Battery pack

Abstract

According to exemplary embodiments, a pack housing is provided. The pack housing comprises: a bottom plate; a cross beam on the bottom plate; multiple bolts fastened to the bottom plate; and multiple shafts fastened to the cross beam, wherein each of the multiple shafts overlaps a corresponding bolt among the multiple bolts in a direction perpendicular to the bottom plate.

Description

battery pack

[0001] The present invention relates to a battery pack. The present application claims the benefit of Korean application No. 10-2024-0152250, filed on October 31, 2024, which is incorporated herein by reference in its entirety.

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as energy sources for various wireless devices such as handsets, laptops, and cordless vacuum cleaners. Recently, as the manufacturing cost per unit capacity of secondary batteries has decreased dramatically due to improved energy density and economies of scale, and as the driving range of BEVs (battery electric vehicles) has increased to a level equivalent to that of fuel vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] The trend in the technological development of secondary batteries for mobility is the improvement of energy density and safety. The safety of secondary batteries for mobility is critical as it is directly related to the lives of passengers. The safety of secondary batteries can be achieved through mechanical robustness, the reliability of electrical insulation, and the delay of heat transfer in the event of a thermal runaway event.

[0004] The problem that the technical concept of the present invention aims to solve is to provide a battery pack having enhanced safety.

[0005] According to exemplary embodiments of the present invention for solving the above-described problem, a battery pack is provided. The battery pack comprises: a pack housing including a base plate and a side wall perpendicular to the base plate; a battery cell assembly on the pack housing; a thermally degradable adhesive layer interposed between the battery cell assembly and the base plate; and a frame cover on the battery cell assembly.

[0006] The decomposition temperature of the above-mentioned thermally decomposable adhesive layer is different from the melting temperature of the above-mentioned flame cover.

[0007] The decomposition temperature of the above thermally decomposable adhesive layer is lower than the melting temperature of the above flame cover.

[0008] The decomposition temperature of the above-mentioned thermally decomposable adhesive layer is in the range of 100°C to 200°C.

[0009] The melting temperature of the above flame cover is 300℃ or higher.

[0010] The battery cell assembly comprises battery cells and thermal separators interposed between the battery cells.

[0011] The decomposition temperature of the above thermally decomposable adhesive layer is different from the melting temperature of each of the above thermal separators.

[0012] The decomposition temperature of the above thermally decomposable adhesive layer is lower than the melting temperature of each of the above thermal separators.

[0013] The melting temperature of each of the above thermal separators is 300°C or higher.

[0014] There are two or more of the battery cells between two adjacent thermal separators.

[0015] The above thermal separators alternate with the battery cells.

[0016] The above pyrolytic adhesive layer includes a polymer resin.

[0017] The above pyrolytic adhesive layer contains polyurethane.

[0018] According to exemplary embodiments of the present invention, when a thermal runway event occurs in a battery cell, the battery cell in which the thermal runway event occurred can be thermally isolated from other battery cells, and thereby the safety of the battery pack can be enhanced.

[0019] The effects obtainable from the exemplary embodiments of the present invention are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure belong from the following description. That is, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0020] FIG. 1 is a plan view showing a battery pack according to exemplary embodiments.

[0021] Figure 2 is a cross-sectional view taken along the cutting line 1A-1A' of Figure 1.

[0022] FIG. 3 is a diagram showing the effect of a battery pack according to exemplary embodiments.

[0023] FIG. 4 is a plan view showing a battery pack according to other exemplary embodiments.

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0025] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0026] In addition, in describing the present invention, if it is determined that a detailed description of related known components or functions may obscure the essence of the invention, such detailed description is omitted.

[0027] Since embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or schematically depicted for clearer explanation. Accordingly, the size or proportion of each component does not entirely reflect the actual size or proportion.

[0028]

[0029] (1st embodiment)

[0030] FIG. 1 is a plan view showing a battery pack (100) according to exemplary embodiments.

[0031] Figure 2 is a cross-sectional view taken along the cutting line 1A-1A' of Figure 1.

[0032] Referring to FIGS. 1 and 2, the battery pack (100) may include a pack housing (110), battery cell assemblies (120), thermally degradable adhesive layers (130), and a flame cover (140). In FIG. 1, the lid (118) of the pack housing (110) and the flame cover (140) are omitted to indicate the arrangement between the components of the battery pack (100). The battery pack (100) may be a final product mounted in an application such as a vehicle.

[0033] The pack housing (110) may provide a space for mounting battery cell assemblies (120). The pack housing (110) may include a bottom plate (111), side walls (112, 113, 114, 115), a center beam (116), cross beams (117), and a lead (118).

[0034] Here, two directions substantially parallel to the mounting surface (111M) of the base plate (111) are defined as the X direction and the Y direction, and a direction substantially perpendicular to the mounting surface (111M) of the base plate (111) is defined as the Z direction. The X direction, the Y direction, and the Z direction may be substantially perpendicular to each other. The mounting surface (111M) may face the battery cell assemblies (120). The base plate (111) may have a flat shape. The base plate (111) may include metal.

[0035] Side walls (112, 113, 114, 115) may be located at the edges of the bottom plate (111). Side walls (112, 113, 114, 115) may be attached to the bottom plate (111). Side walls (112, 113, 114, 115) may be fixed to the bottom plate (111) by methods such as bolting and welding. Side walls (112, 113, 114, 115) may comprise metal.

[0036] The side walls (112, 113) may be substantially perpendicular to the Y direction. The side walls (112, 113) may be spaced apart from each other in the Y direction. The side walls (114, 115) may be substantially perpendicular to the X direction. The side walls (114, 115) may be spaced apart from each other in the X direction. The side walls (112, 113, 114, 115) may horizontally surround the battery cell assemblies (120).

[0037]

[0038] The center beam (116) may extend in the X direction. The center beam (116) may be surrounded by side walls (112, 113, 114, 115). The center beam (116) may be joined to the base plate (111). The center beam (116) may be fixed to the base plate (111) by either welding or bolting. The center beam (116) may comprise metal.

[0039] Each of the cross beams (117) may extend in the Y direction. The cross beams (117) may be surrounded by side walls (112, 113, 114, 115). The cross beams (117) may be joined to the bottom plate (111). A center beam (116) may be located between the cross beams (117). Each of the cross beams (117) may contain metal.

[0040] The center beam (116) and the cross beams (117) can isolate the battery cell assemblies (120) from each other. The battery cell assemblies (120) can be spaced apart in the Y direction with the center beam (116) in between. The center beam (116) can be interposed between the battery cell assemblies (120). The battery cell assemblies (120) can be spaced apart in the X direction with the cross beams (117) in between. The cross beams (117) can be interposed between the battery cell assemblies (120).

[0041] In FIG. 1, the arrangement of battery cell assemblies (120) can be described as a 2 * 2 arrangement. The arrangement of battery cell assemblies (120) disclosed in FIG. 1 is a non-limiting example and does not limit the technical concept of the invention in any sense. A person skilled in the art will be able to easily arrive at battery cell assemblies (120) arranged in an M * N arrangement (where M and N are each integers greater than or equal to 1) based on what is described herein.

[0042] The lead (118) can cover elements mounted inside the battery pack (100), such as battery cell assemblies (120) and electrical components. The lead (118) can be secured to the side walls (112, 113, 114, 115) by mechanical joining means, such as bolting. A gasket may be further provided between the lead (118) and the side walls (112, 113, 114, 115), thereby providing liquid sealing of the battery pack (100).

[0043] Battery cell assemblies (120) may be on a bottom plate (111). Each of the battery cell assemblies (120) may include battery cells (121) and thermal separators (123). Each of the battery cell assemblies (120) may further include first and second integrated circuit assemblies and a Flexible Flat Cable (FFC) assembly connecting them.

[0044] Each of the battery cells (121) may include an electrode assembly, an electrolyte, and a case. Each of the battery cells (121) may be a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell. The electrode assembly of the cylindrical battery cell is embedded in a cylindrical metal can. The electrode assembly of the prismatic battery cell is embedded in a prismatic metal can. The electrode assembly of the pouch-type battery cell is embedded in a pouch case containing an aluminum laminate sheet.

[0045] An electrode assembly includes an anode, a cathode, and a separator interposed between the anode and the cathode. A jelly roll type electrode assembly includes a wound structure of an anode, a cathode, and a separator interposed between them. A stack type electrode assembly includes a plurality of sequentially stacked anodes, a plurality of cathodes, and a plurality of separators interposed between them.

[0046] According to exemplary embodiments, the battery cells (121) may comprise a plurality of banks. Each of the plurality of banks may include one or more parallel-connected battery cells. The plurality of banks may be connected in series with each other. The number of battery cells included in each of the plurality of banks and the number of banks connected in series with each other may be determined according to the voltage and current to be output through each of the battery cell assemblies (120).

[0047] According to exemplary embodiments, each of the thermal separators (123) may be located between the battery cells (121). According to exemplary embodiments, two or more of the battery cells (121) may be located between two adjacent thermal separators (123).

[0048] In FIG. 2, four battery cells (121) are shown forming a subgroup, and the subgroups of battery cells (121) and thermal separators (123) are shown arranged alternately; however, this is for illustrative purposes only and does not limit the technical concept of the invention in any sense. For example, there may be one bank or two banks between adjacent thermal separators (123).

[0049] According to exemplary embodiments, thermal separators (125) may be configured to divide battery cells (121) into two or more groups to delay or prevent a thermal runway event occurring in one group from propagating to another group. Here, thermal runway is an uncontrollable positive feedback condition in which a temperature change in the battery cells (121) further accelerates that temperature change. Battery cells (121) in a thermal runway state exhibit a rapid temperature rise and emit large amounts of high-pressure gas and combustion residue.

[0050] According to exemplary embodiments, each of the thermal separators (123) may have a high melting temperature. According to exemplary embodiments, each of the thermal separators (123) may have a low thermal conductivity.

[0051] According to exemplary embodiments, the melting temperature of each of the thermal separators (123) may be about 300°C or higher. According to exemplary embodiments, the melting temperature of each of the thermal separators (123) may be about 600°C or higher. According to exemplary embodiments, the melting temperature of each of the thermal separators (123) may be about 1000°C or higher. According to exemplary embodiments, the melting temperature of each of the thermal separators (123) may be 1500°C or higher.

[0052] According to exemplary embodiments, the thermal conductivity of each of the thermal separators (123) may be about 20 W / mK or less. According to exemplary embodiments, the thermal conductivity of each of the thermal separators (123) may be about 1 W / mK or less. According to exemplary embodiments, the thermal conductivity of each of the thermal separators (123) may be about 0.3 W / mK or less. The thermal conductivity of each of the thermal separators (123) described above may be measured at room temperature (about 25°C).

[0053] According to exemplary embodiments, each of the thermal separators (123) may comprise a ceramic material such as aluminum oxide (alumina), magnesium oxide (magnesia), silicon dioxide (silica), silicon nitride, silicon carbide (carborundum), and aluminum silicate. According to exemplary embodiments, each of the thermal separators (123) may comprise any one of calcium silicate, calcium-magnesium silicate, and aramid. According to exemplary embodiments, each of the thermal separators (123) may comprise a glass fiber coated with, for example, silicon, acrylic, vermiculite, graphite, and polytetrafluoroethylene (PTFE).

[0054] According to exemplary embodiments, each of the thermal separators (123) may include a compressible material. According to exemplary embodiments, each of the thermal separators (123) may absorb swelling of the battery cells (121).

[0055] The first integrated circuit assembly may include an insulating frame, an integrated circuit, busbars, wiring, and an insulating cover. The integrated circuit assembly may include physical and functional configurations for providing electrical connections between battery cells (121), outputting the resulting voltage of the battery cells (121), and measuring the voltage (or current) of nodes within a circuit composed of battery cells (121).

[0056] The insulating frame may include an insulating material such as plastic. The insulating frame may cover the front of the battery cells (121). The insulating frame may support integrated circuits, bus bars, and wiring.

[0057] The bus bars can be short-circuited to the positive leads of the battery cells of the first bank and the negative leads of one or more battery cells of the last bank. The bus bars can be welded to the positive leads of the battery cells of the first bank and the negative leads of one or more battery cells of the last bank. The resulting voltage of each battery cell (121) of the battery cell assemblies (120) can be output through the bus bars. The bus bars can be fixed to an insulating frame.

[0058] The integrated circuit can be mounted on an insulating frame. Positive leads and negative leads welded to each other can form nodes within each of the battery cell assemblies (120). The integrated circuit can be configured to measure the voltage of the nodes through sensing plates and sensing bars.

[0059] The sensing bars may include a conductive material. The sensing bars may have a rod shape. The sensing bars may be short-circuited to the bus bars. The sensing bars may be coupled to the bus bars. Through the sensing bars, the voltage of the bus bars can be measured.

[0060] Each of the plurality of sensing plates may have a patch shape or a pad shape. The plurality of sensing plates may include a conductive material. The plurality of sensing plates may be short-circuited to corresponding positive leads and negative leads of the battery cells (121).

[0061] Each of the multiple sensing plates can be connected to an integrated circuit. Through the multiple sensing plates, the voltage of multiple nodes within the battery cell assemblies (120) can be measured.

[0062] The insulating cover may include an insulating material such as plastic. The insulating cover may be fitted into an insulating frame. The insulating cover may cover integrated circuits and bus bars, and accordingly, the electrical elements of the first and second integrated circuit assemblies may be protected.

[0063] The second integrated circuit assembly may include an insulating frame, an integrated circuit, busbars, wiring, and an insulating cover. The second integrated circuit assembly is substantially identical to the first integrated circuit assembly except that it does not include busbars.

[0064] The thermally degradable adhesive layers (130) may be located between the battery cell assemblies (120) and the base plate (111). The thermally degradable adhesive layers (130) may be in contact with the battery cell assemblies (120) and the base plate (111). The thermally degradable adhesive layers (130) may secure the battery cell assemblies (120) and the base plate (111). According to exemplary embodiments, the thermally degradable adhesive layers (130) may mediate heat transfer between the battery cell assemblies (120) and the base plate (111) within a normal temperature range. The thermally degradable adhesive layers (130) may degrade if exposed to high-temperature conditions, such as a thermal runaway event.

[0065] The decomposition temperature of each of the thermally decomposable adhesive layers (130) may differ from the melting temperature of each of the thermal separators (123). The decomposition temperature of each of the thermally decomposable adhesive layers (130) may be lower than the melting temperature of each of the thermal separators (123).

[0066] Each of the thermally degradable adhesive layers (130) may comprise a main component (Part A), a curing agent (Part B), a dispersant, and an inorganic filler. The thermally degradable adhesive layers (130) may further comprise viscosity modifiers such as thixotropic agents, diluents, surface treatment agents, and coupling agents. The thermally degradable adhesive layers (130) may be a room-temperature curable composition. That is, the curing reaction of the thermally degradable adhesive layers (130) may start and proceed at room temperature.

[0067] Each subject of the thermally degradable adhesive layers (130) may comprise a thermosetting resin. Each subject of the thermally degradable adhesive layers (130) may comprise a thermoplastic resin. Each subject of the thermally degradable adhesive layers (130) may comprise a polymer resin. The subject of the thermally degradable adhesive layers (130) may comprise polyurethane. If the subject of the thermally degradable adhesive layers (130) is polyurethane, the decomposition temperature of each thermally degradable adhesive layer (130) may be in the range of about 100°C to about 200°C. The thermally degradable adhesive layers (130) may comprise any resin that decomposes in the range of about 100°C to about 200°C.

[0068] The curing agent for each of the thermally degradable adhesive layers (130) may be selected according to the subject of each of the thermally degradable adhesive layers (130). For example, if the subject of each of the thermally degradable adhesive layers (130) is polyurethane, the curing agent may include isocyanates such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, and polymeric methylene diphenyl diisocyanate.

[0069] Each inorganic filler of the thermally degradable adhesive layers (130) may have relatively high thermal conductivity. According to exemplary embodiments, the thermal conductivity of each inorganic filler of the thermally degradable adhesive layers (130) may be about 1 W / mK or higher. According to exemplary embodiments, the thermal conductivity of each inorganic filler of the thermally degradable adhesive layers (130) may be 5 W / mK or higher. According to exemplary embodiments, the thermal conductivity of each inorganic filler of the thermally degradable adhesive layers (130) may be 10 W / mK or higher. According to exemplary embodiments, the thermal conductivity of each inorganic filler of the thermally degradable adhesive layers (130) may be about 15 W / mK or higher.

[0070] According to exemplary embodiments, the inorganic filler of each of the thermally degradable adhesive layers (130) may comprise ceramic. For example, the inorganic filler of each of the thermally degradable adhesive layers (130) may comprise any one of aluminum oxide (Al2O3), aluminum nitride (AlN), boron nitride (BN), silicon nitride (Si3N4), silicon carbide (SiC), beryllium oxide (BeO), zinc oxide (ZnO), aluminum hydroxide (Al(OH)3), and boehmite. Each of the thermally degradable adhesive layers (130) may also comprise a carbon filler. Each of the thermally degradable adhesive layers (130) may comprise, for example, any one of fumed silica, clay, and calcium carbonate.

[0071] The dispersant of each of the thermally degradable adhesive layers (130) can improve the dispersibility of the inorganic filler of each of the thermally degradable adhesive layers (130). The inorganic filler can be uniformly distributed by the dispersant.

[0072] A flame cover (140) may be on the battery cell assemblies (120) and the cross beams (117). The flame cover (140) may be secured to the cross beams (117) by an adhesive layer or by bolting. In FIG. 2, the battery cell assemblies (120) are shown being covered by a single flame cover (140), but are not limited thereto. For example, two of the battery cell assemblies (120) may be covered by a single flame cover (140), or each of the battery cell assemblies (120) may be covered by a separate flame cover (140).

[0073] According to exemplary embodiments, each of the thermal separators (123) of the flame cover (140) may have a high melting temperature. According to exemplary embodiments, each of the thermal separators (123) may have a low thermal conductivity.

[0074] The flame cover (140) may include cutting guides. Each of the cutting guides may be formed by non-cutting processing of the flame cover (140) using a knife or the like. When a thermal runaway event occurs due to the cutting guides, the part of the flame cover (140) where the cutting guides are formed may be easily broken, and accordingly, a venting path may be provided.

[0075] According to exemplary embodiments, the melting temperature of the flame cover (140) may be about 300°C or higher. According to exemplary embodiments, the melting temperature of the flame cover (140) may be about 600°C or higher. According to exemplary embodiments, the melting temperature of the flame cover (140) may be about 1000°C or higher. According to exemplary embodiments, the melting temperature of the flame cover (140) may be 1500°C or higher.

[0076] The decomposition temperature of each of the thermally decomposable adhesive layers (130) may differ from the melting temperature of the flame cover (140). The decomposition temperature of each of the thermally decomposable adhesive layers (130) may be lower than the melting temperature of the flame cover (140).

[0077] According to exemplary embodiments, the thermal conductivity of the flame cover (140) may be about 20 W / mK or less. According to exemplary embodiments, the thermal conductivity of the flame cover (140) may be about 1 W / mK or less. According to exemplary embodiments, the thermal conductivity of the flame cover (140) may be about 0.3 W / mK or less. The thermal conductivity of the flame cover (140) described above may be measured at room temperature (about 25°C).

[0078] According to exemplary embodiments, the flame cover (140) may comprise a ceramic material such as aluminum oxide (alumina), magnesium oxide (magnesia), silicon dioxide (silica), silicon nitride, silicon carbide (carborundum), and aluminum silicate. According to exemplary embodiments, the flame cover (140) may comprise any one of calcium silicate, calcium-magnesium silicate, and aramid. According to exemplary embodiments, the flame cover (140) may comprise glass fiber coated with any one of silicon, acrylic, vermiculite, graphite, and polytetrafluoroethylene (PTFE). According to exemplary embodiments, the flame cover (140) may comprise mica.

[0079] The battery pack may further include exhaust devices coupled to the pack housing (110). The pack housing (110) may include exhaust holes connected to the exhaust devices. In the event that a thermal runaway event occurs in the battery cell assemblies (120), the exhaust devices may be configured to delay heat propagation by releasing high-temperature gas inside the battery pack (100) to the outside.

[0080] The battery pack (100) may further include a Battery Management System (BMS). The BMS may be configured to perform monitoring, balancing, and control of the battery pack (100). Monitoring of the battery pack (100) may include measuring the voltage and current of specific nodes within the battery cell assemblies (120) and measuring the temperature of set locations within the battery pack (100). The battery pack (100) may include instruments for measuring the voltage, current, and temperature described above.

[0081] Balancing of the battery pack (100) is an operation that reduces deviations between battery cell assemblies (120). Control of the battery pack (100) includes preventing overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack (100) can operate under optimal conditions, and accordingly, the shortening of the lifespan of each battery cell assembly (120) can be prevented.

[0082] The battery pack (100) may further include additional electrical components such as a cooling device, a Power Relay Assembly (PRA), and a safety plug. The cooling device may include a cooling fan. The cooling fan can prevent overheating of each of the battery cell assemblies (120) by circulating air inside the battery pack (100). The PRA may be configured to supply or cut off power from the high-voltage battery to an external load (e.g., a vehicle motor). The PRA can protect the battery cell assemblies (120) and the external load (e.g., a vehicle motor) by cutting off power supply to the external load (e.g., a vehicle motor) in situations where abnormal voltage occurs, such as a voltage surge.

[0083] The battery pack (100) may further include a plurality of interbusbars configured to electrically connect battery cell assemblies (120). The battery cell assemblies (120) may be connected in series by the plurality of interbusbars. Accordingly, the battery pack (100) may be configured to output a high voltage to an external load (e.g., a motor of a vehicle).

[0084]

[0085] FIG. 3 is a drawing for explaining the effects of a battery pack (100) according to exemplary embodiments.

[0086] Referring to FIGS. 1 through 3, a thermal runaway event (TP) may occur in some of the battery cells (121). A portion of the flame cover (140) that overlaps with the battery cell (121) where the thermal runaway event (TP) occurred may be broken, and accordingly, a venting hole (140H) may be formed. According to exemplary embodiments, a portion of the thermally degradable adhesive layer (130) adjacent to the battery cell (121) where the thermal runaway event (TP) occurred may be degraded, and accordingly, heat propagation through the base plate (111) may be mitigated or blocked. The thermal separators (123) and the flame cover (140) may isolate the battery cell (121) where the thermal runaway event (TP) occurred or a subgroup of the battery cells (121) where the runaway event (TP) occurred from other battery cells (121), and may block or delay heat propagation.

[0087]

[0088] (2nd Example)

[0089] FIG. 4 is a plan view showing a battery pack (100') according to other exemplary embodiments.

[0090] Referring to FIG. 4, the battery pack (100) may include a pack housing (110), battery cell assemblies (120'), thermally degradable adhesive layers (130), and a flame cover (140). Since the pack housing (110), thermally degradable adhesive layers (130), and flame cover (140) are substantially the same as those described with reference to FIG. 1 through 3, a redundant description thereof is omitted. They are omitted to show the arrangement between the components of the battery pack (100'). The battery pack (100) may be a final product mounted in an application such as a vehicle.

[0091] Each of the battery cell assemblies (120') may include battery cells (121) and thermal separators (123). Each of the battery cell assemblies (120') may further include first and second integrated circuit assemblies and an FFC assembly connecting them.

[0092] The battery cell assemblies (120') may be substantially identical to the battery cell assemblies (120) of FIGS. 1 and FIGS. 2, except for the arrangement of battery cells (121) and thermal separators (123).

[0093] In FIG. 4, the battery cells (121) and thermal separators (123) may alternate in the X direction. One of the thermal separators (123) may be located between two adjacent battery cells (121). One of the battery cells (121) may be located between two adjacent thermal separators (123). The number of thermal separators (123) is greater than the number of multiple battery cells (121), and each of the multiple battery cells is separated from one another by the thermal separators (123), so the safety of the battery pack (100') can be further enhanced.

[0094]

[0095] The present invention has been described in more detail above through drawings and embodiments. However, the configurations described in the drawings or embodiments described in this specification are merely one embodiment of the present invention and do not represent all technical concepts of the present invention; therefore, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

Claims

1. A pack housing comprising a base plate and a side wall perpendicular to the base plate; Battery cell assembly on the above pack housing; A thermally degradable adhesive layer interposed between the battery cell assembly and the base plate; and A battery pack including a frame cover on the battery cell assembly above.

2. In Paragraph 1, A battery pack characterized in that the decomposition temperature of the above-mentioned thermally decomposable adhesive layer is different from the melting temperature of the above-mentioned flame cover.

3. In Paragraph 1, A battery pack characterized in that the decomposition temperature of the thermally decomposable adhesive layer is lower than the melting temperature of the flame cover.

4. In Paragraph 1, A battery pack characterized in that the decomposition temperature of the above-mentioned thermally decomposable adhesive layer is in the range of 100°C to 200°C.

5. In Paragraph 1, A battery pack characterized by the melting temperature of the above-mentioned flame cover being 300℃ or higher.

6. In Paragraph 1, A battery pack characterized by the above-described battery cell assembly comprising battery cells and thermal separators interposed between the battery cells.

7. In Paragraph 6, A battery pack characterized in that the decomposition temperature of the thermally decomposable adhesive layer is different from the melting temperature of each of the thermal separators.

8. In Paragraph 6, A battery pack characterized in that the decomposition temperature of the thermally decomposable adhesive layer is lower than the melting temperature of each of the thermal separators.

9. In Paragraph 6, A battery pack characterized in that the melting temperature of each of the above thermal separators is 300°C or higher.

10. In Paragraph 6, A battery pack characterized by having two or more of the battery cells between two adjacent thermal separators.

11. In Paragraph 6, A battery pack characterized by the above thermal separators alternating with the above battery cells.

12. In Paragraph 1, A battery pack characterized in that the above-mentioned pyrolytic adhesive layer comprises a polymer resin.

13. In Paragraph 1, A battery pack characterized in that the above-mentioned pyrolytic adhesive layer comprises polyurethane.

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