CN115732817A - Cylindrical battery cell, battery pack including the same, and vehicle - Google Patents

Abstract

A cylindrical battery cell, a battery pack including the same, and a vehicle. A cylindrical battery cell according to an embodiment of the present disclosure includes: a jelly roll having a first electrode tab protruding upward and a second electrode tab protruding downward; a battery can configured to receive the jelly roll through the top opening and electrically connected to the second electrode tab; a first collector plate coupled to the first electrode tab at an upper portion of the jellyroll; an insulating shrinkage tube having a first cover portion for covering at least a part of the first collecting plate and a second cover portion for covering a top end of an outer periphery of the jelly roll; and a cap electrically connected to the first collecting plate and configured to cover the opening.

Description

Cylindrical battery cell, battery pack including the same, and vehicle

Technical Field

This application claims priority from korean patent application No.10-2021-0115064, filed in korea at 30.8.2021 and korean patent application No.10-2022-0098565, filed in korea at 8.8.2022, the disclosures of which are incorporated herein by reference.

The present disclosure relates to a cylindrical battery cell, a battery pack including the cylindrical battery cell, and a vehicle including the battery pack.

Background

A secondary battery, which is easily applied according to product groups and has electrical characteristics such as high energy density, is commonly applied not only to portable devices but also to Electric Vehicles (EV) or Hybrid Electric Vehicles (HEV) driven by an electric drive source. These secondary batteries are receiving attention as a new energy source for improving eco-friendliness and energy efficiency, because they have not only a major advantage of significantly reducing the use of fossil fuels but also do not generate any by-products due to the use of energy.

Types of secondary batteries that are currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. Such a unit secondary battery cell, i.e., a unit cell, has an operating voltage of about 2.5V to 4.5V. Therefore, when a higher output voltage is required, the battery pack may be configured by connecting a plurality of battery cells in series. In addition, a plurality of battery cells may be connected in parallel to form a battery pack according to a charge/discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack may be variously set according to a desired output voltage and/or charge/discharge capacity.

On the other hand, as the type of the unit secondary battery cell, a cylindrical, square, and pouch type battery cell is known. In the case of a cylindrical battery cell, a separator, which is an insulator, is interposed between a positive electrode and a negative electrode and is wound to form a jelly-roll type electrode assembly, and then the jelly-roll type electrode assembly is inserted into a battery can to constitute a battery. Further, a lead tab may be connected to an uncoated portion of each of the positive and negative electrodes, and the lead tab is connected to a member serving as an electrode terminal to electrically connect the electrode assembly and the electrode terminal. However, according to the conventional cylindrical battery cell having such a structure, since current is concentrated in the narrow lead tabs coupled to the positive electrode non-coating portion and/or the negative electrode non-coating portion, electrical resistance is large, generated heat is large, and current collection efficiency is not good.

In order to solve this problem, the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are designed to be located at the top and bottom ends of the jelly-roll type electrode assembly, respectively, and the collector plates are coupled to the uncoated portions, thereby proposing a cylindrical battery cell of a structure having improved current collection efficiency.

However, according to such a cylindrical battery cell structure, since the uncoated portion of the positive electrode and the uncoated portion of the negative electrode protrude outside the jelly roll, there is a possibility that the uncoated portion of the positive electrode and the battery can contact each other. If the uncoated portion of the positive electrode and the battery can form an electrical contact, a short circuit may occur. If a short circuit occurs inside the battery, the battery may be heated or explode. Therefore, it is necessary to provide an insulating member for preventing electrical contact between the uncoated portion of the positive electrode protruding upward and the battery can.

Therefore, there is a need to find a method capable of providing a cylindrical battery cell having both low internal resistance of the battery cell and low risk of short circuit, and a battery pack and a vehicle including the same.

Disclosure of Invention

Technical problem

The present disclosure is designed to solve the problems of the related art, and therefore, the present disclosure is directed to reducing the internal resistance of a cylindrical battery cell while preventing an internal short circuit of the battery cell.

Further, the present disclosure is directed to minimizing the space occupied by the components used to prevent contact between the electrode tab of the jelly roll and the battery can, to improve the energy density of the battery cell and to allow the jelly roll to be smoothly inserted into the battery can.

Further, the present disclosure is directed to increasing the ratio of the total height of the jelly roll to the total height of the battery can to improve the energy density of the cylindrical battery cell.

However, 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.

Technical scheme

In one aspect of the present disclosure, there is provided a cylindrical battery cell including: a jelly roll having a first electrode tab protruding upward and a second electrode tab protruding downward; a battery can configured to receive the jelly roll through a top opening and electrically connected to the second electrode tab; a first collecting plate connected to the first electrode tab at an upper portion of the jelly roll; an insulating shrinkage tube having a first cover portion for covering at least a portion of the first collecting plate and a second cover portion for covering a top end of an outer periphery of the jelly roll; and a top cap electrically connected to the first collecting plate and configured to cover the opening.

Here, the diameter of the first collecting plate may correspond to the diameter of the jelly roll.

Further, the diameter of the first collecting plate may be smaller than the diameter of the jelly roll, and the first cover part may cover both the first electrode tab and the first collecting plate.

Meanwhile, the jelly roll may include a first region in which the first electrode tab has a first length and a second region in which the first electrode tab has a second length, the second region being located at an outer peripheral edge of the first region.

The first length may be formed to be longer than the second length.

A distance from an inner circumference of the battery can to a boundary between the first region and the second region may be equal to or longer than a press-in depth of the beading portion formed by pressing in the outer circumference of the battery can.

A lowermost end of the beading portion may be formed below the first collecting plate.

Here, the first collecting plate may cover a first region of the winding core.

At this time, the first cover portion may cover the second region of the winding core and the first collecting plate.

Meanwhile, the first cover portion may be connected to the second cover portion, and a radially extending length of the first cover portion may be formed to be greater than or equal to a press-in depth of a beading portion formed by pressing in an outer circumference of the battery can.

Meanwhile, the insulating shrink tube may include a heat shrinkable material that shrinks when heat is applied.

Meanwhile, the cylindrical battery cell may further include an electrolyte contained in the battery can, and the insulating shrinkage tube may be a material that does not chemically react with the electrolyte.

Meanwhile, the extended length of the second cover part may be greater than or equal to the extended length of the first electrode tab.

Meanwhile, the present disclosure provides a battery pack including at least one battery cell according to the foregoing embodiments.

Further, the present disclosure provides a vehicle comprising at least one battery pack according to the aforementioned embodiments.

Advantageous effects

According to the present disclosure, the internal resistance of the battery cell may be reduced, while the internal short circuit of the battery cell may be prevented.

In particular, according to the present disclosure, it is possible to reduce the internal resistance of the battery cell by forming an electrode tab on each of the upper and lower parts of the electrode assembly to increase the area of the electrode tab.

Further, according to the present disclosure, it is possible to prevent a short circuit inside the cylindrical battery cell by preventing electrical contact between the electrode tab and the battery can through a relatively simple structure.

Further, according to the present disclosure, it is possible to minimize the space occupied by the assembly for preventing contact between the electrode tab of the jelly roll and the battery can. Therefore, according to the present disclosure, the energy density of the battery cell may be improved, and the process of inserting the winding core into the battery can may be smoothly performed.

Further, according to the present disclosure, the ratio of the total height of the jelly roll to the total height of the battery can may be increased, thereby increasing the energy density of the cylindrical battery cell.

Therefore, according to the present disclosure, it is possible to provide a cylindrical battery cell having a structure that reduces internal resistance, prevents internal short circuits, improves process efficiency, and improves energy density, and a battery pack and a vehicle including the same.

In addition, the present disclosure may have various other effects that will be described in various embodiments, or the corresponding description will be omitted for an effect that can be easily inferred by those skilled in the art.

Drawings

The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the disclosure, and therefore, the disclosure is not to be construed as being limited to the accompanying drawings.

Fig. 1 is a diagram for explaining a cylindrical battery cell according to an embodiment of the present disclosure.

Fig. 2 is a longitudinal-sectional perspective view of the cylindrical battery cell of fig. 1.

Fig. 3 is a longitudinal sectional view of the cylindrical battery cell of fig. 1.

Fig. 4 is a perspective view illustrating the inside of the cylindrical battery cell of fig. 1.

Fig. 5 is a diagram for explaining a collector plate according to another embodiment of the present disclosure.

Fig. 6 is a diagram illustrating a cylindrical battery cell according to another embodiment of the present disclosure.

Fig. 7 to 9 are diagrams illustrating cylindrical battery cells according to other embodiments of the present disclosure.

Fig. 10 is a diagram illustrating a battery pack according to an embodiment of the present disclosure.

Fig. 11 is a diagram showing a vehicle according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before 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.

Accordingly, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of this disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of this disclosure.

Furthermore, to facilitate an understanding of the present disclosure, the drawings are not to scale and the dimensions of some of the components may be exaggerated.

Fig. 1 is a view for explaining a cylindrical battery cell according to an embodiment of the present disclosure, and fig. 2 is a longitudinal-sectional perspective view of the cylindrical battery cell of fig. 1. Fig. 3 is a longitudinal sectional view of the cylindrical battery cell of fig. 1, and fig. 4 is a perspective view illustrating the interior of the cylindrical battery cell of fig. 1.

Referring to fig. 1 to 4, a cylindrical battery cell 1 according to an embodiment of the present disclosure includes a winding core 10, a battery can 20, a first collecting plate 30, an insulating shrink tube (insulating shrink tube) 50, and a top cap 60. In addition to the above-described components, the cylindrical battery cell 1 according to the embodiment of the present disclosure may further include a second collecting plate 40 and/or a sealing gasket 70 and/or a connecting plate 80.

The jelly-roll 10 is obtained by winding an electrode assembly of a secondary battery. The jelly roll 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first electrode and the second electrode. That is, the winding core 10 may be manufactured by winding a laminate formed by sequentially stacking a first electrode, a separator, and a second electrode at least once with respect to a winding center C. In this case, a separator may be further provided on the outer circumference of the jelly roll 10 to be insulated from the battery can 20. The first electrode is a positive electrode or a negative electrode, and the second electrode is an electrode having a polarity opposite to that of the first electrode.

Referring to fig. 2 and 3, the jelly roll 10 includes a first electrode tab 11 protruding upward and a second electrode tab 12 protruding downward.

The first electrode includes a first electrode current collector and a first electrode active material coated on one surface or both surfaces of the first electrode current collector. At one end of the first electrode current collector in the width direction (parallel to the Z axis), there is an uncoated portion on which the first electrode active material is not coated. The uncoated portion serves as the first electrode tab 11. The first electrode tab 11 is disposed above the jelly roll 10 accommodated in the battery can 20 in a vertical direction (parallel to the Z-axis).

The second electrode includes a second electrode current collector and a second electrode active material coated on one surface or both surfaces of the second electrode current collector. At the other end of the second electrode current collector in the width direction (parallel to the Z axis), there is an uncoated portion on which the second electrode active material is not coated. The uncoated portion serves as the second electrode tab 12. The second electrode tab 12 is disposed below the jelly roll 10 received in the battery can 20 in a vertical direction (parallel to the Z-axis).

Referring to fig. 1 to 4, the battery can 20 is a cylindrical container having an opening formed at a top side, and is made of a metal material having conductivity. The battery can 20 accommodates the jelly roll 10 through the top opening, and accommodates the electrolyte together.

The battery can 20 is electrically connected to the second electrode tab 12 of the jelly roll 10. Therefore, the battery can 20 has the same polarity as the second electrode tab 12.

The battery can 20 may include a beading portion (crimping) 21 formed on a top end thereof. In addition, the battery can 20 may include a crimping portion (crimping) 22. The crimping portion 21 is formed by being press-fitted into the outer periphery of the battery can 20. The crimping portion 21 prevents the winding core 10 having a size corresponding to the width of the battery can 20 from coming out through the top opening of the battery can 20, and may serve as a support portion on which the top cap 60 is seated.

The curled portion 22 is formed above the beading portion 21. The curled portion 22 has a shape extending and bent to cover the outer circumference of the top cover 60 disposed on the beading portion 21 and a portion of the top surface of the top cover 60.

However, the battery can 20 of the present disclosure may not include the beading portion 21 and/or the crimping portion 22. In this case, in order to fix the winding core 10 and/or fix the top cover 60 and/or seal the battery can 20, a component that can function as a stopper (stopper) of the winding core 10, for example, may be additionally applied, and/or a structure on which the top cover 60 can be placed may be additionally applied, and/or welding may be performed between the battery can 20 and the top cover 60.

Referring to fig. 3 and 4, the cylindrical battery cell 1 according to the embodiment of the present disclosure includes a first collecting plate 30. In addition, the cylindrical battery cell 1 may further include a second collecting plate 40. The first collecting plate 30 and the second collecting plate 40 are made of a metal material having conductivity.

The first collecting plate 30 is coupled to the first electrode tab 11 at the upper portion of the jelly roll 10. A lead line L made of a conductive metal may be connected to the first collecting plate 30. The lead wire L may extend above the winding core 10 and may be directly coupled to the top cover 60 or may be coupled to a connection plate 80 coupled to a bottom surface of the top cover 60.

Referring to fig. 4, the first collecting plate 30 may have, for example, a substantially circular plate shape. Since the first collecting plate 30 has a circular plate shape as described above, the first collecting plate 30 may have a shape corresponding to the top surface of the first electrode tab 11 coupled to the lower portion thereof. Referring to fig. 3, the diameter of the first collecting plate 30 may correspond to the diameter of the jelly roll 10. That is, the first collecting plate 30 may have a shape corresponding to the entire area of the top surface (parallel to the X-Y plane) of the jelly core 10 coupled to the lower portion thereof. According to this structure, since the contact area between the first electrode tab 11 and the first collecting plate 30 is maximized, the internal resistance of the battery can be reduced.

Alternatively, as shown in fig. 5, the first collecting plate 30 may have a substantially circular plate shape and have at least one hole H penetrating in a vertical direction (parallel to the Z-axis). At this time, the shape of the hole H is not limited. Due to the at least one hole H, the electrolyte can be easily injected into the jellyroll 10.

Alternatively, although not shown in the drawings, the first collecting plate 30 may include a plurality of sub-plates extending radially from the center. In this case, the electrolyte can be smoothly injected between the plurality of sub-plates.

Referring to fig. 3, the first collecting plate 30 may be coupled to one end of the first electrode tab 11. Alternatively, unlike the drawing, the end of the first electrode tab 11 may be bent in a direction parallel to the first collecting plate 30 (parallel to the X-Y plane), and in this case, the first collecting plate 30 may be coupled with the facing bent first electrode tab 11. In this case, the energy density can be increased by minimizing the length occupied by the first electrode tab 11 in the height direction (parallel to the Z axis) within the battery can 20. Further, by increasing the coupling area between the first collecting plate 30 and the first electrode tab 11, it is possible to increase the coupling force and reduce the resistance of the contact portion.

The coupling between the first electrode tab 11 and the first collecting plate 30 may be accomplished by, for example, laser welding. The laser welding may be performed by partially melting the base material of the first collecting plate 30, or may be performed using a solder for welding interposed between the first collecting plate 30 and the first electrode tab 11. In this case, the solder may have a lower melting point than the first collecting plate 30 and the first electrode tab 11.

Referring to fig. 2 and 3, the second collecting plate 40 may be coupled to the bottom surface of the jelly roll 10. In this case, one side of the second collecting plate 40 may be coupled to the second electrode tab 12 of the jelly roll 10 by welding, and the other side may be coupled to the inner bottom surface of the battery can 20 by welding. The coupling structure of the second electrode tab 12 and the second collecting plate 40 coupled to the bottom surface of the jelly roll 10 is substantially the same as the first collecting plate 30 coupled to the top surface of the jelly roll 10 as described above.

Referring to fig. 3 and 4, a cylindrical battery cell 1 according to an embodiment of the present disclosure includes an insulating shrink tube 50. The insulating shrink tube 50 may comprise a shrinkable material. Therefore, when the insulating shrinkage tube 50 shrinks after wrapping the jelly roll 10 and the first collecting plate 30 with the insulating shrinkage tube 50, the insulating shrinkage tube 50 can be tightly fixed to the jelly roll 10 and the first collecting plate 30. Therefore, insulation can be reliably ensured.

For example, the insulating shrink tube 50 may comprise a heat shrinkable material that shrinks when heat is applied. For example, the insulating shrink tube 50 may include polyethylene terephthalate (PET) having a heat shrinkable characteristic. However, the material of the insulating and shrinking tube 50 is not limited thereto, and any material that can be heat shrunk without losing insulation may be used for the insulating and shrinking tube 50 of the present disclosure.

Meanwhile, the insulation shrinkage tube 50 may be heat-shrunk in a predetermined temperature range. For example, the predetermined temperature range may be a temperature range including a temperature range generally formed by heat generated inside the secondary battery during charge and discharge of the secondary battery.

Meanwhile, the insulating shrinkage tube 50 may be a material that does not chemically react with the electrolyte contained in the battery can 20. For example, the insulating shrink tube 50 may include polyethylene terephthalate (PET) that does not chemically react with the electrolyte. However, the material of the insulating shrinkage tube 50 is not limited thereto, and any material that does not chemically react with the electrolyte may be used for the insulating shrinkage tube 50 of the present disclosure.

Referring to fig. 3, the insulating shrink tube 50 includes a first cover portion 51 and a second cover portion 52. More specifically, the insulating shrink tube 50 may include a first cover portion 51 covering at least a portion of the first collecting plate 30 and a second cover portion 52 covering a top end of the outer periphery of the jelly roll 10.

Referring to fig. 3 and 4, the second cover portion 52 refers to a portion extending in a vertical direction (parallel to the Z axis) from an edge of the first cover portion 51. The first cover portion 51 refers to all portions of the insulating shrink tube 50 except the second cover portion 52. For example, in fig. 3 and 4, the first cover portion 51 refers to a portion of the insulating shrink tube 50 extending in a horizontal direction (parallel to the X-Y plane).

The first cover portion 51 covers at least a portion of the first collecting plate 30. For example, the first cover part 51 may cover the periphery of the edge of the top surface of the first collecting plate 30. In addition, the first cover part 51 may cover a partial region of the first electrode tab 11 that is not covered by the first collecting plate 30. In addition, the second cover portion 52 covers the top end of the outer periphery of the core 10. The first cover part 51 may be connected to the second cover part 52.

Referring to fig. 3, the radially extending length D1 of the first cover portion 51 may be greater than or equal to the press-in depth B of the beading portion 21 formed in the battery can 20. Here, the radial direction refers to a direction of the radius of the winding core 10. Therefore, electrical contact between the battery can 20 having the second polarity and the first collecting plate 30 having the first polarity can be reliably prevented. Therefore, the safety of the battery can be ensured.

Referring to fig. 3, the extended length D2 of the second cover part 52 may be configured to be greater than or equal to the extended length T of the first electrode tab 11. Accordingly, the second cover portion 52 may cover the first electrode tab 11 such that the first electrode tab 11 is not exposed toward the side wall (inner circumference) of the battery can 20. According to this structure, electrical contact between the battery can 20 having the second polarity and the first electrode tab 11 having the first polarity can be prevented. Therefore, for reliable insulation, the extended length D2 of the second cover part 52 must be at least equal to the extended length T of the first electrode tab 11.

Meanwhile, in order to ensure insulation, the extended length D2 of the second cover part 52 may be formed to be even slightly longer than the extended length T of the first electrode tab 11. In this case, the second cover portion 52 may cover the entire of the region corresponding to the uncoated portion (the portion not coated with the electrode active material) and a part of the region corresponding to the coated portion (the portion coated with the electrode active material) in the height direction (parallel to the Z axis) of the reeling core 10.

Fig. 6 is a view illustrating a cylindrical battery cell according to another embodiment of the present disclosure, and fig. 7 to 9 are views illustrating cylindrical battery cells according to other embodiments of the present disclosure.

Since the cylindrical battery cell 1 according to the embodiment of fig. 6 to 9 is similar to the cylindrical battery cell 1 of the embodiment of fig. 3 and 4, repeated description will be omitted for components that are substantially the same as or similar to those of the foregoing embodiment, and hereinafter, differences from the foregoing embodiment will be mainly described.

Referring to fig. 6, the first cover portion 51 of the insulating shrink tube 50 may cover a large area of the top end of the winding core 10. That is, the first cover portion 51 may cover the remaining area of the top surface except for the portion where the first collecting plate 30 and the lead L are coupled. According to this structure, the risk of short circuit caused by contact between the first collecting plate 30 and the inner surface of the battery can 20 can be further reduced. Further, according to this structure, the coupling area between the insulation shrinkage tube 50 and the first collecting plate 30 is increased, and thus it is possible to prevent the insulation shrinkage tube 50 from being separated from the first collecting plate 30 to deteriorate the insulation performance of the cylindrical battery cell 1.

Referring to fig. 7, in the cylindrical battery cell 1 according to the embodiment of the present disclosure, the diameter of the first collecting plate 30 may be smaller than the diameter of the jelly roll 10. In other words, the radius R30 of the first collecting plate 30 may be smaller than the radius R10 of the jelly roll 10. Even if the diameter of the first collecting plate 30 is smaller than the diameter of the jelly roll 10 as described above, the electrical connection between the first collecting plate 30 and the first electrode tab 11 can be maintained. Due to the above-described structure in which the diameter of the first collecting plate 30 is smaller than that of the jelly roll 10, the electrolyte can be smoothly injected through the region of the top surface of the jelly roll 10 not covered by the first collecting plate 30. Therefore, the electrolyte can be easily injected, and the electrolyte impregnation (impregnation) can be improved. Further, when the diameter of the first collecting plate 30 is smaller than that of the jelly roll 10, the risk of contact between the battery can 20 and the first collecting plate 30 caused by the depression of the battery can 20 according to the formation of the beading portion 21 can be solved. In this case, therefore, the total height of the jelly roll 10 in the battery can 20 can be increased, thereby improving the energy density. The difference between the radius R10 of the jelly roll 10 and the radius R30 of the first collecting plate 30 may be equal to or greater than, for example, the press-in depth of the beading portion 21.

Continuing, referring to fig. 7, the insulating shrink tube 50 may cover a tip end region of the outer circumference of the jelly roll 10, a partial region of the top surface of the first collecting plate 30, and a region of the top surface of the jelly roll 10 not covered by the first collecting plate 30. More specifically, the first cover part 51 may cover the first electrode tab 11 and the first collecting plate 30. That is, the first cover part 51 may cover the top surface of the first collecting plate 30 and the region of the top surface of the jelly roll 10 that is not covered by the first collecting plate 30. Accordingly, the first cover part 51 may have a stepped shape in a region where the first collecting plate 30 and the first electrode tab 11 contact each other. In other words, the first cover part 51 may cover at least a partial area of the top surface of the first collecting plate 30 including the outer peripheral area and the outer periphery of the first collecting plate 30. Meanwhile, the second cover portion 52 may cover the top end of the outer periphery of the core 10.

Referring to fig. 8, in the jelly roll 10 of the present disclosure, the first electrode tab 11 may include a first area A1 in which the first electrode tab 11 has a first length T1 and a second area A2 in which the first electrode tab 11 has a second length T2, and the second area A2 may be located at an outer periphery (outer perimeter) of the first area A1.

Referring to fig. 8, the first length T1 may be formed to be longer than the second length T2. At least a portion of the second region A2 may be located below the beading portion 21 formed in the battery can 20. If the length of the first electrode tab 11 located under the beading portion 21 is shorter than the length of the first electrode tab 11 in other regions, the risk of a short circuit caused by the contact between the beading portion 21 and the first electrode tab 11 may be reduced. The first collecting plate 30 may cover the first area A1 of the jelly roll 10. That is, the diameter of the first collecting plate 30 may be substantially the same as the radial length of the first region A1. Alternatively, although not shown, the radius of the first collecting plate 30 may be configured to be smaller than the distance from the winding center C of the winding core 10 to the boundary of the first and second areas A1 and A2.

The first cover portion 51 may cover the second area A2 of the jelly roll 10 and the first collecting plate 30. Referring to fig. 8, the first cover part 51 may cover the first electrode tab 11 located in the second region A2 of the jelly roll 10, at least a partial region of the top surface of the first collecting plate 30 including the peripheral region, and the outer periphery of the first electrode tab 11 located in the first region A1. In addition, the second cover part 52 may cover the outer circumference of the first electrode tab 11 located in the second region A2.

A distance from the outer circumference of the battery can 20 to a boundary between the first region A1 and the second region A2 may be equal to or longer than a press-in depth of the beading part 21 formed by pressing in the outer circumference of the battery can 20. In this case, the risk of contact between the battery can 20 and the first electrode tab 11 and the risk of contact between the battery can 20 and the first collecting plate 30 due to the formation of the beading portion 21 are greatly reduced. Thus, in this case, the total height of the reeling core 10 can be increased.

On the other hand, when the total height of the jelly roll 10 increases, the beading portion 21 may be formed at a lower position than the first collecting plate 30, or may be formed on the same line as the first collecting plate 30. More specifically, the lowermost end of the crimping portion 21 may be located below the first collecting plate 30 in the height direction (parallel to the Z-axis) of the cylindrical battery cell 1, or at approximately the same height as the first collecting plate 30. According to the above-described structure in which the beading portion 21 is formed at a position lower than the first collecting plate 30 or on the same line as the first collecting plate 30, dead space (dead space) within the battery can 20 can be significantly reduced. Therefore, the energy density of the battery can be increased.

In particular, if the lowermost end of the beading portion 21 is positioned below the first collecting plate 30 in the height direction of the cylindrical battery cell 1, the total height of the jelly roll 10 can be maximized, thereby minimizing the dead space formed between the top cap 60 and the first collecting plate 30. Therefore, the improvement of the energy density of the battery can be maximized.

The first electrode tab 11 located in the second region A2 of fig. 8 may be removed. This is shown in detail in fig. 9. Referring to fig. 9, the jelly roll 10 does not include the first electrode tab 11 in the second area A2. In this case, the total height of the reeling core 10 can be further increased compared to the embodiment shown in fig. 8. Therefore, the dead space in the battery can 20 can be further reduced as compared with fig. 8. Therefore, the energy density of the battery can be maximized.

Meanwhile, in fig. 3, 4 and 6 to 9, the insulating and shrinking tube 50 is shown to be thick for convenience of explanation, but the thickness of the insulating and shrinking tube 50 is actually very thin and approximates to a thin film shape that hardly occupies space. Therefore, the energy density of the cylindrical secondary battery according to the present disclosure may be further increased as compared to the case where a separate insulator is applied to prevent contact between the first collecting plate 30 and the battery can 20 and contact between the first electrode tab 11 and the battery can 20. Further, in the cylindrical secondary battery according to the present disclosure, since the thickness of the insulation shrinkage tube 50 is small, the coupling body may be smoothly inserted into the battery can 20 in a state in which the insulation shrinkage tube 50 is applied to the coupling body of the jelly roll 10 and the first collecting plate 30 to complete the insulation process. Therefore, productivity can be improved in manufacturing the cylindrical battery cell 1, and there is less risk of product defects occurring during the insertion of the coupled body of the jelly roll 10 and the first collecting plate 30 into the battery can 20.

Referring again to fig. 3, the cylindrical battery cell 1 according to the embodiment of the present disclosure includes a top cap 60.

The cap 60 is electrically connected to the first collecting plate 30 and may cover the opening. The top cover 60 is a member made of a metal material having conductivity, and covers the top opening of the battery can 20. The top cap 60 is electrically connected to the first electrode tab 11 of the jelly roll 10 and is electrically insulated from the battery can 20. Accordingly, the top cap 60 may serve as a first electrode terminal of the cylindrical battery cell 1.

The top cover 60 may be seated on the beading portion 21 formed on the battery can 20. The cap 60 may be secured by forming the curled portion 22. A sealing gasket 70 may be interposed between the top cover 60 and the crimp portion 22 of the battery can 20 to ensure airtightness of the battery can 20 and to electrically insulate between the battery can 20 and the top cover 60.

The top cover 60 may include a protruding portion 61 protruding upward from the center thereof. That is, the protruding portion 61 may protrude upward to facilitate contact with an electrical connection component such as a bus bar.

Referring to fig. 2 and 3, the cylindrical battery cell 1 according to the embodiment of the present disclosure may further include a connection plate 80.

The connection plate 80 may be coupled to a bottom surface of the cap 60 to be electrically connected to the lead line L in contact with the first collecting plate 30. However, as shown in fig. 8 and 9, the connection plate 80 may be omitted to reduce the space within the battery and increase the energy density.

Fig. 10 is a diagram illustrating a battery pack according to an embodiment of the present disclosure.

Referring to fig. 10, a battery pack 3 according to an embodiment of the present disclosure includes a secondary battery assembly electrically connected to a plurality of cylindrical battery cells 1 according to an embodiment of the present disclosure as described above, and a battery pack case 2 for accommodating the secondary battery assembly. In the drawings of the present disclosure, components such as a bus bar and a power terminal for electrical connection are omitted for convenience of explanation.

Fig. 11 is a diagram illustrating a vehicle according to an embodiment of the present disclosure.

Referring to fig. 11, a vehicle V according to an embodiment of the present disclosure may be, for example, a hybrid vehicle or an electric vehicle V, and includes a battery pack 3 according to an embodiment of the present disclosure. According to the embodiment of the present disclosure, the vehicle V operates by receiving electric power from the battery pack 3.

On the other hand, although terms indicating directions such as up and down are used in the present specification, the terms are only for convenience of description, and it is apparent to those skilled in the art of the present disclosure that they may vary according to the position of a target object or the position of an observer.

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.

[ description of symbols ]

V: vehicle with a steering wheel

3: battery pack

2: battery pack case

1: cylindrical battery cell

10: roll core

11: first electrode joint

12: second electrode joint

20: battery can

21: crimping part

22: curled portion

30: first current collecting plate

40: second current collecting plate

50: insulating shrinkage pipe

51: first cover part

52: second cover part

60: top cover

61: projecting part

70: sealing washer

80: connecting plate

L: lead wire

C: center of winding

B: depth of penetration

H: hole(s)

D1: radial extension of the first cover part

D2: extension of the second cover part

R10: radius of winding core

R30: radius of the first collector plate

T: extension of the first electrode contact

T1: a first length

T2: second length

A1: first region

A2: a second region.

Claims (16)

1. A cylindrical battery cell, comprising:

a jelly roll having a first electrode tab protruding upward and a second electrode tab protruding downward;

a battery can configured to receive the jellyroll through a top opening and electrically connected to the second electrode tab;

a first collector plate coupled to the first electrode tab at an upper portion of the jellyroll;

an insulating shrinkage tube having a first cover portion for covering at least a portion of the first collecting plate and a second cover portion for covering a top end of an outer periphery of the jelly roll; and

a top cap electrically connected to the first current collector plate and configured to cover the top opening.

2. The cylindrical battery cell according to claim 1,

wherein a diameter of the first collecting plate corresponds to a diameter of the jelly roll.

3. The cylindrical battery cell according to claim 1,

wherein a diameter of the first collecting plate is smaller than a diameter of the jelly roll, and

wherein the first cover portion covers both the first electrode tab and the first collecting plate.

4. The cylindrical battery cell according to claim 1,

wherein the jellyroll includes a first area in which the first electrode tab has a first length and a second area in which the first electrode tab has a second length, the second area being located at an outer periphery of the first area.

5. The cylindrical battery cell according to claim 4,

wherein the first length is formed to be longer than the second length.

6. The cylindrical battery cell according to claim 5,

wherein a distance from an inner periphery of the battery can to a boundary between the first region and the second region is equal to or longer than a press-in depth of a beading portion formed by pressing in an outer periphery of the battery can.

7. The cylindrical battery cell according to claim 6,

wherein a lowermost end of the crimping portion is formed below the first collecting plate.

8. The cylindrical battery cell according to claim 4,

wherein the first collector plate covers the first region of the jellyroll.

9. The cylindrical battery cell according to claim 8,

wherein the first cover portion covers the second region of the winding core and the first collector plate.

10. The cylindrical battery cell according to claim 1,

wherein the first cover part is connected to the second cover part, and

wherein a radially extending length of the first cover portion is formed to be greater than or equal to a press-in depth of a crimping portion formed by pressing in an outer periphery of the battery can.

11. The cylindrical battery cell according to claim 10,

wherein the top cover is supported by and insulated from the beading portion.

12. The cylindrical battery cell according to claim 1,

wherein the insulating shrink tube comprises a heat shrinkable material that shrinks upon application of heat.

13. The cylindrical battery cell according to claim 1,

wherein the cylindrical battery cell further comprises an electrolyte contained in the battery can, and

wherein the insulating shrink tube is a material that does not chemically react with the electrolyte.

14. The cylindrical battery cell according to claim 1,

wherein an extension length of the second cover part is greater than or equal to an extension length of the first electrode tab.

15. A battery pack comprising at least one cylindrical battery cell according to any one of claims 1 to 14.

16. A vehicle comprising at least one battery pack according to claim 15.

Images