KR-20260067530-A - ELECTRODE ASSEMBLY AND SECONDARY BATTERY INCLUDING THE SAME

Abstract

The present disclosure relates to an electrode assembly and a secondary battery including the same, and aims to solve the problem of suppressing the occurrence of cracks, etc., at the bonding portion of a substrate to which an electrode tab is bonded or around the same. An electrode assembly according to one embodiment may include an electrode comprising a substrate, an electrode tab comprising a first tab portion bonded to the substrate and a second tab portion extending from the first tab portion and disposed externally, and a protective tape attached to the substrate and the electrode tab to cover a part of the first tab portion, including the end portion of the first tab portion.

Inventors

• 장진훈
• 마한솔
• 정수한

Assignees

• 삼성에스디아이 주식회사

Dates

Publication Date

20260513

Application Date

20241106

Claims (20)

1. Electrode including a substrate; An electrode tab comprising a first tab portion bonded to the above-mentioned substrate and a second tab portion extending from the first tab portion and disposed externally; and An electrode assembly comprising a protective tape attached to the substrate and the electrode tab to cover a portion of the first tab portion, including the end portion of the first tab portion.
2. In paragraph 1, An electrode assembly characterized in that, in the overlapping portion where the protective tape and the electrode tab overlap, the first boundary line of the electrode tab corresponding to the end portion and the second boundary line corresponding to the boundary of the protective tape are not parallel.
3. In paragraph 2, An electrode assembly characterized in that, in the overlapping portion, the first boundary line is parallel to the longitudinal direction of the substrate, and the second boundary line has an inclination at a predetermined angle with respect to the first boundary line.
4. In paragraph 3, The electrode assembly is characterized in that the above-mentioned overlapping portion has an isosceles triangle-shaped boundary including the first boundary line and the second boundary line.
5. In paragraph 3, The electrode assembly is characterized by the overlapping portion having a right-angled triangle-shaped boundary including the first boundary line and the second boundary line.
6. In paragraph 3, An electrode assembly characterized in that the above-mentioned overlapping portion has a trapezoidal boundary, and the first boundary line and the second boundary line are non-parallel opposite sides of the trapezoidal shape.
7. In paragraph 1, The above electrode includes a jelly-roll type electrode, and The electrode assembly is characterized in that the electrode tab is positioned such that the second tab portion extends from the first tab portion in the direction of the winding axis of the jelly-hole type electrode.
8. An electrode comprising a retaining portion having an active material layer formed on at least one surface of the substrate and a non-retaining portion having no active material layer formed thereon; An electrode tab comprising a first tab portion bonded to the above-mentioned non-bonded portion and a second tab portion extending from the first tab portion and disposed externally in the width direction of the electrode; and An electrode assembly comprising a protective tape having a first tape portion covering a portion of the first tab portion including the end portion of the first tab portion and a second tape portion attached to the unprotected portion.
9. In paragraph 8, The end portion of the first tab portion has a first boundary line parallel to the longitudinal direction of the electrode, and An electrode assembly characterized in that the second boundary line of the protective tape, which overlaps with the first tab portion, has an inclination at a predetermined angle with respect to the first boundary line.
10. In Paragraph 9, The electrode assembly is characterized in that the protective tape is rhombus-shaped.
11. In Paragraph 10, An electrode assembly characterized in that the first tape portion includes a first vertex which is one vertex of the rhombus shape, and the second tape portion includes the remaining three vertices of the rhombus shape.
12. In Paragraph 11, An electrode assembly characterized in that the second tape portion is folded in the direction of the electrode, wherein each of the first sub-part including a second vertex connected to the first vertex and the third sub-part including a third vertex connected to the first vertex is folded.
13. In Paragraph 12, An electrode assembly characterized in that, in the longitudinal direction of the electrode, the second tape portion and the electrode tab have the same size.
14. In Paragraph 9, The electrode assembly is characterized in that the protective tape has a parallelogram or trapezoidal shape, and one first opposing side of the parallelogram or a parallel second opposing side of the trapezoidal shape is parallel to the width direction of the electrode.
15. In Paragraph 14, An electrode assembly characterized in that the distance between the first opposing side or the second opposing side is equal to or greater than the width of the electrode tab.
16. In Paragraph 9, An electrode assembly characterized in that the first boundary line and the second boundary line meet at the vertex of the electrode tab.
17. Electrode assembly; A case for housing the above electrode assembly; and It includes a pair of terminals electrically connected to the electrode assembly and installed on the outer surface of the case so as to protrude a portion from the case, and The above electrode assembly is, Electrode including a substrate; An electrode tab comprising a first tab portion bonded to the above-mentioned substrate and a second tab portion extending from the first tab portion and disposed externally; and A secondary battery comprising a protective tape attached to the substrate and the electrode tab to cover a portion of the first tab portion, including the end portion of the first tab portion.
18. In Paragraph 17, A secondary battery characterized in that, in the overlapping portion where the protective tape and the electrode tab overlap, the first boundary line of the electrode tab corresponding to the end and the second boundary line corresponding to the boundary of the protective tape are not parallel.
19. In Paragraph 18, A secondary battery characterized in that, in the overlapping portion, the first boundary line is parallel to the longitudinal direction of the above-mentioned material, and the second boundary line has an inclination at a predetermined angle with respect to the first boundary line.
20. In Paragraph 19, A secondary battery characterized in that the above-mentioned overlapping portion has a right-angled triangle-shaped boundary including the first boundary line and the second boundary line.

Description

Electrode assembly and secondary battery including the same The present disclosure relates to an electrode assembly and a secondary battery comprising the same. Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries for hybrid and electric vehicles. Such secondary batteries include electrodes comprising a positive electrode and/or a negative electrode, an electrode assembly comprising the electrodes, a case housing the same, and electrode terminals connected to the electrode assembly. As technology advances, there is a growing demand for high-capacity secondary batteries. Accordingly, while increasing the capacity of the secondary battery itself, multiple secondary batteries can be electrically connected and used. For example, secondary batteries can be applied to electronic devices in the form of a battery module containing multiple secondary batteries and/or a battery pack containing multiple battery modules. Depending on the embodiment, a battery pack may be composed of multiple secondary batteries. In this case, the electronic device is an electronic device requiring high power and/or high capacity, such as an electric vehicle. As the cell capacity of secondary batteries increases, an increase in cell expansion is inevitably entailed. This increased cell expansion can cause various stability issues both inside and outside the secondary battery. In particular, increased stress due to volume expansion at the junctions between dissimilar materials or their surroundings can induce or propagate cracks, potentially leading to increased leakage current, open circuits, or short circuits. Therefore, there is a need for secondary batteries with improved structural stability that can withstand increased cell capacity. The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a perspective view schematically showing an example of the configuration of a battery pack including a plurality of secondary batteries. FIG. 2 is a perspective view schematically showing an example of the configuration of a secondary battery according to an embodiment of the present invention. Figure 3 is a cross-sectional view schematically showing the configuration of the secondary battery of Figure 2. FIG. 4 is a schematic drawing showing an example of a joining portion between an electrode and an electrode tab in an electrode assembly according to an embodiment of the present invention. Figure 5 is a drawing showing another example of a protective tape placed at the end of an electrode tab. Figure 6 is a drawing showing another example of a protective tape placed at the end of an electrode tab. Figure 7a is a drawing showing another example of a protective tape placed at the end of an electrode tab. Figure 7b is a view of Figure 7a from the opposite side of the direction of attachment of only the protective tape. Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor may appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; thus, various equivalents and modifications that can replace them may exist at the time of filing this application. Furthermore, as used in this specification, "comprise" or "include" and/or "comprising" or "including" specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and/or groups thereof, and do not exclude the presence or addition of one or more