battery is widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electrical driving sources.
The secondary battery attracts attention as a new energy source for improving environmental-friendly characteristics and energy efficiency because the secondary battery achieves a primary advantage of innovatively reducing the use of fossil fuel and does not generate any by-products from the use of energy.
Types of secondary batteries currently used widely include a lithium-ion battery, a lithium-polymer battery, a nickel-cadmium battery, a nickel-hydrogen battery, a nickel-zinc battery, and the like. An operating voltage of a unit secondary battery, i.e., a unit battery is about 2.5 V to 4.5 V. Therefore, when an output voltage higher than the operating voltage is required, a plurality of secondary batteries is connected in series and constitutes a battery pack. In addition, the plurality of secondary batteries is connected in parallel and constitutes the battery pack depending on a charge/discharge capacity required for the battery pack. Therefore, the number of secondary batteries included in the battery pack and the type of electrical connection between the secondary batteries may be variously set depending on required output voltages and/or charge/discharge capacities.
To manufacture a battery pack by using a cylindrical secondary battery, typically, a plurality of cylindrical secondary batteries is disposed upright in a housing, and the plurality of cylindrical secondary batteries is electrically connected to each other by connecting upper ends and lower ends of the cylindrical secondary batteries by using positive electrode terminals and negative electrode terminals.
This is because a negative electrode non-coated portion of an electrode assembly accommodated in a battery can extend downward and is electrically connected to a bottom surface of the battery can, and a positive electrode non-coated portion extends upward and is electrically connected to a top cap in the cylindrical secondary battery. That is, in the cylindrical secondary battery, the bottom surface of the battery can is generally used as a negative electrode terminal, and the top cap configured to cover an upper end opening portion of the battery can is generally used as a positive electrode terminal.
However, when the positive electrode terminal and the negative electrode terminal of the cylindrical secondary battery are positioned at the opposite positions, electrical connection components such as busbars for electrically connecting the plurality of cylindrical secondary batteries need to be applied to both the upper and lower portions of the cylindrical secondary battery. This complicates an electrical connection structure of the battery pack.
Moreover, in the above-mentioned structure, components for ensuring electrical insulation and components for ensuring waterproofness need to be individually applied to the upper and lower portions of the battery pack, which increases the number of components to be applied and complicates the structure.
Accordingly, there is a need to develop a cylindrical secondary battery having a structure in which a positive electrode terminal and a negative electrode terminal are provided in the same direction in order to simplify an electrical connection structure between a plurality of cylindrical secondary batteries.
An object of the present invention is to provide a secondary battery and a secondary battery manufacturing method, in which the secondary battery has a structure in which a positive electrode terminal and a negative electrode terminal are provided in the same direction, and a conductive washer component may be applied without limitation related to a thickness and a material thereof, thereby implementing high energy density.
Another object of the present invention is to provide a battery pack and a vehicle including the above-mentioned secondary battery.
However, technical problems to be solved by the present invention are not limited to the above-mentioned technical problems, and other technical problems, which are not mentioned above, may be clearly understood by those skilled in the art from the following description of the invention.
An embodiment of the present invention provides a secondary battery including: an electrode assembly having a first electrode tab and a second electrode tab; a battery can electrically connected to the second electrode tab and having an opening portion configured to accommodate the electrode assembly; a top cap configured to cover the opening portion of the battery can and electrically connected to the first electrode tab; a gasket provided between the battery can and the top cap; a conductive washer electrically connected to the battery can and configured to adjoin at least a part of a peripheral portion of the opening portion; an insulative washer provided between the top cap and the conductive washer and configured to electrically insulate the top cap and the conductive washer; and a fixing member provided between the conductive washer and the insulative washer.
Another embodiment of the present invention provides a method of manufacturing the secondary battery according to the above-mentioned embodiment, the method including: accommodating the electrode assembly, which has the first electrode tab and the second electrode tab, in the battery can electrically connected to the second electrode tab and having an opening portion configured to accommodate the electrode assembly; covering the opening portion of the battery can by coupling: the top cap disposed in the opening portion of the battery can and electrically connected to the first electrode tab; the gasket provided between the battery can and the top cap; the conductive washer electrically connected to the battery can and configured to adjoin at least a part of the peripheral portion of the opening portion; and an insulative washer provided between the top cap and conductive washer and configured to electrically insulate the top cap and the conductive washer; and injecting a curing agent between the conductive washer and the insulative washer.
Still another embodiment of the present invention provides a battery pack including: the secondary battery according to the above-mentioned embodiment; and a pack housing configured to accommodate the secondary battery.
Yet another embodiment of the present invention provides a vehicle including the battery pack according to the above-mentioned embodiment.
According to the cylindrical secondary battery, the conductive washer component and the insulative washer may be provided to expand the negative electrode terminal. The conductive washer component is provided to increase the area in which the connection component such as a busbar may be joined to connect the plurality of cylindrical secondary batteries for constituting the battery pack. Because of the above-mentioned function of the conductive washer component, the conductive washer component needs to have rigidity at a predetermined level or higher to resist deformation that may occur during the welding process.
Because the crimping portion for finishing the opening portion of the cylindrical secondary battery has height dispersion caused by the assembling process, it is not easy to fix the conductive washer seated on the crimping portion. In addition, a method of fixing the conductive washer by using the insulator provided between the conductive washer and the top cap may be considered. However, the conductive washer needs to have rigidity to some extent or more and a thickness at a predetermined level or more in order to implement the structural fixation using the insulator. In a case in which the thickness increases to ensure rigidity of the conductive washer, an electric loss inevitably occurs because of high electrical resistance during a process in which electric current flows toward the busbar at the upper side through the conductive washer.
According to one aspect of the present invention, the unidirectional electrical connection in which the positive electrode terminal and the negative electrode terminal are provided in the same direction is implemented in the cylindrical secondary battery. Further, the conductive washer component, which provides a sufficient area in which the connection component such as the busbar for electrically connecting the secondary batteries may be coupled may be stably seated on the crimping portion.
In addition, according to another aspect of the present invention, the conductive washer component may be applied without limitation related to the thickness and material thereof, thereby ensuring low electrical resistance and increasing energy density of the secondary battery.
The following drawings attached to the present specification illustrate exemplary embodiments of the present invention and serve to further understand the technical spirit of the present invention together with the following detailed description of the present invention, and the present invention should not be interpreted as being limited to the items illustrated in the drawings.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, terms or words used in the specification and the claims should not be interpreted as being limited to a general or dictionary meaning and should be interpreted as a meaning and a concept which conform to the technical spirit of the present invention based on a principle that an inventor can appropriately define a concept of a term in order to describe his/her own invention by the best method. Therefore, the exemplary embodiments disclosed in the present specification and the configurations illustrated in the drawings are just the best preferred exemplary embodiments of the present invention and do not represent all the technical spirit of the present invention. Accordingly, it should be appreciated that various equivalents and modified examples capable of substituting the exemplary embodiments may be made at the time of filing the present application.
Throughout the specification, unless explicitly described to the contrary, the word “comprise/include” and variations such as “comprises/includes” or “comprising/including” will be understood to imply the inclusion of stated elements, not the exclusion of any other elements. In addition, the term “unit”, “part”, or the like, which is described in the specification, means a unit that processes one or more functions or operations. In addition, throughout the specification, the term “A to B” means “A or more and B or less”, i.e., a numerical value range including both A and B. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The embodiment of the present invention provides a secondary battery including: an electrode assembly 10 having a first electrode tab 11 and a second electrode tab 12; a battery can 20 electrically connected to the second electrode tab 12 and having an opening portion configured to accommodate the electrode assembly 10; a top cap 30 configured to cover the opening portion of the battery can 20 and electrically connected to the first electrode tab 11; a gasket 50 provided between the battery can 20 and the top cap 30; a conductive washer 40 electrically connected to the battery can 20 and configured to adjoin at least a part of a peripheral portion of the opening portion; an insulative washer 60 provided between the top cap 30 and the conductive washer 40 and configured to electrically insulate the top cap 30 and the conductive washer 40; and a fixing member 61 provided between the conductive washer 40 and the insulative washer 60.
The secondary battery includes the conductive washer 40 and the insulative washer 60, thereby implementing a unidirectional electrical connection in which a positive electrode terminal and a negative electrode terminal are provided in the same direction. In addition, the secondary battery includes the fixing member 61, such that the conductive washer component may be applied without limitation related to a thickness and a material thereof, thereby ensuring low electrical resistance.
The secondary battery may be a cylindrical secondary battery. The first electrode tab 11 may be a non-coated portion of a first electrode current collector constituting the electrode assembly, the non-coated portion having no first electrode active material. The second electrode tab 12 may be a non-coated portion of a second electrode current collector constituting the electrode assembly, the non-coated portion having no second electrode active material.
The first electrode tab 11 and the second electrode tab 12 may be bent toward a winding center of the electrode assembly.
Since the electrode tab is bent, it is possible to advantageously ensure low electrical resistance and increase energy density of the secondary battery.
Referring to
Referring to
The first electrode plate includes the first electrode current collector and the first electrode active material applied onto one surface or two opposite surfaces of the first electrode current collector. The non-coated portion onto which no first electrode active material is applied is provided at one end of the first electrode current collector based on a width direction (a direction parallel to a Z-axis). The non-coated portion serves as the first electrode tab 11. The first electrode tab 11 is provided at an upper side of the electrode assembly 10 based on a height direction (the direction parallel to the Z-axis), and the electrode assembly 10 is accommodated in the battery can 20.
The second electrode plate includes the second electrode current collector and the second electrode active material applied onto one surface or two opposite surfaces of the second electrode current collector. The non-coated portion onto which no second electrode active material is applied is provided at the other end of the second electrode current collector based on the width direction (the direction parallel to the Z-axis). The non-coated portion serves as the second electrode tab 12. The second electrode tab 12 is provided at a lower side of the electrode assembly 10 based on the height direction (the direction parallel to the Z-axis), and the electrode assembly 10 is accommodated in the battery can 20.
That is, the first electrode tab 11 may be provided at one end of the electrode assembly, and the second electrode tab may be provided at the other end of the electrode assembly.
Referring to
The battery can 20 is electrically connected to the second electrode tab 12 of the electrode assembly 10. Therefore, the battery can 20 has the same polarity as the second electrode tab 12. For example, the second electrode tab 12 may be attached to the battery can 20 by welding.
The battery can 20 has a beading portion 21 and a crimping portion 22 provided at an upper end thereof. The crimping portion 22 may be provided on a peripheral portion of the opening portion of the battery can 20.
The beading portion 21 is formed at the upper side of the electrode assembly 10. The beading portion 21 is formed by pressing a periphery of an outer peripheral surface of the battery can 20. The beading portion 21 prevents the electrode assembly 10, which has a size corresponding to a width of the battery can 20, from being withdrawn through the opening portion of the upper end of the battery can 20. The beading portion 21 may serve as a support portion on which the top cap 30 is seated.
The crimping portion 22 is formed on an upper portion of the beading portion 21. The crimping portion 22 extends and bends to surround a part of an outer peripheral surface of the top cap 30 disposed on the beading portion 21 and surround a part of an upper surface of the top cap 30.
The battery can may have a cylindrical shape. A diameter of a circle of each of the two opposite ends of the battery can may be 30 mm to 55 mm, and a height of the battery can may be 60 mm to 120 mm. For example, a value of circular diameter×height of the cylindrical battery can may be 46 mm×60 mm, 46 mm×80 mm, 46 mm×90 mm, or 46 mm×120 mm.
In particular, for example, the cylindrical secondary battery may be a cylindrical secondary battery having a ratio of a form factor larger than about 0.4 (a ratio of the form factor is defined as a value made by dividing a diameter of the cylindrical secondary battery by a height of the cylindrical secondary battery, i.e., a ratio of a diameter (to a height H).
In this case, the form factor means a value indicating the diameter and the height of the cylindrical secondary battery. For example, the cylindrical secondary battery according to the embodiment of the present invention may be 46110 cell, 48750 cell, 48110 cell, 48800 cell, 46800 cell, and 46900 cell. In the numerical value indicating the form factor, the first two numbers indicate a diameter of the cell, the next two numbers indicate a height of the cell, and the final number 0 indicates that a cross-section of the cell is circular.
The cylindrical secondary battery according to the embodiment of the present invention is an approximately cylindrical cell, and the cylindrical secondary battery may have a diameter of about 46 mm, a height of about 110 mm, and a ratio of the form factor of about 0.418.
The cylindrical secondary battery according to another embodiment is an approximately cylindrical cell, and the battery cell may have a diameter of about 48 mm, a height of about 75 mm, and a ratio of the form factor of about 0.640.
The cylindrical secondary battery according to still another embodiment is an approximately cylindrical cell, and the cylindrical secondary battery may have a diameter of about 48 mm, a height of about 110 mm, and a ratio of the form factor of about 0.418.
The cylindrical secondary battery according to yet another embodiment is an approximately cylindrical cell, and the battery cell may have a diameter of about 48 mm, a height of about 80 mm, and a ratio of the form factor of about 0.600.
The cylindrical secondary battery according to still yet another embodiment is an approximately cylindrical cell, and the cylindrical secondary battery may have a diameter of about 46 mm, a height of about 80 mm, and a ratio of the form factor of about 0.575.
The cylindrical secondary battery according to another further embodiment is an approximately cylindrical cell, and the cylindrical secondary battery may have a diameter of about 46 mm, a height of about 90 mm, and a ratio of the form factor of 0.511.
Referring to
The cylindrical secondary battery 1 according to the embodiment of the present invention has a structure in which both the positive electrode terminal and the negative electrode terminal are provided at the upper side of the cylindrical secondary battery 1, as described below. For this reason, the upper structure is more complicated than the lower structure. Therefore, the venting portion 23 may be formed in the lower surface of the battery can 20 to smoothly discharge gas produced in the battery can 20.
The drawing according to the present invention illustrates only the case in which the venting portion 23 is continuously formed while defining a circle on the lower surface of the battery can 20, but the present invention is not limited thereto. The venting portion 23 may be discontinuously formed while defining a circle on the lower surface of the battery can 20. Alternatively, the venting portion 23 may have a straight shape or other shapes.
Referring to
The top cap 30 is seated on the beading portion 21 formed on the battery can 20 and fixed by the crimping portion 22.
The top cap 30 may include a protruding portion 31 protruding to the outside of the battery can. The protruding portion 31 may protrude to be higher than an upper surface of the conductive washer 40 to be described below so that the protruding portion 31 easily comes into contact with the electrical connection component such as the busbar. The upper surface means a surface directed in a direction toward the outside of the battery can of the cylindrical battery, i.e., a direction toward the opening portion. The lower surface means a surface directed in a direction toward the bottom surface of the battery can.
The gasket 50 may be provided between the battery can and the top cap or between the top cap 30 and the crimping portion 22 of the battery can 20. The gasket 50 serves to ensure sealability of the battery can 20 and implement electrical insulation between the battery can 20 and the top cap 30.
Referring to
The conductive washer 40 extends in a direction toward the central portion from the outer peripheral portion of the upper surface of the conductive washer 40 that adjoins the peripheral portion of the opening portion of the battery can. The conductive washer 40 has a hole formed in a central portion thereof so that the protruding portion 31 of the top cap 30 may be exposed.
The upper surface means a surface directed in a direction toward the outside of the battery can of the cylindrical battery, i.e., a direction toward the opening portion. The lower surface means a surface directed in a direction toward the bottom surface of the battery can. The central portion means a central region of the upper surface and/or the lower surface of the conductive washer 40.
The conductive washer 40 may be electrically connected to the battery can and adjoin at least a part of the peripheral portion of the opening portion or adjoin the crimping portion 22 of the battery can 20. That is, the secondary battery has the crimping portion provided on the peripheral portion of the opening portion of the battery can, and the conductive washer 40 adjoins the crimping portion 22. As the conductive washer 40 adjoins the crimping portion 22, the conductive washer 40 may have the same polarity as the battery can and serve as a second electrode terminal having the second polarity.
The conductive washer 40 may be coupled to the crimping portion 22 by welding, for example. For example, the welding may be laser welding.
The conductive washer 40 is electrically insulated from the top cap 30. The top cap 30 is exposed through the hole formed in the central portion of the conductive washer 40. The conductive washer 40 is spaced apart from the protruding portion 31 of the top cap 30. In addition, the conductive washer 40 is spaced apart upward and downward from the remaining portion except for the protruding portion 31 of the top cap 30. Therefore, the conductive washer 40 may be electrically connected to the second electrode tab 12 and the battery can 20 and serve as the second electrode terminal of the cylindrical secondary battery 1.
That is, the cylindrical secondary battery 1 according to the embodiment of the present invention includes the conductive washer 40, such that the cylindrical secondary battery 1 has the structure in which both the first electrode terminal having the first polarity and the second electrode terminal having the second polarity are disposed in the same direction.
Referring to
This is to increase a coupling area between the electrical connection component and the conductive washer 40 when the electrical connection component such as the busbar is coupled to the conductive washer 40 in order to connect the plurality of cylindrical secondary batteries 1. Since the coupling area between the electrical connection component and the conductive washer 40 is increased as described above, the welding process may be smoothly performed, the fastening force between the two components may be increased, and the electrical resistance on the coupling portion may be reduced.
The upper surface means a surface directed in a direction toward the outside of the battery can of the cylindrical battery, i.e., a direction toward the opening portion. The lower surface means a surface directed in a direction toward the bottom surface of the battery can. The width D2 of the conductive washer 40 means a length extending in the direction toward the central portion from the outer peripheral portion of the upper surface of the conductive washer 40 that adjoins the peripheral portion of the opening portion of the battery can. The width D1 of the upper surface of the crimping portion 22 means a length extending from the peripheral portion of the opening portion of the battery can in the direction toward the central portion from the outer peripheral portion of the upper surface of the battery can. The upper surface of the crimping portion 22 means a portion at the end of the crimping portion 22 except for a curved portion that surrounds lateral and edge portions of the crimping portion 22.
The width D2 of the conductive washer 40 may be set to vary depending on the diameter of the secondary battery. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D2 of the conductive washer 40 may be 10% or more, 11% or more, 12% or more, or 13% or more of a maximum diameter of the cell. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D2 of the conductive washer 40 may be 50% or less, 45% or less, 43% or less, or 40% or less of the maximum diameter of the cell.
The width D1 of the upper surface of the crimping portion 22 is smaller than the width D2 of the conductive washer 40. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D1 of the upper surface of the crimping portion 22 may be 1% or more, 2% or more, or 3% or more of the maximum diameter of the cell. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D1 of the upper surface of the crimping portion 22 may be 13% or less, 12% or less, 11% or less, or 10% or less of the maximum diameter of the cell.
Referring to
For example, the thickness T1 of the crimping portion 22 may be 0.1 mm or more, 0.15 mm or more, 0.2 mm or more, 0.25 mm or more, 0.3 mm or more, or 0.35 mm or more. The thickness T1 of the crimping portion 22 may be 0.75 mm or less, 0.7 mm or less, 0.65 mm or less, 0.6 mm or less, 0.55 mm or less, or 0.5 mm or less.
The thickness T2 of the portion of the conductive washer 40 adjoining the crimping portion 22 may be 0.25 mm or more, 0.3 mm or more, 0.35 mm or more, or 0.4 mm or more. The thickness T2 of the portion of the conductive washer 40 adjoining the crimping portion 22 may be 0.65 mm or less, 0.6 mm or less, 0.55 mm or less, or 0.5 mm or less.
The thickness T′ of the portion of the conductive washer 40, which does not adjoin the crimping portion 22, may be 0.4 mm or more, 0.45 mm or more, or 0.5 mm or more. The thickness T′ of the portion of the conductive washer 40, which does not adjoin the crimping portion 22, may be 0.7 mm or less, 0.65 mm or less, or 0.6 mm or less.
When the thickness of the conductive washer is set to vary depending on the region, the metal thickness may be constant in all routes for electric current, thereby reducing overall resistance.
Meanwhile, referring to
The insertion groove 22a and the insertion protrusion 41 may increase the contact area between the conductive washer 40 and the crimping portion 22, thereby increasing the fastening force and reducing the electrical resistance on the coupling portion. In addition, the insertion groove 22a and the insertion protrusion 41 may guide a seating position of the conductive washer 40 when the conductive washer 40 is seated on the crimping portion 22, thereby preventing the contact between the conductive washer 40 and the protruding portion 31 of the top cap 30. In addition, the insertion groove 22a and the insertion protrusion 41 may prevent the conductive washer 40 from moving on the crimping portion 22 during the welding process, thereby improving the process performance.
Referring to
According to the cylindrical secondary battery 1 according to the embodiment of the present invention, the top cap 30 serves as the first electrode terminal having the first polarity, and the conductive washer 40 serves as the second electrode terminal having the second polarity opposite to the first polarity. Therefore, the top cap 30 and the conductive washer 40 need to be kept in an electrically insulated state. Therefore, the insulative washer 60 may be applied to stably maintain the insulated state.
The insulative washer 60 may be provided between the top cap 30 and the lower surface of the conductive washer 40. As described above, the conductive washer 40 has the width D2 larger than the width D1 of the upper surface of the crimping portion 22 and extends in the direction from the crimping portion 22 toward the protruding portion 31 of the top cap 30. Therefore, the insulative washer 60 may extend to cover an inner surface of the hole formed in the central portion of the conductive washer 40 so that the inner surface of the hole formed in the conductive washer 40 cannot come into contact with the protruding portion 31 of the top cap 30.
When the insulative washer 60 is made of a resin material, the insulative washer 60 may be coupled to the top cap 30 by thermal bonding. In this case, sealability may be improved at the coupling interface between the insulative washer 60 and the top cap 30.
Referring to
The conductive washer 40 and the insulative washer 60 may be coupled by the fixing member 61, and sealability may be improved at the coupling interface between the conductive washer 40 and the insulative washer 60.
Referring to
The conductive washer 40 serves to ensure a sufficient area in which the connection component (e.g., the busbar) is welded to manufacture the battery pack by connecting the plurality of cylindrical secondary batteries. The height dispersion (indicated by the arrow) may occur because of the nature of the crimping process in the upper surface of the crimped region of the cylindrical secondary battery is formed by bending metal. For this reason, it may be difficult to smoothly fix the conductive washer 40 to the crimping portion 22.
The insulative washer 60 may be used to structurally fix the conductive washer 40 in order to fix the conductive washer 40. However, to implement the structural fixation, the rigidity of the conductive washer 40 needs to be ensured to some extent or more, and the thickness of the conductive washer 40 needs to be ensured to a predetermined level or more. The restriction on the rigidity and/or thickness may decrease the range of choice related to the material of the conductive washer 40.
Referring to
For example, the fixing member may be a curing agent. The curing agent may be provided on the coupling interface between the conductive washer 40 and the insulative washer 60 by being injected by a nozzle. For example, any curing agent may be applied to the present invention as long as the curing agent is injected in a liquid state having fluidity and then cured as time passes. The curing agent may be UV resin. In addition, the curing agent is not particularly limited as long as the curing agent may be used in the present technical field.
The curing agent may be provided in an area that is 10%, 15%, 20%, 25%, or 30% or more of an area in which the conductive washer and the insulative washer adjoin each other. The conductive washer fixed by the curing agent in the above-mentioned range is not deformed by an external pressing force.
The curing agent serves to prevent the conductive washer from being deformed by a vacant space when the external pressing force is applied. When the rigidity of the conductive washer is high, sufficient rigidity may be ensured even in a case in which the area in which the conductive washer and the insulative washer adjoin each other is small. The area of the curing agent is not limited to the range of the area in which the conductive washer and the insulative washer adjoin each other as long as the curing agent may maintain the rigidity of the conductive washer even in the case in which the external pressing force is applied.
Since the fixing structure using the fixing member 61 is applied as described above, the rigidity of the conductive washer is not particularly required, such that the material in a condition in which electrical resistance is low may be selected. In addition, since there is no restriction on the thickness of the conductive washer, an overall increase in volume of the secondary battery caused by the application of the conductive washer may be prevented, such that energy density may be improved.
Referring to
A width C by which the insulative washer 60 extends to cover a part of the upper surface of the conductive washer 40 may be 0.1 mm or more, 0.15 mm or more, 0.2 mm or more, 0.25 mm or more, 0.3 mm or more, or 0.35 mm or more. The width C by which the insulative washer 60 extends to cover a part of the upper surface of the conductive washer 40 may be 3 mm or less, 2.5 mm or less, 2 mm or less, 1.5 mm or less, 1 mm or less, or 0.5 mm or less.
The width C by which the insulative washer 60 extends to cover a part of the upper surface of the conductive washer 40 means a length of a portion covered by the insulative washer 60 in a direction from the central portion toward the outer peripheral portion of the width D2 of the conductive washer 40. The width D2 of the conductive washer 40 may be set to vary depending on the diameter of the secondary battery. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D2 of the conductive washer 40 may be 10% or more, 11% or more, 12% or more, or 13% or more of a maximum diameter of the cell. The cylindrical secondary battery is an approximately cylindrical cell. For example, the width D2 of the conductive washer 40 may be 50% or less, 45% or less, 43% or less, or 40% or less of the maximum diameter of the cell.
When the insulative washer 60 extends to the edge region of the upper surface of the conductive washer 40 as described above, the process of seating the conductive washer 40 on the crimping portion 22 may be more accurately and quickly performed. The insulative washer 60 is inserted through the hole of the conductive washer 40 and fixed to the conductive washer 40, and then the coupled body including the conductive washer 40 and the insulative washer 60 is seated on the crimping portion 22 and the top cap 30, such that the conductive washer 40 may be naturally seated on an accurate position. In this case, the protruding portion 31 of the top cap 30 is exposed to the outside of the battery can through the hole formed in the central portion of the insulative washer 60.
The coupled body of the insulative washer 60 and the conductive washer 40 illustrated in
Referring to
Referring to
Although not illustrated in the drawings, the current collecting plate 70 may include a plurality of concave-convex portions radially formed on the lower surface thereof. When the concave-convex portions are formed, the concave-convex portions may be pressed into the electrode tabs 11 and 12 by pushing the current collecting plate 70.
Referring to
Referring to
Referring to
Although not illustrated in the drawings, like the first electrode tab 11, the second electrode tab 12 may also have a shape bent in the direction toward the winding center of the electrode assembly 10.
The insulation plate 80 is disposed between the beading portion 21 and the upper end of the electrode assembly 10 or between the beading portion 21 and the current collecting plate 70 coupled to the upper portion of the electrode assembly 10 and prevents the contact between the first electrode tab 11 and the battery can 20 or the contact between the current collecting plate 70 and the battery can 20.
The insulation plate 80 has a lead hole 81 through which the lead 72, which extends upward from the current collecting plate 70 or the first electrode tab 11, may be extended.
The lead 72 is extended upward through the lead hole 81 and coupled to a lower surface of the connection plate 90 or a lower surface of the top cap 30. As described above, the cylindrical secondary battery 1 according to the embodiment of the present invention has a structure in which the top cap 30 and the conductive washer 40 provided at one side of the battery can 20 based on the longitudinal direction (the direction parallel to the Z-axis in
The embodiment of the present invention provides a method of manufacturing the secondary battery according to the embodiment of the present invention, the method including: accommodating the electrode assembly 10, which has the first electrode tab and the second electrode tab, in the battery can 20 electrically connected to the second electrode tab and having the opening portion configured to accommodate the electrode assembly; covering the opening portion of the battery can by coupling: the top cap 30 disposed in the opening portion of the battery can 20 and electrically connected to the first electrode tab; the gasket 50 provided between the battery can and the top cap; the conductive washer 40 electrically connected to the battery can and configured to adjoin at least a part of the peripheral portion of the opening portion; and the insulative washer 60 provided between the top cap and the conductive washer and configured to electrically insulate the top cap 30 and the conductive washer 40; and injecting the curing agent between the conductive washer 40 and the insulative washer 60.
The embodiment of the present invention provides a method of manufacturing the secondary battery according to the embodiment of the present invention the method including: accommodating the electrode assembly 10, which has the first electrode tab and the second electrode tab, in the battery can 20 electrically connected to the second electrode tab and having the opening portion configured to accommodate the electrode assembly; covering the opening portion of the battery can 20 by coupling: a top cap 30 disposed in the opening portion of the battery can 20 and electrically connected to the first electrode tab; the gasket 50 provided between the battery can and the top cap; and the insulative washer 60 provided on the outer peripheral surface of the top cap; injecting the curing agent on the insulative washer 60; and coupling the conductive washer 40 to the curing agent, the conductive washer 40 being electrically connected to the battery can 20 and configured to adjoin at least a part of the peripheral portion of the opening portion.
The curing agent may be injected through the nozzle. As described above, any curing agent may be applied to the present invention as long as the curing agent is injected in a liquid state having fluidity and then cured as time passes.
The injection includes a case in which the curing agent is injected between the conductive washer 40 and the insulative washer 60 and a case in which the curing agent is applied onto the insulative washer 60.
Referring to
Referring to
The present invention has been described with reference to the limited embodiments and the drawings, but the present invention is not limited thereto. The described embodiments may be changed or modified by those skilled in the art to which the present invention pertains within the technical spirit of the present invention and within the scope equivalent to the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0024411 | Feb 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/002676 | 2/23/2022 | WO |
