KR-20260062389-A - lithium Battery structure to prevent thermal runaway using fireproof polyurethane

Abstract

According to one aspect of the present invention, a battery pack may be provided comprising: a battery module formed by connecting a plurality of batteries; a thermal barrier formed in the form of a partition wall that surrounds a portion excluding a portion through which a harness and a bus bar can pass, spaced apart from the battery module, and having a thermal barrier space formed therein; a polyurethane container formed as a container for storing a polyurethane solution disposed inside the thermal barrier space; a gas container connected to the polyurethane container for storing gas so as to be injected with a gas injection gas; a gas injection shut-off valve that receives a signal and operates to control the operation of injecting the gas stored in the gas container into the polyurethane container; a unidirectional valve for controlling the pressure of expansion when gas is injected from the gas container; a heat transfer shut-off controller for controlling the operation of the gas injection shut-off controller; and a controller signal line formed as a signal transmission signal line connecting the heat transfer shut-off controller and the gas injection shut-off controller.

Inventors

• 김태경

Assignees

• 주식회사 서연이화

Dates

Publication Date

20260507

Application Date

20241029

Claims (5)

1. A battery module (100) formed by connecting multiple batteries; A heat-blocking film (200) formed in the form of a bulkhead that surrounds a portion excluding a portion through which a harness and a bus bar can pass, spaced apart from the battery module (100); A polyurethane container (300) formed as a container for storing a polyurethane solution, disposed inside the above-mentioned heat-blocking space (200a); A gas container (400) in which gas is stored so that a spray gas can be injected, connected to the above polyurethane container (300); A gas injection blocker (500) that receives a signal and operates to control the operation of injecting the gas stored in the gas container (400) into the polyurethane container (300); A one-way valve (600) for controlling the pressure of expansion when gas is injected into the above gas container (400); A heat transfer blocking controller (700) that controls the operation of the above gas injection blocking device (500); and A battery pack comprising: a controller signal line (800) formed as a signal transmission signal line connecting the heat transfer blocking controller (700) and the gas injection blocking device (500).
2. In claim 1 The polyurethane solution stored in the above polyurethane container (300) is a battery pack that is a polyurethane of flame retardant grade B1.
3. In claim 1 The above heat-blocking space (200a) A battery pack formed in a form in which the path of a busbar is open, connected to a battery module (100), a polyurethane container (300), a gas container (400), a gas injection blocker (500), and a one-way valve (600).
4. In claim 3 The above battery pack is A cell temperature/voltage detection step (S1) that detects cell temperature and voltage and compares them with cell set temperature and voltage; After the cell temperature/voltage detection step (S1) is performed, a heat transfer blocking controller operation step (S2) in which the heat transfer blocking controller (700) sends a signal to form an opening operation of the gas injection blocking device (500); After the above heat transfer blocking controller operation step (S2) is performed, the gas injection blocker (500) is opened, and the passage between the gas container (400) and the polyurethane container (300) that was blocked is opened in a gas injection blocker opening step (S3); A battery pack in which a polyurethane injection step (S4) is formed, wherein, after the above gas injection blocker opening step (S3) is performed, the polyurethane solution stored in the above polyurethane container (300) is sprayed to completely block the above heat blocking space (200a) from the nearby area.
5. In claim 1 The above controller signal line (800) is The above heat transfer blocking controller (700) and the above gas injection blocking device (500) are connected so that they can transmit signals to each other. A battery pack formed to connect the above-mentioned heat transfer blocking controller (700) and the unidirectional valve (600).

Description

Battery pack structure to prevent thermal runaway using fireproof polyurethane The present invention relates to a battery pack structure for blocking thermal runaway transfer using fire-resistant polyurethane. Currently, most devices that use electricity as their primary energy source, such as electric vehicles and industrial vehicles, utilize lithium-based batteries. These lithium-based batteries offer significant advantages over conventional lead-acid batteries in terms of power output and energy storage density. Despite their high cost and fire hazards, the use of lithium-based batteries continues to expand due to their superior performance. The most critical drawback of lithium-based batteries is the occurrence of thermal runaway within the battery cells during unstable use or storage; once thermal runaway occurs, it cannot be extinguished using conventional fire suppression methods. This issue causes catastrophic human and material damage not only to users but also to surrounding facilities. In particular, automotive battery packs are designed with energy density, water and dust resistance, cooling, and shock resistance as standard features. Consequently, when thermal runaway occurs, heat transfer to neighboring cells is prone to occur sequentially, leading to extensive damage as the runaway continues until the battery pack and the vehicle are completely consumed by fire. Even if automotive lithium battery packs are managed and used in a stable environment, unexpected vehicle accidents can result in fatal consequences. Furthermore, since most battery packs are located in the undercarriage of the vehicle, it is difficult to secure sufficient time to ensure the escape of the driver and passengers in the event of thermal runaway caused by an impact. FIG. 1 is a drawing showing a battery pack structure according to one embodiment of the present invention. Figure 2 is a drawing showing a battery module placed in the battery pack illustrated in Figure 1. FIG. 3 is a flowchart illustrating a heat transfer blocking operation according to the temperature of a battery pack according to one embodiment of the present invention. FIG. 4 is a flowchart showing the heat transfer blocking operation according to the voltage of a battery pack according to one embodiment of the present invention. Figure 5(a) is a graph showing the temperature change of the cell in a thermal runaway situation, and Figure 5(b) is a graph showing the situation where a problem occurred in the battery output in a thermal runaway situation. Embodiments of the present invention will be described below with reference to the attached drawings. For convenience, detailed descriptions of components that obscure the technical essence of the present invention or are known will be omitted in the following description. The following embodiments are provided to more fully explain the invention to those skilled in the art to which the invention pertains. The following embodiments are provided to aid in understanding the invention, and the technical concept of the invention is not necessarily limited to the specific embodiments described below. The invention should be understood to broadly include various types of equivalents, substitutions, modifications, etc., that embody the technical concept described in the following embodiments. The terms used in the following embodiments are provided to more completely explain specific embodiments in the same context as above. Accordingly, the terms used in the following embodiments should not be interpreted to reduce, limit, or restrict the technical scope of the invention. In the following description, singular expressions may be interpreted to include the plural unless explicitly excluded by the context. Furthermore, in the following description, the expression "includes" means that the components, parts, actions, features, steps, numbers, etc. described in the description exist, and does not mean that the addition of one or more other components, parts, actions, features, steps, numbers, etc., is excluded. In the following description, terms such as "first," "second," etc., may be used to distinguish specific components from other components. However, the above terms are used solely for the purpose of distinguishing specific components from others for the sake of clarity in the explanation, and the technical concept of each component should not be interpreted restrictively by the above terms. FIG. 1 is a drawing showing a battery pack structure according to one embodiment of the present invention. Referring to FIG. 1, the battery pack structure according to the present embodiment comprises a battery module (100) formed by connecting a plurality of batteries, a thermal insulation film (200) formed in the form of a partition wall that surrounds a portion excluding a portion through which a harness and a bus bar can pass, spaced apart from the battery module (100) and forming a thermal insulation space (200a), a pol