Heating assembly, battery pack, and vehicle

Abstract

The present invention relates to a battery pack comprising: a heating assembly comprising a base member, a heating member provided on one surface or both surfaces of the base member, and a heat transfer member covering the heating member and contacting battery cells to transfer heat to the battery cells; and a cell block assembly contacting one surface or both surfaces of the heating assembly.

Description

Heating assembly, and battery pack and vehicle

[0001] The present invention relates to a heating assembly, a battery pack, and a vehicle, and more specifically, to a heating assembly for adjusting the temperature conditions of a lithium-sulfur cell, and a battery pack and a vehicle including the same.

[0002] As the application areas of secondary batteries expand to electric vehicles (EVs) and energy storage systems (ESS), lithium-ion secondary batteries, which have a relatively low energy storage density relative to weight (~250 Wh / kg), have limitations in application.

[0003] In contrast, lithium-sulfur secondary batteries are receiving attention as a next-generation secondary battery technology because they can theoretically achieve a high energy storage density (~2,600 Wh / kg) relative to their weight.

[0004] A lithium-sulfur rechargeable battery is a battery system that uses a sulfur-based material with sulfur-sulfur bonds as the positive electrode active material and lithium metal as the negative electrode active material. Such lithium-sulfur rechargeable batteries have the advantage that sulfur, the main material for the positive electrode, is abundant globally, non-toxic, and has a low weight per atom.

[0005] In lithium-sulfur rechargeable batteries, during discharge, lithium, the negative electrode active material, releases electrons and becomes ionized through oxidation, while sulfur-based materials, the positive electrode active material, accept electrons and are reduced. In this process, the oxidation of lithium is the oxidation of lithium metal into a lithium cation form by releasing electrons.

[0006] In addition, the reduction reaction of sulfur is a process in which sulfur-sulfur bonds accept two electrons and are converted into sulfur anions. Lithium cations generated by the oxidation reaction of lithium are transferred to the anode through the electrolyte and combine with sulfur anions generated by the reduction reaction of sulfur to form a salt.

[0007] Lithium-sulfur cells (batteries) having the characteristics described above have a high energy density per unit weight and can be widely used not only in automobiles but also in aircraft, but a heating device is required to maintain the cell temperature at 30°C in consideration of the operating environment.

[0008] In other words, lithium-sulfur cells have a high energy density per unit weight, making them highly promising for use in aircraft requiring lightweight construction. However, aircraft operate at various altitudes ranging from the atmosphere to the stratosphere. For instance, considering the environment of an aircraft used in the stratosphere, where external temperatures are around -85°C, it is difficult to meet the temperature conditions required for cell operation using only the insulation layer inside the pack. Therefore, unlike conventional batteries used in automobiles that require cooling structures, aircraft require heating structures; furthermore, due to the need for lightweight design, it is difficult to use existing heating devices that are bulky and heavy.

[0009] The present invention was devised to solve the problems of the prior art described above, and aims to provide a heating assembly, a battery pack, and a vehicle that can easily meet the temperature conditions required for the operation of a lithium-sulfur cell, reduce volume, and reduce weight.

[0010] A heating assembly according to a preferred embodiment of the present invention for achieving the above-mentioned purpose may include a base member, a heating member provided on one or both sides of the base member, and a heat transfer member that covers the heating member and contacts a battery cell to transfer heat to the battery cell.

[0011] The heating element may be a heating wire or a planar heating element.

[0012] The material of the heat transfer member may be a thermal resin.

[0013] The heat transfer resin can be a urethane-based resin.

[0014] The heat transfer member can diffuse the heat generated from the heat source to the battery cells and bond and fix the battery cells.

[0015] A battery pack according to the present invention may include a heating assembly; and a cell block assembly comprising at least one battery cell and in contact with one or both sides of the heating assembly.

[0016] The battery pack according to the present invention may further include a pack housing that accommodates a heating assembly and a cell block assembly.

[0017] The cell block assemblies are positioned on both sides with the heating assembly in between, and the two cell block assemblies can be connected to each other.

[0018] The battery pack according to the present invention further includes a fastening member for fastening two cell block assemblies together, and when the two cell block assemblies are fastened using the fastening member, a heating assembly can be firmly fixed while being in close contact between them.

[0019] The pack housing may include a lower tray and an upper cover.

[0020] The battery cell can be a lithium-sulfur cell.

[0021] According to the heating assembly, battery pack, and vehicle of the present invention, the temperature within the battery pack can be maintained at an appropriate operating temperature for the battery cells using the heating assembly, thereby allowing the volume and weight of the battery pack to be reduced. For example, the temperature conditions required for the operation of the battery cells can be met even in extreme situations where the external temperature is approximately -85°C.

[0022] In addition, heat generated from the heat source can be evenly transferred to the battery cells through the heat transfer element constituting the heating assembly, and by applying a thermal resin as the heat transfer element, the cell stack in which the heating assembly and battery cells are stacked can be mutually fixed.

[0023] Figure 1 is a drawing showing a vehicle equipped with a battery pack.

[0024] Figure 2 is a perspective view of a battery pack.

[0025] Figure 3 is an exploded view of a battery pack.

[0026] FIG. 4 is a perspective view showing cell block assemblies combined on both the upper and lower sides with a heating assembly in between.

[0027] FIG. 5 is a cross-sectional view showing the heating assembly firmly fixed between the upper and lower cell block assemblies.

[0028] FIG. 6 is an exploded perspective view showing the heating assembly and the cell block assembly disassembled.

[0029] Figure 7 is an enlarged view of section A of Figure 5.

[0030] Hereinafter, a heating assembly, a battery pack, and a vehicle according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0031]

[0032] Figure 1 is a drawing showing a vehicle equipped with a battery pack.

[0033] A vehicle (1), such as an electric vehicle or a hybrid vehicle, may be equipped with one or more battery packs (10). The battery packs (10) can supply electrical energy required for various operations of the vehicle (1). Additionally, the vehicle (1) may include various other components in addition to the battery packs (10). For example, the vehicle (1) may further include a vehicle body, a motor, an electronic control unit (ECU), and other control devices.

[0034]

[0035] FIG. 2 is a perspective view of a battery pack, and FIG. 3 is an exploded perspective view of a battery pack.

[0036] A battery pack (10) according to the present invention may include a pack housing (100), a cell block assembly (200), a heating assembly, and a BMS (400, Battery Management System).

[0037] The pack housing (100) accommodates a cell block assembly (200), a heating assembly, and a BMS (400) inside, and may include a lower tray (110) and an upper cover (120). The cell block assembly (200) may be arranged vertically with the heating assembly in between and accommodated within the pack housing (100) in a mutually connected state. The BMS (400) may be connected to the side of the cell block assembly (200).

[0038] A cell block assembly (200) can accommodate multiple battery cells stacked left and right within a cell frame using a cell stack. The cell frame may include a front and rear plate and side plates, and the front and rear plates may be fastened to the side plates using fastening members such as bolts. The battery cells accommodated in the cell block assembly (200) may be lithium-sulfur cells.

[0039] As described above, in a lithium-sulfur cell, during discharge, lithium, the negative electrode active material, releases electrons and becomes ionized, thereby undergoing oxidation, while sulfur-based materials, the positive electrode active material, accept electrons and undergo reduction. At this time, the oxidation reaction of lithium is a process in which lithium metal releases electrons and is converted into a lithium cation. The reduction reaction of sulfur is a process in which sulfur-sulfur bonds accept two electrons and are converted into a sulfur anion. The lithium cations generated by the oxidation reaction of lithium are transferred to the positive electrode through the electrolyte and combine with the sulfur anions generated by the reduction reaction of sulfur to form a salt.

[0040] Lithium-sulfur cells with such characteristics have a high energy density per unit weight, making them widely applicable not only to automobiles but also to aircraft. In particular, they can be used in high-altitude unmanned aerial vehicles.

[0041] The heating assembly is positioned between the upper layer cell block assembly (200) and the lower layer cell block assembly (200), and can be firmly fixed by being located between them when the upper and lower cell block assemblies (200) are firmly connected to each other. The heating assembly can create temperature conditions suitable for operating the battery cells by generating heat and transferring it to the battery cells of the cell block assembly (200). The detailed structure of the heating assembly will be described in detail in the description of FIGS. 5 to 7 to be described later.

[0042] The BMS (400) controls the battery cells to maintain them in an optimal state and extend their lifespan, and is electrically connected to the battery cells and can also be electrically connected to the heating assembly. For example, the BMS (400) can optimize the temperature conditions of the battery cells by controlling the operation of the heating assembly. To this end, temperature sensors may be provided inside the pack housing (100) and inside the cell block assembly (200), and the amount of heat generated by the heating assembly can be controlled according to the signals detected by each sensor.

[0043]

[0044] FIG. 4 is a perspective view showing cell block assemblies joined to the upper and lower sides with a heating assembly in between, FIG. 5 is a cross-sectional view showing the heating assembly firmly fixed between the upper and lower cell block assemblies, FIG. 6 is an exploded perspective view showing the heating assembly and cell block assembly disassembled, and FIG. 7 is an enlarged view of section A of FIG. 5.

[0045] The heating assembly (300) is positioned between the upper layer cell block assembly (200) and the lower layer cell block assembly (200), and can be firmly fixed between the two cell block assemblies (200) when the upper and lower cell block assemblies (200) are fastened to each other by a long fastening bolt (500). Bolt through holes (211) through which the fastening bolt (500) passes can be formed in the two side plates (210) constituting the cell block assembly (200).

[0046] The fastening bolt (500) penetrates the bolt through holes (211) from top to bottom, and its end is screwed into a bolt fastening hole (not shown) formed in the lower tray (110), thereby allowing the lower tray (110), the lower layer cell block assembly (200), and the upper layer cell block assembly (200) to be firmly fastened. In the case of the heating assembly (300), the fastening bolt (500) does not penetrate and directly fasten it, but it can be placed between the upper layer cell block assembly (200) and the lower layer cell block assembly (200) and be firmly fixed when they are firmly fastened.

[0047] The heating assembly (300) generates heat under the control of the BMS (400) and transfers the heat to the battery cells (220) of the cell block assembly (200), and may include a base member (310), a heating member (320), and a heat transfer member (330).

[0048] The base member (310) is formed in the shape of a wide plate and can be molded from an insulating material.

[0049] The heating element (320) can be a heating wire or a planar heating element and can be operated to generate heat when power is applied through the power supply line of the BMS (400). The amount of heat generated from the heating element (320) can be controlled by the BMS (400). The heating element (320) can be arranged on the upper and lower surfaces of the base member (310), respectively.

[0050] The heat transfer member (330) is evenly provided on the upper and lower surfaces of the base member (310) to cover the heat-generating member (320) and simultaneously contacts the battery cells (220) through the cell stack to transfer heat to the battery cells (220). The heat transfer member (330) may be a thermal resin and may be evenly applied to the upper and lower surfaces of the base member (310). This heat transfer member (330) can evenly diffuse the heat emitted from the heat-generating member (320) and transfer it uniformly to the battery cells (220). In addition, the heat transfer member (330) may also perform the role of fixing the cell stack. To this end, a two-component (main component + hardener) type urethane material may be applied as the heat transfer resin, but is not limited thereto and various known materials may be applied.

[0051] A pair of cell block assemblies (200) and a heating assembly (300) can be bonded together by the adhesive force of a heat transfer member (330) constituting the heating assembly (300), and when two cell block assemblies (200) arranged with the heating assembly (300) in between are firmly fastened by a fastening bolt (500), the heating assembly (300) can be firmly attached to the cell block assemblies (200) in between, thereby strengthening the bonding state.

[0052] Through this adhesive and fastening structure, heat generated in the heating assembly (300) can be smoothly transferred to the battery cells (220) constituting the cell block assembly (200), and the interior of the battery pack (10) can be easily maintained at a temperature suitable for the operation of the battery cells (220).

[0053]

[0054] As described above, a heating assembly, a battery pack, and a vehicle according to a preferred embodiment of the present invention have been described in detail with reference to the attached drawings; however, the present invention is not limited to the above-described embodiment and can be implemented in various modified ways within the scope of the claims.

[0055] For example, in an embodiment of the present invention, the battery cell may be a lithium-sulfur cell, but is not limited thereto and may be other known types of cells. Additionally, in an embodiment of the present invention, the battery pack is exemplified as being mounted on a vehicle, but is not limited thereto and may be mounted on other known means such as an aircraft.

[0056] [Explanation of the symbol]

[0057] 1 : Vehicle 10 : Battery Pack

[0058] 100 : Pack housing 110 : Bottom tray

[0059] 120 : Upper cover 200 : Cell block assembly

[0060] 210 : Side plate 211 : Bolt through hole

[0061] 220: Battery cell 300: Heating assembly

[0062] 310 : Base member 320 : Heating member

[0063] 330 : Heat transfer element 400 : BMS

[0064] 500 : Fastening bolt

Claims

1. Base member; A heating element provided on one or both sides of the base member; and A heating assembly comprising: a heat transfer member that covers the heating member and contacts the battery cell to transfer heat to the battery cell.

2. In Paragraph 1, The above heating element is a heating wire or a planar heating chain, a heating assembly.

3. In Paragraph 1, A heating assembly in which the material of the above-mentioned heat transfer member is thermal resin.

4. In Paragraph 3, A heating assembly in which the heat transfer resin is a urethane-based resin.

5. In Paragraph 3, The above heat transfer member is a heating assembly that diffuses heat generated from the above heating member to the battery cells and adhesively fixes the battery cells.

6. A heating assembly according to any one of claims 1 to 5; and A battery pack comprising at least one battery cell and a cell block assembly in contact with one or both sides of the heating assembly.

7. In Paragraph 6, A battery pack further comprising a pack housing that accommodates the heating assembly and the cell block assembly.

8. In Paragraph 6, A battery pack in which the cell block assemblies are positioned on both sides with the heating assembly in between, and the two cell block assemblies are connected to each other.

9. In Paragraph 8, It further includes a fastening member that fastens both cell block assemblies together, A battery pack in which the heating assembly is firmly fixed while closely adhering to the space between the two cell block assemblies when the two cell block assemblies are connected using the above-mentioned connecting member.

10. In Paragraph 7, The above pack housing is a battery pack comprising a lower tray and an upper cover.

11. In Paragraph 6, The above battery cell is a lithium-sulfur cell, and the battery pack.

12. A vehicle comprising the battery pack of claim 6.

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