KR-20260067449-A - BIPOLAR STACK CELL AND BATTERY PACK COMPRISING THE SAME

KR20260067449AKR 20260067449 AKR20260067449 AKR 20260067449AKR-20260067449-A

Abstract

According to one embodiment of the present invention, a bipolar stack cell comprising a current collector, an anode layer, a cathode layer, and a separator, wherein A bipolar stack cell comprises three or more bipolar unit cells, and The above bipolar unit cell is, A single-sided positive cell formed on one side of the outermost edge of the bipolar stack cell, wherein a positive material layer is formed on one surface of the current collecting substrate; a single-sided negative cell formed on the other side of the outermost edge of the bipolar stack cell, wherein a negative material layer is formed on one surface of the current collecting substrate; and a double-sided unit cell formed between the single-sided positive cell and the single-sided negative cell, wherein a positive material layer and a negative material layer are respectively formed on both sides of the current collecting substrate; comprising A bipolar stack cell and a battery pack are provided, wherein the above-described single-sided positive cell and the above-described single-sided negative cell each have the positive material layer and the negative material layer located inside the bipolar stack cell, respectively, and the current collecting materials are located at the outermost edge.

Inventors

장성만
김동규
김상훈
이종혁

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260513
Application Date: 20241104

Claims (14)

A bipolar stack cell comprising a current collector, an anode layer, a cathode layer, and a separator, A bipolar stack cell comprises three or more bipolar unit cells, and The above bipolar unit cell is, A single-sided positive cell formed on one side of the outermost edge of the bipolar stack cell, wherein a positive material layer is formed on one surface of the current collecting substrate; a single-sided negative cell formed on the other side of the outermost edge of the bipolar stack cell, wherein a negative material layer is formed on one surface of the current collecting substrate; and a double-sided unit cell formed between the single-sided positive cell and the single-sided negative cell, wherein a positive material layer and a negative material layer are respectively formed on both sides of the current collecting substrate; comprising The above-described single-sided positive cell and the above-described single-sided negative cell are bipolar stack cells in which the positive material layer and the negative material layer are each located inside the bipolar stack cell, and the current collecting materials are located at the outermost edge.
In paragraph 1, The above bipolar stack cell further comprises an electrolyte, wherein the electrolyte is a solid electrolyte or a cured gel electrolyte.
In paragraph 1, The above bipolar stack cell further includes an insulating frame that surrounds the side portion and is joined to the outermost current collection materials to seal the interior.
In paragraph 3, The above insulating frame is a bipolar stack cell made of polyolefin.
In paragraph 4, The above insulating frame is a bipolar stack cell in which a waterproof film is coated on the above polyolefin substrate.
In paragraph 5, The above waterproof film is a bipolar stack cell, which is a bonded film of metal and polyethylene terephthalate (PET).
In paragraph 6, The above metal is a bipolar stack cell made of aluminum (Al).
In paragraph 3, The above bipolar stack cell further comprises an electrolyte, wherein the electrolyte is a solid electrolyte, a cured gel electrolyte, or a liquid electrolyte.
In paragraph 1 or 3, The current collecting substrate of the above-mentioned single-sided anode cell is an Al-Cu clad current collector, a laminated current collector in which an Al current collector and a Cu current collector are bonded with a conductive adhesive, stainless steel, stainless steel surface-treated with a heterogeneous element, or aluminum (Al). The current collecting substrate of the above-described single-sided cathode cell is an Al-Cu clad current collector, a laminated current collector in which an Al current collector and a Cu current collector are bonded with a conductive adhesive, stainless steel, stainless steel surface-treated with a heterogeneous element, or copper (Cu). The above-described double-sided unit cell is a bipolar stack cell comprising an Al-Cu clad current collector, a stacked current collector in which an Al current collector and a Cu current collector are bonded with a conductive adhesive, stainless steel, or stainless steel surface-treated with a heterogeneous element.
In paragraph 1 or 3, The above-mentioned anode layer is a bipolar stack cell that is a dry anode.
In paragraph 1 or 3, The above separator is a polymer substrate, an SRS separator having a structure in which an organic-inorganic mixed coating layer is formed on one or both sides of the polymer substrate, a cured gel electrolyte, or a solid electrolyte in a bipolar stack cell.
In paragraph 1 or 3, A bipolar stack cell in which a positive terminal is formed on the current collection substrate of the above-mentioned single-sided positive cell and a negative terminal is formed on the current collection substrate of the above-mentioned single-sided negative cell.
In Paragraph 12, A bipolar stack cell in which the positive terminal and the negative terminal each have a contact area with the current collecting substrate of 50% to 100% of the total area of the current collecting substrate.
A battery pack comprising a bipolar stack cell according to paragraph 1 or 3.

Description

Bipolar stack cell and battery pack comprising the same The present invention relates to a bipolar stack cell and a battery pack including the same. Recently, as the application areas of lithium-ion batteries have rapidly expanded to include not only power supply for electronic devices such as electrical, electronic, telecommunications, and computers, but also power storage for large-area devices such as automobiles and power storage systems, there is a growing demand for high-capacity, high-output, and high-stability secondary batteries. The electrodes used in such secondary batteries can be classified into monopolar electrodes, in which an active material with the same polarity is coated on both sides of a current collector, and bipolar electrodes, in which an active material with different polarities is coated on both sides of a current collector. Secondary batteries utilizing monopolar electrodes have connections between the electrodes, which can lead to a decrease in output due to the electrical resistance of these connections. Furthermore, temperature rise caused by Joule heating can cause various issues regarding cell safety, and battery components for heat dissipation, thermal monitoring, and wiring occupy a significant amount of space within the battery pack, resulting in poor space efficiency. In contrast, secondary batteries utilizing bipolar electrodes stack electrodes without connections, thereby minimizing electrode connection resistance and providing excellent output performance. Additionally, because the structure and components are simplified, they offer good space efficiency, which can significantly improve energy density and output density per unit volume compared to conventional lithium-ion batteries. Accordingly, bipolar batteries of various structures are currently being developed. FIG. 1 is a schematic cross-sectional view of a bipolar stack cell according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a bipolar stack cell according to another embodiment of the present invention. Figure 3 is an exploded perspective view of the bipolar stack cell of Figure 2. Figure 4 is a schematic cross-sectional view of the insulating frame of Figure 3. FIG. 5 is a schematic cross-sectional view of a current collection substrate according to one example of the present invention. Hereinafter, terms and words used in this specification and claims shall not be interpreted as being limited to their ordinary or dictionary meanings, but shall be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and/or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned. In this specification, when a part is described as including a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. In addition, the term “consists of” as used in this specification means that only the component is present, or that other substances are present in addition to the component at a level of impurities (within 1% by weight based on the total weight). Furthermore, “one side” or “the other side” means opposite sides with a certain component in between. Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described below. Also, in this specification and drawings, like reference numerals indicate like components. According to one embodiment of the present invention, a bipolar stack cell is provided. FIG. 1 schematically illustrates a cross-sectional view of a bipolar stack cell (100) according to one embodiment of the present invention. Referring to FIG. 1, the bipolar stack cell (100) comprises three or more bipolar unit cells (101, 102, 103), and the bipolar unit cells (101, 102, 103) comprise a single-sided positive cell (101) formed on one side of the outermost edge of the bipolar stack cell (100), a single