Secondary battery

Abstract

A secondary battery is disclosed. The secondary battery includes an electrode assembly, a case that accommodates the electrode assembly, a current collector plate that is welded to the electrode assembly and the case, and a cover plate that is on the current collector plate and seals the case.

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 not designed to be charged (or recharged), secondary batteries are designed to be (re)charged and (re)discharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, tablets, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as batteries for powering motors in hybrid vehicles, electric vehicles, and other energy storage units.

[0003] A secondary battery typically includes an electrode assembly with positive and negative electrodes, a housing containing the electrode assembly, and terminals connected to the electrode assembly. Secondary batteries can be classified according to their shape, such as cylindrical, prismatic, and pouch-type. As an example, a cylindrical secondary battery typically includes an electrode assembly, a can, a lid assembly, and a gasket for insulating the can and lid assembly. The negative electrode component of the electrode assembly is electrically connected to the bottom of the can, giving the can a negative polarity, and the positive electrode component of the electrode assembly is electrically connected to the terminals of the lid assembly, giving the lid assembly a positive polarity.

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

[0005] Embodiments of this disclosure provide a secondary battery with improved structural stability.

[0006] The secondary battery according to an embodiment of the present disclosure includes: an electrode assembly; a housing for housing the electrode assembly; a current collector welded to the electrode assembly and the housing; and a cover plate on the current collector and sealing the housing.

[0007] Additionally, the current collector may include: a disc-shaped body; an electrode welding portion inside the body and welded to the electrode assembly; and a housing welding portion outside the body and welded to the housing.

[0008] Alternatively, the slit can be located between the body and the electrode welding section.

[0009] In addition, the slit can be C-shaped or U-shaped.

[0010] In addition, the shell welding section can extend from the body toward the shell.

[0011] In addition, the shell welding part can be welded to the shell's rolled edge.

[0012] Additionally, the housing welded portion may include a bent portion that bends toward the cover plate.

[0013] In addition, the manifold can have a through hole corresponding to the center of the cover plate.

[0014] In addition, secondary batteries may also include an insulating gasket between the welded portion of the casing and the cover plate.

[0015] In addition, the outer diameter of the current collector can be larger than the outer diameter of the electrode assembly. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of a secondary battery according to an embodiment of the present disclosure.

[0017] Figure 2 yes Figure 1 Enlarged view of part II.

[0018] Figure 3 This is a plan view of the first current collector of a secondary battery according to an embodiment of the present disclosure. Detailed Implementation

[0019] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0020] Examples of this disclosure are provided to more fully explain aspects and features of this disclosure to those skilled in the art, and the following embodiments may be modified in various other forms. That is, this disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will convey aspects and features of this disclosure to those skilled in the art.

[0021] It will be understood that when an element or layer is referred to as being "on," "connected to," or "bonded to" another element or layer, it can be directly on, directly connected to, or directly bonded to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on," "directly connected to," or "directly bonded to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "bonded" or "connected" to a second element, the first element can be directly bonded to or directly connected to the second element, or the first element can be indirectly bonded to or indirectly connected to the second element via one or more intermediary elements.

[0022] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals denote 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, the use of "may" in describing embodiments of this disclosure refers to "one or more embodiments of this disclosure." When a statement such as "at least one of..." follows a list of elements, it modifies the entire list of elements without modifying any individual elements within that list. As used herein, the term "use" and its variations may be considered synonymous with the term "utilize" and its variations, respectively. As used herein, the terms "substantially," "about," and similar terms are used as approximate terms rather than terms of degree and are intended to account for inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0023] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion.

[0024] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” may be used herein to describe the relationship of one element or feature to other elements or features as shown in the accompanying drawings. It will be understood that spatial relative terms are intended to cover different orientations of the device in use or operation other than those depicted in the drawings. For example, if the device in the drawings is flipped, an element described as “below” or “under” other elements or features will subsequently be positioned “above” or “above” said other elements or features. Thus, the term “below” can include both above and below orientations. The device may be otherwise positioned (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein should be interpreted accordingly.

[0025] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit the disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “an” are also intended to include the plural forms. It will also be understood that when the terms “comprising,” “including,” and / or variations thereof are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0026] Figure 1 This is a cross-sectional view of a secondary battery 100 according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A magnified view of part II, and Figure 3 This is a plan view of the first current collector 140 of the secondary battery 100 according to an embodiment of the present disclosure.

[0027] 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 120, a cover plate 130, a first current collector 140 and a first insulating pad 150, a second current collector 160, a riveting terminal 170 and a second insulating pad 180.

[0028] The electrode assembly 110 includes a first electrode plate, a second electrode plate, and a diaphragm.

[0029] 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 have a negative electrode coated portion and a negative electrode uncoated portion. At the negative electrode coated portion, a negative electrode active material is coated onto a negative electrode current collector made of a conductive metal sheet (e.g., copper or nickel foil or mesh). At the negative electrode uncoated portion, no negative electrode active material is coated. The negative electrode active material can include, for example, carbon-based materials, Si, Sn, tin oxide, tin alloy composites, transition metal oxides, lithium metal nitrites, or metal oxides, but this disclosure is not limited thereto.

[0030] 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 embodiment, the second electrode plate can have a positive electrode coated portion and a positive electrode uncoated portion. At the positive electrode coated portion, the positive electrode active material is coated onto a positive electrode current collector made of a highly conductive metal sheet (e.g., aluminum foil or mesh). At the positive electrode uncoated portion, the positive electrode active material is not coated. The positive electrode active material can include, for example, chalcogenides, such as composite metal oxides (e.g., LiCoO2, LiMn2O4, LiNiO2, or LiNiMnO2), but this disclosure is not limited thereto.

[0031] A diaphragm is placed between the first electrode plate and the second electrode plate, and prevents electrical short circuits between the first electrode plate and the second electrode plate. The diaphragm can be made of, for example, polyethylene, polypropylene, or a porous copolymer of polyethylene and polypropylene, but this disclosure is not limited thereto.

[0032] Electrode assemblies 110 may be stacked in the order of a first electrode plate, a diaphragm, a second electrode plate, and a diaphragm, and wound in a so-called jelly roll shape. In some embodiments, the uncoated negative electrode portion is positioned at one end of the electrode assembly 110 (e.g., at one end of the electrode assembly 110 in its axial direction), and the uncoated positive electrode portion is disposed at the other end of the electrode assembly 110 (e.g., the opposite end). In the following, embodiments in which the uncoated negative electrode portion is positioned at the upper end of the electrode assembly 110 and the uncoated positive electrode portion is disposed at the lower end of the electrode assembly 110 will be described in more detail.

[0033] The housing 120 has a cylindrical shape in which one side (e.g., one end) is open and the other side (e.g., the other end) is closed to accommodate the electrode assembly 110. In the figures, the upper end (or upper surface) of the housing 120 is open and its lower end (or lower surface) is closed.

[0034] The housing 120 may include a rolled edge (e.g., rolled edge) 121 recessed at its upper portion to prevent the cover plate 130 from moving downward (or falling) and a crimped portion (e.g., crimping member) 122 bent inward at its upper portion to prevent the cover plate 130 from separating upward from the housing 120.

[0035] The housing 120 may include a riveting hole (e.g., a riveting opening) 123 for mounting the riveting terminal 170 on the lower surface.

[0036] The cover plate 130 is attached to the upper end of the housing 120 and seals the upper surface of the housing 120. For example, with the first insulating gasket 150 placed between the housing 120 and the cover plate 130, the cover plate 130 is positioned on the rolled edge 121 of the housing 120, and the crimping portion 122 is formed by bending the upper end of the housing 120 inward, thereby fixing the cover plate 130.

[0037] The cover plate 130 may include a safety vent 131 and an electrolyte injection port (e.g., an electrolyte injection opening) 132.

[0038] When gas is generated inside the secondary battery 100, the safety vent 131 prevents the secondary battery 100 from exploding by automatically releasing excess gas and pressure. For this purpose, the safety vent 131 can be formed in the cover plate 130 as a notch for inducing a cut.

[0039] The electrolyte injection port 132 is used to inject electrolyte into the interior of the secondary battery 100 after assembly, and is sealed by a plug 133 after electrolyte injection. The electrolyte injection port 132 may be located at the center of the cover plate 130.

[0040] The first current collector 140 contacts the upper end of the electrode assembly 110 (e.g., the uncoated negative electrode portion) and is electrically connected to the housing 120. Therefore, the housing 120 has a negative polarity.

[0041] Additional reference Figure 3 The first current collector 140 includes a main body 141, an electrode welding part 142, and a shell welding part 143.

[0042] The main body 141 has a disc shape to correspond to the housing 120.

[0043] The electrode welding portion 142 of the first current collector 140 will be welded to the electrode assembly 110 and disposed inside the body 141. In the drawings, the electrode welding portion 142 includes a plurality (e.g., six) of electrode welding portions arranged at equal intervals along the circumferential direction of the body 141. The number, size, shape, arrangement, etc. of the electrode welding portions 142 can be varied appropriately.

[0044] The housing weld portion 143 of the first manifold 140 will be welded to the housing 120 and disposed on the exterior of the main body 141. For example, the housing weld portion 143 extends outward from the main body 141 toward the housing 120. In the drawings, the housing weld portion 143 includes a plurality (e.g., six) of housing weld portions shown as being arranged at equal intervals along the circumferential direction of the main body 141. The number, size, shape, arrangement, etc., of the housing weld portions 143 can be appropriately varied.

[0045] The housing weld portion 143 is bent upward relative to the main body 141 and can be welded to the rolled edge portion 121 of the housing 120. Therefore, the housing weld portion 143 is supported on the rolled edge portion 121 of the housing 120, thus allowing the first manifold 140 to be installed more stably.

[0046] Furthermore, the first manifold 140 may include a slit (e.g., an elongated opening) 144 between the body 141 and the electrode welding portion 142. The slit 144 can partially separate the electrode welding portion 142 from the body 141. Therefore, when the electrode assembly 110 flows (e.g., moves or expands and contracts) in which the electrode welding portion 142 is welded to the electrode assembly 110, the electrode welding portion 142 can also flow or deform relative to the body 141, thereby preventing unintentional deformation or twisting of other portions of the first manifold 140. The slit 144 is formed to partially surround the electrode welding portion 142 (e.g., extending around the electrode welding portion 142 in a plan view or around the periphery of the electrode welding portion 142). In the figures, the slit 144 is shown as being formed in a C-shape or a U-shape, but this is merely an example.

[0047] The first current collector 140 includes a bend 145 additionally bent inside the housing weld portion 143. In the figures, the bend 145 is shown bent upwards again toward the cover plate 130, but the number of corrugations (e.g., bends) can be increased or decreased. After the first current collector 140 is mounted on the electrode assembly 110 and the cover plate 130 is mounted on the first current collector 140, the upper part of the housing 120 is slightly deformed inwards as a whole when the upper end of the housing 120 is bent inwards to form the crimp portion 122. Here, the deformation can be absorbed by the bend 145, thereby preventing unintentional deformation or twisting of other parts of the first current collector 140.

[0048] The first manifold 140 may include a through-hole (e.g., an opening) 146 through which electrolyte can flow when electrolyte is injected. The through-hole 146 may be located in a region of the first manifold 140 corresponding to (e.g., aligned with) the center of the cover plate 130.

[0049] The total outer diameter of the first current collector 140 is greater than the outer diameter of the electrode assembly 110.

[0050] A first insulating gasket 150 is disposed between the cover plate 130 and the first current collector 140 (e.g., the housing weld portion 143 of the first current collector 140) to electrically insulate the cover plate 130 and the first current collector 140 from each other. The first insulating gasket 150 is also disposed between the housing 120 and the cover plate 130 to electrically insulate the housing 120 and the cover plate 130 from each other. Therefore, the cover plate 130 itself is non-polar.

[0051] The second current collector 160 contacts the lower end of the electrode assembly 110 (e.g., the uncoated positive electrode portion) and is electrically connected to the riveting terminal 170. Therefore, the riveting terminal 170 has a positive polarity.

[0052] Similar to the first current collector 140, the second current collector 160 has a body formed in a disk shape corresponding to the housing 120, and an electrode welding portion is disposed inside the body for welding to the electrode assembly 110. The electrode welding portion of the second current collector 160 may have a slit therein to partially separate the electrode welding portion from the body. Because the features of the second current collector 160 are similar to those of the first current collector 140 as described above, a repeated description thereof is omitted.

[0053] The riveting terminal 170 is mounted in the riveting hole 123 within the housing 120. The riveting terminal 170 is actually mounted in the form of a rivet and may include, for example, a shaft 171 passing through the riveting hole 123 of the housing 120, a first flange 172 extending radially outward from the lower end of the shaft 171 beyond the edge of the riveting hole 123, and a second flange 173 extending beyond the edge of the riveting hole 123. Therefore, the second manifold 160 contacts the upper end of the shaft 171 and / or the upper end of the second flange 173.

[0054] The second insulating gasket 180 is disposed between the housing 120 and the riveting terminal 170, and electrically insulates the housing 120 and the riveting terminal 170 from each other.

[0055] As described above, embodiments of this disclosure provide a secondary battery capable of maintaining structural stability by welding current collectors to the electrode assembly and the housing respectively and electrically connecting them.

[0056] Furthermore, the electrode weld portion welded to the electrode assembly is at least partially separated from the main body through a slit, so that the electrode weld portion can also flow or deform relative to the main body when the electrode assembly flows. Therefore, other portions of the first current collector and / or other portions of the second current collector will not be unintentionally deformed or twisted, thereby further improving the structural stability of the secondary battery.

[0057] Furthermore, corrugations (e.g., bends) are formed at the housing welds to the housing, so that when the housing deforms, for example, with a reduced diameter, the deformation can be absorbed by the bends. Therefore, other portions of the first current collector and / or the second current collector will not unintentionally deform or twist, thereby further improving the structural stability of the secondary battery.

[0058] The foregoing embodiments are merely some examples of secondary batteries according to this disclosure, and this disclosure is not limited to these embodiments. Those skilled in the art will understand that various changes in form and detail can be made to the described embodiments without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A secondary battery, the secondary battery comprising: The electrode assembly includes a first electrode plate, a second electrode plate, and a diaphragm; A housing that houses the electrode assembly, the housing comprising an open first side and a closed second side opposite to the first side; A cover plate that seals the first side of the housing; A current collector is located between the electrode assembly and the cover plate, and the current collector is welded to the first electrode plate of the electrode assembly and the housing. as well as A riveting terminal is located on the second side of the housing, and the riveting terminal is electrically connected to the second electrode plate of the electrode assembly. The current collector plate includes: The main body is disc-shaped; A housing welded portion, surrounding the body, wherein the edge of the housing welded portion is welded to the housing; and The curved portion bends along the direction of the cover plate inside the welded portion of the housing.

2. The secondary battery according to claim 1, wherein, The collector plate also includes: An electrode welding section is located inside the main body and is welded to the electrode assembly.

3. The secondary battery according to claim 2, wherein, The slit is between the body and the electrode welding section.

4. The secondary battery according to claim 3, wherein, The slit is C-shaped or U-shaped.

5. The secondary battery according to claim 2, wherein, The welded portion of the housing extends from the body toward the housing.

6. The secondary battery according to claim 5, wherein, The shell welding part is welded to the shell rolled edge part.

7. The secondary battery according to claim 2, wherein, The manifold has a through hole corresponding to the center of the cover plate.

8. The secondary battery according to claim 2, wherein the secondary battery further comprises an insulating gasket between the welded portion of the housing and the cover plate.

9. The secondary battery according to claim 1, wherein, The outer diameter of the current collector is larger than the outer diameter of the electrode assembly.

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