Secondary battery

Abstract

A secondary battery is disclosed. The secondary battery includes an electrode assembly including a first electrode plate, a second electrode plate, and a separator, a case including a first side having an opening to accommodate the electrode assembly, a cover plate sealing the first side of the case, a first current collector plate disposed between the electrode assembly and the cover plate, a conductive paste electrically connecting the case and the first current collector plate while physically fixing the case and the first current collector plate, a terminal disposed on a second side of the case, and a second current collector plate electrically connecting the second electrode plate and the terminal.

Description

Technical Field

[0001] An aspect of the embodiments of this disclosure relates to a secondary battery. Background Technology

[0002] Unlike primary batteries, which are non-rechargeable, secondary batteries can be charged and discharged. Low-capacity secondary batteries are widely used in small portable electronic devices, such as smartphones, feature phones, tablets, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are typically used to power the motors in hybrid vehicles and electric vehicles.

[0003] A secondary battery may include an electrode assembly containing a positive and a negative electrode, a housing or container holding the electrode assembly, terminals connected to the electrode assembly, and other components. Based on shape, secondary batteries can be classified as cylindrical, prismatic, and pouch-type.

[0004] The information disclosed in this background section is provided to enhance the understanding of the background of the invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0005] According to an embodiment of the present disclosure, a secondary battery with increased sealing strength and improved safety is provided.

[0006] A secondary battery according to one or more embodiments of the present disclosure may include: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a housing including a first side with an opening for receiving the electrode assembly; a cover plate sealing the first side of the housing; a first current collector plate disposed between the electrode assembly and the cover plate; conductive paste electrically connecting the housing and the first current collector plate while physically fixing the housing and the first current collector plate; terminals disposed on a second side of the housing; and a second current collector plate electrically connecting the second electrode plate and the terminals.

[0007] In one or more embodiments, the conductive paste may be located in the region corresponding to the boundary between the inner peripheral surface of the housing and the edge of the first current collector plate.

[0008] In one or more embodiments, the conductive paste may be located between the cover plate and the first current collector plate.

[0009] In one or more embodiments, the cover plate may include a receiving portion that provides space in which the conductive paste is located.

[0010] In one or more embodiments, the receiving portion can be formed by bending the edge of the cover away from the first current collector plate.

[0011] In one or more embodiments, the first current collector plate may include a first region in contact with the first electrode plate and a second region in contact with the cover plate, and the first current collector plate is elastically deformable and bendable such that the first region has a height difference relative to the second region.

[0012] In one or more embodiments, the cover plate may have an electrolyte injection hole formed therein.

[0013] In one or more embodiments, the housing includes a curved portion, and the secondary battery also includes a gasket between the curved portion and the cover plate. Attached Figure Description

[0014] Figure 1 This is a schematic cross-sectional view of a secondary battery according to an embodiment of the present disclosure.

[0015] Figure 2 yes Figure 1 An enlarged view of region "A" in the image.

[0016] Figure 3 This is a perspective view of the first current collector plate of a secondary battery according to an embodiment of the present disclosure. Detailed Implementation

[0017] Some embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings.

[0018] The embodiments of this disclosure are provided to explain this disclosure more fully, and the following embodiments may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will convey to those skilled in the art the aspects and features of this disclosure.

[0019] Additionally, for the sake of brevity and clarity, the dimensions or thicknesses of various components may be exaggerated in the accompanying drawings. The same reference numerals always refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, it will be understood that when element A is referred to as being "connected to" element B, element A may be directly connected to element B, or one or more intermediate elements C may exist between element A and element B, such that element A and element B are indirectly connected to each other.

[0020] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” or “including” and / or variations thereof are used in this specification, they indicate the presence of the stated features, quantities, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or groups thereof.

[0021] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various components, elements, regions, layers, and / or parts, these components, elements, regions, layers, and / or parts should not be limited by these terms. These terms are used to distinguish one component, element, region, layer, and / or part from another component, element, region, layer, and / or part. Thus, for example, without departing from the teachings of this disclosure, the first component, first element, first region, first layer, and / or first part discussed below may be designated as a second component, second element, second region, second layer, and / or second part.

[0022] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” may be used herein to describe the relationship between one element or feature and another (other) element or feature as shown in the figures. It will be understood that spatial relative terms are intended to include different orientations of the device in use or operation other than those depicted in the figures. For example, if the element or feature in the figures were flipped, an element described as “below” or “under” another element or feature would subsequently be positioned “above” or “above” said other element or feature. Thus, the exemplary term “below” can encompass both above and below orientations.

[0023] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept pertains. It is also understood that terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant field and are explicitly defined herein, unless they are interpreted in an ideal or overly formal sense.

[0024] Figure 1 This is a schematic cross-sectional view of a secondary battery according to an embodiment of the present disclosure; Figure 2 yes Figure 1 An enlarged view of region "A" in the image; Figure 3 This is a perspective view of the first current collector plate of a secondary battery according to an embodiment of the present disclosure.

[0025] Reference Figure 1 and Figure 2 According to an embodiment of the present disclosure, the secondary battery 100 includes an electrode assembly 110, a housing or canister 120, a cover plate 130, a first gasket 140, a first current collector plate 150, a terminal 160, a second gasket 170, and a second current collector plate 180.

[0026] The electrode assembly 110 includes a first electrode plate, a second electrode plate, and a separator.

[0027] The first electrode plate can be either a negative electrode plate or a positive electrode plate. When the first electrode plate is a negative electrode plate, it can include, for example, a negative electrode coated portion on a negative electrode current collector plate made of a thin conductive metal plate (e.g., a copper or nickel foil or mesh) where a negative electrode active material is coated, and a negative electrode uncoated portion where no negative electrode active material is coated, but is not limited thereto. Here, the negative electrode active material can be made of, for example, carbon-based materials, Si, Sn, tin oxide, tin alloy composites, transition metal oxides, lithium metal nitrites, or metal oxides, but is not limited thereto.

[0028] The second electrode plate can be either a negative electrode plate or a positive electrode plate. As described above, when the first electrode plate is a negative electrode plate, the second electrode plate can be a positive electrode plate. In this case, the second electrode plate can include a positive electrode coated portion on a positive electrode current collector plate made of a thin metal plate (e.g., aluminum foil or mesh) with excellent conductivity, wherein a positive electrode active material is coated thereon, and a positive electrode uncoated portion in which no positive electrode active material is coated. Here, the positive electrode active material can be, for example, a chalcogenide compound, such as a composite metal oxide (e.g., LiCoO2, LiMn2O4, LiNiO2, LiNiMnO2, etc.), but is not limited thereto.

[0029] A separator is placed between the first electrode plate and the second electrode plate to prevent or substantially prevent short circuits between the first electrode plate and the second electrode plate. The separator can be made of, for example, polyethylene, polypropylene, or porous copolymers of polyethylene and polypropylene, but is not limited thereto.

[0030] The electrode assembly 110 can be stacked, for example, in such a way that the lower end of the first electrode plate protrudes lower than the lower end of the second electrode plate, and the upper end of the second electrode plate protrudes higher than the upper end of the first electrode plate, and thus can be wound in the form of a jelly roll.

[0031] In one embodiment, the housing 120 is shaped as a cylinder having an open surface for accommodating the electrode assembly 110 and another closed surface (e.g., opposite surfaces). Figure 1The diagram shows the lower surface as open and the upper surface as closed, but the upper surface may be open and the lower surface closed as needed. However, for purposes of understanding, as shown in the figures, the following description will focus on the case where the upper surface is closed and the lower surface is open. In an embodiment, the housing 120 may have a protrusion 121 and a curved portion 122 formed at its lower portion. When the first current collector plate 150 is mounted, the protrusion 121 protrudes slightly inward from the upper side of the first current collector plate 150 (see reference). Figure 1 This is to support the first current collector plate 150. Additionally, when installing the cover plate 130, refer to... Figure 1 The curved portion 122, for example, is bent inward from the underside of the cover plate 130 by using a crimping process to cover the edge of the cover plate 130, thereby preventing or substantially preventing the cover plate 130 from separating.

[0032] The cover plate 130 is shaped to correspond to the lower surface of the housing 120 (e.g., in a disc shape) and is used to seal the lower surface of the housing 120. In an embodiment, the cover plate 130 has a notch 131 formed in a specific shape (e.g., a predetermined shape) at a specific location (e.g., a predetermined location). The notch 131 serves as a safety vent. Therefore, when gas is generated inside the secondary battery 100 due to abnormal operation and the internal pressure exceeds a certain pressure, the cover plate 130 automatically cuts along the notch 131 by force to quickly release the gas and pressure, thereby preventing or substantially preventing the secondary battery 100 from exploding. In an embodiment, a receiving portion 132 is formed at the edge of the cover plate 130, the receiving portion 132 being partially spaced from the first current collector plate 150 to provide space therebetween (e.g., a predetermined space). This space allows for the placement of conductive paste P, which will be described later. Figure 1 The cover plate 130 is shown to have a generally plate shape, and the receiving portion 132 is formed by bending the edge of the cover plate 130 as a whole away from or away from the edge of the first current collector plate 150. In this case, the conductive paste P is positioned in the space defined by the inner circumferential surface or inner circumferential surface of the housing 120, the edge of the cover plate 130, and the edge of the first current collector plate 150.

[0033] In one embodiment, the first gasket 140 may be installed between the curved portion 122 of the housing 120 and the edge of the cover plate 130, which increases the sealing strength.

[0034] The first current collector plate 150 is disposed inside the housing 120 between the electrode assembly 110 and the cover plate 130, and electrically connects the first electrode plate of the electrode assembly 110 and the cover plate 130 to each other. As described above, when the first electrode plate of the electrode assembly 110 is a negative electrode plate, the first current collector plate 150, the housing 120 and the cover plate 130 in contact with the first current collector plate 150 have negative polarity.

[0035] The housing 120 and the first current collector plate 150 can be bonded to each other using conductive paste P. To do this, firstly, with the electrode assembly 110 installed in the housing 120, the first current collector plate 150 is positioned below the electrode assembly 110 so that it contacts the first electrode plate of the electrode assembly 110, and conductive paste P is applied to the area corresponding to the boundary between the inner circumferential surface of the housing 120 and the edge of the first current collector plate 150. Next, the lower surface of the housing 120 is closed with a cover plate 130 so that it contacts the first current collector plate 150, and in this embodiment, the conductive paste P is cured by localized hot pressing. Subsequently, a first gasket 140 is provided at the edge of the cover plate 130, and the lower end of the housing 120 is bent inward to secure the cover plate 130.

[0036] By using conductive paste P in this manner, in addition to fixing the cover plate 130 by using the bent portion 122, the first current collector plate 150 is also fixed by using conductive paste P, thereby further improving the sealing strength.

[0037] The conductive paste P itself can be a material known in the art. Furthermore, referring to this disclosure, those skilled in the art can electrically connect the housing 120 and the first current collector plate 150 while simultaneously physically fixing the housing 120 and the first current collector plate 150, and will be able to appropriately select and use materials without unsuitable physical properties for application in secondary batteries; therefore, a detailed description thereof will be omitted.

[0038] Although the bonding of housing 120 and first current collector plate 150 to each other via conductive paste P has been described above, cover plate 130 may also be bonded together via conductive paste P as needed. For example, conductive paste P may be applied in a relatively small volume than the receiving portion 132 of cover plate 130 to the region corresponding to the boundary between the inner peripheral surface of housing 120 and the edge of first current collector plate 150, thereby bonding housing 120 and first current collector plate 150 to each other via conductive paste P. Alternatively, cover plate 130 may also be bonded via conductive paste P by applying conductive paste P in a volume substantially the same as or slightly larger than the receiving portion 132 of cover plate 130.

[0039] In the embodiments, reference is made to Figure 3The first current collector plate 150 can be integrally formed as a disc and can be configured such that the first region 151 is cut into a curved shape relative to the second region 152. In an embodiment, the first current collector plate 150, including the first region 151 which mainly contacts the first electrode plate of the electrode assembly 110 and the second region 152 which mainly contacts the cover plate 130, can be configured to be elastically deformably bent so that the first region 151 has a height difference (e.g., vertical offset) relative to the second region 152. Therefore, even if tolerances occur in the electrode assembly 110, housing 120, cover plate 130, first current collector plate 150, etc. during manufacturing, assembly can be performed using the flexible first current collector plate 150 such that the first region 151 is in close contact with the first electrode plate of the electrode assembly 110 and the second region 152 is in close contact with the cover plate 130.

[0040] In an embodiment, the cover plate 130 may or may not have an electrolyte injection hole formed therein. Figure 1 This illustration shows the absence of an electrolyte injection hole. If an electrolyte injection hole is formed, the following process can be performed as described above: after the first current collector plate 150 is set to apply conductive paste P, the lower surface of the housing 120 is sealed with a cover plate 130 to allow the conductive paste P to cure; then the cover plate 130 is fixed using a pressing process, for example, electrolyte can be injected through the electrolyte injection hole, and then sealed. If no electrolyte injection hole is formed, a process can be performed such that an electrolyte solution can be injected through the lower surface of the housing 120 before the lower surface of the housing 120 is sealed with the cover plate 130.

[0041] Terminal 160 is mounted on the upper surface of housing 120. Figure 1 In this embodiment, terminal 160 is mounted by riveting. That is, a hole is formed in the upper surface of housing 120, through which terminal 160 is disposed and secured by supporting its upper end on the upper side of housing 120 and its lower end on the lower side of second current collector plate 180. In this embodiment, a second washer 170 is installed between housing 120 and terminal 160 to insulate housing 120 and terminal 160 from each other. Therefore, in this embodiment, terminal 160 has a positive polarity. However, this construction of the positive electrode terminal is merely an example, and the scope of this disclosure is not limited thereto. For example, those skilled in the art will readily understand that the positive terminal can be constructed in a manner different from that of a conventional cylindrical secondary battery.

[0042] As described above, according to one or more embodiments of this disclosure, the sealing strength can be increased by using conductive paste to electrically connect the housing and the first current collector while simultaneously physically securing the housing and the first current collector.

[0043] In addition, since welding is not used to connect the housing and the first current collector board, the possibility of spatter being generated during welding and the possibility of reduced safety due to spatter can be eliminated.

[0044] Although some exemplary embodiments for implementing secondary batteries according to this disclosure have been described herein, this disclosure is not limited to the exemplary embodiments, and those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as set forth in the claims.

Claims

1. A secondary battery, the secondary battery comprising: The electrode assembly includes a first electrode plate, a second electrode plate, and a separator; The housing includes a first side having an opening for accommodating the electrode assembly; A cover plate that seals the first side of the housing; A first collector plate is arranged between the electrode assembly and the cover plate; Conductive paste is used to electrically connect the housing and the first current collector plate, while simultaneously physically fixing the housing and the first current collector plate. Terminals are arranged on the second side of the housing; as well as The second collector board electrically connects the second electrode plate and the terminal.

2. The secondary battery according to claim 1, wherein The conductive paste is located in the area corresponding to the boundary between the inner circumferential surface of the housing and the edge of the first current collector plate.

3. The secondary battery according to claim 1, wherein The conductive paste is located between the cover plate and the first current collector plate.

4. The secondary battery according to claim 1, wherein The cover plate includes a receiving portion that provides space in which the conductive paste is located.

5. The secondary battery according to claim 4, wherein The receiving portion is formed by bending the edge of the cover away from the first current collector plate.

6. The secondary battery according to claim 1, wherein The first current collector plate includes a first region in contact with the first electrode plate and a second region in contact with the cover plate, and the first current collector plate is elastically deformable and bendable such that the first region has a height difference relative to the second region.

7. The secondary battery according to claim 1, wherein The cover plate has an electrolyte injection hole formed therein.

8. The secondary battery according to claim 1, wherein The housing includes a curved portion, and the secondary battery also includes a gasket between the curved portion and the cover plate.

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