Patent Application
20250015404
The present application claims priority to Korean Patent Application No. 10-2022-0014957 filed on Feb. 4, 2022 and No. 10-2022-0088960 filed on Jul. 19, 2022 in the Republic of Korea, the disclosures of which are incorporated herein by reference.
The present disclosure relates to a battery, and a battery pack and a vehicle including the same. More particularly, the present disclosure relates to a battery having a structure capable of minimizing movement of an internal electrode assembly, and a battery pack and a vehicle including the same.
In a battery, a jelly-roll having a shape in which a positive electrode tab and a negative electrode tab are extended upwards and downwards along the height direction may be applied to a housing in order to maximize current collection efficiency. In a battery to which a jelly-roll having the above structure is applied, a current collector may be used as a medium for connecting the positive electrode tab and the negative electrode tab to the terminal and the housing, respectively.
In this case, for example, the positive electrode current collector may be coupled with the positive electrode tab while covering one surface of the jelly-roll and, and the negative electrode current collector may be coupled with the negative electrode tab while covering the other surface of the jelly-roll. In addition, the positive electrode current collector may be electrically connected to the terminal, and the negative electrode current collector may be electrically connected to the housing.
In the battery having the structure as described above, a relatively large empty space may be formed between the negative electrode current collector and the cap. In addition, an empty space may also be formed between the bottom surface of the housing located opposite to the cap and the positive electrode current collector.
These empty spaces may cause the jelly-roll to move inside the housing, especially in the upper and lower direction, namely along the height direction of the battery. When the jelly-roll moves up and down like this, damage may occur to the joint between the current collector and the electrode tab, and in addition, damage may occur to the joint between the current collector and the housing and the joint between the current collector and the terminal.
Therefore, it is necessary to reduce the movement space of the jelly-roll as much as possible. In addition, if additional parts applied to reduce the movement space of the jelly-roll are used, the complexity of the process and the manufacturing cost may increase, so there is a need to solve these problems by using parts that have already been applied in the past.
The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to preventing damage to an electrical coupling portion caused by the movement of a jelly-roll inside a housing.
In addition, the present disclosure is directed to preventing the complexity of the manufacturing process and increase in manufacturing cost caused by the application of additional parts by preventing the movement of the jelly-roll by utilizing parts that have already been applied in the past in battery manufacturing.
In another aspect, the present disclosure may also be directed to preventing abnormal deformation of a spacer assembly due to force applied to the spacer assembly during the manufacturing process of the battery.
The technical objects to be solved by the present disclosure are not limited to the above, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following disclosure.
In one aspect of the present disclosure, there is provided a battery, comprising: an electrode assembly having a first uncoated portion and a second uncoated portion: a housing having an open portion formed at one side and configured to accommodate the electrode assembly through the open portion: a first current collector coupled with the first uncoated portion and located inside the housing: a cap configured to cover the open portion; and a spacer assembly having a spacer portion interposed between the first current collector and the cap and configured to prevent movement of the electrode assembly, a gasket portion interposed between the housing and the cap and configured to seal the gap between the cap and the housing, and a connection portion configured to connect the spacer portion and the gasket portion and to rotate the spacer portion when a force exceeding a criterion value is applied in a direction from the gasket portion toward the spacer portion.
The connection portion may include a plurality of bridges arranged to be spaced apart from each other along a circumferential direction of the electrode assembly.
Each of the plurality of bridges may include a first portion connected to the spacer portion; and a second portion connected to the gasket portion.
The first portions of the plurality of bridges may be tilted to form a predetermined angle with a radial direction of the electrode assembly and connected to the spacer portion, respectively.
The first portions of the plurality of bridges may be tilted in the same direction.
The first portion and the second portion may be connected with each other while forming a predetermined angle.
The spacer portion may have a height corresponding to the distance between the first current collector and the cap.
The spacer portion may be located in the center on one surface of the electrode assembly.
The spacer portion may have a spacer hole formed at a position corresponding to a winding center hole of the electrode assembly.
The spacer assembly may have an ejection preventing portion configured to intersect the spacer hole.
The housing may include a beading portion formed by press-fitting an outer circumference; and a crimping portion configured to extend and bend so that an end of the crimping portion defining the open portion under the beading portion surrounds an edge of the cap.
The gasket portion may be bent along the crimping portion to surround the edge of the cap.
The plurality of bridges may be configured not to contact the first current collector.
The plurality of bridges may be configured not to contact the cap.
The first current collector may include a support portion located in the center on one surface of the electrode assembly: an uncoated portion coupling portion configured to extend from the support portion and coupled to the first uncoated portion; and a housing contact portion configured to extend from the support portion or extend from an end of the uncoated portion coupling portion and interposed between the housing and the gasket portion.
The housing may include a beading portion formed by press-fitting a part of a sidewall thereof toward the inside; and a crimping portion configured to extend and bend so that an end of the crimping portion defining the open portion under the beading portion surrounds an edge of the cap, and
The cap may include a venting portion having a thinner thickness compared to the surrounding region, and
The connection portion may be located not to overlap with the housing contact portion along a height direction of the battery.
In another aspect of the present disclosure, there is also provided a battery pack, which comprises the battery an embodiment of the present disclosure.
In another aspect of the present disclosure, there is also provided a vehicle, which comprises the battery pack an embodiment of the present disclosure.
According to an embodiment of the present disclosure, the movement of the jelly-roll inside the housing is minimized, thereby preventing damage to an electrical coupling portion.
According to another embodiment of the present disclosure, the complexity of the manufacturing process and the increase in manufacturing cost may be prevented by utilizing parts that have already been applied in the past instead of additionally applying parts for preventing movement of the jelly-roll.
According to still another embodiment of the present disclosure, abnormal deformation of the spacer assembly due to force applied to the spacer assembly during the manufacturing process of the battery may be prevented. Meanwhile, since abnormal deformation of the spacer assembly is prevented, it is possible to effectively prevent product defects from occurring by the force applied to the current collector and/or the electrode assembly due to deformation of the spacer assembly.
The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawing.
Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.
In addition, in order to help understanding of the present disclosure, the accompanying drawings are not drawn to scale, and the dimensions of some components may be exaggerated. In addition, the same reference numerals may be assigned to the same elements in different embodiments.
When it is explained that two objects are ‘identical’, this means that these objects are ‘substantially identical’. Accordingly, the substantially identical objects may include deviations considered low in the art, for example, deviations within 5%. Also, when it is explained that certain parameters are uniform in a region, this may mean that the parameters are uniform in terms of an average.
Although the terms first, second or the like are used to describe different elements, these elements are not limited by the terms. These terms are used to distinguish one element from another, and unless stated to the contrary, a first element may be a second element.
Throughout the specification, unless stated otherwise, each element may be singular or plural.
When an element is “above (or under)” or “on (or below)” another element, the element can be on an upper surface (or a lower surface) of the other element, and intervening elements may be present between the element and the other element on (or below) the element.
Additionally, when an element is referred to as being “connected”, “coupled” or “linked” to another element, the element can be directly connected or coupled to the other element, but it should be understood that intervening elements may be present between each element, or each element may be “connected”, “coupled” or “linked” to each other through another element.
Throughout the specification, “A and/or B” refers to either A or B or both A and B unless expressly stated otherwise, and “C to D” refers to C or greater and D or smaller unless expressly stated otherwise.
Referring to
Referring to
The electrode assembly 10 may have, for example, a jelly-roll shape. That is, the electrode assembly 10 may be manufactured by winding a laminate, which is formed by sequentially laminating a first electrode, a separator and a second electrode at least once. The jelly-roll type electrode assembly 10 may have a winding center hole C formed at its center and extending along a height direction (direction parallel to Z-axis). Meanwhile, an additional separator may be provided on the outer circumference of the electrode assembly 10 for insulation from the housing 20.
The first electrode includes a first conductive substrate and a first electrode active material layer coated on one surface or both surfaces of the first conductive substrate. At one end of the first conductive substrate in the width direction (direction parallel to Z-axis), a first uncoated portion not coated with the first electrode active material is provided. The first uncoated portion has a shape extending from one end to the other end along the longitudinal direction of the first electrode when the first electrode is in an unfolded state. The first uncoated portion 11 may function as a first electrode tab. The first uncoated portion 11 is provided on one surface of the electrode assembly 10. More specifically, the first uncoated portion 11 is provided at the lower portion of the electrode assembly 10 accommodated in the housing 20 in the height direction (direction parallel to Z-axis).
The second electrode includes a second conductive substrate and a second electrode active material layer coated on one surface or both surfaces of the second conductive substrate. At the other end of the second conductive substrate in the width direction (direction parallel to Z-axis), an uncoated portion not coated with the second electrode active material is provided. The second uncoated portion has a shape extending from one end to the other end along the longitudinal direction of the second electrode when the second electrode is in an unfolded state. The second uncoated portion 12 may function as a second electrode tab. The second uncoated portion 12 is provided on the other surface of the electrode assembly 10. More specifically, the second uncoated portion 12 is provided at the upper portion of the electrode assembly 10 accommodated in the housing 20 in the height direction (direction parallel to Z-axis).
That is, the first uncoated portion 11 and the second uncoated portion 12 protrusively extend in opposite directions along the height direction (direction parallel to Z-axis) of the electrode assembly 10, namely along the height direction of the cylindrical battery 1, and are exposed to the outside of the separator.
Meanwhile, referring to
In the present disclosure, a positive electrode active material coated on the positive electrode current collector and a negative electrode active material coated on the negative electrode current collector may employ any active material known in the art without limitation.
In one example, the positive electrode active material may include an alkali metal compound expressed by a general formula A [AxMy]O2+z (A includes at least one element among Li, Na and K; M includes at least one element selected from is Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Mo, Sc, Zr, Ru, and Cr; x≥0, 1≤x+y≤2, −0.1≤z≤2; and the stoichiometric coefficients of x, y and z and components included in M are selected so that the compound maintains electrical neutrality).
In another example, the positive electrode active material may be an alkali metal compound xLiM1O2-(1−x)Li2M2O3 disclosed in U.S. Pat. Nos. 6,677,082, 6,680,143, et al., wherein M1 includes at least one element having an average oxidation state 3; M2 includes at least one element having an average oxidation state 4; and 0≤x≤1).
In still another example, the positive electrode active material may be lithium metal phosphate expressed by a general formula LiaM1xFe1-xM2yP1-yM3zO4-z (M1 includes at least one element selected from the Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M2 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V and S; M3 includes a halogen element optionally including F: 0<a≤2, 0≤x≤1, 0≤y<1, 0≤z<1; the stoichiometric coefficients of a, x, y and z and components included in M1, M2, and M3 are selected so that the compound maintains electrical neutrality), or Li3M2(PO4)3 (M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al).
Preferably, the positive electrode active material may include primary particles and/or secondary particles in which the primary particles are aggregated.
In one example, the negative electrode active material may employ carbon material, lithium metal or lithium metal compound, silicon or silicon compound, tin or tin compound, or the like. Metal oxides such as TiO2 and SnO2 with a potential of less than 2V may also be used as the negative electrode active material. As the carbon material, low-crystalline carbon, high-crystalline carbon or the like may be used.
The separator may employ a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, ethylene/hexene copolymer, ethylene/methacrylate copolymer, or the like, or laminates thereof. As another example, the separator may employ a common porous nonwoven fabric, for example, a nonwoven fabric made of high melting point glass fiber, polyethylene terephthalate fiber, or the like.
At least one surface of the separator may include a coating layer of inorganic particles. It is also possible that the separator itself is made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure coupled with a binder so that interstitial volumes exist among adjacent particles.
The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. The inorganic particles may include at least one material selected from the group consisting of Pb(Zr,Ti) O3 (PZT), Pb1-xLaxZr1-yTiyO3 (PLZT), PB(Mg3Nb2/3) O3, PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.
The electrolyte may be a salt having a structure like A+B−. Here, A+ includes an alkali metal cation such as Li+, Na+, or K+, or a combination thereof, and B− includes at least one anion selected from the group consisting of F−, Cl−, Br−, I−, NO3−, N(CN)2−, BF4−, ClO4−, AlO4−, AlCl4−, PF6−, SbF6−, AsF6−, BF2C2O4−, BC4O8−, (CF3)2PF4−, (CF3)3PF3−, (CF3)4PF2−, (CF3)5PF−, (CF3)6P−, CF3SO3−, C4F9SO3−, CF3CF2SO3−, (CF3SO2)2N−, (FSO2)2N−, CF3CF2 (CF3)2CO−, (CF3SO2)2CH−, (SF5)3C−, (CF3SO2)3C−, CF3 (CF2)7SO3−, CF3CO2−, CH3CO2−, SCN− and (CF3CF2SO2)2N−.
The electrolyte may also be dissolved in an organic solvent. The organic solvent may employ propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.
Referring to
The housing 20 is electrically connected to the electrode assembly 10. The housing 20 is connected to the first uncoated portion 11 of the electrode assembly 10. Accordingly, the housing 20 has electrically the same polarity as the first uncoated portion 11.
Referring to
The crimping portion 22 is formed below the beading portion 21. The crimping portion 22 has a shape extending and bending so that the end defining the open portion of the housing 20 surrounds the periphery of the edge of the cap 40 in a state where the periphery of the edge of the spacer assembly 50 is interposed therebetween.
Referring to
Referring to
The uncoated portion coupling portion 32 extends from the support portion 31 and is coupled with the first uncoated portion 11. The uncoated portion coupling portion 32 may be provided in plural, for example. In this case, the plurality of uncoated portion coupling portions 32 may have a shape radially extending from the support portion 31. The housing contact portion 33 may extend from the support portion 31 as shown in
The housing contact portion 33 may be provided in plural, for example. In this case, as shown in
Referring to
When the housing 20 of the present disclosure includes the beading portion 21, the cap 40 may be seated on the beading portion 21 formed in the housing 20. In addition, when the housing 20 of the present disclosure includes the crimping portion 22, the cap 40 is fixed by the crimping portion 22. Between the cap 40 and the crimping portion 22 of the housing 20, the periphery of the edge of the spacer assembly 50 is interposed to ensure airtightness of the housing 20.
Referring to
As shown in
Meanwhile, when the venting portion 41 has a closed loop shape as shown in
Referring to
In another aspect, the spacer assembly 50 may include, for example, a spacer portion 51, a gasket portion 52, and a connection portion 53. The spacer assembly 50 may further include an ejection preventing portion 54 in addition to the components described above. The spacer portion 51 may be interposed between the first current collector 30 and the cap 40 to prevent movement of the electrode assembly 10. The spacer portion 51 may have a height corresponding to a distance between the first current collector 30 and the cap 40. In this case, the spacer portion 51 may effectively prevent the electrode assembly 10 from moving inside the housing 20 due to the gap formed between the first current collector 30 and the cap 40. Accordingly, the spacer portion 51 may prevent damage to the coupling portion between the electrode assembly 10 and the first current collector 30 and/or the coupling portion between the first current collector 30 and the housing 20.
The spacer portion 51 may be located approximately at the center on one surface of the bottom end of the electrode assembly 10. The spacer portion 51 may include a spacer hole H2 formed at a position corresponding to the winding center hole C of the electrode assembly 10. The spacer hole H2, like the first current collector hole H1 described above, may function as a passage for inserting a welding rod or a passage for laser irradiation. The spacer hole H2, like the first current collector hole H1 described above, may also function as a passage through which electrolyte may be smoothly impregnated into the electrode assembly 10 when the electrolyte is injected.
Meanwhile, the spacer portion 51 may cover the support portion 31 of the first current collector 30 so that the support portion 31 is not exposed to the outside of the spacer portion 51. That is, the outer diameter of the top end of the spacer portion 51 may be substantially equal to or larger than the outer diameter of the support portion 31. In this case, the spacer portion 51 may effectively press the first current collector 30.
In another aspect, the spacer portion 51 may be configured to cover at least a part of the welding portion formed by welding the uncoated portion coupling portion 32 of the first current collector 30 and the first uncoated portion 11. That is, the radius of the top end of the spacer portion 51 may be greater than the distance from the welding portion closest to the core of the electrode assembly 10 to the core of the electrode assembly 10. In this case, the spacer portion 51 may effectively prevent a phenomenon that the welding portion of the first current collector 30 and the first uncoated portion 11 is damaged during a crimping process or a sizing process, for example.
In another aspect, the spacer portion 51 may be located more inward toward the core than the venting portion 41 so as not to cover the venting portion 41 formed in the cap 40. That is, the radius measured at the top end of the spacer portion 51 may be smaller than the distance from the center of the cap 40 to the venting portion 41. This is to prevent the rupture pressure of the venting portion 41 from being different from the design value because the venting portion 41 is covered by the spacer assembly 50.
The gasket portion 52 is interposed between the housing 20 and the cap 40. The gasket portion 52 may have a shape extending along the inner circumference of the housing 20. When the housing 20 includes the crimping portion 22, the gasket portion 52 may be bent together along the bent shape of the crimping portion 22 to cover the circumferential region of the edge of the cap 40. In another aspect, the gasket portion 52 may be bent along the crimping portion 22 to fill the gap between the housing contact portion 33 and the cap 40 while covering the edge of the cap 40. As such, the gasket portion 52 may improve the fixing force of the cap 40 and the sealing force of the housing 20.
Meanwhile, in the gasket portion 52, the thickness between the housing contact portion 33 and the cap 40 may be smaller than the thickness between the beading portion 21 and the cap 40. This is because the gasket portion 52 may be compressed more in an area where the housing contact portion 33 is interposed between the housing 20 and the beading portion 21 compared to other areas. Accordingly, in the gasket portion 52, the compression rate between the housing contact portion 33 and the cap 40 may be greater than the compression rate between the beading portion 21 and the cap 40. Alternatively, the gasket portion 52 may be configured such that the compression rate between the housing contact portion 33 and the cap 40 is approximately the same as the compression rate between the beading portion 21 and the cap 40. In this case, as the compression rate of the gasket portion 52 varies for each area, it is possible to prevent a phenomenon that the sealing force is partially lowered.
The connection portion 53 connects the spacer portion 51 and the gasket portion 52 to each other. The connection portion 53 may be configured to rotate the spacer portion 51 when a force exceeding a criterion value is applied in a direction from the gasket portion 52 toward the spacer portion 51. Here, the rotation of the spacer portion 51 means clockwise or counterclockwise rotation approximately along the circumferential direction of the electrode assembly 10. Specifically, for example, in manufacturing the cylindrical battery 1, when force is applied in a direction from the outside of cylindrical battery 1 toward the center as in the case where a crimping process is performed, the connection portion 53 may be configured to apply the force in the direction of rotating the spacer portion 51.
Accordingly, in the cylindrical battery 1 according to the present disclosure, even when an external force is applied, the spacer assembly 50 may effectively disperse the force without causing abnormal deformation.
The connection portion 53 may include, for example, a plurality of bridges 53a spaced apart from each other along the circumferential direction of the electrode assembly 10. In this case, the space formed between the bridges 53a adjacent to each other may function as a passage for smooth electrolyte circulation. In another aspect, the space formed between the bridges 53a adjacent to each other may function as a passage through which an internal gas is smoothly discharged when venting occurs due to an increase in internal pressure.
Meanwhile, each of the plurality of bridges 53a may include a first portion connected to the spacer portion 51 and a second portion connected to the gasket portion 52. The first portions of the plurality of bridges 53a may be tilted to form a predetermined angle with the radial direction of the electrode assembly 10 and connected to the spacer portion 51, respectively. If the force transmitted through the bridge 53a is transmitted approximately perpendicularly to the outer circumference of the spacer portion 51 along the radial direction of the electrode assembly 10, there is a high risk of deformation of the bridge 53a and the possibility that the spacer portion 51 deviates from the installation position may increase. Therefore, by forming a predetermined angle at the connection part between the bridge 53a and the spacer portion 51, the force applied from the outside of the battery 1 toward the center acts in the direction of rotating the spacer portion 51, thereby minimizing or preventing deformation of the bridge 53a.
Meanwhile, when the connection portion 53 includes a plurality of bridges 53a, the first portions of the plurality of bridges 53a may be tilted in the same direction on a plane (X-Y plane), respectively. For example, the plurality of bridges 53a may be substantially spirally formed in a clockwise or counterclockwise direction. According to this structure of the present disclosure, when a force acting on the plurality of bridges 53a by an external force equally acts on the spacer portion 51 in any one of a clockwise direction and a counterclockwise direction, the spacer portion 51 may smoothly rotate.
The ejection preventing portion 54 may be configured to intersect the spacer hole H2. The ejection preventing portion 54 may be configured to reduce an open area of the spacer hole H2. The ejection preventing portion 54 may have, for example, a substantially cross shape. However, this is only an exemplary form of the ejection preventing portion 54, and the shape of the ejection preventing portion 54 is not limited thereto.
The ejection preventing portion 54 may be provided at a position corresponding to the winding center hole of the electrode assembly 10 and the first current collector hole H1 of the first current collector 30. The ejection preventing portion 54 may prevent the winding center of the electrode assembly 10 from ejecting to the outside of the housing 20 when venting occurs due to an increase in pressure inside the housing 20.
Referring to
Meanwhile, in
As shown in
In this case, even if the shape deformation of the spacer assembly 50 occurs due to a sizing process of compressing the cylindrical battery 1 along the height direction (direction parallel to the Z axis), a crimping process, or other causes, the interference between the connection portion 53 of the spacer assembly 50 and the housing contact portion 33 of the first current collector 30 may be minimized. In particular, when the bridge 53a is configured not to contact the cap 40, even if the shape of the housing 20 is deformed due to a sizing process or an external impact, the possibility of shape deformation of the bridge 53a may be reduced.
Meanwhile, the components constituting the spacer assembly 50 may be integrally formed. For example, the spacer assembly 50 in which the spacer portion 51, the gasket portion 52 and the connection portion 53 are integrated may be manufactured by injection molding. That is, the cylindrical battery 1 of the present disclosure may obtain both the effect of strengthening the sealing force for the open portion of the housing 20 and the effect of preventing movement of the electrode assembly 10 as a single component configured through modified manufacture of the gasket parts used to seal the open portion of the housing 20. Therefore, according to the present disclosure, the complexity of the manufacturing process and the increase in manufacturing cost caused by the application of additional components may be prevented. Moreover, according to the structure of the spacer assembly 50 of the present disclosure, for example, when an external force such as a crimping process is applied, the force applied approximately along the radial direction to the connection portion 53 of the spacer assembly 50 may be shifted to a direction of rotating the spacer portion 51. Accordingly, the spacer portion 51 may be finely rotated clockwise or counterclockwise on a plane (X-Y plane) (for example, approximately 1 degree may be rotated), whereby stress is not accumulated in the connection portion 53 and thus it is possible to prevent interference with the current collector 30 due to deformation of the connection portion 53.
Referring to
Meanwhile, when an external force is applied through the crimping process to the battery to which the spacer assembly not having the stress relieving structure shown in
Referring to
As described above, in the present disclosure, since the housing 20 is electrically connected to the first uncoated portion 11 of the electrode assembly 10, the closed portion formed at the top end of the housing 20 may function as the first electrode terminal 20a having first polarity. Meanwhile, since the terminal 60 is electrically connected to the second uncoated portion 12 of the electrode assembly 10, the terminal 60 exposed to the outside of the housing 20 may function as the second electrode terminal.
That is, the cylindrical battery 1 of the present disclosure has a structure in which a pair of electrode terminals 60, 20a are located in the same direction. Therefore, in the case of electrically connecting a plurality of cylindrical batteries 1, it is possible to dispose electrical connecting parts such as bus bars on only one side of the cylindrical batteries 1. In this case, it is possible to simplify the battery pack structure and improve energy density. In addition, since the cylindrical battery 1 has a structure in which one surface of the housing 20 having a substantially flat shape may be used as the first electrode terminal 20a, when bonding electrical connection parts such as bus bars to the first electrode terminal 20a, a sufficient bonding area may be obtained. Accordingly, the cylindrical battery 1 may secure sufficient bonding strength between the electrical connection parts and the first electrode terminal 20a, and resistance at the bonding region may be reduced to a desirable level.
As described above, when the terminal 60 functions as the second electrode terminal, the terminal 60 is electrically insulated from the housing 20 having the first polarity. Electrical isolation between the housing 20 and the terminal 60 may be realized in various ways. For example, insulation may be realized by interposing an insulating gasket G between the terminal 60 and the housing 20. Alternatively, insulation may be realized by forming an insulating coating layer on a part of the terminal 60. Alternatively, the terminal 60 and the housing 20 may be arranged to be spaced apart from each other so as not to contact each other, and the terminal 60 may be structurally firmly fixed. Alternatively, among the methods described above, a plurality of methods may be applied together.
Meanwhile, when the insulating gasket G is applied for electrical insulation and riveting is applied to fix the terminal 60, the insulating gasket G may be deformed together during riveting of the terminal 60 so as to be bent toward the inner surface of the closed portion at the top end of the housing 20. In the case where the insulating gasket G is made of a resin material, the insulating gasket G may be coupled to the housing 20 and the terminal 60 by thermal fusion. In this case, airtightness at the coupling interface between the insulating gasket G and the terminal 60 and the coupling interface between the insulating gasket G and the housing 20 may be enhanced.
Referring to
Referring to
In addition to the above, the insulator 80 may also be interposed between the top end of the outer circumference of the electrode assembly 10 and the inner surface of the housing 20. In this case, it is possible to prevent the second uncoated portion 12 of the electrode assembly 10 from contacting the inner surface of the sidewall of the housing 20 and thus causing a short circuit.
The insulator 80 may have a height corresponding to the distance between the closed portion formed at the top end of the housing 20 and the electrode assembly 10 or the distance between the closed portion and the second current collector 70. In this case, it is possible to prevent the electrode assembly 10 from moving inside the housing 20, thereby significantly reducing the risk of damage to the coupling region for electrical connection between parts. When the insulator 80 is applied together with the spacer assembly 50 described above, the effect of preventing movement of the electrode assembly 10 may be maximized.
The insulator 80 may have an opening formed at a position corresponding to the winding center hole C of the electrode assembly 10. Through the opening, the terminal 60 may directly contact the second current collector 70.
The cylindrical battery 1 of the present disclosure described above has a structure in which resistance is minimized by expanding the welding area through the bending surface of the uncoated portion, multiplexing the current path by using the first current collector 30, and minimizing the length of the current path. The AC resistance of the cylindrical battery 1, measured through a resistance meter between the positive electrode and the negative electrode and between the terminal 60 and the flat surface 20a therearound, may be approximately 0.5 milliohm to 4 milliohm, preferably approximately 1 milliohm to 4 milliohm, which is suitable for rapid charging.
Preferably, the cylindrical battery may be, for example, a cylindrical battery whose form factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by height, namely a ratio of diameter (Φ) to height (H)) is greater than about 0.4.
Here, the form factor means a value indicating the diameter and height of a cylindrical battery. Preferably, the cylindrical battery may have a diameter of 40 mm to 50 mm and may have a height of 60 mm to 130 mm. The cylindrical battery according to an embodiment of the present disclosure may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the numerical value representing the form factor, first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height of the battery.
When an electrode assembly having a tab-less structure is applied to a cylindrical battery having a form factor ratio of more than 0.4, the stress applied in the radial direction when the uncoated portion is bent is large, so that the uncoated portion may be easily torn. In addition, when welding the current collector to the bending surface region of the uncoated portion, it is necessary to sufficiently increase the number of stacked layers of the uncoated portion in the bending surface region in order to sufficiently secure the welding strength and lower the resistance. This requirement may be achieved by the electrode and the electrode assembly according to the embodiments (modifications) of the present disclosure.
A battery according to an embodiment of the present disclosure may be an approximately cylindrical battery, whose diameter is approximately 46 mm, height is approximately 110 mm, and form factor ratio is 0.418.
A battery according to another embodiment may be an approximately cylindrical battery, whose diameter is about 48 mm, height is about 75 mm, and form factor ratio is 0.640.
A battery according to still another embodiment may be an approximately cylindrical battery, whose diameter is approximately 48 mm, height is approximately 110 mm, and form factor ratio is 0.418.
A battery according to still another embodiment may be an approximately cylindrical battery, whose diameter is approximately 48 mm, height is approximately 80 mm, and form factor ratio is 0.600.
A battery according to still another embodiment may be an approximately cylindrical battery, whose diameter is approximately 46 mm, height is approximately 80 mm, and form factor ratio is 0.575.
Conventionally, batteries having a form factor ratio of about 0.4 or less have been used. That is, conventionally, for example, 1865 battery, 2170 battery, etc. were used. The 1865 battery has a diameter of approximately 18 mm, height of approximately 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.
Referring to
In each cylindrical battery 1, the terminal 60 may have a positive polarity, and the outer surface 20a of the closed portion of the housing 20 may have a negative polarity, or vice versa.
Preferably, the plurality of cylindrical batteries 1 may be arranged in a plurality of columns and rows. Columns are provided in a vertical direction based on the drawing, and rows are provided in a left and right direction based on the drawing. In addition, in order to maximize space efficiency, the cylindrical batteries 1 may be arranged in a closest packing structure. The closest packing structure is formed when an equilateral triangle is formed by connecting the centers of the terminals 60 exposed out of the battery 20 to each other. Preferably, the bus bar 150 may be disposed on the upper portion of the plurality of cylindrical batteries 1, more preferably between adjacent columns. Alternatively, the bus bar 150 may be disposed between adjacent rows.
Preferably, the bus bar 150 connects the cylindrical batteries 1 arranged in the same column in parallel to each other, and connects the cylindrical batteries 1 arranged in two neighboring columns in series with each other.
Preferably, the bus bar 150 may include a body portion 151, a plurality of first bus bar terminals 152 and a plurality of second bus bar terminals 153 for serial and parallel connection.
The body portion 151 may extend between the terminals 60 of neighboring cylindrical batteries 1, namely between the columns of the cylindrical batteries 1. Alternatively, the body portion 151 may extend along the column of the cylindrical batteries 1, and may be regularly bent like a zigzag shape.
The plurality of first bus bar terminals 152 may protrusively extend from one side of the body portion 151 toward the terminal 60 of each cylindrical battery 1 and may be electrically coupled to the terminal 60. The electrical coupling between the first bus bar terminal 152 and the terminal 60 may be achieved by laser welding, ultrasonic welding, or the like. In addition, the plurality of second bus bar terminals 153 may be electrically coupled to the outer surface 20a of each cylindrical battery 1 from the other side of the body portion 151. The electrical coupling between the second bus bar terminal 153 and the outer surface 20a may be performed by laser welding, ultrasonic welding, or the like.
Preferably, the body portion 151, the plurality of first bus bar terminals 152 and the plurality of second bus bar terminals 153 may be made of one conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present disclosure is not limited thereto. In a modified example, the body portion 151, the plurality of first bus bar terminals 152 and the second bus bar terminals 153 may be manufactured as separate pieces and then coupled to each other by welding or the like.
In the cylindrical battery 1 according to the present disclosure, since the terminal 60 having a positive polarity and the outer surface 20a of the closed portion of the housing 20 having a negative polarity are located in the same direction, it is easy to electrically connect the cylindrical batteries 1 using the bus bar 150.
In addition, since the terminal 60 of the cylindrical battery 1 and the outer surface 20a of the closed portion of the housing 20 have a large area, the coupling area of the bus bar 150 may be sufficiently secured to sufficiently reduce the resistance of the battery pack including the cylindrical battery 1.
Referring to
Referring to
The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0014957 | Feb 2022 | KR | national |
| 10-2022-0088960 | Jul 2022 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/001074 | 1/20/2023 | WO |
