Energy Storage Device

Abstract

The present invention relates to an energy storage device including a modular case having a plurality of accommodating spaces; a plurality of bare cells accommodated in each of the accommodating spaces; and a cover coupled to the modular case to cover the accommodating spaces, wherein the modular case directly contacts and supports the bare cells accommodated in each of the accommodating spaces, and a pressure-bearing ratio calculated as a ratio of the volume of the bare cells to the volume of the accommodating spaces for each of the accommodating spaces is 95% or less.

Description

[Technical Field]

[0001] The present invention relates to an energy storage device for storing energy, such as electrical energy. [Background technology]

[0002] Batteries and capacitors are typical energy storage devices that store electrical energy. Among these capacitors, ultra-capacitors (UC) have high efficiency, a semi-permanent lifespan, and quick charge / discharge characteristics, and are therefore forming a market as an energy storage device that can compensate for the short cycle and instantaneous high voltage issues that are the weaknesses of secondary batteries.

[0003] Due to these advantages, ultracapacitors are widely used not only as auxiliary power sources for mobile devices such as mobile phones, tablet PCs, and laptops, but also as main or auxiliary power sources for electric vehicles, hybrid vehicles, solar power supplies, road signs, and uninterruptible power supplies (UPS), which require high capacity.

[0004] FIG. 1 is a schematic side view of an energy storage device according to the prior art.

[0005] Referring to FIG. 1, a conventional energy storage device 100 includes a plurality of bare cells 110, a plurality of cell cases 120 for housing the bare cells 110, and a module case 130 for housing the cell cases 120.

[0006] The bare cells 110 may be housed in the cell cases 120, respectively. The cell cases 120 housing the bare cells 110 may be housed in the module case 130. Accordingly, the energy storage device 100 according to the prior art may be modularized in a state where the bare cells 110 are housed in the cell cases 120.

[0007] Here, the energy density can be increased by increasing the number of bare cells 110 housed in the module case 130, but the energy storage device 100 according to the conventional technology has a problem that it is difficult to increase the energy density because the volume occupied by the cell case 120 inside the module case 130 acts as dead space. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to solve the above-mentioned problems, and aims to provide an energy storage device that can prevent a decrease in energy density due to a cell case that houses a bare cell. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the present invention can include the following configuration.

[0010] The energy storage device according to the present invention may include a modular case having a plurality of storage spaces formed therein; a plurality of bare cells accommodated in the storage spaces; and a cover coupled to the modular case to cover the storage spaces. The modular case may be in direct contact with the bare cells accommodated in the storage spaces to support the bare cells. A pressure-bearing ratio calculated as a ratio of the volume of the bare cells to the volume of the storage spaces for each storage space may be 95% or less. [Effects of the Invention]

[0011] According to the present invention, the following effects can be achieved.

[0012] The present invention can be embodied so that bare cells are directly supported in a module case without a cell case. Accordingly, the volume of the module case that would have been occupied by the cell case can be used as space to accommodate the bare cells. Therefore, the present invention can increase the energy density by increasing the volume of the bare cells.

[0013] The present invention is embodied to have a pressure capacity that can secure a space for containing gas discharged from the bare cell during use. Therefore, the present invention can reduce the risk of explosion due to gas discharged from the bare cell, thereby improving the reliability and safety of the product.

[0014] The present invention is embodied to have a pressure-bearing ratio that can increase the volume of the bare cell while reducing the risk of explosion due to gas discharged from the bare cell. Therefore, the present invention can improve the reliability and safety of the product, and can also provide improved product performance by further increasing the energy density through the increased volume of the bare cell. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic side view of an energy storage device according to the prior art;

[0016] [Figure 2] 1 is a schematic perspective view of an energy storage device according to the present invention;

[0017] [Figure 3] 1 is a schematic exploded perspective view of an energy storage device according to the present invention;

[0018] [Figure 4] 1 is a conceptual diagram illustrating a bare cell in an energy storage device according to the present invention. FIG.

[0019] [Figure 5]4 is a conceptual cross-sectional view of the energy storage device according to the present invention taken along line II in FIG. 3 for explaining the pressure receiving rate.

[0020] [Figure 6] 4 is a schematic exploded cross-sectional view of the energy storage device according to the present invention taken along line II in FIG. 3.

[0021] [Figure 7] FIG. 2 is a schematic bottom perspective view of a cover of the energy storage device according to the present invention.

[0022] [Figure 8] 4 is a schematic cross-sectional view of the energy storage device according to the present invention taken along line II in FIG. 3.

[0023] [Figure 9] FIG. 2 is a schematic plan view of a module case in the energy storage device according to the present invention.

[0024] [Figure 10] FIG. 9 is a schematic enlarged cross-sectional view showing a portion A of FIG. 8 in an enlarged manner.

[0025] [Figure 11] FIG. 2 is a schematic partial perspective view illustrating a support member in the energy storage device according to the present invention.

[0026] [Figure 12] 12 is a schematic cross-sectional view taken along line II-II in FIG. 11.

[0027] [Figure 13] FIG. 13 is a schematic cross-sectional view taken along line III-III in FIG. 12.

[0028] [Figure 14] 1 is a schematic plan view of an energy storage device according to the present invention;

[0029] [Figure 15] 1 is a conceptual bottom perspective view illustrating a connection relationship between a bare cell, a bus bar, and an external terminal in an energy storage device according to the present invention. FIG.

[0030] [Figure 16] FIG. 2 is a schematic bottom perspective view of a bus bar in the energy storage device according to the present invention.

[0031] [Figure 17] 1 is a schematic bottom perspective view of an external terminal in an energy storage device according to the present invention; FIG.

[0032] [Figure 18] 3 is a schematic exploded perspective view illustrating a connection relationship between a bare cell and an internal terminal in the energy storage device according to the present invention; FIG.

[0033] [Figure 19] 1 is a conceptual side view illustrating a connection relationship between a bare cell, an internal terminal, and a bus bar in an energy storage device according to the present invention. FIG.

[0034] [Figure 20] FIG. 2 is a schematic perspective view of an internal terminal in the energy storage device according to the present invention.

[0035] [Figure 21] 12 is a conceptual cross-sectional view showing the connection relationship between the internal terminal and the bare cell in the energy storage device according to the present invention, taken along line II-II in FIG. 11. DETAILED DESCRIPTION OF THE INVENTION

[0036] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an energy storage device according to the present invention will be described in detail with reference to the accompanying drawings.

[0037] 2 and 3, an energy storage device 1 according to the present invention is for storing electrical energy. The energy storage device 1 according to the present invention may be implemented by modularizing a plurality of ultra-capacitors (UCs). The energy storage device 1 according to the present invention may include a bare cell 2, a module case 3, and a cover 4.

[0038] 2 to 4, the bare cell 2 is housed in the module case 3. The bare cell 2 is called an electrode element and may refer to an ultracapacitor without a cell case (120, shown in FIG. 1) attached thereto. The bare cell 2 may be housed in the module case 3 without the cell case (120, shown in FIG. 1). Accordingly, the energy storage device 1 according to the present invention can utilize the volume occupied by the cell case (120, shown in FIG. 1) inside the module case 3 as a space for housing the bare cell 2, thereby enabling the energy density to be further increased through the increased volume of the bare cell 2.

[0039] The bare cell 2 may be formed by winding a first electrode 21, a second electrode 22 having the opposite polarity to the first electrode 21, and a separator 23 disposed between the first electrode 21 and the second electrode 22 to electrically separate the first electrode 21 and the second electrode 22. In one embodiment, if the first electrode 21 is a positive electrode (+), the second electrode 22 is a negative electrode (-). Conversely, if the first electrode 21 is a negative electrode (-), the second electrode 22 is a positive electrode (+). The bare cell 2 may be wound in the order of the separator 23, the first electrode 21, the separator 23, and the second electrode 22. The bare cell 2 may also be wound in the order of the separator 23, the second electrode 22, the separator 23, and the first electrode 21.

[0040] The first electrode 21 may include a first active material layer 211 formed using activated carbon on a metal current collector (not shown), and a first electrode lead 212 connected to one side of the first active material layer 211. In this case, the first electrode lead 212 is formed from a region of the current collector where the first active material layer 211 is not formed.

[0041] The second electrode 22 may include a second active material layer 221 formed using activated carbon on a metal current collector (not shown), and a second electrode lead 222 connected to one side of the second active material layer 221. In this case, the second electrode lead 222 is formed from a region of the current collector where the second active material layer 221 is not formed.

[0042] In the above-described embodiment, the current collectors constituting the first electrode 21 and the second electrode 22 may be formed using metal foil. The current collectors serve as paths for the transfer of charges emitted or supplied from the first active material layer 211 and the second active material layer 221. The first active material layer 211 and the second active material layer 221 may be formed by coating both sides of the current collectors. The first active material layer 211 and the second active material layer 221 are portions where electrical energy is stored.

[0043] In one embodiment, the first electrode 21 and the second electrode 22 may be wound such that the first electrode lead 212 is located on the upper side of the bare cell 2 and the second electrode lead 222 is located on the lower side of the bare cell 2.

[0044] Meanwhile, the bare cell 2 may be impregnated with an electrolyte for charging electrical energy. In this case, the process of impregnating the bare cell 2 with the electrolyte may be performed by immersing the bare cell 2 in a container filled with the electrolyte for a certain period of time. The process of impregnating the bare cell 2 with the electrolyte may be performed while the bare cell 2 is housed in the module case 3.

[0045] 2 to 4, the module case 3 is for accommodating the bare cell 2. The module case 3 may have an accommodating space 31 formed therein. The bare cell 2 may be accommodated in the module case 3 by being accommodated in the accommodating space 31. The accommodating space 31 may be embodied as a groove formed at a certain depth from the top surface of the module case 3. The module case 3 may directly contact the bare cell 2 accommodated in the accommodating space 31 to support the bare cell 2. That is, the bare cell 2 may be directly supported by the module case 3 without the cell case (120, shown in FIG. 1). Accordingly, the energy storage device 1 according to the present invention is embodied such that the volume of the cell case (120, shown in FIG. 1) in the accommodating space 31 can be used as at least one of a space for accommodating the bare cell 2 and an empty space. Therefore, the energy storage device 1 according to the present invention is embodied such that at least one of an increase in the volume of the empty space in the accommodating space 31 and an increase in energy density due to an increase in the volume of the bare cell 2 are achieved.

[0046] A plurality of the accommodating spaces 31 may be formed in the module case 3. The accommodating spaces 31 may be spaced apart from one another along a first axis direction (X-axis direction). The bare cells 2 may be accommodated in the accommodating spaces 31, respectively, and thus may be spaced apart from one another along the first axis direction (X-axis direction). Although FIG. 3 illustrates four accommodating spaces 31 formed in the module case 3, the number of accommodating spaces 31 is not limited thereto, and the module case 3 may be formed with two, three, five or more accommodating spaces 31.

[0047] 2 to 6, the module case 3 may include a bottom member 32, a side wall member 33, and a partition member .

[0048] The bottom member 32 is disposed under the receiving space 31. The bottom member 32 may have a supporting force for supporting the bare cell 2 received in the receiving space 31. The bottom member 32 is generally formed in a rectangular plate shape and may be disposed horizontally.

[0049] The side wall member 33 protrudes upward from the outer surface of the bottom member 32. The module case 3 may include a plurality of the side wall members 33. The side wall members 33 may protrude upward from different sides of the bottom member 32. In this case, the accommodating space 31 may be disposed inside the side wall members 33. The side wall members 33 may be generally formed in a rectangular plate shape and may be disposed upright in the vertical direction.

[0050] The partition member 34 serves to divide the accommodating space 31. The partition member 34 may protrude upward from the bottom member 32 between the side wall members 33. Accordingly, the partition member 34 may be disposed between the accommodating spaces 31. In this case, the partition member 34 may be disposed between the accommodating spaces 31 based on the first axis direction (X-axis direction). The module case 3 may include at least one partition member 34. When the number of accommodating spaces 31 is N (N is an integer greater than 1), the module case 3 may include (N-1) partition members 34. When a plurality of partition members 34 are provided, the partition members 34 may be disposed spaced apart from each other along the first axis direction (X-axis direction). The partition member 34 may be generally formed in a rectangular plate shape and disposed upright in the vertical direction.

[0051] The partition member 34, the side wall member 33, and the bottom member 32 may be integrally formed. In this case, the partition member 34, the side wall member 33, and the bottom member 32 may be integrally formed through injection molding.

[0052] 2 to 6, the cover 4 is intended to be coupled to the module case 3. The cover 4 is coupled to the module case 3 to cover the accommodating space 31. Accordingly, the accommodating spaces 31 may be implemented as spaces spatially separated from each other. For each of the accommodating spaces 31 spatially separated by the coupling between the cover 4 and the module case 3, a pressure-receiving ratio calculated as a ratio of the volume V2 of the bare cell 2 to the volume V1+V2 of the accommodating space 31 may be 95% or less. Here, the volume V2 of the bare cell 2 is calculated by multiplying the area of ​​the bottom by the height, and V1 may refer to the volume of the space that remains empty after the bare cell 2 is accommodated in the accommodating space 31. In this case, the volume V1+V2 of the accommodating space 31 may refer to the entire volume when the bare cell 2 is not accommodated. The pressure-receiving ratio may be calculated using the following mathematical formula 1:

[0053] [Mathematical formula 1]

[0054] JPEG0007732070000001.jpg19118

[0055] Since the pressure receiving rate of each of the receiving spaces 31 is 95% or less, the energy storage device 1 according to the present invention can improve the reliability and safety of the product by reducing the risk of explosion during use, and can improve the product performance by increasing the energy density.

[0056] First, gas may be discharged from the bare cells 2 housed in each of the receiving spaces 31 during use, and in the comparative example where the pressure-receiving rate of each of the receiving spaces 31 exceeds 95%, there is a high risk of explosion due to the gas discharged from the bare cells 2 housed in each of the receiving spaces 31. As a result, the comparative example has a problem of reduced reliability and safety of the product.

[0057] To solve this problem, the energy storage device 1 according to the present invention is embodied such that the pressure receiving rate of each of the accommodation spaces 31 is 95% or less, thereby ensuring a space capable of accommodating gas discharged from the bare cells 2 housed in each of the accommodation spaces 31 during use. Therefore, the energy storage device 1 according to the present invention can reduce the risk of explosions or the like caused by gas discharged from the bare cells 2 housed in each of the accommodation spaces 31, thereby further improving the reliability and safety of the product.

[0058] Second, the energy storage device 1 according to the present invention can increase the pressure rate of each of the accommodating spaces 31 up to 95%, thereby reducing the risk of explosions due to gas discharged from the bare cells 2 accommodated in each of the accommodating spaces 31, and can also increase the volume V2 of the bare cells 2 accommodated in each of the accommodating spaces 31. Therefore, the energy storage device 1 according to the present invention can further improve the reliability and safety of the product, and can also provide further improved product performance by increasing the energy density through the increase in the volume V2 of the bare cells 2 accommodated in each of the accommodating spaces 31.

[0059] The pressure ratio of each of the accommodating spaces 31 may be 50% or more. In the comparative example, in which the pressure ratio of each of the accommodating spaces 31 is less than 50%, the space available for accommodating gas discharged from the bare cells 2 accommodated in each of the accommodating spaces 31 may be increased, but the volume V2 of the bare cells 2 accommodated in each of the accommodating spaces 31 may be reduced too much. As a result, the comparative example may have reduced product performance due to a reduced energy density. In contrast, in the embodiment, the pressure ratio of each of the accommodating spaces 31 is 50% or more, thereby reducing the risk of explosion due to gas discharged from the bare cells 2 accommodated in each of the accommodating spaces 31 while preventing the volume V2 of the bare cells 2 accommodated in each of the accommodating spaces 31 from being reduced too much. Therefore, the embodiment can improve product reliability and safety while providing improved product performance through increased energy density.

[0060] The cover 4 and the module case 3 may be formed of a material that does not react with the electrolyte impregnated in the bare cell 2, such as a material with low conductivity. This is to prevent defects such as a short circuit from occurring when the electrolyte leaks from the bare cell 2, since the bare cell 2 is accommodated in the accommodation space 31 without the cell case (120, shown in FIG. 1).

[0061] For example, the cover 4 and the module case 3 may be made of a plastic material. Accordingly, the cover 4 and the module case 3 may prevent defects such as a short circuit even if electrolyte leaks from the bare cell 2. The cover 4 and the module case 3 may be made of a plastic material and coupled to each other. In this case, the pressure resistance of each of the accommodating spaces 31 may be determined by the pressure-bearing rate of each of the accommodating spaces 31. The pressure resistance of each of the accommodating spaces 31 may refer to the strength of the cover 4 and the module case 3 to withstand the internal pressure of each of the accommodating spaces 31 without damage or breakage. If the cover 4 and the module case 3 are made of an aluminum material, the pressure resistance of each of the accommodating spaces 31 may be 15 bar or more. However, if the cover 4 and the module case 3 are made of a plastic material, the pressure resistance of each of the accommodating spaces 31 may be approximately 4 bar to 8 bar. In this case, the pressure-bearing rate of each of the accommodating spaces 31 may be 50% to 95%.

[0062] The cover 4 and the module case 3 may be joined by welding using a laser. In this case, the module case 3 may be formed to have a lower laser transmittance than the cover 4. Accordingly, a laser irradiated from above the cover 4 passes through the cover 4 and melts the boundary between the cover 4 and the module case 3, thereby joining the cover 4 and the module case 3. Therefore, the energy storage device 1 according to the present invention may not only firmly join the cover 4 and the module case 3 through welding, but also improve the ease of the welding work. The cover 4 and the module case 3 may be formed of different materials, so that they have different laser transmittances.

[0063] The cover 4 and the module case 3 may be formed of the same material. The cover 4 and the module case 3 may be formed using polyamide. The cover 4 and the module case 3 may be formed using at least one of DuPont's ZYTEL, MINLON, DELRIN, CRASTIN, RYNITE, ETPV, and SORONA.

[0064] 2 to 8, the cover 4 may include a cover member 41 and a plurality of spacing members 42.

[0065] The cover member 41 is for covering the receiving space 31. When the cover 4 and the module case 3 are combined, the cover member 41 is disposed on the upper side of the module case 3 to cover the receiving space 31. The cover member 41 is generally formed in a rectangular plate shape and may be disposed lying in the horizontal direction.

[0066] The spacing member 42 protrudes from the cover member 41. When the cover 4 and the module case 3 are coupled together, the spacing member 42 can be inserted into the accommodating space 31. Accordingly, the spacing member 42 can support the bare cell 2 so that the bare cell 2 is positioned at a distance from the cover member 41 in the accommodating space 31. Therefore, the energy storage device 1 according to the present invention can secure additional space between the bare cell 2 and the cover member 41 by using the spacing member 42. Accordingly, the energy storage device 1 according to the present invention can easily adjust the pressure-bearing ratio for each of the accommodating spaces 31 by adjusting the height, thickness, etc. of the spacing member 42. Furthermore, when gravity acts on the cover 4, such as when the cover 4 is turned upside down so that it is positioned below the module case 3, the energy storage device 1 according to the present invention can contain the leaked electrolyte by utilizing the space between the bare cell 2 and the cover member 41. Therefore, the energy storage device 1 according to the present invention can reduce the risk of short circuits caused by electrolyte leaking from the bare cell 2, thereby further improving product reliability and safety.

[0067] Each of the spacing members 42 may include a spacing groove 421 and a spacing surface 422 .

[0068] The spacing groove 421 is for inserting the bare cell 2. The spacing groove 421 may be implemented as a groove formed with a certain depth in the spacing member 42. When the cover 4 and the module case 3 are coupled together, a portion of the bare cell 2 accommodated in the receiving space 31 may be inserted into the spacing groove 421.

[0069] The spacing surface 422 comes into contact with the bare cell 2 inserted into the spacing groove 421. The spacing surface 422 is a surface disposed facing the spacing groove 421. The spacing surface 422 may be formed as a curved surface corresponding to the periphery of the bare cell 2. Accordingly, the spacing surface 422 supports the bare cell 2 inserted into the spacing groove 421, thereby limiting the distance that the bare cell 2 can move due to vibration, shaking, etc.

[0070] A plurality of the spacing members 42 may be inserted into each of the accommodating spaces 31. In this case, the spacing members 42 may be arranged in each of the accommodating spaces 31 spaced apart from one another along the second axis direction (Y-axis direction). The second axis direction (Y-axis direction) and the first axis direction (X-axis direction) are axial directions that are perpendicular to one another on a horizontal plane. The spacing members 42 inserted into each of the accommodating spaces 31 can support different portions of the bare cell 2, thereby more stably supporting the bare cell 2.

[0071] The cover 4 may include a plurality of connecting members 43 .

[0072] The connecting members 43 are respectively coupled to the spacing members 42 spaced apart from each other along the second axis (Y-axis direction). Accordingly, the spacing members 42 connected by the connecting members 43 can more firmly support the bare cell 2. The connecting members 43, 43' may be coupled to both sides of the spacing members 42 spaced apart from each other along the second axis (Y-axis direction). The spacing members 42 spaced apart from each other along the second axis (Y-axis direction) and the connecting members 43, 43' may be integrally formed. During the process of coupling the cover 4 and the module case 3, the connecting members 43, 43' may contact the side wall member 33 or the partition member 34 or the partition member 34. Accordingly, the connecting members 43, 43' guide the coupling position between the cover 4 and the module case 3, thereby improving ease of coupling between the cover 4 and the module case 3. In addition, the connecting members 43, 43' are inserted into the receiving space 31 and supported by the module case 3, thereby restricting the relative movement of the cover 4 with respect to the module case 3. Therefore, the energy storage device 1 according to the present invention can more stably support the bare cell 2 by using the connecting members 43, 43'.

[0073] Here, the module case 3 may be implemented such that the bare cell 2 is disposed at a position spaced apart from the bottom member 32. To this end, the module case 3 may include a plurality of support members 35.

[0074] The support members 35 protrude from the bottom member 32. The support members 35 may protrude upward from the bottom member 32 in each of the receiving spaces 31. Accordingly, the support members 35 may support the bare cell 2 so that the bare cell 2 is spaced apart from the bottom member 32 in the receiving space 31. Therefore, the energy storage device 1 according to the present invention can secure additional space between the bare cell 2 and the bottom member 32 by using the support members 35. Accordingly, the energy storage device 1 according to the present invention can easily adjust the pressure-bearing ratio for each of the receiving spaces 31 by adjusting the height, thickness, etc. of the support members 35. Furthermore, when gravity acts on the bottom member 32, the energy storage device 1 according to the present invention can contain the leaked electrolyte by utilizing the space between the bare cell 2 and the bottom member 32, even if the electrolyte leaks from the bare cell 2. Therefore, the energy storage device 1 according to the present invention can reduce the risk of a short circuit or the like caused by electrolyte leaking from the bare cell 2, thereby further improving product reliability and safety.

[0075] Each of the support members 35 may include a support groove 351 and a support surface 352 .

[0076] The support groove 351 is for inserting the bare cell 2. The support groove 351 may be implemented as a groove formed with a certain depth in the support member 35. A part of the bare cell 2 accommodated in the receiving space 31 may be inserted into the support groove 351.

[0077] The support surface 352 comes into contact with the bare cell 2 inserted into the support groove 351. The support surface 352 is a surface disposed facing the support groove 351. The support surface 352 may be formed as a curved surface corresponding to the periphery of the bare cell 2. Accordingly, the support surface 352 supports the bare cell 2 inserted into the support groove 351, thereby limiting the distance that the bare cell 2 can move due to vibration, shaking, etc.

[0078] A plurality of the support members 35 may be inserted into each of the accommodating spaces 31. In this case, the support members 35 may be arranged spaced apart from each other along the second axis direction (Y-axis direction) in each of the accommodating spaces 31. Accordingly, the support members 35 inserted into each of the accommodating spaces 31 may support different portions of the bare cell 2, thereby more stably supporting the bare cell 2.

[0079] Each of the support members 35 may be formed to have the same length as the receiving space 31 based on the first axis direction (X-axis direction). Accordingly, both sides of the support member 35 may be coupled to the side wall member 33 and the partition member 34 or may be coupled to the partition member 34. Therefore, the energy storage device 1 according to the present invention can strengthen the supporting force of the support member 35 by using the side wall member 33 and the partition member 34, and can be embodied to more stably support the bare cell 2 by using the support member 35.

[0080] Meanwhile, the energy storage device 1 according to the present invention may include at least one of the support member 35 and the spacing member 42. When both the support member 35 and the spacing member 42 are included, as shown in Fig. 8, the energy storage device 1 according to the present invention may increase the support area for supporting the bare cell 2 by using the support member 35 and the spacing member 42, thereby more stably supporting the bare cell 2.

[0081] 2 to 10 , the cover 4 may be coupled to the module case 3 so as to contact the side wall member 33 and the partition wall member 34. The cover 4 may also contact a flange portion 36 of the module case 3. The flange portion 36 protrudes outward from the upper portion of the side wall member 33. The flange portion 36 reinforces the strength of the side wall member 33, thereby preventing bending deformation of the side wall member 33. For example, when the module case 3 is manufactured through injection molding, the flange portion 36 reduces shrinkage or the like that occurs in the side wall member 33, thereby preventing bending deformation or the like from occurring in the side wall member 33. By preventing deformation or the like from occurring in the side wall member 33 using the flange portion 36, the energy storage device 1 according to the present invention can prevent separation of the welding path when the cover 4 and the module case 3 are coupled by welding. Therefore, the energy storage device 1 according to the present invention can improve the welding quality between the cover 4 and the module case 3, thereby further increasing the pressure resistance of each of the accommodation spaces 31. Accordingly, the energy storage device 1 according to the present invention can be embodied to have sufficient pressure resistance and durability even when the cover 4 and the module case 3 are made of a plastic material. Furthermore, the energy storage device 1 according to the present invention can increase the blocking force that blocks electrolyte leaked from one of the receiving spaces 31 from flowing to other receiving spaces 31 by improving the welding quality of the cover 4 and the module case 3. Therefore, the energy storage device 1 according to the present invention can reduce the risk of short circuits caused by electrolyte leakage, thereby improving the reliability and safety of the product.

[0082] When the sidewall members 33 are connected to each other to form a rectangular parallelepiped, the flange portions 36 may protrude outward from the sidewall members 33 to form a rectangular ring shape. The portions of the flange portions 36 [hereinafter referred to as "first flange portions"] coupled to the sidewall members 33 [hereinafter referred to as "first sidewall members"] spaced apart along the first axis direction (X-axis direction) may be wider than the portions of the flange portions 36 [hereinafter referred to as "second flange portions"] coupled to the sidewall members 33 [hereinafter referred to as "second sidewall members"] spaced apart along the second axis direction (Y-axis direction). The width of the second flange portions may refer to the length of the second flange portions protruding from each of the second sidewall members based on the second axis direction (Y-axis direction). The width of the first flange portions may refer to the length of the second flange portions protruding from each of the second sidewall members based on the first axis direction. The first flange portion 36 may refer to the length of the first flange portion protruding from each of the first side wall members based on the Y-axis direction. The second side wall members are connected to each other by the partition wall member 34 and have greater strength than the first side wall members, so even if the second flange portion is formed with a thinner width than the first flange portion, the second side wall members can have sufficient strength. Therefore, the energy storage device 1 according to the present invention can be implemented to reduce the cost of materials for implementing the flange portion 36 while ensuring sufficient strength for the side wall members 33 by using the flange portion 36.

[0083] A fastening hole H2 may be formed in the cover 4. In this case, a fastening hole H1 may also be formed in the flange portion 36. Fastening members (not shown), such as bolts, may be fastened to the fastening holes H1 and H2. Accordingly, the cover 4 and the module case 3 are more firmly coupled by the fastening members, thereby further increasing the pressure resistance of each of the accommodating spaces 31. A plurality of the fastening holes H2 may be formed in the cover 4. The fastening holes H2 may be formed at positions spaced apart from each other and penetrating the cover member 41. A plurality of the fastening holes H1 may be formed in the flange portion 36. The fastening holes H1 may be formed at positions spaced apart from each other and penetrating the flange portion 36. The fastening holes H1 and H2 may be disposed at positions corresponding to each other.

[0084] 2 to 10, the energy storage device 1 according to the present invention may include a welded joint 5. As shown in FIG.

[0085] The welded joint 5 connects the module case 3 and the cover 4. The welded joint 5 may be disposed between the module case 3 and the cover 4. When the module case 3 and the cover 4 are in contact with each other, the welded joint 5 can fuse to connect the module case 3 and the cover 4. The welded joint 5 may be formed to protrude from either the module case 3 or the cover 4. The welded joint 5 may be formed to protrude from each of the module case 3 and the cover 4. The welded joint 5 may be formed of the same material as the module case 3 or the cover 4.

[0086] The welded joint 5 may include a sidewall joint member 51 .

[0087] The sidewall connecting member 51 connects the sidewall member 33 and the cover 4. As shown in Fig. 9, the sidewall connecting member 51 may be formed on the upper surface of the sidewall member 33. As shown in Fig. 10, the sidewall connecting member 51 may be formed on the lower surface of the cover member 41 corresponding to the upper surface of the sidewall member 33. The sidewall connecting member 51 may be formed in the shape of a closed ring along the sidewall member 33.

[0088] The sidewall connecting member 51 can connect the upper surface of the sidewall member 33 and the lower surface of the cover 4 at a position closer to the inner surface 331 of the sidewall member 33 than the outer surface 361 of the flange portion 36. Accordingly, the energy storage device 1 according to the present invention can further increase the pressure resistance of each of the accommodation spaces 31. This can be explained in detail as follows.

[0089] First, when gas is discharged from the bare cell 2 housed in the receiving space 31 during use, the internal pressure caused by the gas generates concentrated stress at the boundary between the cover 4 and the inner surface 331 of the side wall member 33. Accordingly, in the comparative example in which the side wall connecting member 51 is disposed closer to the outer surface 361 of the flange portion 36 than the inner surface 331 of the side wall member 33, it is difficult to withstand the concentrated stress at the boundary, and the pressure resistance of each receiving space 31 is inevitably reduced.

[0090] Next, in the case of an embodiment in which the side wall connecting member 51 is disposed closer to the inner surface 331 of the side wall member 33 than the outer surface 361 of the flange portion 36, the side wall connecting member 51 can connect the upper surface of the side wall member 33 and the lower surface of the cover 4 at a position closer to the boundary portion. Accordingly, the embodiment can increase durability to withstand stress concentrated at the boundary portion, thereby further increasing the pressure resistance strength of each of the receiving spaces 31.

[0091] The sidewall connecting members 51 may be disposed inside the fastening holes H1 formed in the flange portion 36. That is, the fastening holes H1 may be disposed outside the sidewall connecting members 51. Accordingly, the energy storage device 1 according to the present invention is embodied such that the sidewall connecting members 51 and the fastening members fastened to the fastening holes H1 do not affect each other while connecting the cover 4 and the module case 3, thereby further increasing the pressure resistance of each of the accommodation spaces 31. Although not shown, the sidewall connecting members 51 may be formed on both the upper surfaces of the sidewall members 33 and the upper surfaces of the flange portion 36.

[0092] The welded joint 5 may include a bulkhead joint member 52 .

[0093] The bulkhead connecting member 52 connects the bulkhead member 34 and the cover 4. As shown in FIG. 9, the bulkhead connecting member 52 may be formed on the upper surface of the bulkhead member 34. As shown in FIG. 10, the bulkhead connecting member 52 may be formed on the lower surface of the cover member 41 corresponding to the upper surface of the bulkhead member 34. Since the bulkhead connecting member 52 connects the bulkhead member 34 and the cover 4 and the sidewall connecting member 51 connects the sidewall member 33 and the cover 4, the energy storage device 1 according to the present invention can strengthen the connecting force between the module case 3 and the cover 4. Therefore, the energy storage device 1 according to the present invention can further increase the pressure resistance of each of the accommodation spaces 31. When the module case 3 includes a plurality of the bulkhead members 34, the welded joint 5 may include a plurality of the bulkhead connecting members 52. In this case, the bulkhead connecting members 52 may be disposed at positions corresponding to each of the bulkhead members 34.

[0094] 9, the partition wall connecting members 52 and the side wall connecting members 51 are connected to each other to form a closed loop for each of the accommodating spaces 31. Accordingly, the energy storage device 1 according to the present invention can individually seal the accommodating spaces 31 using the welded joints 5. Therefore, the energy storage device 1 according to the present invention can improve the airtightness of each of the accommodating spaces 31. Furthermore, if electrolyte leaks from the bare cell 2 in one of the accommodating spaces 31, the welded joints 5 can prevent the leaked electrolyte from flowing to other accommodating spaces 31. Therefore, the energy storage device 1 according to the present invention can reduce the risk of short circuits caused by the collection of leaked electrolyte in one of the accommodating spaces 31, thereby further improving the reliability and safety of the product.

[0095] 2 to 13, the energy storage device 1 according to the present invention may include a plurality of bus bars 6.

[0096] Each of the bus bars 6 electrically connects at least two of the bare cells 2. When the bare cells 2 are connected in series, each of the bus bars 6 can electrically connect two bare cells 2. In this case, each of the bus bars 6 can be inserted into one partition member 34 and disposed in two receiving spaces 31, thereby electrically connecting two bare cells 2. When the bare cells 2 are connected in parallel, all of the bare cells 2 housed in the module case 3 can be electrically connected. In this case, the bare cells 2 can be inserted into all of the partition members 34 of the module case 3 and disposed in all of the receiving spaces 31, thereby electrically connecting all of the bare cells 2. The bus bars 6 can be connected to the module case 3 through insert molding. Meanwhile, both ends of the bare cells 2 housed in the receiving spaces 31 can be electrically connected to the bus bars 6. The bus bars 6 can be formed of a conductive material.

[0097] The bus bar 6 may be electrically connected to the bare cell 2 in the receiving space 31. In this case, the module case 3 may include a plurality of support members 37.

[0098] The support member 37 supports the bus bar 6. The support member 37 may protrude upward from the bottom member 32 in each of the accommodating spaces 31. The bus bar 6 may be firmly supported by being coupled to the support member 37 in the accommodating space 31, and thus may be stably maintained in a state in which it is electrically connected to the bare cell 2. Two support members 37 may be disposed in each of the accommodating spaces 31, spaced apart from each other along the second axis direction (Y-axis direction). In this case, the bus bar 6 may be coupled to each of the two support members 37.

[0099] Each of the support members 37 may be formed to have the same length as the receiving space 31 based on the first axis direction (X-axis direction). Accordingly, both sides of each of the support members 37 may be coupled to the side wall members 33 and the partition members 34 or may be coupled to the partition members 34. Therefore, the energy storage device 1 according to the present invention can strengthen the supporting force of the support members 37 by using the side wall members 33 and the partition members 34, and can therefore be embodied to more stably support the bus bars 6 by using the support members 37.

[0100] Each of the support members 37 may include an inner support surface 371 , an outer support surface 372 , and an upper support surface 373 .

[0101] The support inner surface 371 is disposed to face the bare cell 2 accommodated in the receiving space 31. The support inner surface 371 may be formed to form a plane parallel to the vertical direction. The bus bar 6 may be disposed between the bare cell 2 and the support inner surface 371.

[0102] The outer support surface 372 is disposed to face the sidewall member 33. The outer support surface 372 may be disposed at a position spaced apart from the sidewall member 33. Accordingly, a separation space may be provided between the outer support surface 372 and the sidewall member 33 in the second axis direction (Y-axis direction). A flow prevention member (not shown) for preventing the flow of the busbar 6 may be inserted into the separation space when the busbar 6 is coupled to the support member 37 through insert molding or double injection. The flow prevention member may correspond to a part of a mold of an injection molding machine. Accordingly, the energy storage device 1 according to the present invention may utilize the separation space to improve the ease of coupling the busbar 6 to the support member 37 and to accurately couple the busbar 6 to the support member 37. Furthermore, the energy storage device 1 according to the present invention may prevent the busbar 6 from being partially covered with burrs. If the busbar 6 is covered with burrs, contact resistance increases. Therefore, the energy storage device 1 according to the present invention can reduce contact resistance between the busbar 6 and the bare cell 2 by preventing burrs from being formed on the busbar 6. Therefore, the energy storage device 1 according to the present invention can improve electrical connectivity between the busbar 6 and the bare cell 2. The busbar 6 and the support member 37 can be coupled to each other through insert molding.

[0103] The upper supporting surface 373 is connected to the inner supporting surface 371 and the outer supporting surface 372. When the cover 4 and the module case 3 are combined, the upper supporting surface 373 faces the cover 4. The upper supporting surface 373 can support the upper portion of the bus bar 6. Accordingly, the support member 37 can more firmly support the bus bar 6 using the upper supporting surface 373.

[0104] Each of the support members 37 may include a support groove 374 .

[0105] The support groove 374 is formed on the outer support surface 372. The support groove 374 may be embodied as a groove formed to a certain depth on the outer support surface 372. Since the volume of the separation space is increased by the support groove 374, the energy storage device 1 according to the present invention can further strengthen the force preventing the busbar 6 from moving by increasing the area where the movement prevention member contacts the busbar 6. Therefore, the energy storage device 1 according to the present invention can further improve the ease and accuracy of the connection work of connecting the busbar 6 to the support member 37 and further improve the electrical connection between the busbar 6 and the bare cell 2.

[0106] The support groove 374 may be formed to increase in size as it extends upward. Accordingly, the portion of the support member 37 where the support groove 374 is formed may be embodied to have a thickness in the second axis direction (Y-axis direction) that decreases as it protrudes upward. Therefore, the energy storage device 1 according to the present invention may be embodied such that the flow prevention member can be easily inserted into the separated space and easily separated from the separated space by increasing the area of ​​the entrance of the separated space.

[0107] 13, the support grooves 374 may be formed on both sides of the support body 375 based on the first axis direction (X-axis direction). The support body 375 may refer to a portion of the outer support surface 372 where the support grooves 374 are not formed. When the anti-fluid movement member is inserted into the support grooves 374, both sides of the support body 375 may guide the movement of the anti-fluid movement member. The support body 375 may be formed to have a height greater than the portion where the support grooves 374 are formed. In this case, the support body 375 may support a portion of the upper protrusion member 62. The support body 375 may be formed to have a height greater than the portion where the support grooves 374 are formed but less than the height of the side wall member 33. Accordingly, in the energy storage device 1 according to the present invention, when the cover 4 and the module case 3 are joined by welding, the support body 375 may be less likely to interfere with the welding operation. Therefore, even if the energy storage device 1 according to the present invention includes the support body 375, the ease and accuracy of the welding operation for joining the cover 4 and the module case 3 by welding can be improved.

[0108] Although not shown, the support groove 374 may be formed on one side of the support body 375 or the other side of the support body 375 based on the first axis direction (X-axis direction). The support groove 374 may be formed on the front surface of the outer support surface 372.

[0109] Each of the bus bars 6 may include a bus bar body 61 and an upper protruding member 62 .

[0110] The busbar body 61 is in contact with the support inner surface 371. The busbar body 61 may be disposed between the bare cell 2 accommodated in the accommodating space 31 and the support member 37. The busbar body 61 may be electrically connected to the bare cell 2 accommodated in the accommodating space 31. The busbar body 61 may be disposed upright in the vertical direction.

[0111] The upper protruding member 62 protrudes from the busbar body 61. The upper protruding member 62 may be supported by the support member 37 by contacting the support upper surface 373. Accordingly, the busbar 6 may be more firmly supported by the support member 37 and more stably maintained in a state electrically connected to the bare cell 2. The upper protruding member 62 may protrude from an upper portion of the busbar body 61 toward the support member 37. The upper protruding member 62 and the busbar body 61 may be integrally formed.

[0112] Referring to FIGS. 2 to 17, each of the bus bars 6 may include a detection member 63.

[0113] The detection member 63 protrudes from the busbar body 61. When the busbar body 61 is disposed between the bare cell 2 accommodated in the accommodating space 31 and the sidewall member 33, the detection member 63 may protrude from the busbar body 61 toward the bare cell 2 accommodated in the accommodating space 31. When the upper protruding member 62 is provided, the detection member 63 and the upper protruding member 62 may protrude in opposite directions. The detection member 63 may protrude from a lower portion of the busbar body 61. The detection member 63 and the busbar body 61 may be integrally formed.

[0114] When the detection member 63 is provided, the module case 3 may include a detection hole 38. The detection hole 38 may be formed by penetrating the bottom member 32. Accordingly, the energy storage device 1 according to the present invention is embodied such that electrical connection to the detection member 63 can be made from the outside of the module case 3 through the detection hole 38 without separating the bare cell 2 housed inside the module case 3. Therefore, the energy storage device 1 according to the present invention may perform a monitoring operation for monitoring the voltage of the bare cell 2 and a balancing operation for adjusting the voltage of the bare cell 2 without separating the bare cell 2 housed inside the module case 3. Accordingly, the energy storage device 1 according to the present invention may improve the ease of the monitoring and balancing operations and reduce the time required for the monitoring and balancing operations. The detection hole 38 may be formed by penetrating the bottom member 32 at a position corresponding to the detection member 63. The module case 3 may have a plurality of detection holes 38.

[0115] The detection member 63 may be disposed between the bare cells 2 based on the first axis direction (X-axis direction). Accordingly, the detection member 63 may be disposed at a position that does not interfere with the electrical connection between the bus bar 6 and the bare cell 2. For example, as shown in FIG. 15, if a first bus bar 6a among the bus bars 6 is electrically connected to a first bare cell 2a and a second bare cell 2b among the bare cells 2, the first detection member 63a of the first bus bar 6a may be disposed between the first bare cell 2a and the second bare cell 2b based on the first axis direction (X-axis direction). In this case, the first bare cell 2a and the second bare cell 2b may be spaced apart from each other along the first axis direction (X-axis direction) and housed in different housing spaces (31, shown in FIG. 6). The first detection member 63a may protrude toward a partition member (34, shown in FIG. 6) disposed between the first bare cell 2a and the second bare cell 2b.

[0116] Meanwhile, when each bus bar 6 is electrically connected to two bare cells 2 to connect the bare cells 2 in series, the detection member 63 of the bus bar 6 disposed on one side of the bare cell 2 (hereinafter referred to as the "first detection member") and the detection member 63 of the bus bar 6 disposed on the other side of the bare cell 2 (hereinafter referred to as the "second detection member") may be disposed to be offset from each other based on the second axis direction (Y axis direction). In this case, the first detection member and the second detection member may be disposed at positions spaced apart from each other based on the first axis direction (X axis direction). Accordingly, as shown in FIG. 14, the detection hole 38 corresponding to the first detection member and the detection hole 38' corresponding to the second detection member may be disposed to be offset from each other based on the first axis direction (X axis direction).

[0117] Each of the bus bars 6 may include an insertion hole 631 .

[0118] The insertion hole 631 is formed to penetrate the detection member 63. The bus bar 6 may be coupled to the module case 3 such that the insertion hole 631 is positioned corresponding to the detection hole 38. Accordingly, the energy storage device 1 according to the present invention is electrically connected to the detection member 63 outside the module case 3 through the detection hole 38 and the insertion hole 631, and is electrically connected to the bare cell 2 housed in the module case 3 through the detection member 63. A screw may be formed on the inner surface of the detection member 63 in which the insertion hole 631 is formed. In this case, a detection device (not shown) for performing the monitoring and balancing operations may be inserted into the insertion hole 631 and fastened to the detection member 63. Therefore, the energy storage device according to the present invention can firmly maintain the detection member 63 in an electrically connected state, thereby improving the stability of the monitoring and balancing operations.

[0119] Each of the bus bars 6 may include a lower protruding member 64 .

[0120] The lower protruding member 64 protrudes from the busbar body 61. When the busbar body 61 is disposed between the bare cell 2 housed in the receiving space 31 and the support member 37, the lower protruding member 64 may protrude toward the support member 37. In this case, the lower protruding member 64 may be inserted into and coupled to the bottom member 32 so as to be disposed below the support member 37. Accordingly, the lower protruding member 64 is firmly supported by the bottom member 32, so that the busbar 6 may be more stably maintained in a state electrically connected to the bare cell 2. If the detection member 63 is provided, the lower protruding member 64 and the detection member 63 may protrude in opposite directions with respect to the second axis direction (Y-axis direction). Accordingly, the lower protruding member 64 may be disposed at a position that does not interfere with monitoring and balancing operations using the detection member 63. The lower protruding member 64 may protrude from a lower portion of the busbar body 61. The lower protruding member 64 and the busbar body 61 may be integrally formed.

[0121] 2 to 17, the energy storage device 1 according to the present invention may include an external terminal 7.

[0122] The external terminal 7 is electrically connected to at least one of the bare cells 2. The external terminal 7 may be made of a conductive material. One side of the external terminal 7 may be connected to at least one of the bare cells 2 inside the module case 3, and the other side of the external terminal 7 may be disposed outside the module case 3. The other side of the external terminal 7 may be electrically connected to an external device (not shown) outside the module case 3. The external device performs a predetermined task on the bare cell 2 through the external terminal 7. For example, the external device may be a management device that manages power. The external device may also be the detection device. The external terminal 7 may be coupled to the module case 3 through insert molding.

[0123] 15, the external terminal 7 may be electrically connected to a first bare cell 2a of the bare cells 2. One side of the first bare cell 2a may be electrically connected to the first bus bar 6a, and the other side may be electrically connected to the external terminal 7. The energy storage device 1 according to the present invention may include a plurality of external terminals 7. In this case, the external terminals 7, 7' may be electrically connected to different bare cells 2. The external terminals 7, 7' may be electrically connected to the bare cells 2 arranged at both ends in the first axis direction (X-axis direction), respectively.

[0124] The external terminal 7 may include a pull-out member 71 .

[0125] The lead-out member 71 protrudes to the outside of the module case 3. The lead-out member 71 may be electrically connected to the external device outside the module case 3. Accordingly, the energy storage device 1 according to the present invention can improve the ease of electrically connecting the external device to the bare cells 2 housed in the module case 3 by using the lead-out member 71. Meanwhile, when an even number of accommodating spaces 31 are formed in the module case 3 and an even number of bare cells 2 are housed therein, the lead-out members 71, 71' (shown in FIG. 15) of the external terminals 7, 7' may protrude to the outside of the module case 3 in the same direction based on the second axis direction (Y-axis direction). When an odd number of accommodating spaces 31 are formed in the module case 3 and an odd number of bare cells 2 are housed therein, the lead-out members 71, 71' of the external terminals 7, 7' may protrude to the outside of the module case 3 in opposite directions based on the second axis direction (Y-axis direction).

[0126] The external terminal 7 may be arranged alongside the bus bar 6 along the first axis direction (X-axis direction). The external terminal 7 may be supported by the support member 37. In this case, the external terminal 7 may include an external terminal body 72 and a protruding member 73.

[0127] The external terminal body 72 contacts the support inner surface 371. The external terminal body 72 may be disposed between the bare cell 2 accommodated in the accommodating space 31 and the support member 37. The external terminal body 72 may be electrically connected to the bare cell 2 accommodated in the accommodating space 31. The external terminal body 72 may be disposed upright in the vertical direction. The drawer member 71 may be coupled to the external terminal body 72. The drawer member 71 may protrude from a lower portion of the external terminal body 72 toward the support member 37. The drawer member 71 may be inserted into the support member 37 and the side wall member 33 and protrude to the outside of the module case 3. The external terminal body 72 and the drawer member 71 may be integrally formed. The drawer member 71 may be disposed lying horizontally in the horizontal direction.

[0128] The protruding member 73 protrudes from the external terminal body 72. The protruding member 73 may be supported by the support member 37 by contacting the support upper surface 373. Accordingly, the external terminal 7 may be more firmly supported by the support member 37, and may be more stably maintained in a state electrically connected to the bare cell 2. The protruding member 73 may protrude from an upper portion of the external terminal body 72 toward the support member 37. The protruding member 73 and the external terminal body 72 may be integrally formed. The protruding member 73 may be disposed lying in the horizontal direction.

[0129] 2 to 21, the energy storage device 1 according to the present invention may include a plurality of internal terminals 8.

[0130] The internal terminals 8 are to be connected to the bare cells 2, respectively. The internal terminals 8 may be connected to the bus bars 6. In the case of a bare cell 2 having both sides electrically connected to different bus bars 6, the internal terminal 8 connected to one side of the bare cell 2 and the internal terminal 8 connected to the other side of the bare cell 2 may be connected to different bus bars 6. In the case of a bare cell 2 having one side electrically connected to the bus bar 6 and the other side electrically connected to the external terminal 7, the internal terminal 8 connected to one side of the bare cell 2 may be connected to the bus bar 6, and the internal terminal 8 connected to the other side of the bare cell 2 may be connected to the external terminal 7. The internal terminals 8 may be formed of a conductive material.

[0131] Each of the internal terminals 8 may include an internal terminal body 81 .

[0132] The internal terminal body 81 is disposed between the bare cell 2 and the bus bar 6. The internal terminal body 81 is connected to the bare cell 2 and the bus bar 6, respectively, to electrically connect the bare cell 2 and the bus bar 6. An inner surface of the internal terminal body 81 may be connected to the first electrode lead 212 or the second electrode lead 222 of the bare cell 2. An outer surface of the internal terminal body 81 may be connected to the bus bar body 61 of the bus bar 6.

[0133] The inner surface of the internal terminal body 81 and the bare cell 2 may be connected by a plurality of body welds (91, shown in FIGS. 19 and 20). The body welds 91 may firmly connect the inner surface of the internal terminal body 81 and the bare cell 2 by welding. Accordingly, the energy storage device 1 according to the present invention may improve the stability of the electrical connection between the internal terminal 81 and the bare cell 2 by using the body welds 91. The body welds 91 may connect one of the first electrode 21 and the second electrode 22 of the bare cell 2 to the inner surface of the internal terminal body 81. The body welds 91 may be arranged spaced apart from each other in a circumferential direction based on the center of the internal terminal body 81.

[0134] Each of the internal terminals 8 may include a plurality of connecting members 82 .

[0135] The connecting member 82 is connected to the bare cell 2. The connecting member 82 may protrude from the inner surface of the internal terminal body 81 toward the bare cell 2. Accordingly, when the internal terminal 8 and the bare cell 2 are coupled together, the connecting member 82 applies pressure to the bare cell 2. Therefore, the energy storage device 1 according to the present invention can increase the connection force between the internal terminal 8 and the bare cell 2 by using the connecting member 82. The connecting member 82 may apply pressure to either the first electrode 21 or the second electrode 22 of the bare cell 2.

[0136] The connecting members 82 and the body welds 91 may be spaced apart from each other. When the connecting members 82 are spaced apart from each other in the circumferential direction based on the center of the inner terminal body 81, the body welds 91 may be spaced apart from each other in the circumferential direction based on the center of the inner terminal body 81. For example, as shown in FIG. 20, the connecting members 82 and the body welds 91 may be alternately arranged in multiple positions in the circumferential direction based on the center of the inner terminal body 81. Accordingly, the body welds 91 may be located in a portion of the inner terminal body 81 that does not protrude toward the bare cell 2. Therefore, the energy storage device 1 according to the present invention is embodied to increase the distance between the connection position where the connecting members 82 are connected to the bare cell 2 and the welding position (shown by dotted lines in FIG. 21) where the body welds 91 weld the inner surface of the inner terminal body 81 to the bare cell 2. Accordingly, the energy storage device 1 according to the present invention can prevent a short circuit from occurring in the bare cell 2 during the process of welding the inner surface of the internal terminal body 81 to the bare cell 2. Meanwhile, the body welded portion 91 can be formed by welding from the outer surface of the internal terminal body 81, as indicated by the arrow in FIG.

[0137] Each of the internal terminals 8 may include a terminal protruding member 83 .

[0138] The terminal protruding member 83 protrudes from the internal terminal body 81. The terminal protruding member 83 may be in contact with the upper protruding member 62 of the bus bar 6 and supported by the bus bar 6. Accordingly, the internal terminal 8 is firmly supported by the bus bar 6, and thus may be stably maintained in a state where it is connected to the bare cell 2 and the bus bar 6. In this case, the upper protruding member 62 may be supported by the support upper surface 373 of the support member 37. The terminal protruding member 83 may protrude from an upper portion of the internal terminal body 81 toward the side wall member 33. The terminal protruding member 83 and the internal terminal body 81 may be integrally formed.

[0139] The terminal protruding member 83 and the upper protruding member 62 may be connected by an upper weld (92, shown in FIG. 19 ). The upper weld 92 can firmly connect the terminal protruding member 83 and the upper protruding member 62 by welding. Accordingly, the energy storage device 1 according to the present invention can further improve the stability of the electrical connection between the internal terminal 8 and the bus bar 6 by using the upper weld 92. Furthermore, the energy storage device 1 according to the present invention can improve the ease of welding work by vertically welding the internal terminal 8 and the bus bar 6 by using the terminal protruding member 83 and the upper protruding member 62. The energy storage device 1 according to the present invention includes a plurality of the upper welds 92, and can connect the internal terminal 8 and the bus bar 6 by welding, respectively.

[0140] Each of the internal terminals 8 may include a plurality of impregnation holes 84 .

[0141] The impregnation holes 84 may be formed through the internal terminal body 81. The impregnation holes 84 may be used as passages for impregnating the bare cell 2 with electrolyte. Accordingly, the energy storage device 1 according to the present invention is embodied such that an impregnation operation of impregnating the bare cell 2 with electrolyte is performed through the impregnation holes 84 with the internal terminal 8 coupled to the bare cell 2. Therefore, the energy storage device 1 according to the present invention may improve the ease of the impregnation operation.

[0142] The impregnation holes 84 may be formed to penetrate each of the connecting members 82. In this case, the impregnation holes 84 may be spaced apart from each other in the circumferential direction based on the center of the inner terminal body 81. Any one of the impregnation holes 84 may be formed to penetrate the center of the inner terminal body 81.

[0143] The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it will be apparent to those skilled in the art that various substitutions, modifications and alterations are possible within the scope of the technical idea of ​​the present invention.

Claims

1. An energy storage device, a modular case having a plurality of storage spaces formed therein; a plurality of bare cells accommodated in each of the accommodation spaces; and a cover coupled to the module case to cover the accommodation space, the module case directly contacts the bare cells accommodated in each of the accommodation spaces to support the bare cells; A pressure receiving rate calculated by the ratio of the volume of the bare cell to the volume of the storage space for each storage space is 95% or less, The module case a bottom member disposed below the bare cell accommodated in the accommodation space; a plurality of sidewall members projecting upwardly from the outer surface of the base member; and and at least one partition member protruding upward from the bottom member between the side wall members to partition the storage space, The energy storage device is a plurality of bus bars electrically connecting at least two of the bare cells; The module case includes a plurality of support members protruding upward from the bottom member in each of the receiving spaces, 10. An energy storage device, wherein each of the support members supports the bus bar.

2. a welded joint for joining the module case and the cover, 2. The energy storage device of claim 1, wherein the welded joints include a side wall joint member that joins the side wall members to the cover, and a partition wall joint member that joins the partition wall member to the cover.

3. The energy storage device according to claim 2 , wherein the side wall connecting members and the partition wall connecting members are connected to each other to form a closed loop for each of the receiving spaces.

4. Each of the support members a support inner surface arranged to face the bare cell accommodated in the accommodation space; and The energy storage device according to claim 1 , further comprising a support upper surface for supporting an upper portion of the bus bar.

5. Each of the bus bars includes a bus bar body contacting the inner support surface and an upper protruding member protruding from the bus bar body, The energy storage device according to claim 4 , wherein the upper protruding member is supported by the support member while contacting the support upper surface.

6. The module case has the accommodating spaces spaced apart from each other along a first axis direction, The energy storage device of claim 1 , wherein each of the support members has the same length as the receiving space in the first axial direction.

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