KR-20260065322-A - POUCH-TYPE BATTERY CELL COMPRISING SELF-HEALING POLYMER COATING LAYER

Abstract

The present invention relates to a pouch-type battery cell comprising an electrode assembly including a positive electrode, a negative electrode, and a separator, and a pouch-type outer casing in which the electrode assembly is housed, wherein the pouch-type outer casing comprises a self-healing polymer coating layer. The pouch-type battery cell according to the present invention is provided with a polymer coating layer having a self-healing function, so that physical damage such as cracks occurring on the surface of the battery cell due to external impact, vibration, etc. is immediately repaired, thereby preventing cracks in the battery cell and the resulting thermal runaway in advance, and thus preventing fires caused by damage to the battery cell.

Inventors

• 박성영
• 김찬후

Assignees

• 국립공주대학교 산학협력단

Dates

Publication Date

20260508

Application Date

20241101

Claims (5)

1. An electrode assembly comprising an anode, a cathode, and a separator; Electrolyte; and A pouch-type battery cell comprising: a pouch-type outer material accommodating the electrode assembly and the electrolyte; A pouch-type battery cell characterized in that the above-mentioned pouch-type outer material includes a self-healing polymer coating layer.
2. In paragraph 1, The above pouch-type outer material includes an inner resin layer, a metal foil layer, and an outer resin layer, and A pouch-type battery cell characterized by having a self-healing polymer coating layer formed on the surface of the outer resin layer.
3. In paragraph 1, The above self-healing polymer coating layer is, A pouch-type battery cell characterized by comprising: a polymer matrix; and self-healing microcapsules and a catalyst dispersed within the polymer matrix.
4. In paragraph 3, A pouch-type battery cell characterized in that the polymer matrix is composed of a covalent self-healing polymer and a supramolecular network self-healing polymer.
5. An electric vehicle battery module comprising a plurality of pouch-type battery cells as described in any one of paragraphs 1 to 4.

Description

Pouch-type battery cell comprising a self-healing polymer coating layer The present invention relates to a pouch-type battery cell mounted on an electric vehicle, etc., and more specifically, to a pouch-type battery cell having a configuration that can fundamentally prevent the possibility of fire caused by damage to the battery cell. Since it is desirable for medium-to-large battery modules used in electric vehicles and the like to be manufactured with the smallest possible size and weight, pouch-type battery cells and prismatic battery cells, which can be packed with high density and have a low weight-to-capacity ratio, are mainly used as unit cells for medium-to-large battery modules. In particular, pouch-type battery cells using materials such as aluminum laminate sheets as exterior materials are gaining popularity due to advantages such as low weight, low manufacturing costs, and ease of shape deformation. Although pouch-type battery cells are still widely used in electric vehicles today, they were used much more frequently than other battery types during the early days of EV adoption. Since early electric vehicles utilized internal combustion engine platforms, pouch-type batteries were suitable because they could be freely cut and processed to fit into available space. Furthermore, because the energy density of early batteries was much lower than it is today, pouch-type batteries were highly preferred as they allowed for maximizing driving range by utilizing the available space within the vehicle. However, unlike prismatic and cylindrical batteries, where the outer can of the battery cell acts as a partition in the event of a fire, pouch-type batteries use thin outer materials such as aluminum laminate sheets. Because of this structural weakness against external impact, there is a high risk of fire caused by the pouch breaking due to external shocks or vibrations, which allows the internal electrolyte to leak out and react with oxygen. Additionally, they have the disadvantage of being vulnerable to thermal runaway, a phenomenon where heat is generated beyond the capacity of the battery cell to release. In describing the present invention, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted. Since embodiments according to the concept of the present invention may be subject to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. The present invention will be described in detail below. The present invention relates to a pouch-type battery cell having a self-healing polymer coating layer formed on the surface of the battery cell to prevent fire in an electric vehicle by preemptively blocking cracks in the battery cell and resulting thermal runaway that may occur due to external impacts or collisions applied to the pouch-type battery cell mounted on an electric vehicle, etc. The pouch-type battery cell according to the present invention comprises an electrode assembly and a pouch-type outer material in which the electrode assembly is housed, wherein the pouch-type outer material comprises a coating layer containing a self-healing polymer. The above pouch-type outer material may be composed of a structure in which an inner resin layer, a metal foil layer, and an outer resin layer are sequentially laminated, and a self-healing polymer coating layer may be formed over the entire surface of the outer resin layer. At this time, the self-healing polymer coating layer may include a polymer matrix and self-healing microcapsules and a catalyst dispersed within the polymer matrix. The self-healing microcapsule included in the self-healing polymer coating layer comprises a core containing a self-healing polymer and a shell surrounding the core. At this time, the self-healing polymer included in the core may be a polymer selected from epoxy resin, dimethylnorbornene ester (DNE), dicyclopentadiene (DCPD), polydimethylsilox