A battery pack with a flame-resistant coating and a method for production thereof

Abstract

The invention relates to a rechargeable battery pack (10) having a coating (20) wrapped around its outer surface to enhance fire safety. The invention is characterized in that said coating (20) comprises a layer of flame-resistant fabric (21), and a layer of a polyimide-based insulating tape (22) on top of said flame-resistant fabric (21) and / or between said flame-resistant fabric (21) and the battery pack (10). It also relates to a method for producing said battery pack (10).

Description

[0001] DESCRIPTION

[0002] A BATTERY PACK WITH A FLAME-RESISTANT COATING AND A METHOD FOR PRODUCTION THEREOF

[0003] Technical Field

[0004] The invention relates to a battery pack having a fireproof and flame-resistant coating structure for ensuring fire safety, and a method for manufacturing said battery pack.

[0005] State of the Art

[0006] Currently, battery packs are typically encased in PVC film, heat-shrink tubing, or plastic enclosures. However, these materials have certain drawbacks. Listed below are some of the problems that may arise from the use of these materials:

[0007] These materials are flammable and may cause the fire to spread in the event of a thermal runaway.

[0008] They provide insufficient protection against external heat, which can trigger a chain reaction in a fire.

[0009] They have limited chemical and physical durability and do not provide protection against punctures or tears.

[0010] Rechargeable lithium-ion batteries, in particular, can overheat due to thermal runaway. The flammability of current coating materials results in the spread and acceleration of the fire in such situations. Additionally, when battery packs are exposed to an external fire, the coating materials ignite rapidly, facilitating the fire’s spread to the battery cells and potentially triggering a chain reaction. This situation can lead to device damage, battery explosions, and serious safety risks.

[0011] Battery packs with sealed casings used in cell phones and some small electronic devices are susceptible to physical damage such as tearing and puncturing because they do not use flame-resistant fabric lining. Additionally, existing solutions are insufficient for protecting battery packs of larger sizes and capacities. Many devices produced by variousmanufacturers on the market have battery packs that are larger in size and capacity than those found in mobile phones and some small electronic devices.

[0012] Companies operating in the battery packaging and energy storage sectors typically use traditional coating methods. The application of fireproof and flame-resistant fabric coating technology remains limited.

[0013] During a patent search conducted based on the state of the art, U.S. Patent No. 12,159,990 B2 was discovered. This document states that the flame-resistant fabric is shaped into a box that fits a battery pack and is placed between a battery cell and the battery housing. The flame-resistant fabric is made of high-silica fiber fabric or alumina fiber fabric. Although the flame-resistant fabric provides protection against fire, it is not suitable for liquid and chemical insulation. Additionally, aluminum-coated fabrics, which can be selected for their heat-reflective properties, possess electrical conductivity. Therefore, this document does not eliminate the need for a structure that provides both fire resistance and electrical and liquid insulation.

[0014] As a result, due to the shortcomings described above and the inadequacy of existing solutions in this area, it has become essential to make improvements in the relevant technical field.

[0015] Object of the Invention

[0016] The present invention relates to a battery pack with a coating structure that meets the requirements mentioned above and eliminates all disadvantages, as well as a method for production thereof.

[0017] The primary object of the invention is to enhance safety, minimize the risk of thermal runaway, and ensure fire safety by coating battery packs with a flame-resistant and fire-resistant fabric and insulating tape. A polyimide-based insulating tape (such as the commercially available Kapton™) used in the coating ensures protection of electronic circuits against water / moisture, chemicals, and temperatures up to 400°C, while also providing electrical insulation. In addition to its insulating properties, the flame-resistantfeature of the aforementioned polyimide-based insulating tape contributes to enhanced fire safety.

[0018] Another object of the invention is to ensure that no design changes are required to the battery compartments of newly manufactured devices, as the battery pack wrapped in the fire-retardant coating described in the invention continues to fit into existing battery compartments.

[0019] Another object of the invention is to have a wide range of applications in both industrial and consumer electronics sectors. The battery packs produced in accordance with the invention will be compatible with various devices currently in use on the market and will significantly enhance the battery packs’ resistance to physical impacts and fire safety.

[0020] The battery pack featuring a flame-resistant coating described in this invention can be used in the following areas:

[0021] - Small household appliances: Robot vacuum cleaners, upright vacuum cleaners, portable electric devices

[0022] - Light electric vehicles: Electric scooters, electric bicycles, electric motorcycles - Heavy industry and automotive sector: Electric vehicles, electric construction machinery

[0023] - Industrial power tools: Drills, portable power systems

[0024] - Energy storage systems: Solar energy storage units, UPS power supplies, lithium-ion battery packs.

[0025] The structural and characteristic features of the invention, as well as all its advantages, will be more clearly understood through the detailed description provided below, which refers to the figures shown, and therefore it is essential to take these figures and the detailed description into account when evaluating the invention.

[0026] Description of the Figures

[0027] The embodiment and advantages of the present invention can best be understood by referring to the figures described below.Figure 1: A schematic view of an alternative embodiment of the battery pack of the invention having a flame-resistant coating.

[0028] Figure 2: A schematic view showing the layers of an alternative embodiment of the battery pack of the invention having a flame-resistant coating.

[0029] Figure 3: A representative view showing the layers of yet another alternative embodiment of the battery pack with a flame-resistant coating described in the invention.

[0030] References

[0031] 10. Battery pack

[0032] 11. Cable connection

[0033] 20. Coating

[0034] 21. Flame-resistant fabric

[0035] 22. Insulating tape

[0036] Detailed Description of the Invention

[0037] In this detailed description, the preferred embodiments of the battery pack (10) with the fire-resistant coating (21) of the invention, as well as the production method, are described solely for the purpose of facilitating a better understanding of the subject matter.

[0038] Figure 1 shows a representative view of an alternative embodiment of the battery pack (10) with the coating (20) of the invention; Figures 2 and 3 show representative views of alternative embodiments illustrating the layers of the coating (20) of the invention. The lower layer of the said flame-resistant coating (20) comprises a flame-resistant fabric (21). Said flame-resistant fabric (21) is preferably an aluminized para-aramid fabric. Said aluminized para-aramid fabric is resistant to temperatures exceeding 1000°C. The battery pack (10) is fully covered by wrapping it with the fabric such that the aluminized surface faces outward, thereby positioning it to reflect external heat.

[0039] The coating process was performed by cutting said flame-resistant fabric (21) to fit the dimensions of the battery pack (10) to be coated. A layer of a polyimide-based insulating tape (22) is present on top of said flame-resistant fabric (21) and / or between the flame-resistant fabric (21) and the battery pack (10). In a preferred embodiment of the invention,a layer of polyimide-based insulating tape (22) is used in two layers: one between the battery pack (10) and the flame-resistant fabric (21), and another on the outer surface of the flame-resistant fabric (21). In another preferred embodiment, two layers of insulating tape (22) may also be used on top of each other. Said insulating tape (22) holds the seams and folds of the flame-resistant fabric (21) in place.

[0040] Prior to coating, ceramic fiber adhesive is preferably applied to the inner surface or edges of the flame-resistant fabric (21). Said ceramic fiber adhesive is heat-resistant to temperatures exceeding 1200°C. If the ceramic fiber adhesive is to be applied to the inner surface or edges of the flame-resistant fabric, the battery pack (10) is first wrapped with a polyimide-based insulating tape (22) for insulation.

[0041] The basic steps required to prepare the battery pack (10) from its initial assembly to the point of sale are as follows:

[0042] a. Preparing the battery pack (10) with series and parallel connections, along with the BMS circuit and cable / socket connections (11), b. Preparing a flame-resistant fabric (21) by cutting it to fit the dimensions of the battery pack (10),

[0043] c. Completely wrapping the battery pack (10) with the flame-resistant fabric (21),

[0044] d. Coating the area around said flame-resistant fabric (21) and / or the space between the flame-resistant fabric (21) and the battery pack (10) with a polyimide-based insulating tape (22).

[0045] Additionally, prior to step “c,” there is a step involving the application of ceramic fiber adhesive of the desired thickness to the inner surface or edges of the flame-resistant fabric (21). For this step, it is preferable to place a polyimide-based insulating tape (22) between the fabric (21) and the battery pack (10) for insulation.

[0046] After the preparation step, there are the following steps:

[0047] - Securing the edges of the flame-resistant fabric (21) (preferably using glass fiber sewing thread or an adhesive with suitable properties, such as cyanoacrylate)

[0048] - wrapping the perimeter of said polyimide-based insulating tape (22) with heat-shrink tubing,- placing the wrapped battery pack (10) into the battery compartment, - performing testing and labeling procedures.

Claims

CLAIMS1. A rechargeable battery pack (10) designed to enhance fire safety, having a coating (20) wrapped around its outer surface, characterized in that the coating (20) comprises the following:a layer of flame-resistant fabric (21),a layer of a polyimide-based insulating tape (22) on top of said flame-resistant fabric (21) and / or between the flame-resistant fabric (21) and the battery pack (10).

2. The coated (20) battery pack (10) according to claim 1, characterized in that it comprises a ceramic fiber adhesive located on the inner surface or edges of said flame-resistant fabric (21).

3. The coated (20) battery pack (10) according to claim 1, characterized in that the fire-resistant fabric (21) comprises two layers of a polyimide-based insulating tape (22).

4. The coated (20) battery pack (10) according to claim 1, characterized in that said flame-resistant fabric (21) is an aluminized para-aramid fabric.

5. The coated (20) battery pack (10) according to claim 4, characterized in that the aluminum-coated surface of said aluminum-coated para-aramid fabric is positioned to face outward.

6. The coated (20) battery pack (10) according to claim 1 or 3, characterized in that it comprises a heat-shrink tubing surrounding said polyimide-based insulating tape (22).

7. The coated (20) battery pack (10) according to claim 1, characterized in that it includes glass fiber sewing thread or adhesive for securing the flame-resistant fabric (21) on its inner surface or edges.

8. A method for producing a rechargeable battery pack (10) having a flame-resistant coating (20) according to any one of claims 1 to 7, for the purpose of enhancing fire safety, characterized in that it comprises the following steps:a. providing a battery pack (10),b. preparing a flame-resistant fabric (21) by cutting it to fit the dimensions of the battery pack (10),c. completely wrapping the battery pack (10) with the flame-resistant fabric (21),d. coating the area around said flame-resistant fabric (21) and / or the space between the flame-resistant fabric (21) and the battery pack (10) with a polyimide-based insulating tape (22).

9. The method according to claim 8, characterized in that it comprises the step of covering the perimeter of said flame-resistant fabric (21) with two layers of polyimide-based insulating tape (22) applied one on top of the other.

10. The method according to claim 8, characterized in that it comprises the step of applying a ceramic fiber adhesive to the inner surface or edges of the flame- resistant fabric (21) prior to step “c”.

11. The method according to claim 8, characterized in that it comprises the step of securing the edges of the flame-resistant fabric (21) after step “c”.

12. The method according to claim 11, characterized in that said securing step is performed using glass fiber sewing thread or an adhesive.

13. The method according to claim 8, characterized in that it comprises the step of covering the periphery of said polyimide-based insulating tape (22) with heatshrink tubing after step “d.”

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