Secondary battery

Abstract

The present invention relates to a secondary battery supporting a central portion of an electrode assembly to enhance stability and reliability. For example, a secondary battery is disclosed, which includes an electrode assembly formed by winding a first electrode plate, a separator, and a second electrode plate; a case for accommodating the electrode assembly; a current collector plate electrically connected to the first electrode plate and bonded to an upper portion of the electrode assembly; and a core insulating member bonded to a winding center of the electrode assembly at an upper portion of the current collector plate, wherein the core insulating member includes an insertion portion having an inner hole and a flange portion extending in a horizontal direction from an upper end of the insertion portion.

Description

Technical Field

[0001] This invention relates to a secondary battery. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are rechargeable. Low-capacity secondary batteries, consisting of individual cells, can be used to power various portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders. High-capacity secondary batteries, with dozens of cells connected in a battery pack, can be used to power motor drives, such as those in hybrid or electric vehicles. These lithium-ion secondary batteries can be classified according to their construction as cylindrical, prismatic, and pouch-shaped secondary batteries.

[0003] Specifically, a cylindrical secondary battery typically includes a cylindrical electrode assembly, a cylindrical housing to which the electrode assembly is attached, an electrolyte injected into the housing to enable the movement of lithium ions, and a cover assembly attached to one side of the housing to prevent electrolyte leakage and to prevent the electrode assembly from separating.

[0004] The information disclosed in this background section is only intended 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] Technical issues

[0006] The present invention provides a secondary battery that supports the center of an electrode assembly to enhance stability and reliability.

[0007] Technical solution

[0008] The secondary battery according to the present invention may include: an electrode assembly formed by winding a first electrode plate, a separator, and a second electrode plate; a housing for accommodating the electrode assembly; a current collector electrically connected to the first electrode plate and coupled to the upper part of the electrode assembly; and a core insulating member coupled to the winding center of the electrode assembly at the upper part of the current collector, wherein the core insulating member includes an insertion portion having an inner hole and a flange portion extending horizontally from the upper end of the insertion portion.

[0009] The current collector may include a central hole formed in the center, and the insertion part can be inserted into the electrode assembly through the central hole.

[0010] The length of the insertion part can be greater than the length of the first electrode plate protruding from the upper end of the diaphragm.

[0011] The insertion portion can be formed vertically from the flange portion.

[0012] The upper and lower diameters of the inner hole can be equal, and the thickness of the upper end of the insertion part can be greater than the thickness of the lower end.

[0013] The upper diameter of the inner hole can be larger than the lower diameter, and the thickness of the upper and lower ends of the insertion part can be equal.

[0014] The core insulating component may be located between the flange and the insertion portion, and may also include a fixing groove to which the current collector is fixed.

[0015] The insertion part may include a cutout that extends from the top to the bottom and divides the insertion part into multiple areas.

[0016] The cut can be opened when the electrolyte is injected into the shell.

[0017] The core insulation component may also include an extension that extends horizontally from one side of the flange to cover a portion of the current collector.

[0018] Beneficial effects

[0019] In a secondary battery according to an embodiment of the present invention, by including a core insulating member incorporated into the winding center of the electrode assembly, the central portion of the electrode assembly can be prevented from collapsing after electrolyte injection, thereby enhancing the stability and reliability of the secondary battery. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view showing a secondary battery according to an embodiment of the present invention.

[0021] Figure 2 This is an exploded perspective view showing a portion of a secondary battery.

[0022] Figure 3a This is a perspective view showing the core insulating member according to an embodiment of the present invention, and Figure 3b This is its sectional view.

[0023] Figure 4a This is a perspective view showing the core insulating member according to another embodiment of the present invention, and Figure 4b This is its sectional view.

[0024] Figure 5a This is a perspective view showing the core insulating member according to another embodiment of the present invention, and Figure 5b This is its sectional view.

[0025] Figure 6 This is a cross-sectional view showing the core insulating member according to another embodiment of the present invention.

[0026] Figure 7aThis is a front view showing the core insulating member according to another embodiment of the present invention, and Figure 7b This is its floor plan.

[0027] Figure 8a This indicates when electrolyte is injected. Figure 7a A front view of the state of the core insulating component, and Figure 8b This is its floor plan.

[0028] Figure 9 This is a cross-sectional view showing the core insulating member according to another embodiment of the present invention. Detailed Implementation

[0029] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0030] Examples of the invention are provided to explain the invention more fully to those skilled in the art, and the examples below can be modified in various other forms. However, the invention can be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will convey aspects and features of the invention to those skilled in the art.

[0031] Additionally, for the sake of brevity and clarity, the dimensions or thicknesses of various components have been exaggerated in the accompanying drawings. The same reference numerals consistently 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.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit disclosure. 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” and / or “including” are used in this specification, it indicates the presence of the stated features, quantities, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or groups thereof.

[0033] Figure 1 This is a cross-sectional view showing a secondary battery according to an embodiment of the present invention. Figure 2 This is an exploded perspective view showing a portion of a secondary battery. Figure 3a This is a perspective view showing the core insulating member according to an embodiment of the present invention, and Figure 3b This is its sectional view.

[0034] Reference Figure 1 and Figure 2According to an embodiment of the present invention, the secondary battery 100 includes an electrode assembly 110, a first current collector 120, a second current collector 130, a housing 140, a cover assembly 150, and a core insulating member 160.

[0035] The electrode assembly 110 may include a first electrode plate 111, a second electrode plate 112, and a diaphragm 113 disposed between the first electrode plate 111 and the second electrode plate 112. The electrode assembly 110 may be formed by winding a laminate of the first electrode plate 111, the diaphragm 113, and the second electrode plate 112 in the form of a jelly roll. Here, the first electrode plate 111 may be used as a positive electrode, and the second electrode plate 112 may be used as a negative electrode.

[0036] The first electrode plate 111 can be formed by applying a first electrode active material (such as a transition metal oxide) to a first electrode current collector formed of a metal foil (such as aluminum). In the first electrode plate 111, a first electrode uncoated portion 111a may be formed, where no first electrode active material is applied. The first electrode uncoated portion 111a may protrude above the electrode assembly 110 for electrical connection to the first current collector 120. In some examples, the first electrode uncoated portion 111a may protrude beyond the second electrode plate 112 and the diaphragm 113.

[0037] The second electrode plate 112 can be formed by applying a second electrode active material (such as graphite or carbon) to a second electrode current collector formed of a metal foil (such as copper or nickel). In the second electrode plate 112, an uncoated portion 112a of the second electrode, uncoated with the second electrode active material, can be formed. The uncoated portion 112a can protrude to the lower portion of the electrode assembly 110 for electrical connection to the second current collector 130. In some examples, the uncoated portion 112a can protrude below the first electrode plate 111 and the diaphragm 113.

[0038] The first current collector 120 can be attached to the upper part of the electrode assembly 110 and can be electrically connected to the uncoated portion 111a of the first electrode. The first current collector 120 can be formed of a circular plate to correspond to the cross-section of the electrode assembly 110. The first current collector 120 may include a central hole 121, an outer peripheral hole 122, a solder joint 123, and a lead connector 124.

[0039] The central hole 121 can be located at the center of the first current collector 120, and the peripheral hole 122 can be located on the outer periphery of the central hole 121. Electrolyte can be injected into the housing 140 through the central hole 121 and the peripheral hole 122. In addition, the core insulating member 160 can be attached to the central hole 121.

[0040] The lead connector 124 can be electrically connected to one side of the first current collector 120. The peripheral hole 122 may not be formed in the portion of the first current collector 120 that connects to the lead connector 124. The lead connector 124 can be connected to the cover assembly 150 to electrically connect the first current collector 120 to the cover assembly 150. That is, one end of the lead connector 124 can be electrically connected to the first current collector 120, and the other end of the lead connector 124 can be electrically connected to the cover assembly 150. Of course, the lead connector 124 can be integrally formed with the first current collector 120. For example, a portion of the first current collector 120 can be formed as an extension to constitute the lead connector 124, and the lead connector 124 can be bent to electrically connect to the cover assembly 150.

[0041] The welding portion 123 is formed in the form of a groove protruding downward from the first manifold 120, and multiple welding portions can be formed. For example, such as Figure 2 As shown, the welding portion 123 includes four grooves and can be arranged in a "+" shape. That is, each welding portion 123 can be arranged to be spaced apart from each other at a 90-degree interval relative to the center of the first current collector 120. Meanwhile, in this invention, the number of welding portions 123 is not limited, and the number of welding portions 123 can be no less than four or fewer. In some examples, the welding portions 123 can be located between the outer peripheral holes 122. The welding portions 123 can be welded to the first electrode uncoated portion 111a of the electrode assembly 110. In this case, the welding portions 123 can be connected to the first electrode uncoated portion 111a by laser welding, ultrasonic welding, resistance welding, etc.

[0042] The second current collector 130 can be attached to the lower part of the electrode assembly 110 and can be electrically connected to the uncoated portion 112a of the second electrode. The second current collector 130 can be formed of a circular plate to correspond to the cross-section of the electrode assembly 110. The second current collector 130 may include a connecting portion 131, an outer peripheral hole 132, and a welding portion 133.

[0043] The connecting portion 131 may be formed to protrude downward from the second manifold 130. The connecting portion 131 may be formed approximately at the center of the second manifold 130 and may be electrically connected to the base plate 142 of the housing 140, which will be described later. In some examples, the connecting portion 131 may be formed in a portion corresponding to the center hole 121 of the first manifold 120. For example, the connecting portion 131 may be electrically connected to the housing 140 by laser welding, ultrasonic welding, resistance welding, etc.

[0044] A peripheral hole 132 may be formed around the connecting portion 131. The peripheral hole 132 is a hole through which the electrolyte moves, and multiple peripheral holes 132 may be formed in the second current collector 130. In some examples, the peripheral holes 132 may be formed between the weld portions 133.

[0045] The weld portion 133 is formed in the form of a groove protruding upward from the second manifold 130, and multiple weld portions 133 can be formed. For example, as... Figure 2 As shown, the welding portion 133 can have four grooves and can be arranged in a "+" shape. That is, the welding portion 133 can be formed in the same way as the welding portion 123 of the first current collector 120, but the only difference is that the protruding directions are opposite to each other. The welding portion 133 can be welded to the uncoated portion 112a of the second electrode of the electrode assembly 110. Here, the welding portion 133 can be connected to the uncoated portion 112a of the second electrode by laser welding, ultrasonic welding, resistance welding, etc.

[0046] The housing 140 includes a side plate 141 and a bottom plate 142. The side plate 141 is a cylinder with a predetermined diameter to form a space for accommodating the electrode assembly 110, and the bottom plate 142 seals the lower part of the side plate 141. After the electrode assembly 110 is inserted, the top opening of the housing 140 is opened to seal the electrode assembly 110. A rolled edge portion 143 for preventing movement of the electrode assembly 110 may be formed at the upper part of the housing 140. In addition, a crimping portion 144 for fixing the cover assembly 150 is formed at the uppermost end of the housing 140.

[0047] The cover assembly 150 includes an upper cover 151, a safety vent 152 attached to the lower part of the upper cover 151, a lower cover 153 attached to the lower part of the safety vent 152, an insulator 154 located between the safety vent 152 and the lower cover 153, a sub-board 155 attached to the lower part of the lower cover 153 and electrically connected to the safety vent 152, and a gasket 156 disposed between the outer periphery of the safety vent 152 and the housing 140. The sub-board 155 is electrically connected to the lead connector 124 of the first current collector 120.

[0048] The core insulating member 160 may be coupled to the center of the electrode assembly 110. Specifically, the core insulating member 160 is coupled to the center hole 121 of the first current collector 120 coupled to the upper part of the electrode assembly 110, and may be located at the winding center of the electrode assembly 110. In some examples, the core insulating member 160 may be formed of an insulating material. The core insulating member 160 may include an insertion portion 161 and a flange portion 165.

[0049] The insertion portion 161 can be formed as a cylinder with an inner hole 162. Electrolyte can be injected into the housing 140 through the inner hole 162. In some examples, the upper and lower diameters of the inner hole 162 can be equal. The insertion portion 161 can extend downward from the flange 165. In some examples, the insertion portion 161 can be formed vertically from the flange 165. The insertion portion 161 can penetrate the central hole 121 of the first current collector 120 and be inserted into the winding center of the electrode assembly 110. Here, since the insertion portion 161 is inserted into the central hole 121, the diameter of the inner hole 162 is smaller than the diameter of the central hole 121. The insertion portion 161 can be inserted into the center of the electrode assembly 110 to prevent the first electrode plate 111, the second electrode plate 112, or the diaphragm 113 from bending or collapsing toward the center of the electrode assembly 110.

[0050] The length of the insertion portion 161 can be greater than the length of the uncoated portion 111a of the first electrode. Since the uncoated portion 111a protrudes above the diaphragm 113 and the second electrode plate 112, the insertion portion 161 should be formed to have a length at least greater than the uncoated portion 111a, and thus simultaneously support the first electrode plate 111, the second electrode plate 112, and the diaphragm 113. In some examples, the length of the insertion portion 161 can be greater than the length by which the first electrode plate 111 in the electrode assembly 110 protrudes from the diaphragm 113. Furthermore, the thickness T1 of the insertion portion 161 can be formed such that the upper and lower ends are equal.

[0051] The flange 165 may be formed to extend outward (horizontally) from the top of the insertion portion 161. The flange 165 may extend to the outside of the inner hole 162 and may partially cover the upper part of the first manifold 120. For example, the flange 165 may extend in a generally annular shape to the outside of the central hole 121 of the first manifold 120. In some examples, the flange 165 may not cover the outer peripheral hole 122 and the weld portion 123.

[0052] As described above, the core insulating member 160 can be coupled to the winding center of the electrode assembly 110 to support the electrode assembly 110, thereby preventing the central portion of the electrode assembly 110 from collapsing after electrolyte injection, thereby enhancing the stability and reliability of the secondary battery 100.

[0053] Various embodiments of the core insulating component will be described below.

[0054] Figure 4a This is a perspective view showing the core insulating member according to another embodiment of the present invention, and Figure 4b This is its sectional view.

[0055] Reference Figure 4a and Figure 4bThe core insulating member 260 may include an insertion portion 261 and a flange portion 265. To facilitate insertion into the center hole 121 and the winding center of the electrode assembly 110, the insertion portion 261 may be formed to taper from top to bottom. That is, the thickness T1 of the upper end of the insertion portion 261 may be greater than the thickness T2 of the lower end (T1>T2). In this case, the inner hole 262 may be formed such that the diameters of the upper and lower ends are equal. In some examples, the outer diameter of the insertion portion 261 may be formed to decrease from top to bottom. In other words, the outer surface of the insertion portion 261 may be formed to be inclined.

[0056] Figure 5a This is a perspective view showing the core insulating member according to another embodiment of the present invention, and Figure 5b This is its sectional view.

[0057] Reference Figure 5a and Figure 5b The core insulating member 360 may include an insertion portion 361 and a flange portion 365. The insertion portion 361 may be formed in a funnel shape with a diameter that gradually decreases from top to bottom. Additionally, an inner hole 362 for injecting electrolyte may be formed inside the insertion portion 361, and the inner hole 362 may be formed such that the diameter of the upper end is larger than the diameter of the lower end. In this case, the insertion portion 361 may be formed to have the same thickness T1 at its upper and lower ends. As described above, since the diameter of the insertion portion 361 gradually decreases from top to bottom, the core insulating member 360 can be easily inserted into the first current collector 120 and the electrode assembly 110.

[0058] Figure 6 This is a cross-sectional view showing the core insulating member according to another embodiment of the present invention.

[0059] Reference Figure 6 The core insulating component 460 may include an insertion portion 461, an inner hole 462, a flange portion 465, and a fixing groove 467. Figure 6 The core insulating component 460 is similar to Figure 5b The core insulating member 360 may also include a fixing groove 467. For example, the insertion portion 461, the inner hole 462, and the flange portion 465 may correspond to... Figure 5b The insertion part 361, the inner hole 362 and the flange part 365.

[0060] A fixing groove 467 may be formed between the flange portion 465 and the insertion portion 461. The fixing groove 467 may be located at the lower part of the flange portion 465 and the upper end of the insertion portion 461. The fixing groove 467 may be formed around the upper end of the insertion portion 461. The fixing groove 467 may be a groove formed from the outer surface (surface) of the insertion portion 461 inward (i.e., towards the center of the core insulating member 460). Therefore, a step is created between the fixing groove 467 and the insertion portion 461. The fixing groove 467 can be used to fix the core insulating member 460 to the first current collector 120. For example, when the core insulating member 460 is inserted into the center hole 121 of the first current collector 120, the first current collector 120 around the center hole 121 is inserted into the fixing groove 467. In addition, due to the step between the fixing groove 467 and the insertion portion 461, the core insulating member 460 can not easily separate from the center hole 121 and can be stably fixed to the first current collector 120.

[0061] Figure 7a This is a front view showing the core insulating member according to another embodiment of the present invention, and Figure 7b This is its floor plan. Figure 8a This indicates when electrolyte is injected. Figure 7a A front view of the state of the core insulating component, and Figure 8b This is its floor plan.

[0062] Reference Figure 7a and Figure 7b The core insulating member 560 may include an insertion portion 561 and a flange portion 565. Here, the flange portion 565 may be formed to correspond to the flange portions 165, 265, 365 and 465 described above.

[0063] The insertion portion 561 can be divided into multiple regions by a cutout 561a formed on its side. The cutout 561a can be formed to extend from the top to the bottom of the insertion portion 561. The upper end of the insertion portion 561 is connected to the flange portion 565. Additionally, as... Figure 7b As shown, in the insertion portion 561, the areas separated by the cutout portion 561a are in contact with each other during normal time, thus the inner hole 562 formed inside the insertion portion 561 is not visible. However, when the core insulating member 560 is attached to the first current collector 120 and the electrode assembly 110 and electrolyte is injected, the multiple areas of the insertion portion 561 and the cutout portion 561a can be separated from each other due to the electrolyte. Therefore, as... Figure 8a and Figure 8b As shown, when electrolyte is injected, the cut portions 561a of the insertion portion 561 can be spaced apart to form an inner hole 562, and the electrolyte can be injected into the electrode assembly 110 through the inner hole 562.

[0064] Figure 9This is a cross-sectional view showing the core insulating member according to another embodiment of the present invention.

[0065] Reference Figure 9 The core insulating member 660 may include an insertion portion 661, an inner hole 662, a flange portion 665, and an extension portion 669. Figure 9 The core insulating component 660 can be similar to Figure 5b The core insulating member 360 may also include an extension 669. For example, the insertion portion 661, the inner hole 662, and the flange portion 665 may be formed corresponding to... Figure 5b The insertion part 361, the inner hole 362 and the flange part 365.

[0066] The extension 669 may be formed to extend horizontally from one side of the flange 665. In some examples, the extension 669 may extend to the upper portion of the first current collector 120 to cover a portion of the outer peripheral hole 122. Alternatively, the extension 669 may not extend from the first current collector 120 to the portion forming the lead contact 124. That is, the core insulating member 660 includes the extension 669 extending to one side of the flange 665, and therefore may be asymmetrical. The extension 669 extends to the upper portion of the first current collector 120 to prevent the first current collector 120 from deforming or lifting when the housing 140 is pressed or bent.

[0067] While the foregoing embodiments have been provided for implementing the secondary battery according to the invention, it should be understood that the embodiments described herein should be considered descriptive only and not for limiting purposes, and various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0068] Industrial applicability

[0069] The invention can be applied to the field of secondary batteries.

Claims

1. A secondary battery, the secondary battery comprising: An electrode assembly is formed by winding a first electrode plate, a diaphragm, and a second electrode plate. A housing for accommodating the electrode assembly; A current collector is electrically connected to the first electrode plate and is attached to the upper part of the electrode assembly; as well as The core insulating component is attached to the winding center of the electrode assembly at the upper part of the current collector. The core insulating member includes an insertion portion having an inner hole and a flange portion extending horizontally from the upper end of the insertion portion. The current collector is formed of a circular plate corresponding to the cross-section of the electrode assembly, and includes a central hole formed therein. The insertion part is inserted into the electrode assembly through the central hole. The first electrode plate includes the uncoated portion of the first electrode. In this configuration, the uncoated portion of the first electrode protrudes beyond the diaphragm. The uncoated portion of the first electrode protrudes to the upper part of the electrode assembly to be electrically connected to the current collector.

2. The secondary battery according to claim 1, wherein, The length of the insertion portion is greater than the length of the first electrode plate protruding from the upper end of the diaphragm.

3. The secondary battery according to claim 1, wherein, The insertion portion is formed vertically from the flange portion.

4. The secondary battery according to claim 1, wherein, The upper and lower diameters of the inner hole are equal, and the thickness of the upper end of the insertion part is greater than the thickness of the lower end.

5. The secondary battery according to claim 1, wherein, The upper diameter of the inner hole is larger than the lower diameter, and the thickness of the upper and lower ends of the insertion part is equal to that of each other.

6. The secondary battery according to claim 1, wherein, The core insulating component also includes a fixing groove located between the flange and the insertion portion, and the current collector is fixed to the fixing groove.

7. The secondary battery according to claim 1, wherein, The insertion portion includes a cutout extending from the top to the bottom and dividing the insertion portion into multiple regions.

8. The secondary battery according to claim 7, wherein, The cut-out portion opens when the electrolyte is injected into the casing.

9. The secondary battery according to claim 1, wherein, The core insulating member also includes an extension that extends horizontally from one side of the flange to cover a portion of the current collector.

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