Battery assembly and device including the same

Abstract

A battery assembly according to one embodiment of the present invention comprises a plurality of battery cells; It includes a cell frame in which the battery cells are housed; and an inlet port and an outlet port for circulating the refrigerant. Inside the cell frame, a cooling channel is provided through which the refrigerant flows in direct contact with at least a portion of the battery cells, and at least a portion of the battery cells include a surface treatment portion.

Description

Technology Field

[0001] The present invention relates to a battery assembly and a device including the same, and more specifically, to a battery assembly capable of effectively controlling temperature variations between battery cells and a device including the same. Background Technology

[0002] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0004] These lithium-ion batteries are configured as modules by connecting multiple battery cells in series or parallel, and multiple modules are combined with control / protection systems such as a Battery Management System (BMS) and a Battery Disconnect Unit (BDU), as well as a cooling system, to form a battery pack. At this time, if the differences in heat generation characteristics between battery cells are not properly managed, problems may arise where only specific cells experience excessive temperature increases or rapid cooling. Since this is a major cause of battery performance degradation and shortened lifespan, effective thermal management technology in battery assemblies is emerging as a very important challenge.

[0005] Generally, various cooling methods, such as air and water cooling, have been proposed for the thermal management of battery assemblies; however, it is difficult to simultaneously achieve high cooling efficiency and weight reduction. In particular, if battery cells are not cooled uniformly, temperature variations between cells increase, which can ultimately degrade the safety and performance of the entire battery assembly. Therefore, technologies that reduce temperature variations by having each battery cell come into direct contact with a refrigerant or by applying partial surface treatments are recognized as important, and active research is being conducted on technologies to manage battery cells so that they operate stably even under repeated charge and discharge cycles. The problem to be solved

[0006] The problem that the present invention aims to solve is to reduce the temperature difference between a plurality of battery cells in direct contact with a refrigerant inside a battery assembly, and to suppress cell degradation caused by excessive cooling or local overheating, thereby improving the overall performance and lifespan of the battery.

[0007] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention. means of solving the problem

[0008] A battery assembly according to one embodiment of the present invention comprises a plurality of battery cells; It includes a cell frame in which the battery cells are housed; and an inlet port and an outlet port for circulating the refrigerant. Inside the cell frame, a cooling channel is provided through which the refrigerant flows in direct contact with at least a portion of the battery cells, and at least a portion of the battery cells include a surface treatment portion.

[0009] Some of the above battery cells include the surface treatment portion, and the battery cells including the surface treatment portion may be adjacent to the inlet port than the battery cells not including the surface treatment portion.

[0010] The above surface treatment part may include a heat-shrinkable polymer film or a hot-melt material.

[0011] The above surface treatment portion is formed in a plurality of zones spaced apart along the longitudinal direction of the battery cell, and the heat shrink polymer film layer and the hot melt material layer can be applied alternately in each zone.

[0012] Some of the above surface treatment parts may have a thickness different from other of the above surface treatment parts.

[0013] The battery cells including the relatively thick surface treatment portion may be adjacent to the inlet port than the battery cells including the relatively thin surface treatment portion.

[0014] The above surface treatment unit can selectively cover only a portion of the exterior of the battery cell.

[0015] The above surface treatment part can cover a portion of the upper part of the battery cell.

[0016] The above surface treatment part can cover a lower part of the battery cell.

[0017] The above surface treatment unit can cover the entire surface outside the battery cell.

[0018] The above cooling channels are multiple, and the cooling channels may be arranged along the length direction of the battery cell to which the battery cell extends.

[0019] A portion of the above surface treatment portion may cover a portion of the side of the battery cell corresponding to the cooling channels.

[0020] The flow direction of the refrigerant in any one of the above cooling channels and the flow direction of the refrigerant in another of the above cooling channels may be opposite to each other.

[0021] The area of ​​contact between at least one of the cooling channels, in which the flow direction of the refrigerant matches, and the battery cell may be 30% or more and 70% or less of the area of ​​contact between all of the cooling channels and the battery cell.

[0022] The above cooling channels include a first cooling channel and a second cooling channel, and the refrigerant may flow through the first cooling channel before the second cooling channel.

[0023] The above surface treatment portion may be formed on a part of the battery cell corresponding to the first cooling channel and may not be formed on another part of the battery cell corresponding to the second cooling channel.

[0024] The thickness of the surface treatment portion formed on a part of the battery cell corresponding to the first cooling channel may be thicker than the thickness of the surface treatment portion formed on another part of the battery cell corresponding to the second cooling channel.

[0025] One of the above cooling channels may be connected to the inlet port, and another of the above cooling channels may be connected to the outlet port.

[0026] According to another embodiment of the present invention, a device comprising at least one battery assembly is provided. Effects of the invention

[0027] According to embodiments of the present invention, a plurality of battery cells are in direct contact with a refrigerant, and the rate of heat exchange in each cell can be controlled by zone through a surface treatment unit. This prevents rapid cooling or overheating of a specific cell that may occur at the initial stage of refrigerant inflow, and mitigates temperature variations throughout the battery assembly.

[0028] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0029] FIG. 1 is a perspective view showing a battery assembly according to one embodiment of the present invention. Figure 2 is a plan view showing the battery assembly of Figure 1. Figure 3 is a plan view showing the battery assembly of Figure 1 viewed from a different angle than that of Figure 2. Figure 4 is an exploded perspective view showing the battery assembly of Figure 1. Figure 5 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 3. FIG. 6 is a perspective view showing a battery cell according to one embodiment of the present invention. Figure 7 is a plan view showing the battery cell of Figure 6. FIGS. 8 to 11 are plan views showing battery assemblies according to various embodiments of the present invention. FIG. 12 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of FIG. 6. FIG. 13 is a cross-sectional view showing a battery cell according to another embodiment of the present invention. FIGS. 14 and FIGS. 15 are cross-sectional views showing a battery assembly according to other embodiments of the present invention. Specific details for implementing the invention

[0030] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0031] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0032] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0033] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0034] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0035] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0036] FIG. 1 is a perspective view showing a battery assembly according to one embodiment of the present invention. FIG. 2 is a plan view showing the battery assembly of FIG. 1. FIG. 3 is a plan view showing the battery assembly of FIG. 1 viewed from an angle different from that of FIG. 2. FIG. 4 is an exploded perspective view showing the battery assembly of FIG. 1. FIG. 5 is a cross-sectional view showing a section cut along the cutting line A-A' of FIG. 3. FIG. 6 is a perspective view showing a battery cell according to one embodiment of the present invention. FIG. 7 is a plan view showing the battery cell of FIG. 6. FIG. 8 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0037] Referring to FIGS. 1 to 8, a battery assembly (100) according to one embodiment of the present invention comprises: a plurality of battery cells (110); a cell frame (120) in which the battery cells (110) are housed; and an inlet port (130) and an outlet port (140) for circulating a refrigerant. Inside the cell frame (120), a cooling channel (160) is provided in which the refrigerant flows in direct contact with at least a portion of the battery cells (110), and at least a portion of the battery cells includes a surface treatment portion (111).

[0038] The battery cell (110) according to the present embodiment may be of various forms, such as a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell. For example, as shown in FIG. 4, the battery cell (110) according to the present embodiment may be a cylindrical battery cell. Although the cylindrical battery cell (110) is described below, the battery cell (110) according to the present embodiment is not limited thereto, and various types of battery cells may be applied.

[0039] The battery assembly (100) according to the present embodiment may include a plurality of battery cells (110). The plurality of battery cells (110) may be arranged along the xy plane of FIG. 4 while standing upright so that the sides of the battery cell (110) bodies face each other. Electrode terminals may protrude along the +z-axis direction of FIG. 4.

[0040] Additionally, the battery assembly (100) may include a busbar frame assembly (150). The busbar frame assembly may include a busbar frame on which busbars are arranged. The busbar frame assembly may include at least one busbar connected to an electrode terminal (112). Additionally, the busbar frame assembly may include a printed circuit board. The printed circuit board is configured to sense voltage data or thermal data of the battery cells (110). For example, the printed circuit board may be connected to the electrode terminal (112) or the busbar of the battery cells (110). Accordingly, voltage data of each battery cell (110) can be sensed and transmitted externally. The busbar frame assembly (150) may electrically connect the battery cells (110) in series or in parallel.

[0041] The cell frame (120) may be positioned to cover the upper and lower surfaces and a portion of the sides of the battery cells (110), as shown in FIG. 4. The cell frame (120) may be intended to protect the battery cells (110) and the electrical components connected thereto from external physical impact.

[0042] The cell frame (120) has a portion open so that the electrodes of the stored multiple battery cells can be exposed to the outside, and a bus bar may be positioned around the open area. A battery cell (110) can be fitted and stored in a cell frame hole provided in the cell frame (120). The cell frame (120) can be provided in various shapes and materials so that multiple battery cells can each be fitted. For example, the cell frame (120) can be provided by injection molding.

[0043] A cooling channel (160) may be formed inside the cell frame (120). The cooling channel (160) may flow a refrigerant while in direct contact with at least a portion of the battery cell (110).

[0044] Some battery cells (110) may have a surface treatment portion (111) applied, which covers at least a portion of the surface of the battery cell (110) to control heat exchange characteristics with the refrigerant. This allows the necessary cooling effect to be selectively provided when the battery cell (110) comes into contact with the refrigerant flowing through the cooling channel (160).

[0045] The refrigerant can be introduced into the cell frame (120) through the inlet port (130) and then discharged out of the cell frame (120) through the outlet port (140). The inlet port (130) may be positioned at an angle in the +x-axis direction relative to a virtual line passing through the center of the cell frame (120) while parallel to the y-axis of FIG. 1. The outlet port (140) may be positioned at an angle in the -x-axis direction relative to a virtual line passing through the center of the cell frame (120) while parallel to the y-axis of FIG. 1. The inlet port (130) and the outlet port (140) must be positioned in this way so that the refrigerant can flow through the entire space inside the cell frame (120) and evenly cool all the battery cells (110). If the inlet port (130) and the outlet port (140) are located together in the center of the cell frame (120), the refrigerant will flow only to the central part, which has the least flow resistance, so the refrigerant will not flow well to the battery cells (110) located on the outer part of the cell frame (120). Consequently, this results in a cooling imbalance in the battery assembly (100). Furthermore, if the inlet port (130) and the outlet port (140) are located together on one side of an imaginary line passing through the center of the cell frame (120) while parallel to the y-axis of FIG. 1, the refrigerant will flow only to some of the outer battery cells (110) adjacent to the side of the skewed direction, and thus a cooling imbalance will occur inside the battery assembly (100).

[0046] Additionally, unlike what is shown in FIG. 1, the inlet port (130) and the outlet port (140) may be located on opposite sides of the cell frame (120). When the inlet port (130) and the outlet port (140) are arranged in this way, the refrigerant can be guided to flow evenly through all the battery cells (110) inside the cell frame (120). Additionally, within the cell frame (120), the refrigerant can maintain a unidirectional flow.

[0047] There are no special restrictions on the material of the refrigerant in the present invention, but in one embodiment of the present invention, the refrigerant may be cooling oil. Additionally, the refrigerant may be insulating oil. Since the refrigerant comes into direct contact with the battery cell (110), other electrical components, and busbar frame assembly (150), etc., within the cell frame (120), it needs to be electrically insulated. Therefore, the refrigerant may be insulating oil, which is a material having insulating properties.

[0048] The refrigerant introduced into the inlet port (130) can travel along the cooling path (160) inside the cell frame (120). During travel, the refrigerant can come into direct contact with at least some surface of the battery cell (110) to absorb heat. Surface treatment sections (111) provided on some of the battery cells (110) can adjust the contact area and heat transfer characteristics of the refrigerant. For example, a battery cell (110) with a surface treatment section (111) applied can limit or promote a desired level of heat absorption in contact with the refrigerant. Such a configuration can reduce the temperature difference between the battery cells (110) and prevent a specific cell from being excessively cooled. After absorbing heat while passing through the cooling path (160), the refrigerant can be discharged through the outlet port (140).

[0049] When a refrigerant flows through a cooling channel (160) penetrating the interior of a cell frame (120) in which a battery cell (110) is housed, some battery cells (110) including a surface treatment portion (111) can control the cooling speed. This configuration can ensure thermal balance between each battery cell (110) and mitigate temperature deviations. Additionally, it can prevent the deterioration of the battery cells (110) due to temperature deviations during long-term use, and contribute to maintaining cell performance and extending lifespan. Since the refrigerant is in direct contact with the surface of the battery cell (110), effective heat dissipation is possible, and the temperature distribution can be optimized in response to differences in heat generation characteristics between the battery cells (110). Ultimately, this results in increased cooling efficiency while maintaining more stable energy supply characteristics.

[0050] FIG. 9 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0051] Referring to FIGS. 1 to 9, some of the battery cells (110) include a surface treatment portion (111), and the battery cells (110) including the surface treatment portion (111) may be adjacent to the inlet port (130) than the battery cells (110) that do not include the surface treatment portion (111).

[0052] By applying a surface treatment portion (111) to the battery cell (110) according to the present embodiment, rapid cooling that may occur at the moment the battery cell (110) comes into direct contact with the refrigerant can be mitigated or accelerated. When the refrigerant flows in near the inlet port (130), the battery cell (110) with the surface treatment portion (111) can control the cooling speed above a certain level. This allows for preventing excessive cooling from being concentrated on a specific battery cell (110).

[0053] If some battery cells (110) are designed to have a surface treatment section (111) and the battery cells (110) are positioned close to the inlet port (130), heat exchange can be controlled so that it is not excessively uneven in the initial section where the refrigerant is introduced. For example, the problem of the refrigerant introduced through the inlet port (130) rapidly cooling only a specific battery cell (110) in the initial section can be reduced. Battery cells (110) without a surface treatment section (111) can be located relatively far from the inlet port (130). This helps the refrigerant gradually absorb heat and uniformly cool the entire battery assembly (100). Additionally, since the battery cells (110) including the surface treatment section (111) can mitigate the initial cooling shock, a result can be expected where the temperature difference between battery cells (110) is reduced.

[0054] By arranging only some of the battery cells (110) to have a surface treatment section (111), the temperature balance between the area adjacent to the inlet port (130) and other areas can be controlled more precisely. This can reduce the problem of temperature differences between battery cells (110) accumulating over a long period. As a result, the rate of degradation of the battery cells (110) is mitigated, and their lifespan can be extended. In particular, since the refrigerant absorbs heat uniformly during repeated charging and discharging, the difference in heat generation characteristics between the battery cells (110) can be maintained at a small level. Through this, a stable energy supply environment can be created, and the cooling efficiency of the entire battery cell (110) can also be improved.

[0055] The surface treatment part (111) may include a heat-shrinkable polymer film or a hot-melt material.

[0056] The surface treatment portion (111) according to the present embodiment covers at least a portion of the outer surface of the battery cell (110) and can perform the role of controlling the rate of heat transfer with the refrigerant. The heat-shrinkable polymer film can shrink at a specific temperature and adhere to the surface of the battery cell (110). This difference helps to finely balance the temperature in the path where the refrigerant flows and can provide a customized cooling effect according to the heat generation characteristics of the battery cell (110).

[0057] The thickness or application area of ​​the surface treatment section (111) can be configured differently depending on the heat generation pattern of the battery cell (110). For example, a heat-shrinkable polymer film with a thickness of 100 μm can be applied to the part that the refrigerant first contacts, and a hot-melt material with a thickness of 75 μm can be selectively applied to the final section of the refrigerant flow. By arranging them in this way, excessive cooling during the initial refrigerant inflow can be mitigated so that it is not concentrated on a specific battery cell (110), and the refrigerant can be induced to absorb heat more quickly in the later section. In this process, the material difference and thickness variation of the surface treatment section (111) act in combination to contribute to reducing the temperature variation along the direction of refrigerant flow.

[0058] Consequently, by including a heat-shrink polymer film or a hot-melt material in the surface treatment section (111), the heat generation characteristics between the battery cells (110) can be made uniform and the temperature variation can be reduced. Since the surface of the battery cell (110) is effectively cooled even during repeated charge-discharge cycles, the rate of degradation can be slowed down and the lifespan can be extended. In addition, the entire battery assembly (100) can maintain a stable energy supply state for a long time. A properly designed surface treatment section (111) allows heat to be efficiently released or absorbed from the surface of the battery cell (110) even when the refrigerant flow rate or temperature fluctuates, and as a result, the temperature variation between the battery cells (110) can be minimized.

[0059] FIG. 10 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0060] Referring to FIGS. 1 to 7 and FIG. 10, the surface treatment portion (111) is formed in a plurality of sections spaced apart along the longitudinal direction of the battery cell (110), and a heat-shrinkable polymer film layer and a hot-melt material layer can be alternately applied to each section.

[0061] Considering the characteristic that the battery cell (110) may have different patterns of heat generation along its length, the surface treatment section (111) can be divided into zones. Specifically, multiple zones can be established along the length of the battery cell (110). For example, a heat-shrinkable polymer film layer can be applied in the first zone, and a hot-melt material layer can be applied in the second zone. By configuring them alternately in this way, the rate of heat absorption or dissipation varies by zone, thereby creating a balanced temperature distribution throughout the battery cell (110).

[0062] Battery cells (110) having a relatively thick surface treatment portion (111) may be closer to the inlet port (130) than battery cells (110) having a relatively thin surface treatment portion (111).

[0063] The thick surface treatment portion (111) can mitigate rapid heat exchange that occurs when the refrigerant flowing in through the inlet port (130) comes into contact. This mitigation action can prevent the battery cell (110) from being excessively cooled and can also reduce temperature variations that may occur near the inlet port (130).

[0064] For example, a surface treatment section (111) with a thickness of 100 μm can be applied to a battery cell (110) close to the inlet port (130), and a surface treatment section (111) with a thickness of 75 μm can be placed on a battery cell (110) located far from the inlet port (130). A battery cell (110) having a thick surface treatment section (111) receives a cooling effect gradually upon initial refrigerant inflow, thereby preventing the problem of a specific battery cell (110) rapidly dropping in temperature. On the other hand, a battery cell (110) having a thin surface treatment section (111) comes into contact with a refrigerant whose temperature has already risen to some extent, allowing it to naturally release or absorb heat. If the relatively thick surface treatment section (111) is concentrated near the inlet port (130) and the thin surface treatment section (111) is placed in other areas, the rate at which heat is absorbed in each battery cell (110) can be appropriately distributed. This configuration maintains a stable temperature distribution and prevents cooling from being concentrated in certain areas. As a result, the rate of degradation between battery cells (110) is suppressed even during repeated charging and discharging, and the overall temperature balance can be improved.

[0065] By alternately applying a heat-shrinkable polymer film layer and a hot-melt material layer, heat generated inside the battery cell (110) can be effectively dispersed while reducing overheating concentrated in specific areas. Since the surface treatment portion (111) of each area appropriately distributes heat transfer resistance, the temperature difference that may occur between battery cells (110) can be reduced. That is, by arranging the layers differently for each area, the phenomenon of heat remaining excessively in only specific areas can be prevented, and even when charging and discharging are repeated for a long period, the battery cell (110) can be cooled evenly, thereby suppressing degradation. This configuration maintains a stable operating temperature while operating the battery assembly (100), and as a result, improvements in lifespan and performance can be expected.

[0066] FIG. 11 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0067] Referring to FIGS. 1 to 7 and FIG. 11, some of the surface treatment portions (111) may have a thickness different from other surface treatment portions (111) among the surface treatment portions (111).

[0068] For example, a surface treatment section (111) with a thickness of 100 μm can be applied to the area adjacent to the refrigerant inlet section of the battery cell (110), and a surface treatment section (111) with a relatively thin thickness of 75 μm can be applied to the area adjacent to the refrigerant outlet section. That is, a thickly coated surface treatment section (111) can be provided in the area where initial cooling is concentrated, so that heat transfer with the refrigerant proceeds slowly. On the other hand, a thin surface treatment section (111) can be provided on the opposite side of the battery cell (110) to help the refrigerant absorb heat quickly.

[0069] By distributing surface treatment sections (111) of different thicknesses among the battery cells (110) in this manner, the cooling rate generated when the refrigerant comes into direct contact with the battery cells (110) can be controlled differently. The area where the thick surface treatment section (111) is applied can maintain a gradual cooling rate in the initial section where the refrigerant temperature is low, while the area where the thin surface treatment section (111) is applied can effectively absorb heat in the later section where the refrigerant temperature has risen. This differential thickness distribution evenly distributes heat exchange between the battery cells (110) along the path where the refrigerant flows, and consequently, can increase the overall cooling efficiency. This can mitigate the excessive cooling of specific battery cells (110) within the battery assembly (100) and induce a balanced temperature distribution throughout the entire length direction.

[0071] FIG. 12 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of FIG. 6.

[0072] Referring to FIGS. 6 and FIGS. 12, the surface treatment portion (111) can selectively cover only a portion of the outside of the battery cell (110).

[0073] The surface treatment section (111) can be applied to areas where heat is concentrated on the surface of the battery cell (110) or areas where cooling is required as a priority, and the surface treatment section (111) can be not applied to other areas. This method reduces the amount of cooling material used compared to covering the entire surface, and allows for efficient heat exchange by placing the heat management material only in the necessary areas.

[0074] For example, the surface treatment section (111) can be placed only on the part of the side of the battery cell (110) that generates the most heat. In this case, either a heat-shrinkable polymer film or a hot-melt material can be selected and used, and the surface treatment section (111) can be omitted on the remaining parts. Through partial application, problems such as a specific area not being excessively cooled and other areas not being properly cooled can be mitigated. Additionally, if the heat generation characteristics fluctuate, the placement area of ​​the surface treatment section (111) can be readjusted to optimize cooling efficiency.

[0075] A surface treatment portion (111) that partially covers the outside of the battery cell (110) can reduce the cost of cooling materials and reduce problems such as overcooling or localized heat generation, while stably maintaining the temperature balance of the battery cell (110). Compared to a method of uniformly covering the entire surface area, it can also mitigate weight increase and reduce the rate of degradation that may occur during long-term use of the battery cell (110).

[0076] FIG. 13 is a cross-sectional view showing a battery cell according to another embodiment of the present invention.

[0077] Referring to FIGS. 6 and FIGS. 13, the surface treatment portion (111) can cover a portion of the upper part of the battery cell (110).

[0078] By applying a surface treatment portion (111) that covers a portion of the upper part, intensive thermal management can be provided to the necessary area while reducing manufacturing costs and weight increase compared to unnecessarily covering the entire battery cell (110). By reinforcing the upper area where cooling is less or where heat generation characteristics are special, the temperature difference between battery cells (110) within the battery assembly (100) is reduced, and a uniform heat distribution can be maintained even when the charging and discharging process is repeated. This can be expected to mitigate long-term degradation of the battery cell (110) and slow down capacity reduction, thereby improving the stability and performance of the battery assembly (100).

[0079] Referring again to FIGS. 6 and FIGS. 12, the surface treatment portion (111) can cover a lower part of the battery cell (110).

[0080] The surface treatment portion (111) according to the present embodiment can cover a portion of the lower part of the battery cell (110). When a refrigerant is introduced through the inlet port (130) and first comes into contact with the lower part of the battery cell (110), applying the surface treatment portion (111) to this area can control excessive cooling so that it is not concentrated on a specific battery cell (110). Since the configuration partially covers a portion of the lower part, the necessary cooling effect can be secured while reducing the use of unnecessary materials.

[0081] The surface treatment portion (111) covering a portion of the lower part is advantageous for weight reduction and cost savings compared to a method covering the entire area, and can also improve thermal management efficiency. Since the refrigerant first comes into contact with the lower part of the cell, the partially applied surface treatment portion (111) can suppress temperature deviations and reduce problems such as overcooling or localized heat generation. As a result, the degradation of the battery cell (110) during repeated charging and discharging is mitigated, and stable cooling performance can be maintained throughout the battery assembly (100).

[0082] Referring again to FIG. 6, the surface treatment portion (111) can cover the entire surface outside the battery cell (110).

[0083] If the surface treatment section (111) is configured to surround the entire surface, the ambient temperature of the battery cell (110) can be suppressed from being uneven, and the degradation that occurs during long-term operation can also be delayed.

[0084] The method of covering the entire surface maximizes cooling efficiency and can reduce problems such as cooling being concentrated in specific areas or cooling being insufficient. Since the entire battery cell (110) is placed in the same thermal management environment, the temperature of the battery cell (110) does not fluctuate drastically even when repeated charging and discharging over a long period, thereby suppressing the degradation of its lifespan. In addition, since a uniform cooling state is maintained, stability is increased during the energy release or heat dissipation process, and the reliability of the battery assembly (100) can be improved.

[0085] FIG. 14 is a cross-sectional view showing a battery assembly according to another embodiment of the present invention.

[0086] Referring to FIGS. 1 to 7 and FIG. 14, the cooling channels (160) are multiple, and the cooling channels (160) can be arranged along the length direction of the battery cell (110) to which the battery cell (110) extends.

[0087] In this embodiment, the cooling channel (160) may be configured to have a multi-layer cooling structure. That is, when cooling a plurality of battery cells (110), a plurality of cooling channels corresponding to different layers, such as a first cooling channel (161) and a second cooling channel (162), may be provided so that some areas of the battery cells (110) come into contact with a cold refrigerant relatively early, while other areas come into contact with a refrigerant whose temperature has risen relatively later.

[0088] For example, a temporal and temperature gap occurs such that some areas of the battery cell (110) adjacent to the inlet port (130) are cooled first by the second cooling channel (162), while other areas of the same cell (110) are cooled later by the first cooling channel (161). Conversely, although the cell (110) relatively close to the outlet port (140) may be exposed to a refrigerant that has already risen in temperature, there is an advantage in that the overall cooling variation is mitigated because a refrigerant that has risen in temperature relatively less can be additionally supplied through another cooling channel.

[0089] By applying a multi-layer cooling channel structure like this, the refrigerant is more evenly distributed and circulated across all battery cells (110) compared to a single channel structure, so the cooling imbalance between battery cells (110) can be significantly reduced. As a result, a situation in which only a specific battery cell (110) becomes excessively hot or rapidly cooled is prevented, thereby improving the safety and lifespan of the battery assembly (100) even during repeated charging and discharging for a long time.

[0090] In addition, if the first cooling channel (161) and the second cooling channel (162) are configured to have different flow directions, local temperature variations that are prone to occur when the refrigerant flows in only one direction can be further mitigated. This is because the refrigerant absorbs heat from each battery cell (110) as it passes through the channels, and the refrigerant temperature that has already risen in some channels can be mixed with or redistributed with the refrigerant at a relatively lower temperature in other channels. Such channel arrangements or flow directions can be combined in various ways according to design requirements, and a specific multi-layer cooling design can be implemented by appropriately adjusting the number or arrangement shape of the cooling channels (160) as mentioned in the prior specification.

[0091] Ultimately, through the multi-layer cooling channel structure described above, the temperature difference between battery cells (110) is reduced, and the problem of cooling being concentrated in specific areas is minimized, thereby further enhancing the thermal management efficiency of the battery assembly (100). This provides significant advantages in terms of long-term stability, extended lifespan, and safety of the battery assembly (100).

[0092] Multiple cooling channels (160) may be arranged at regular intervals in accordance with the direction in which the battery cell (110) extends. If each cooling channel (160) is configured to be in direct contact with or close to the outer surface of the battery cell (110), uniform cooling can be achieved over the entire length of the battery cell (110).

[0093] By arranging multiple cooling channels (160) along the longitudinal direction of the battery cell (110), the refrigerant can uniformly cool the entire battery cell (110). In other words, it is possible to prevent the phenomenon where the temperature drops rapidly only in specific areas and to mitigate the problem of heat generation being partially concentrated within the battery cell (110) during long-term charging and discharging. As a result, the heat difference between the battery cells (110) is reduced, slowing down the rate of degradation and improving the performance and stability of the battery assembly (100).

[0094] Referring again to FIGS. 1 to 7, FIGS. 14, and FIGS. 15, a portion of the surface treatment portion (111) may cover a portion of the side of the battery cell (110) corresponding to the cooling channels (160).

[0095] The surface treatment portion (111) applied to a part of the side can control the heat exchange rate as the refrigerant flows along the side of the cell. By selectively applying the surface treatment portion (111) only to the area in direct contact with the path through which the refrigerant flows, cooling performance can be increased while reducing the use of unnecessary materials.

[0096] For example, if the cooling channel (160) is structured to run along the center of the side of the cell, a heat-shrinkable polymer film or hot-melt material can be applied only around the center to accelerate or limit heat transfer with the refrigerant. This partially dispersed surface treatment (111) can effectively suppress cooling or temperature rise concentrated only in specific areas compared to a method that uniformly covers the entire side of the battery cell (110).

[0097] A surface treatment section (111) covering a portion of the side of a battery cell (110) corresponding to a cooling channel (160) can reduce temperature differences between battery cells (110) and mitigate the rate of degradation. Since the heat generated inside the battery cell (110) is properly controlled as it passes through the surface treatment section (111) in the path where the refrigerant flows, it is possible to prevent localized overcooling from occurring only in a specific battery cell (110) or, conversely, the accumulation of overheating. This can contribute to increasing the long-term usage stability and cooling efficiency of the battery assembly (100) and extending the lifespan of the battery cell (110).

[0098] Referring again to FIGS. 1 to 7, FIGS. 14, and FIGS. 15, the flow direction of the refrigerant in any one of the cooling channels (160) and the flow direction of the refrigerant in another of the cooling channels (160) may be opposite to each other.

[0099] The cell frame (120) may include a top cell frame (120a), a middle cell frame (120b), and a bottom cell frame (120c). The refrigerant may be introduced into the space between the middle cell frame (120b) and the bottom cell frame (120c) through an inlet port (130), pass through the space between the middle cell frame (120b) and the top cell frame (120a), and be discharged through an outlet port (140).

[0100] Battery cells (110) can be stored in the cell frame (120) by being inserted into holes provided in the top cell frame (120a), middle cell frame (120b), and bottom cell frame (120c). The bottom cell frame (120c) can be located at the bottom, the top cell frame (120a) can be located at the top, and the middle cell frame (120b) can be located between the top cell frame (120a) and the bottom cell frame (120b).

[0101] The top cell frame (120a) may be partially open while covering the upper surface (in the +z-axis direction of FIG. 4) of the battery cells (110). Specifically, the top cell frame (120a) may be open to correspond to the shape of each battery cell (110). The upper portions of the battery cells (110) may be partially fitted into the holes inside the top cell frame (120a). The circumference of the holes forming part of the top cell frame (120a) may correspond to the circumference of the battery cells (110).

[0102] The middle cell frame (120b) may be open on both sides (in the z-axis direction of FIG. 4) while wrapping around a portion of the sides of the battery cells (110). Specifically, the middle cell frame (120b) may be open to correspond to the shape of each battery cell (110). The middle portions of the battery cells (110) may be partially fitted into the holes inside the middle cell frame (120b). The circumference of the holes forming part of the middle cell frame (120b) may correspond to the circumference of the battery cells (110).

[0103] The bottom cell frame (120c) may be partially open while covering the lower surface (in the -z-axis direction of FIG. 4) of the battery cells (110). Specifically, the bottom cell frame (120c) may be open to correspond to the shape of each battery cell (110). The lower portions of the battery cells (110) may be partially fitted into the holes inside the bottom cell frame (120c). The circumference of the holes forming part of the bottom cell frame (120c) may correspond to the circumference of the battery cells (110).

[0104] The top cell frame (120a), middle cell frame (120b), and bottom cell frame (120b) may be a structure that is combined with each other while housing the battery cells (110). The top cell frame (120a), middle cell frame (120b), and bottom cell frame (120b) can physically protect the battery cells (110).

[0105] The refrigerant can be introduced into the space between the middle cell frame (120b) and the bottom cell frame (120c) through the inlet port (130). The refrigerant can cool the battery cells (110) as it passes through the space between the middle cell frame (120b) and the bottom cell frame (120c). In this process, since the refrigerant is evenly distributed as it passes between each battery cell (110), it can provide uniform cooling across the entire battery cell (110) rather than cooling concentrated on a specific battery cell (110). This can have the effect of minimizing the temperature difference between the battery cells (110), thereby preventing performance degradation of the battery assembly (100) and extending the efficiency and lifespan of the battery assembly (100).

[0106] After passing through the space between the middle cell frame (120b) and the bottom cell frame (120c), the refrigerant can move to the space between the middle cell frame (120b) and the top cell frame (120a). At this time, the flow direction of the refrigerant passing through the space between the middle cell frame (120b) and the bottom cell frame (120c) and the flow direction of the refrigerant moving to the space between the middle cell frame (120b) and the top cell frame (120a) may be opposite to each other. As it passes through this space, the refrigerant comes into contact with the battery cell (110) once again to perform additional cooling. That is, the structure allows the refrigerant to continuously cool the battery cell (110) in two stages, thereby removing the remaining heat after the first cooling more effectively.

[0107] By configuring cooling channels (160) in which the refrigerant flows in opposite directions, balanced cooling performance can be maintained without uneven heat exchange even during long-term operation. This opposite flow structure can induce the refrigerant flowing through each cooling channel (160) to independently absorb or release heat. Through this, the refrigerant temperature can flow distributed along the entire channel without rising rapidly only in specific sections. For example, among the cooling channels (160) arranged side by side, the first channel can be configured to move from left to right, and the second channel can be configured to move from right to left. In this way, since the refrigerant moves while absorbing heat in different paths, a uniform temperature distribution can be expected without the cooling action being concentrated only in specific parts. In addition, by balancing the flow resistance within the cooling channels (160), the problem of flow rate deviation can be mitigated. Therefore, stable cooling is possible even in environments requiring repeated charging and discharging or high output, and a uniform temperature distribution can be maintained for a long time.

[0108] The area of ​​contact between at least one cooling channel (160) among the cooling channels (160) that matches the flow direction of the refrigerant and the battery cell (110) may be 30% or more and 70% or less of the area of ​​contact between all cooling channels (160) and the battery cell (110).

[0109] By distributing the area where each cooling channel (160) comes into direct contact with the surface of the battery cell (110) differently, it is possible to ensure that a specific cooling channel (160) does not play an excessive role in the overall cooling process. When two or more cooling channels (160) are arranged side by side along one side of the battery cell (110), the cooling channels (160) with the same flow direction can be designed to cover an area of ​​more than 30% and less than 70% of the cell surface. By partitioning in this way, the refrigerant is uniformly distributed across the cell surface, and the problem of heat exchange being concentrated in only some cooling channels (160) can be mitigated. Additionally, by finely adjusting the cross-sectional area or position of each cooling channel (160), the rate of heat exchange between the area where the refrigerant enters and the area where it exits can be matched as needed.

[0110] If a portion of the cooling channel (160) with the same flow direction covers only a certain proportion of the surface of the battery cell (110), the problem of excessive heat exchange being concentrated in a specific channel can be mitigated. Cooling proceeds evenly over the entire surface of the battery cell (110), and degradation or localized overheating can be suppressed. In other words, since the division of roles among the multiple cooling channels (160) is balanced, the thermal deviation that may occur during long-term charging and discharging can be reduced, thereby extending the lifespan of the battery cell (110).

[0111] Referring again to FIGS. 1 to 7 and FIG. 14, the cooling channels (160) include a first cooling channel (161) and a second cooling channel (162), and the refrigerant may flow through the first cooling channel (161) before the second cooling channel (162).

[0112] The cooling channel (160) according to the present embodiment includes a first cooling channel (161) and a second cooling channel (162), and the refrigerant may flow through the first cooling channel (161) before the second cooling channel (162). This allows the refrigerant to first perform rapid heat absorption that may occur upon initial inflow in the first cooling channel (161), and then additionally release residual heat while passing through the second cooling channel (162).

[0113] Battery cells (110) placed within the battery assembly (100) may be exposed to a cooling channel (160) in a stacked state. The first cooling channel (161) may be connected more directly to the inlet port (130), and the second cooling channel (162) may be placed closer to the outlet port (140). For example, the first cooling channel (161) may be placed at the bottom of the battery cell (110) to allow the heat generated in the battery cell (110) to be absorbed intensively as soon as the refrigerant is introduced. Afterward, the refrigerant may pass through the second cooling channel (162) to further absorb the remaining heat in the middle or upper part of the battery cell (110). By undergoing this stepwise cooling process, the cooling is not concentrated in a specific area, and the entire battery cell (110) can dissipate heat evenly.

[0114] A structure in which the refrigerant flows first through the first cooling channel (161) prevents supercooling confined to a specific area and allows for fine control of the initial heat transfer process of the refrigerant. The second cooling channel (162) supports the refrigerant, which has already partially absorbed heat, to release additional heat, thereby reducing the temperature difference between the battery cells (110). As a result, degradation or localized overheating within the battery assembly (100) is mitigated, and stable cooling performance can be maintained even in situations of repeated charging and discharging over a long period.

[0115] FIG. 15 is a cross-sectional view showing a battery assembly according to another embodiment of the present invention.

[0116] Referring to FIGS. 1 to 7 and FIG. 15, the surface treatment portion (111) may be formed on a part of the battery cell (110) corresponding to the first cooling channel (161) and may not be formed on another part of the battery cell (110) corresponding to the second cooling channel (162).

[0117] The area corresponding to the first cooling channel (161) can be set as a zone where heat generation is relatively high or where cooling concentration is required. The area corresponding to the second cooling channel (162) can be configured to exclude the surface treatment section (111) to facilitate direct contact with the refrigerant. For example, a surface treatment section (111) made of a heat-shrinkable polymer film or a hot-melt material can be placed in the area adjacent to the first cooling channel (161) on the side of the battery cell (110). The rate of heat exchange with the refrigerant in this area can be controlled, and the surface treatment section (111) can be omitted in the area where the second cooling channel (162) passes, so that the refrigerant can directly contact the surface of the battery cell (110). Through this, the cooling rate can be maintained gradually in a specific area, while rapid heat absorption or heat release can be induced in another area.

[0118] By forming a surface treatment section (111) only in the area corresponding to the first cooling channel (161), the use of unnecessary cooling materials can be reduced and cooling tailored to the thermal management requirements of each zone can be enabled. In the area where the surface treatment section (111) is applied, a sudden drop in temperature is prevented, and in the area where the surface treatment section (111) is omitted, the refrigerant immediately absorbs heat, thereby reducing the temperature difference between battery cells (110). As a result, degradation is mitigated even in a long-term repeated charging and discharging environment, and stable cooling efficiency can be maintained.

[0119] The thickness of the surface treatment portion (111) formed on a part of the battery cell (110) corresponding to the first cooling channel (161) may be thicker than the thickness of the surface treatment portion (111) formed on another part of the battery cell (110) corresponding to the second cooling channel (162).

[0120] Since the area closer to the first cooling channel (161) is a zone where the initial refrigerant flows in rapidly, a relatively thick surface treatment portion (111) may be applied to prevent excessive cooling or to control the heat exchange rate. For example, the surface treatment portion (111) formed on a part of the battery cell (110) corresponding to the first cooling channel (161) may be a heat-shrinkable polymer film or hot-melt material with a thickness of 100 μm. On the other hand, the surface treatment portion (111) formed on a part of the battery cell (110) corresponding to the second cooling channel (162) may have a relatively thin thickness of 75 μm. By creating such a difference in thickness, the amount of heat exchange at the initial moment when the refrigerant flows in can be appropriately controlled to prevent the temperature from dropping excessively rapidly in a specific zone, and to enable more rapid heat release in the latter part of the cooling flow.

[0121] By applying a thick surface treatment portion (111) in the area corresponding to the first cooling channel (161), overcooling or thermal shock can be prevented when the refrigerant flows in, and the temperature difference between the battery cells (110) can be reduced. In the area corresponding to the second cooling channel (162), a thin surface treatment portion (111) is placed so that the refrigerant can re-absorb the increased temperature and distribute heat evenly. As a result, each battery cell (110) in the battery assembly (100) is cooled evenly, and degradation or local overheating can be suppressed during repeated charging and discharging processes.

[0122] Referring again to FIGS. 1 to 5, FIGS. 8 to 11, and FIGS. 14 to 17, any one of the cooling channels (160) may be connected to an inlet port (130), and another of the cooling channels (160) may be connected to an outlet port (140).

[0123] In the cooling channel (160) connected to the inlet port (130), a refrigerant is initially introduced to come into direct contact with the battery cell (110) and absorb heat. In the cooling channel (160) connected to the outlet port (140), the refrigerant, which has already passed through the battery cell (110) and whose temperature has risen, is discharged, allowing the cooling flow of the entire system to continue smoothly.

[0124] By separating the cooling path (160) connected to the inlet port (130) and the cooling path (160) connected to the outlet port (140), the refrigerant can circulate by absorbing heat from the battery cell (110) in stages, causing the temperature to rise evenly. This can help mitigate situations where excessive cooling or heat is concentrated in a specific area and help reduce temperature variations among all battery cells (110). Even during repeated charging and discharging processes, the refrigerant circulation flow is maintained stably, which can suppress deterioration or localized overheating. As a result, a long lifespan and a uniform thermal management environment can be established during the operation of the battery assembly (100).

[0125] According to another embodiment of the present invention, a device comprising at least one battery assembly (100) is provided.

[0126] One or more battery assemblies (100) according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system, to form a battery pack.

[0127] Battery packs can be applied to various devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but are not limited to these; they can be applied to various devices capable of using secondary batteries.

[0128] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0129] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0130] 100: Battery assembly 110: Battery cell 111: Surface treatment section 120: Cell Frame 130: Inlet Port 140: Outlet Port 150: Busbar frame assembly 160: Cooling Euro

Claims

Claim 1 Multiple battery cells; A cell frame in which the above battery cells are housed; and It includes an inlet port and an outlet port for circulating the above refrigerant; and The interior of the cell frame is provided with a cooling channel through which a refrigerant flows in direct contact with at least a portion of the battery cell. A battery assembly in which at least some of the above battery cells include a surface treatment portion. Claim 2 A battery assembly according to claim 1, wherein some of the battery cells include the surface treatment portion, and the battery cells including the surface treatment portion are adjacent to the inlet port than the battery cells not including the surface treatment portion. Claim 3 A battery assembly according to claim 1, wherein the surface treatment portion comprises a heat-shrinkable polymer film or a hot-melt material. Claim 4 In paragraph 3, the surface treatment portion is formed in a plurality of zones spaced apart along the longitudinal direction of the battery cell, and the heat shrink polymer film layer and the hot melt material layer are alternately applied in each zone of the battery assembly. Claim 5 A battery assembly in which, in claim 1, some of the surface treatment portions have a thickness different from that of other surface treatment portions. Claim 6 In paragraph 5, the battery assembly, wherein the battery cells having a relatively thick surface treatment portion are adjacent to the inlet port than the battery cells having a relatively thin surface treatment portion. Claim 7 In paragraph 1, A battery assembly in which the above surface treatment part selectively covers only a portion of the outside of the battery cell. Claim 8 In claim 1, the surface treatment portion covers a portion of the upper part of the battery cell, a battery assembly. Claim 9 In claim 1, the surface treatment portion covers a lower portion of the battery cell, the battery assembly. Claim 10 In claim 1, the surface treatment portion covers the entire surface outside the battery cell, the battery assembly. Claim 11 A battery assembly according to claim 1, wherein the cooling channels are plural and the cooling channels are arranged along the longitudinal direction of the battery cell in which the battery cell extends. Claim 12 In claim 11, a battery assembly wherein a portion of the surface treatment portion covers a portion of the side of the battery cell corresponding to the cooling channels. Claim 13 A battery assembly according to claim 11, wherein the flow direction of the refrigerant in any one of the cooling channels and the flow direction of the refrigerant in another of the cooling channels are opposite to each other. Claim 14 A battery assembly according to claim 11, wherein the area of ​​the surface where at least one of the cooling channels, in which the flow direction of the refrigerant matches, contacts the battery cell is 30% or more and 70% or less of the area where all of the cooling channels contact the battery cell. Claim 15 In claim 11, the cooling channels include a first cooling channel and a second cooling channel, and the refrigerant flows through the first cooling channel before the second cooling channel in a battery assembly. Claim 16 In claim 15, the surface treatment portion is formed on a part of the battery cell corresponding to the first cooling channel and is not formed on another part of the battery cell corresponding to the second cooling channel. Claim 17 A battery assembly in which, in claim 15, the thickness of the surface treatment portion formed on a part of the battery cell corresponding to the first cooling channel is thicker than the thickness of the surface treatment portion formed on another part of the battery cell corresponding to the second cooling channel. Claim 18 A battery assembly in which, in paragraph 11, one of the cooling channels is connected to the inlet port and the other of the cooling channels is connected to the outlet port. Claim 19 A device comprising a battery assembly according to paragraph 1.

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