Secondary battery module and method for manufacturing secondary battery module

Abstract

The present invention relates to a secondary battery module having a plurality of secondary batteries installed in a case, the module including: secondary batteries having two side surfaces which are flat and parallel to each other; and a case including a bottom formed in a lateral direction thereof, two side wall portions vertically standing in parallel to each other in a longitudinal direction of the bottom from both ends of the bottom, and a top portion extending between upper ends of each of the side wall portions and disposed in parallel to the bottom, the case having the plurality of secondary batteries stacked in a thickness direction thereof and installed therein, the secondary batteries being installed such that the side surfaces of the secondary batteries located at outermost sides thereof respectively face the side wall portions, wherein the case has a rib formed on an inner side of a corner connecting the bottom and the side wall portion such that a thickness of the corner is thicker than other portions.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2020-0128353, filed on October 5, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a secondary battery module having multiple secondary batteries installed in a housing and a method for manufacturing the secondary battery module, and more specifically, to a secondary battery module and a method for manufacturing the secondary battery module in which the behavior of the outermost secondary battery and the behavior of the lower end of the installed secondary battery are more stably controlled when expansion occurs in the secondary batteries installed in the housing. Background Technology

[0003] High-energy-density secondary batteries are installed in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric drive sources, as well as portable devices.

[0004] Such secondary batteries not only have the major advantage of significantly reducing the use of fossil fuels, but also have the following additional advantages: since they do not produce any byproducts from energy use, they are attracting much attention as a new energy source for improving environmental friendliness and energy efficiency. Therefore, research on secondary batteries is being actively carried out.

[0005] Rechargeable batteries widely used in recent years include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. Furthermore, the operating voltage of a single rechargeable battery cell (i.e., a single battery cell) is approximately 2.5V to approximately 4.2V.

[0006] Therefore, when a higher output voltage is required, multiple individual secondary batteries are connected to form a secondary battery module, and multiple secondary battery modules are assembled to form a secondary battery pack.

[0007] Here, a secondary battery module is constructed by assembling cylindrical secondary batteries or by assembling pouch-shaped secondary batteries.

[0008] The secondary battery module, composed of pouch-type secondary batteries, has the following structure: a secondary battery 1 with two flat and equal side surfaces is installed in a housing 2 having a rectangular cross-section in its thickness direction, as shown below. Figure 1a As shown, Figure 1a The diagram shows multiple secondary batteries 1 installed in a housing 2 with a conventional structure. Furthermore, pads 3 made of elastic material are installed between the inner wall of the housing 2 and the outermost shell to cushion external impacts.

[0009] In the case of pouch-type secondary batteries, due to the side reactions of repeated charging and discharging, the internal electrolyte evaporates and produces gas, which causes the secondary battery to expand in volume.

[0010] Here, the expansion of the secondary battery can be controlled by the rigidity of the material of the casing 2. However, when the volume of each secondary battery 1 increases, the secondary battery 1 placed on the outermost side deforms more.

[0011] Furthermore, since expansion typically tends to occur in the middle portion of the secondary battery 1, the appearance of the expansion in the secondary battery module according to the related technology is simplified. As a result, the inner wall of the housing 2 is subjected to greater pressure at the narrow point, thereby degrading the control efficiency of the expansion of the secondary battery 1.

[0012] In other words, as shown in the cross-sectional view of the pad 3 located between the outermost secondary battery 1 and the inner wall of the casing 2, the pressure is concentrated only in the central portion of the inner wall of the casing 2 to produce compression. On the other hand, the pressure is not applied to both ends, thus no compression is produced.

[0013] This is because the pressure acting on casing 2 is not dispersed, resulting in relatively large deformation of casing 2. Furthermore, although large deformation occurs at the center of the secondary battery, the deformation at both ends ( Figure 1a and Figure 1b The upper and lower ends of the secondary battery 1 are not effectively supported, which poses a risk of damage. Specifically, when the secondary battery 1 comes into contact with the housing 2, it moves while in close contact with the housing 2, thus generating friction on the contact surface, which may lead to the risk of tearing or damage to the pouch of the secondary battery 1. In addition, when the pouch is torn, not only is the secondary battery 1 damaged, but the secondary battery modules that are electrically connected to each other may also be defective. Summary of the Invention

[0014] Technical issues

[0015] Therefore, the main objective of this invention is to provide a secondary battery module and a method for manufacturing the secondary battery, wherein when the secondary battery expands, the pressure applied to the casing is more effectively dispersed to minimize casing deformation, and the two ends of the secondary battery are more effectively supported. Figure 1a and Figure 1b (The upper and lower ends of the middle).

[0016] Technical solution

[0017] To achieve the above objectives, the present invention provides a secondary battery module and a method for manufacturing the secondary battery.

[0018] According to the present invention, a secondary battery module comprising a plurality of secondary batteries mounted in a housing, the secondary battery module comprising: a secondary battery having two flat and parallel side surfaces; and a housing comprising a bottom formed in a horizontal direction, two side walls perpendicularly erected in a longitudinal direction at both ends of the bottom, and a top extending from the upper end of each side wall and disposed parallel to the bottom, wherein the plurality of secondary batteries are mounted to be stacked in their thickness direction such that the side surfaces of the two outermost secondary batteries face the side walls respectively, wherein ribs are formed on the inner side of each edge connecting the bottom and the side walls of the housing to each other, having a thickness greater than that of other portions.

[0019] Ribs can be formed with an inclined shape, such that the thickness of the ribs gradually increases from each one in the sidewalls to the bottom.

[0020] Additionally, the secondary battery module may include pads made of an elastic material and disposed between each sidewall and the side surface of the outermost secondary battery.

[0021] The pads can be positioned between each sidewall and the side surface of the secondary battery in a pressed state at the point of contact with the rib.

[0022] Ribs can be formed on the inside of each edge in which one end of the bottom is connected to the edge of each sidewall and the other end of the bottom is connected to the edge of each sidewall.

[0023] The resin can be applied to one or more surfaces, namely the bottom surface and the top surface, which are respectively facing the two sides of the secondary battery, and the resin adheres to fix the secondary battery.

[0024] A chamfer can be formed on the outside of each edge, where the bottom two ends are connected to the edge of the sidewall and the top two ends are connected to the edge of the sidewall.

[0025] Furthermore, the present invention can also provide a method for manufacturing a secondary battery module having the above-described structure.

[0026] According to a method for manufacturing a secondary battery module according to the present invention, in which a plurality of secondary batteries are mounted in a housing, the method includes: a step (S10) of mounting pads in the housing, the housing including a bottom formed in a horizontal direction, two side walls perpendicularly erected to each other in a longitudinal direction at both ends of the bottom, and a top extending from the upper end of each side wall and disposed parallel to the bottom; and a step (S20) of mounting a plurality of secondary batteries in the housing such that the pads are in close contact with each side wall, wherein, in the step (S20) of mounting the secondary batteries in the housing, the secondary batteries are mounted in a stacked manner such that at least a portion of the pads is pressed between each side wall of the housing and the side surface of each secondary battery.

[0027] Ribs can be formed on the inside of the edge that connects the bottom to each sidewall, so that they are thicker than other parts, so that the pads are pressed by the ribs while the secondary battery is installed.

[0028] The method may also include the step of applying resin to one or more of the bottom and top surfaces, with the resin adhering to fix each secondary battery.

[0029] Technical effect

[0030] In the secondary battery module according to the invention, ribs may be formed inside each of the bottom and sidewalls of the housing to more effectively support the ends of the secondary battery (see...). Figure 2 (Lower end). Therefore, movement of the lower end of the secondary battery can be prevented to suppress damage.

[0031] More specifically, this prevents the bag from being damaged due to friction between the secondary battery and the casing. Additionally, when the cooling device is attached to the outside of the bottom of the casing, the movement of the lower end of the secondary battery can be fixed in its original position, thus preventing deterioration of cooling efficiency and further reducing the likelihood of damage.

[0032] In addition, in this invention, since the pads are mounted in a previously compressed state by the ribs, the movement of the lower end of the secondary battery 10 can be supported relatively more firmly, and the resin 40 can be additionally applied to the bottom surface of the housing 20 to further reduce the possibility of the lower end of the secondary battery 10 moving. Attached Figure Description

[0033] Figure 1a This diagram illustrates the state in which multiple secondary batteries are installed in a housing having a structure according to the relevant technology.

[0034] Figure 1b This is a simplified diagram illustrating the state of expansion in a secondary battery module according to the relevant technology.

[0035] Figure 2 This is an example of a cross-sectional view of a secondary battery according to the present invention.

[0036] Figure 3 This is an example Figure 2 An enlarged view of part A.

[0037] Figure 4 This is a partially enlarged view illustrating the housing according to the present invention.

[0038] Figure 5a This diagram illustrates the state where only the lower end of the solder pads is pressed between the outermost secondary battery and the side wall of the casing.

[0039] Figure 5b This diagram illustrates a state where only the upper and lower ends of the solder pads are pressed between the outermost secondary battery and the side wall of the casing.

[0040] Figure 6 This is a simplified diagram illustrating the state of expansion in a secondary battery module according to the present invention. Detailed Implementation

[0041] In the following description, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings, in a manner that enables those skilled in the art to readily implement the inventive concept. However, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

[0042] For the sake of clear description of the invention, parts that are not relevant to the description have been omitted, and the same reference numerals are assigned to the same or similar parts throughout the specification.

[0043] Furthermore, the terms or words used in this specification and claims should not be construed as having a general meaning or a dictionary-based meaning, but should be interpreted as meanings and concepts that are within the scope of this invention, based on the principle that the inventor can appropriately define the concepts of the terms to best describe or explain his or her invention.

[0044] This invention relates to a secondary battery module in which a plurality of secondary batteries are installed in a housing, and a method for manufacturing the secondary battery module. Embodiments according to the invention will be described in more detail below with reference to the accompanying drawings.

[0045] First Implementation Method

[0046] This invention provides a method for manufacturing a secondary battery module, as a first embodiment. Figure 2 This is an example of a cross-sectional view of a secondary battery according to the present invention. Figure 3 This is an example Figure 2 An enlarged view of part A, and Figure 4 This is a partially enlarged view illustrating the housing according to the present invention.

[0047] Referring to the accompanying drawings, the method for manufacturing a secondary battery module provided by the present invention includes the steps of mounting a plurality of secondary batteries 10 in a housing 20, namely, the steps of mounting solder pads 30 in the housing 20 (S10), mounting secondary batteries 10 in the housing 20 (S20), and mounting secondary batteries in the housing 20 (S20).

[0048] The housing 20 provided in this embodiment includes a bottom 20a formed in the horizontal direction, two side walls 20b and 20c that are perpendicularly erected to each other in the longitudinal direction at both ends of the bottom 20a, and a top 20d that extends from the upper end of each side wall 20b and 20c and is disposed parallel to the bottom 20a.

[0049] Additionally, before installing the secondary battery 10, install both the side walls 20b and 20c of the housing 20 so that the pad 30 contacts both the side walls 20b and 20c.

[0050] In the process of mounting the pad 30 in the housing 20 (S10), the pad 30 has two surfaces that are parallel to each other. Here, one of the two surfaces of the pad 30 is mounted to contact the sidewalls 20b and 20c.

[0051] When the pads 30 are fully installed, the process of installing the secondary batteries 10 into the housing 20 is performed (S20). A predetermined number of secondary batteries 10 are installed, with the pads 30 positioned between their two sides. The secondary batteries 10 can be installed one after another through the opening of the housing 20, or multiple stacked secondary batteries 10 can be installed in the housing 20. Furthermore, at this time, the pads 30 can be additionally installed at the intervals between the predetermined number of secondary batteries 10.

[0052] Specifically, the outermost pad 30 provided in this embodiment has at least a portion of the pad 30 previously pressed between the side walls 20b and 20c of the housing 20 and the side surface of the secondary battery 10.

[0053] In other words, ribs 21 are formed on the inner side of each edge of the bottom 20a and side walls 20b and 20c of the connecting housing 20, so that they have a thicker thickness than other parts, so that the pads 30 are previously pressed by the ribs 21 while the secondary battery 10 is being installed.

[0054] Before the process of mounting the pads 30 in the housing 20 (S10) or between the process of mounting the pads 30 in the housing 20 (S10) and the process of mounting the secondary battery 10 in the housing 20 (S20), an additional process of applying resin 40 to the inner surface of the bottom 20a or the top 20d is performed.

[0055] In other words, such as Figure 6 As shown, it illustrates a simplified state when expansion occurs in the secondary battery module according to the invention, in which resin 40 can be applied to control the behavior of the upper or lower end of the secondary battery 10 at the bottom 20a or top 20d side of the housing in contact with the secondary battery 10.

[0056] Second Implementation Method

[0057] The present invention provides a secondary battery module manufactured by the manufacturing method according to the first embodiment, as a second embodiment.

[0058] The secondary battery module provided in this embodiment has the following structure: a plurality of secondary batteries 10 are installed in the housing 20, and a solder pad 30 is installed between the outermost secondary battery 10 and the side walls 20b and 20c of the housing 20.

[0059] The secondary battery 10 is a conventional pouch-type secondary battery with the following structure: the electrode assembly is installed in the pouch and has two flat side surfaces that are parallel to each other.

[0060] The housing 20 includes a bottom 20a formed in the horizontal direction, two side walls 20b and 20c that are perpendicular to each other in the longitudinal direction at both ends of the bottom 20a, and a top 20d that extends from the upper end of each side wall 20b and 20c and is disposed parallel to the bottom 20a.

[0061] Furthermore, multiple secondary batteries 10 are stacked in the thickness direction, and the side surfaces of the two outermost secondary batteries 10 are mounted in the housing 20 so as to face the side walls 20b and 20c respectively.

[0062] In the housing 20 provided in this embodiment, ribs 21 are formed on the inner side of each edge that connects the bottom 20a of the housing 20 to the side walls 20b and 20c, so as to have a thicker thickness than the other parts.

[0063] Rib 21 is formed with an inclined shape, such that its thickness gradually increases from each sidewall 20b and 20c toward the bottom 20a.

[0064] like Figure 2 and Figure 4 As shown, in the housing 20 provided in this embodiment, ribs 21 are formed on the inner side of each edge that connects one end of the bottom 20a to an edge of a side wall 20b and the edge that connects the other end of the bottom 20a to an edge of another side wall 20b.

[0065] Furthermore, although not shown in the accompanying drawings, rib 21 may be formed on the inside of each edge of the edge that connects one end of the top 20d to the edge of a sidewall 20b and the edge that connects the other end of the top 20d to the edge of the sidewall 20c.

[0066] In addition, pads 30 made of elastic material are installed between each sidewall 20b and 20c of the housing 20 and the side surface of the outermost secondary battery 10.

[0067] Therefore, as Figure 5a(This illustrates a configuration where only the lower end of the pad 30 is pressed between the outermost secondary battery 10 and each sidewall 20b and 20c of the casing 20) and Figure 5b As shown (which illustrates the state of pressing the upper and lower ends of the pad between each sidewall 20b and 20c of the outermost secondary battery 10 and the housing 20), depending on the number of times the rib 21 is formed, the pad 30 can be installed with only the lower end of the pad 30 pressed or with both the lower and upper ends of the pad 30 pressed.

[0068] In other words, the pads 30 are positioned in a pressed state at the point of contact with the ribs 21, between each of the sidewalls 20b and 20c and the side surface of the secondary battery 10. Therefore, as Figure 6 As shown (which illustrates a simplified state when expansion occurs in the secondary battery module according to the invention), when the secondary battery 10 expands, the central portion of the pad 30 is pressed by the expansion, and the entire pad 30 can be pressed evenly at the lower (and upper) ends.

[0069] In addition, such as Figure 6 As shown, the resin 40 used to adhere and fix the secondary battery 10 is applied to one or more surfaces of the bottom 20a and the top 20d, which are respectively facing the two sides of the secondary battery 10.

[0070] Therefore, in the secondary battery module provided in this embodiment, since the lower end of the secondary battery 10 is fixed by the resin 40 and supported by the pre-pressed pad 30, the movement of the pad 30 due to its elastic deformation is restricted (since the lower end of the pad was previously pressed, the compressibility of the pad is reduced, thereby reducing the range of movement of the secondary battery).

[0071] Therefore, even if the secondary battery 10 expands due to expansion, the lower end of the secondary battery 10 can be fixed to the bottom of the housing 20 to prevent damage to the secondary battery 10. That is, the sliding of the secondary battery 10 can be fixed at the bottom 20a to prevent the secondary battery pouch from being damaged by the pushing of the secondary battery 10 (because the lower end of the secondary battery is attached to the resin 40, if the lower end of the secondary battery is pushed to move, the lower end of the secondary battery may be easily damaged).

[0072] On the outside of each edge that connects the two ends of the bottom 20a to the edges of the sidewalls 20b and 20c and the two ends of the top 20d to the edges of the sidewalls 20b and 20c, a chamfer 22 is formed with its sharp portion being chamfered.

[0073] In the secondary battery module according to the present invention, the pads 30 can be formed on the inner side of the bottom 20a and side walls 20b and 20c of the housing 20 to more effectively support the ends of the secondary battery. Figure 2(Lower end of the secondary battery 10). Therefore, the movement of the lower end of the secondary battery 10 can be restricted, thereby suppressing damage to the secondary battery 10.

[0074] More specifically, this prevents the bag from being damaged due to friction between the secondary battery 10 and the housing 20. Additionally, when the cooling device is attached to the outside of the bottom of the housing, the movement of the lower end of the secondary battery can be fixed to its original position, thereby preventing deterioration of cooling efficiency and further reducing the likelihood of damage.

[0075] In addition, in this invention, since the pad 30 is installed in a previously compressed state via the rib 21, the movement of the lower end of the secondary battery 10 can be supported relatively more firmly, and the resin 40 can be additionally applied to the bottom surface of the housing 20 to further reduce the possibility of the lower end of the secondary battery 10 moving.

[0076] Although embodiments of the invention have been described with reference to specific examples, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

[0077] [List of reference numerals]

[0078] 10: Secondary batteries

[0079] 20: Shell

[0080] 30: Solder pads

[0081] 40: Resin

Claims

1. A secondary battery module, the secondary battery module comprising: Multiple secondary batteries, each having two flat and parallel side surfaces; A housing, in which the plurality of secondary batteries are mounted, the housing including a bottom formed in a horizontal direction, two sidewalls perpendicularly erected to each other in a longitudinal direction at both ends of the bottom, and a top extending from the upper end of each of the sidewalls and disposed parallel to the bottom, wherein the plurality of secondary batteries are mounted in a stacked manner in their thickness direction such that the side surfaces of the two outermost secondary batteries respectively face the sidewalls; and The pads, made of an elastic material, are disposed in the sidewalls between each of them and the side surface of the outermost secondary battery. Ribs are formed on the inner side of each edge connecting the bottom and sidewalls of the housing to each other, so as to have a greater thickness than other parts. The ribs are formed with an inclined shape, such that the thickness of the ribs gradually increases from each of the sidewalls to the bottom. The pads are positioned between each of the sidewalls and the side surface of the secondary battery, with each pad pressed at the point of contact with the rib. When the secondary battery expands, the central portion of the pad is pressed down by the expansion, and the entire pad is pressed down uniformly. In this process, resin is applied to one or more surfaces of the bottom and the top, which are respectively facing the two sides of the secondary battery, and the resin adheres to fix the secondary battery in place.

2. The secondary battery module according to claim 1, wherein, The ribs are formed on the inside of each edge of the edge that connects one end of the bottom to each of the sidewalls and the edge that connects the other end of the bottom to each of the sidewalls.

3. The secondary battery module according to claim 1, wherein, A chamfer is formed on the outer side of each of the edges that connect the two ends of the bottom to the edges of the sidewall and the two ends of the top to the edges of the sidewall.

4. A method for manufacturing a secondary battery module, wherein a plurality of secondary batteries are mounted in a housing, the method comprising: The process of mounting pads made of elastic material in the housing, the housing including a bottom formed in a horizontal direction, two side walls that are perpendicular to each other in a longitudinal direction at both ends of the bottom, and a top extending from the upper end of each of the side walls and disposed parallel to the bottom; The process of installing the plurality of secondary batteries in the housing such that the solder pads are in close contact with each of the sidewalls; as well as The process of applying resin to one or more of the bottom and top surfaces, wherein the resin adheres to secure each of the secondary batteries. In the process of installing the secondary battery into the housing, the secondary batteries are stacked such that at least a portion of the pads are pressed between each of the sidewalls of the housing and the side surface of each of the secondary batteries. Ribs are formed on the inner edge of each of the sides that connect the bottom to the sides, having a greater thickness than other parts, so that the pads are pressed down by the ribs during the installation of the secondary battery. The ribs are formed with an inclined shape, such that the thickness of the ribs gradually increases from each of the sidewalls to the bottom. The pads are positioned between each of the sidewalls and the side surface of the secondary battery, with each pad pressed at the point of contact with the rib. When the secondary battery expands, the central portion of the pad is pressed by the expansion, and the entire pad is pressed evenly.

Images