KR-20260063785-A - Electrode assembly and secondary battery cell including the same, and secondary battery pack and vehicle including the secondary battery cell

Abstract

The present invention provides an electrode assembly for a secondary battery cell comprising a first electrode, a separator, and a second electrode, wherein the separator is pressed against the first electrode or the second electrode.

Inventors

• 고우석

Assignees

• 주식회사 엘지에너지솔루션

Dates

Publication Date

20260507

Application Date

20241031

Claims (13)

1. An electrode assembly for a secondary battery cell comprising a first electrode, a separator, and a second electrode, The above separator is pressed against the first electrode or the second electrode, Electrode assembly.
2. In claim 1, The first electrode or the second electrode is a negative electrode, Electrode assembly.
3. In claim 2, The above separator is pressed against the upper and lower surfaces of the cathode, Electrode assembly.
4. In claim 2, The above separator is pressed onto the edge portions on both sides of the cathode, Electrode assembly.
5. In claim 4, The central portion of the above separator is separated from the above cathode, Electrode assembly.
6. In claim 4, The above separator is pressed against the above cathode by a thermal pressing method, Electrode assembly.
7. In claim 4, The above separator is compressed against the above cathode by an ultrasonic compression method, Electrode assembly.
8. In claim 4, The above separator and the above cathode are bonded by an adhesive, Electrode assembly.
9. In claim 8, The above adhesive is, An adhesive that is any one of epoxy adhesive, polyurethane adhesive, or silicone adhesive, Electrode assembly.
10. An electrode assembly according to any one of claims 1 to 9; and A secondary battery cell comprising a battery housing in which the above electrode assembly is accommodated.
11. A secondary battery cell according to claim 10 and a pack housing in which a plurality of said secondary battery cells are provided and housed, Secondary battery pack.
12. Characterized by including a secondary battery cell according to claim 10, automobile.
13. Characterized by including a secondary battery pack according to claim 11, automobile.

Description

Electrode assembly and secondary battery cell including the same, and secondary battery pack and vehicle including the secondary battery cell The present invention relates to an electrode assembly and a secondary battery cell including the same, a secondary battery pack including the secondary battery cell, and an automobile. Specifically, the invention relates to an electrode assembly and a secondary battery cell including the same that can prevent the separator from shrinking due to a rise in internal temperature when the secondary battery cell is exposed to a high-temperature environment, a secondary battery pack including the secondary battery cell, and an automobile. Secondary batteries, which offer high applicability across product categories and possess electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy. Currently, widely used types of rechargeable batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of such a unit secondary battery cell is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a secondary battery pack is formed by connecting multiple secondary battery cells in series. In addition, a secondary battery pack is sometimes configured by connecting multiple secondary battery cells in parallel, depending on the charge and discharge capacity required for the secondary battery pack. Accordingly, the number of secondary battery cells included in the above secondary battery pack can be set to vary depending on the required output voltage and/or charge/discharge capacity. Meanwhile, cylindrical, prismatic, and pouch-type secondary battery cells are known as types of unit secondary battery cells. In the case of a cylindrical secondary battery cell, an insulating separator is interposed between the positive and negative electrodes, and the separator is wound to form a jellyroll-shaped electrode assembly, which is then inserted into a battery housing to constitute the secondary battery cell. Figure 1 is a diagram showing the structure of an electrode assembly included in a cylindrical secondary battery cell according to the prior art. The electrode assembly (A) includes a first electrode (11) having a first polarity, a second electrode (12) having a second polarity, a separator (13) interposed between the first electrode (11) and the second electrode (12), and an insulating layer (14) covering at least a portion of the first electrode (11). The first electrode (11) is a positive or negative electrode, and the second electrode (12) corresponds to an electrode having a polarity opposite to that of the first electrode (11). The first electrode (11) and the second electrode (12) may have a sheet shape. The electrode assembly (A) may have, for example, a jelly-roll shape. That is, the electrode assembly (A) can be manufactured by winding a laminate formed by sequentially stacking the first electrode (11), the separator (13), the second electrode (12), and the separator (13) at least once, with respect to the winding center. In this case, an additional separator (13) may be provided on the outer surface of the electrode assembly (A) to insulate it from the battery housing. The separator (13) may include a porous substrate and a heat-resistant coating layer formed on at least one surface of the substrate. The heat-resistant coating layer may include inorganic particles and/or heat-resistant polymer particles and a binder. The first electrode (11) and the second electrode (12) may include an uncoated portion (11a, 12a) at the long end where the active material layer is not coated. The first electrode (11) and the second electrode (12) may include a retaining portion (11b, 12b) on which an active material layer is coated in an area excluding the uncoated portion (11a, 12a). FIG. 2 is a schematic diagram showing the arrangement of the first electrode, the separator, and the second electrode in the electrode assembly of FIG. 1, and FIG. 3 is a diagram showing the state in which the separator of FIG. 2 is contracted. When the temperature of a secondary battery cell rises due to reasons such as exposure to a high-temperature environment or heat generation caused by internal reactions, the separator of the electrode assembly shrinks. As such, if the separator shrinkage phenomenon occurs due to the temperature rise inside the secondary battery cell, a space is created between the first electrode and the second electro