Secondary battery

Abstract

Disclosed is a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case in which the electrode assembly is accommodated and both end portions of which are open; a first cover plate coupled to one end portion of the case; a second cover plate coupled to the other end portion of the case; a first cover member configured to cover the first cover plate and having a first electrode terminal exposed toward an upper portion; and a second cover member configured to cover the second cover plate and having a second electrode terminal exposed toward an upper portion, a first electrode pin of the electrode assembly penetrating the first cover plate and being electrically connected to the first electrode terminal of the first cover member, and a second electrode pin of the electrode assembly penetrating the second cover plate and being electrically connected to the second electrode terminal of the second cover member. The present invention has the effect that the efficiency of a manufacturing process can be improved by reducing the welding length of a cover plate, and the manufacturing process is easily managed.

Description

Technical Field

[0001] This invention relates to secondary batteries. Background Technology

[0002] Lithium-ion prismatic batteries used in electric vehicles typically have a narrower width and greater thickness compared to pouch cells. This increases the number of electrode assemblies produced by winding or stacking, thus requiring significant investment. Furthermore, increasing the width of prismatic battery cells reduces the dimensional stability of the casing and lengthens the weld length of the cap plate, leading to difficulties in process management. Summary of the Invention

[0003] Technical issues

[0004] This invention provides a secondary battery that can reduce the welding length of the cover plate.

[0005] Furthermore, the present invention provides a secondary battery in which the exhaust direction is directed toward the lower part of the casing during exhaust.

[0006] Furthermore, the present invention provides a secondary battery that can reduce the number of electrode assemblies by increasing the size of the electrode assembly housed inside the casing.

[0007] Technical solution

[0008] A secondary battery according to an embodiment of the present invention includes: an electrode assembly comprising a first electrode plate, a second electrode plate, and a separator; a housing housing the electrode assembly and open at both ends; a first cover plate coupled to one end of the housing; a second cover plate coupled to the other end of the housing; a first cover member configured to cover the first cover plate and having a first electrode terminal exposed upwards; and a second cover member configured to cover the second cover plate and having a second electrode terminal exposed upwards. The first electrode pin of the electrode assembly passes through the first cover plate and is electrically connected to the first electrode terminal of the first cover member. The second electrode pin of the electrode assembly passes through the second cover plate and is electrically connected to the second electrode terminal of the second cover member.

[0009] Technical effect

[0010] The present invention has the advantages of improving manufacturing process efficiency by reducing the welding length of the cover plate and making the manufacturing process easier to manage.

[0011] Furthermore, by directing the exhaust gas towards the lower part of the outer casing during exhaust, the present invention can improve stability.

[0012] Furthermore, it has the effect of improving energy efficiency by increasing the size of the electrode assembly housed inside the casing. Attached Figure Description

[0013] Figure 1 A perspective view illustrating a secondary battery according to an exemplary embodiment of the present invention;

[0014] Figure 2 An exploded perspective view of a secondary battery according to an exemplary embodiment of the present invention is provided.

[0015] Figure 3 A cross-sectional view illustrating a secondary battery according to an exemplary embodiment of the present invention;

[0016] Figure 4 An explanatory diagram illustrating the venting of a secondary battery according to an exemplary embodiment of the present invention;

[0017] Figure 5 This is an explanatory diagram illustrating the case where a secondary battery according to an exemplary embodiment of the present invention is provided in a vehicle.

[0018] Explanation of reference numerals in the attached figures

[0019] 100: Secondary battery

[0020] 110: Electrode assembly; 120: Housing

[0021] 130: First cover plate 140: Second cover plate

[0022] 150: First cover component; 160: Second cover component Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. However, embodiments of the present invention can be varied in many different ways, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the purpose of providing embodiments of the present invention is to provide a more complete explanation of the invention to those skilled in the art. For clarity, the shapes and sizes of elements in the figures may be exaggerated.

[0024] Figure 1 A perspective view of a secondary battery according to an exemplary embodiment of the present invention is provided. Figure 2 To illustrate an exploded perspective view of a secondary battery according to an exemplary embodiment of the present invention, Figure 3 A cross-sectional view of a secondary battery according to an exemplary embodiment of the present invention is shown.

[0025] See Figures 1 to 3 According to an exemplary embodiment of the present invention, the secondary battery 100 may be configured to include an electrode assembly 110, a housing 120, a first cover plate 130, a second cover plate 140, a first cover component 150, and a second cover component 160.

[0026] The electrode assembly 110 includes a first electrode plate 111, a second electrode plate 112, and a separator 113, which are formed in the shape of a thin plate or a rod. It can be formed in various forms as needed, such as a stacked type or a wound type. As an example, the first electrode plate 111 can act as a cathode, and the second electrode plate 112 can act as an anode.

[0027] The first electrode plate 111 can be formed, for example, by coating a first electrode active material such as graphite or carbon onto a first electrode current collector formed of a metal foil such as copper, copper alloy, nickel, or nickel alloy. Furthermore, the first electrode plate 111 includes a first electrode uncoated portion 111a, which is a region where the first electrode active material is not coated. The first electrode uncoated portion 111a serves as a current flow channel between the first electrode plate 111 and the outside of the first electrode plate 111. Additionally, the first electrode plate 111 may have a first electrode lead 111b connected to the first electrode uncoated portion 111a. The first electrode lead 111b is configured to penetrate the first cover plate 130, and a sealing film 111c for sealing the first cover plate 130 can be wound around the first electrode lead 111b. As an example, the first electrode lead 111b can be soldered to the first electrode uncoated portion 111a. Furthermore, the first electrode lead 111b can be made of copper or a copper alloy.

[0028] The second electrode plate 112 can be formed, for example, by coating a second electrode current collector made of a metal foil such as aluminum or an aluminum alloy with a second electrode active material such as a transition metal oxide. The second electrode plate 112 includes an uncoated portion 112a, which is a region where the second electrode active material is not coated. The uncoated portion 112a also serves as a current flow channel between the second electrode plate 112 and the outside of the second electrode plate 112. Additionally, the second electrode plate 112 may have a second electrode pin 112b connected to the uncoated portion 112a. The second electrode pin 112b is configured to penetrate the second cover plate 140, and a sealing film 112c for sealing the second cover plate 140 can be wound around the second electrode pin 112b. As an example, the second electrode pin 112b can be welded to the uncoated portion 112a. Furthermore, the second electrode pin 112b can be made of aluminum or an aluminum alloy.

[0029] The separator 113 is located between the first electrode plate 111 and the second electrode plate 112 and serves to prevent short circuits and allow lithium ions to migrate. For example, the separator 113 can be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene.

[0030] In addition, the first electrode plate 111, the second electrode plate 112, and the partition plate 113 can extend in the width direction of the outer casing 120 ( Figure 1The electrode assembly 110 is arranged along the Y-axis direction. This increases the volume occupied by the electrode assembly 110 within the housing 120, thereby improving energy efficiency. The definition of the term "direction" is as follows: the length direction refers to... Figure 1 The X-axis direction, the so-called height direction refers to Figure 1 The Z-axis direction.

[0031] In other words, the electrode assembly 110 is formed such that its length in the longitudinal direction is greater than its length in the width direction and its length in the height direction.

[0032] Additionally, the electrode assembly 110 and the electrolyte are housed together in the casing 120. The electrolyte can be prepared by adding lithium salts such as LiPF6 and LiBF4 to organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). Furthermore, the electrolyte can be in liquid or gel form.

[0033] The housing 120 may have a rectangular box shape with open ends, and the interior of the housing 120 houses the electrode assembly 110. The housing 120 may be manufactured by injection molding, thereby saving manufacturing costs. As an example, to provide mechanical strength for the secondary battery 100, the housing 120 may be made of metals such as aluminum or stainless steel.

[0034] The first cover plate 130 is attached to one end of the outer casing 120. For example, the outer casing 120 and the first cover plate 130 can be joined by welding. The first cover plate 130 can be made of metals such as aluminum or stainless steel. The first cover plate 130 has a first through hole 131 through which a first electrode pin of the first electrode plate passes, and the first electrode pin protrudes to the outside through the first through hole 131. A sealing film is provided on the first electrode pin, thus the first through hole 131 can be sealed. The first cover plate 130 also has an exhaust port 132a for venting gas when the internal pressure of the internal space sealed by the outer casing 120, the first cover plate 130, and the second cover plate 140 increases. An exhaust component 132 can be provided on the exhaust port 132a. The exhaust component 132 functions to break when the internal pressure increases to a certain level, allowing the internal gas to escape to the outside. Furthermore, for attachment to the first cover component 150, one side of the first cover plate 130 can be formed with a discontinuous edge.

[0035] The second cover plate 140 is attached to the other end of the outer casing 120. For example, the outer casing 120 and the second cover plate 140 can be joined by welding. The second cover plate 140 can be made of metals such as aluminum or stainless steel. The second cover plate 140 has a second through hole 141 through which the second electrode pin of the second electrode plate passes, and the second electrode pin protrudes to the outside through the second through hole 141. Since a sealing film is provided on the second electrode pin, the second through hole 141 can be sealed. The second cover plate 140 may also have an electrolyte inlet 142 for injecting electrolyte into the internal space formed by the outer casing 120, the first cover plate 130, and the second cover plate 140. The electrolyte inlet 142 can be sealed by a sealing component (not shown) after the electrolyte injection is complete. Furthermore, for attachment to the second cover component 160, one side of the second cover plate 140 may be formed with a discontinuous edge.

[0036] Furthermore, the first cover plate 130 and the second cover plate 140 are welded to the outer casing 120, and the length of the upper outer perimeter of the outer casing 120 is greater than the sum of the lengths of the outer perimeters of the two ends of the outer casing 120. That is, the weld length of the first cover plate 130 and the second cover plate 140 is shorter than that of the prior art where the cover plate is located on the upper part of the outer casing. This facilitates the setting and management of process conditions for the welding joining process. Moreover, it can reduce the risk of electrolyte leakage caused by welding quality.

[0037] The first cover member 150 is configured to cover the first cover plate 130 and has a first electrode terminal 151 exposed upwards. As an example, the first cover member 150 may have a first body 152 covering the first cover plate 130 and a first extension 153 extending from the top of the first body 152 and disposed on the top of the housing 120. Furthermore, the first body 152 and the first extension 153 may be configured to be substantially perpendicular. The first electrode terminal 151 may have a first engagement portion 151a disposed on the first body 152 and a first terminal portion 151b connected to the first engagement portion 151a and exposed upwards on the first extension 153. As an example, the first terminal portion 151b may have a thickness greater than the first engagement portion 151a, and the first terminal portion 151b and the first engagement portion 151a may be configured to be substantially perpendicular. Additionally, the first cover component 150 may be provided with a flow channel 154 for gas flowing into the housing 120 through an exhaust hole facing the first cover plate 130, and an outlet 155 for discharging gas to the lower part of the housing 120. Thus, as... Figure 4As shown in the detailed diagram, the gas discharged from the housing 120 can be discharged to the lower part of the housing 120 through the flow channel 154 and the discharge port 155 of the first cover member 150. Therefore, even when the secondary battery 100 is installed in a vehicle, it can be ensured that the gas discharged from the housing 120 will not be discharged towards the adjacent secondary battery 100 or the upper side. As described above, even when the secondary battery 100 is installed in a vehicle, the gas is still sprayed towards the lower side of the secondary battery 100, thus reducing the discomfort caused to vehicle passengers.

[0038] The second cover member 160 is configured to cover the second cover plate 140 and may have a second electrode terminal 152 exposed at its upper part. As an example, the second cover member 160 may have a second body 162 covering the second cover plate 140 and a second extension 163 extending from the upper surface of the second body 162 and disposed on the upper surface of the housing 120. Furthermore, the second body 162 and the second extension 163 may be configured to be substantially perpendicular. The second electrode terminal 161 may have a second engagement portion 161a disposed on the second body 162 and a second terminal portion 161b connected to the second engagement portion 161a and exposed at the upper surface of the second extension 163. As an example, the second terminal portion 161b may have a thickness greater than the second engagement portion 161a, and the second terminal portion 161b and the second engagement portion 161a may be configured to be substantially perpendicular. Additionally, the second cover component 160 may be provided with an insulating layer 164 for insulating the second electrode terminal 161, the insulating layer 164 being disposed around the second joint portion 161a.

[0039] In addition, such as Figure 5 As shown, multiple secondary batteries 100 are manufactured as modules for use in vehicles or ESS systems. Bus bars 200 are provided at the first electrode terminals, second electrode terminals 151 and 161 located on the upper part of the housing 120, thereby improving manufacturing efficiency.

[0040] Furthermore, as described above, when the internal pressure of the secondary battery 100 increases, causing the venting component 132 to rupture and release gas, the gas is released towards the lower part of the outer casing 120. Therefore, when the secondary battery 100 is used in a vehicle, the discomfort caused to vehicle passengers by gas venting can be reduced.

[0041] Furthermore, by aligning the electrode assembly 110 with the width of the housing 120, the number of electrodes required for stacking can be reduced, thereby saving manufacturing costs during mass production.

[0042] Furthermore, since the first cover plate 130 and the second cover plate 140 are joined to both ends of the outer casing 120, the welding length can be reduced, thus facilitating process condition setting and management. Additionally, the risk of electrolyte leakage due to welding quality issues can be reduced.

[0043] Furthermore, compared to the same housing 120 volume, the volume of the electrode assembly 110 housed inside the housing 120 can be increased, thereby improving energy efficiency.

[0044] The embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto. Various modifications and variations can be made within the scope of the technical concept of the present invention as described in the claims, which will be obvious to those skilled in the art.

Claims

1. A secondary battery, wherein, include: An electrode assembly, comprising a first electrode plate, a second electrode plate, and a separator; A housing that contains the electrode assembly and is open at both ends; A first cover plate is attached to one end of the outer casing; A second cover plate is attached to the other end of the outer casing; A first cover component is configured to cover the first cover plate in the longitudinal direction of the housing and has a first electrode terminal exposed to the top of the housing; as well as A second cover component is configured to cover the second cover plate in the longitudinal direction of the housing and has a second electrode terminal exposed to the top of the housing; The first electrode pin of the electrode assembly passes through the first cover plate and is electrically connected to the first electrode terminal of the first cover component. The second electrode pin of the electrode assembly passes through the second cover plate and is electrically connected to the second electrode terminal of the second cover component. The first cover component covers at least a portion of the top surface of the housing in the height direction, the height direction of the housing being perpendicular to the length direction of the housing, and The second cover component covers at least a portion of the top surface of the housing in the height direction of the housing.

2. The secondary battery according to claim 1, wherein: The first cover plate has an exhaust component with an exhaust port for discharging gas when the internal pressure increases. The first cover component has a flow channel portion that is configured toward the vent hole and into which gas from the housing flows in, and an outlet portion that discharges the gas toward the lower part of the housing.

3. The secondary battery according to claim 1, wherein: The second cover component has an insulating layer for insulating the second electrode terminal.

4. The secondary battery according to claim 1, wherein: The second cover plate has an electrolyte injection port for injecting electrolyte into the housing.

5. The secondary battery according to claim 1, wherein: The first cover member has a first body that covers the first cover plate in the length direction of the outer shell and a first extension that extends from the top surface of the first body and is disposed on the top surface of the outer shell in the height direction of the outer shell.

6. The secondary battery according to claim 5, wherein: The first electrode terminal has a first engagement portion disposed on the first body and a first terminal portion connected to the first engagement portion and exposed above the first extension portion.

7. The secondary battery according to claim 2, wherein: The second cover member has a second body that covers the second cover plate in the length direction of the housing and a second extension that extends from the top surface of the second body and is disposed on the top surface of the housing in the height direction of the housing.

8. The secondary battery according to claim 7, wherein: The second electrode terminal has a second engagement portion disposed on the second body and a second terminal portion connected to the second engagement portion and exposed on the upper surface of the second extension portion.

9. The secondary battery according to claim 1, wherein: The first electrode plate, the second electrode plate, and the partition plate of the electrode assembly are arranged in the width direction of the outer casing, and the width direction of the outer casing is perpendicular to the length and height directions of the outer casing.

10. The secondary battery according to claim 1, wherein: The first electrode pin and the second electrode pin are provided with sealing films for sealing the housing.

11. The secondary battery according to claim 1, wherein: The first cover plate and the second cover plate are joined to the outer casing by welding. The length of the upper outer perimeter of the outer shell is greater than the sum of the lengths of the outer perimeters of the two ends of the outer shell.

12. The secondary battery according to claim 1, wherein: The length of the electrode assembly is greater than its length in the width direction and its length in the height direction.

13. The secondary battery according to claim 1, wherein: The first electrode pin and the second electrode pin are disposed toward both ends of the housing along the length direction of the housing and are connected to the first electrode terminal and the second electrode terminal, respectively. The first electrode terminal and the second electrode terminal have a bent shape such that they are connected to the first electrode pin and the second electrode pin at both ends of the housing, and one end is exposed to the top of the housing in the height direction of the housing.

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