Battery cell, manufacturing method thereof, and direct water-cooling battery module including the same

Abstract

The present invention relates to a battery cell, a manufacturing method thereof, and a battery module including the same. A battery cell according to one aspect of the present invention includes an electrode assembly, a case that houses the electrode assembly, a plating layer formed on an outer surface of the case, a scratch area formed by removing a portion of the plating layer, and a porous coating layer that is disposed to surround the scratch area and includes a sacrificial metal having a higher metal ionization tendency than the plating layer.

Description

[Technical field]

[0001] The present invention relates to a battery cell that can improve the corrosion resistance of a battery cell by using a sacrificial metal that has a higher metal ionization tendency than a battery cell case, a manufacturing method thereof, and a direct water-cooling battery module including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0134064 dated October 18, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] Batteries used in environmentally friendly vehicles are required to have high output, and therefore generate a large amount of heat. In order to improve the performance and life of the battery, it is very important to efficiently dissipate the heat generated by the battery and prevent the battery from overheating.

[0004] Conventionally, as cooling systems for dissipating heat from a battery, a direct air cooling system, an indirect water cooling system, a direct water cooling system, and the like are known.

[0005] In the direct water cooling method, the battery cells are directly immersed in the coolant so that the heat of the battery cells is directly dissipated into the coolant.

[0006] FIG. 1 is a schematic configuration diagram of a conventional battery module 10. As shown in FIG.

[0007] 1, a direct water-cooling type battery module 10 includes a cell frame 11 and a plurality of battery cells 12. The plurality of battery cells 12 are spaced apart from each other in the cell frame 11. The cell frame 11 is provided so that cooling water can flow therein.

[0008] In general, the battery cell 12 has an exterior case that houses the internal electrodes and is made of nickel-plated iron. Therefore, if the battery cell 12 is directly immersed in cooling water, the exterior case is vulnerable to corrosion due to the nature of the material. In addition, the exterior case has polarity and is therefore vulnerable to electrical insulation.

[0009] In the conventional direct water-cooling battery module 10, insulating oil or special cooling water N (for example, NOVEC (registered trademark) of 3M Company) is used to prevent corrosion of the battery cells 12.

[0010] However, insulating oil has the problem of being vulnerable to fire, and special cooling water such as 3M's NOVEC (registered trademark) is excellent as a cooling water for battery cells in that it is non-polar and resistant to corrosion, but it is expensive, which increases the unit manufacturing cost of battery modules.

[0011] In addition, when applying an anti-rust liquid to the exterior case of the battery cell 12 to prevent corrosion of the battery cell 12 as in the conventional method, a post-processing step is required in which the exterior case of the battery cell 12 is wrapped with a non-woven fabric or the like to retain the anti-rust liquid.

[0012] Furthermore, even if an anti-rust liquid is applied to the exterior case of the battery cell 12, the anti-rust agent flows off the exterior case of the battery cell due to surface tension, and the anti-rust agent is not evenly applied to the exterior case. Summary of the Invention [Problem to be solved by the invention]

[0013] An object of the present invention is to provide a battery cell capable of improving the corrosion resistance of a battery cell by using a sacrificial metal that has a higher metal ionization tendency than a battery cell case, a manufacturing method thereof, and a direct water-cooling battery module including the same. [Means for solving the problem]

[0014] In order to solve the above-mentioned problems, a battery cell according to one embodiment of the present invention includes an electrode assembly, a case that accommodates the electrode assembly, a plating layer formed on an outer surface of the case, a scratch area formed by removing a portion of the plating layer, and a porous coating layer that is disposed to surround the scratch area and includes a sacrificial metal having a higher metal ionization tendency than the plating layer.

[0015] The scratch region may include a plurality of non-plated portions in which a portion of the plating layer has been removed, and a plating portion in which the plating layer remains between two adjacent non-plated portions.

[0016] Also, the porous coating layer may be provided such that at least a portion of the porous coating layer is inserted into the scratched area and contacts the outer surface of the case via the non-plated portion.

[0017] In addition, the porous coating layer may have a smaller thickness in a region surrounding the plating layer than in a region surrounding the scratch region.

[0018] Also, the porous coating layer may be formed by spraying the sacrificial metal onto the scratch area.

[0019] Also, the plating layer may be a nickel plating layer, and the sacrificial metal may be one or more selected from the group consisting of aluminum, magnesium, zinc, an aluminum alloy, a magnesium alloy, and a zinc alloy.

[0020] Also, the scratch area may be provided by scratching the plating layer with a laser.

[0021] In addition, the battery cell may further include a waterproof sheet including a polymer film and surrounding the porous coating layer.

[0022] In addition, a battery module according to one embodiment of the present invention includes a plurality of battery cells, a cell frame in which the plurality of battery cells are arranged at a distance from each other and in which coolant can flow between the plurality of battery cells, and a coolant supply unit for supplying coolant to the inside of the cell frame.

[0023] The cooling water supply unit is provided to supply cooling water that is not insulated.

[0024] In addition, a method for manufacturing a battery cell according to one embodiment of the present invention includes the step (a) of forming a scratch area on a plating layer provided on an outer surface of a case, and the step (b) of forming a porous coating layer covering the scratch area by spraying molten sacrificial metal together with compressed air onto the scratch area.

[0025] The scratch area may be formed to include a plurality of non-plated areas in which a portion of the plating layer has been removed, and a plating area in which the plating layer remains between two adjacent non-plated areas.

[0026] Also, the porous coating layer may be formed such that at least a portion of the porous coating layer contacts the outer surface of the case via the non-plated portion.

[0027] The compressed air may be injected at a pressure ranging from 12,000 psi to 16,000 psi.

[0028] The compressed air can be jetted at a velocity in the range of 2000 m / s to 2200 m / s.

[0029] In addition, in the step (a), the scratch area may be formed by removing the plating layer with a laser.

[0030] In addition, the method for manufacturing a battery cell may further include, after step (b), a step of heat-shrinking a waterproof film onto a case so that the porous coating layer is not exposed to the outside. Effect of the Invention

[0031] As described above, the battery cell according to at least one embodiment of the present invention, the manufacturing method thereof, and the direct water-cooling battery module including the same have the following advantages.

[0032] By providing a scratch area in the plating layer of the case and covering the scratch area with a porous coating layer, it is possible to facilitate the movement of electrons between the porous coating layer and the outer surface of the case from which the plating layer has been removed via the scratch area, thereby improving the corrosion resistance of the case.

[0033] In addition, since the sacrificial metal, which has a higher ionization tendency than the case, undergoes an ionization reaction with moisture and is oxidized earlier than the case, the corrosion resistance of the case can be improved.

[0034] In addition, a porous coating layer can be formed covering the scratched area by injecting molten sacrificial metal into the case together with high-pressure compressed air, thereby increasing the bonding strength between the porous coating layer and the case, thereby improving the durability of the case.

[0035] In addition, since the porous coating layer is formed by a thermal spray coating method, it can have a fine porous structure, and thus the contact area with moisture and air can be increased.

[0036] In addition, the movement of electrons between the case and the porous coating layer can be facilitated through the scratched area, thereby improving the stability of the electrical connection between the case and the porous coating layer.

[0037] In addition, by improving the corrosion resistance of the battery cells, a direct water-cooling method can be realized by using low-cost general cooling water that is not insulated, instead of expensive special cooling water that is insulated. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 is a schematic configuration diagram of a conventional battery module. [Diagram 2] FIG. 1 is a schematic diagram illustrating a configuration of a direct water-cooling battery module according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention. [Figure 4] FIG. 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention. [Diagram 5] FIG. 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention. [Figure 6] 1A to 1C are diagrams illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 7] 1A to 1C are diagrams illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 8] 1A to 1C are diagrams illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 9] 1A to 1C are diagrams illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 10] 1A to 1C are diagrams illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 11] FIG. 1 is a schematic diagram showing a thermal spray coating apparatus used in a method for manufacturing a battery cell. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Hereinafter, a battery cell (hereinafter also referred to as a "battery cell for direct water cooling") according to one embodiment of the present invention, a manufacturing method thereof, and a battery module for direct water cooling (hereinafter also referred to as a "battery module") including the same will be described in detail with reference to the drawings.

[0040] In addition, regardless of the drawing symbols, the same or similar reference numbers will be used for the same or corresponding components, and duplicate descriptions will be omitted. For convenience of explanation, the size and shape of each component shown may be exaggerated or reduced.

[0041] FIG. 2 is a diagram that shows a schematic diagram of a direct water-cooling battery module 100 according to one embodiment of the present invention, and FIGS. 3 to 5 are diagrams that show schematic cross-sectional views of a battery cell 120 according to one embodiment of the present invention.

[0042] Specifically, FIG. 3 shows a case with a scratch area provided, FIG. 4 shows a case with a porous coating layer formed, and FIG. 5 shows a case with a waterproof sheet covering the porous coating layer.

[0043] As shown in FIG. 2 , a direct water-cooling battery module 100 according to an embodiment of the present invention includes a cell frame 110, at least one direct water-cooling battery cell 120, and a general cooling water W.

[0044] Referring to FIG. 2, a battery module 100 according to an embodiment of the present invention includes a plurality of battery cells 120, a cell frame 110 that houses the plurality of battery cells 120, and a coolant supply unit 160.

[0045] Specifically, the battery module 100 includes a plurality of battery cells 100, a cell frame 110 in which a plurality of battery cells 120 are arranged at a distance from each other and in which coolant W can flow between the plurality of battery cells 120, and a coolant supply unit 160 for supplying coolant W to the inside of the cell frame 110.

[0046] The battery module 100 may have a direct water-cooling structure in which the battery cells 120 are directly cooled through cooling water W.

[0047] 2, the cell frame 110 has a predetermined space therein and is configured to allow the coolant W to flow within the space. The coolant W may be supplied to the internal space of the cell frame 110 and then discharged to the outside of the cell frame 110. To this end, the battery module 100 may include a coolant discharge unit for discharging the coolant W to the outside of the cell frame 110. The coolant supply unit 160 may include a coolant storage tank and a pump. The coolant supply unit 160 may be configured to supply the coolant W that is not insulated. The coolant W may be coolant commonly used in vehicles.

[0048] 3 to 5, a battery cell 120 according to one embodiment of the present invention includes an electrode assembly 127, a case 121, a plating layer 122, a scratch area S provided on the plating layer 122, and a porous coating layer 123 surrounding the scratch area S.

[0049] In addition, the battery cell 120 may include a waterproof sheet 125 including a polymer film and arranged to surround the porous coating layer 123 .

[0050] The battery cell 120 includes an electrode assembly 127, a case 121 that houses the electrode assembly 127, a plating layer 122 formed on the outer surface of the case 121, a scratch area S formed by removing a portion of the plating layer 122, and a porous coating layer 123 that is disposed to surround the scratch area S and contains a sacrificial metal having a higher metal ionization tendency than the plating layer 122.

[0051] 2, when the direct water-cooling battery cell 100 is immersed in cooling water W, the moisture may be transferred to the porous coating layer 123. At this time, the ionization reaction of the sacrificial metal of the porous coating layer 123 with respect to moisture is greater than the metal ionization reaction of the case 121 with respect to moisture, so that the corrosion resistance of the case 121 can be improved.

[0052] In addition, when the direct water-cooling battery cell 120 is immersed in the cooling water W, the water in the cooling water W undergoes an ionization reaction with the sacrificial metal of the porous coating layer due to the difference in metal ionization reaction between the case 121 and the porous coating layer 123, and as a result, the metal ionization reaction of the case 121 is suppressed, thereby preventing corrosion of the case 121.

[0053] The electrode assembly 127 is housed in the case 121 and includes a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes. The electrodes and the separator may be integrated to form the electrode assembly 127. For example, the electrode assembly 127 may be a jelly-roll type electrode assembly in which sheet-shaped positive and negative electrodes are wound up with a separator interposed therebetween, a stack type electrode assembly in which a plurality of positive and negative electrodes are stacked in order with a separator interposed therebetween, or a stack / folding type electrode assembly in which unit cells in which a predetermined number of positive and negative electrodes are stacked with a separator interposed therebetween are placed on a separator film and wound up in order.

[0054] In addition, the case 121 accommodates the electrode assembly 127 and serves to protect the battery cell 120 from external impact. The case 121 may be cylindrical, pouch-shaped, or prismatic, for example, the case 121 may be cylindrical. In particular, the electrode assembly 127 may be a wound jelly-roll type electrode assembly, the case 121 may be a cylindrical case, and the direct water-cooling battery cell 120 may be a cylindrical battery cell.

[0055] Also, the case 121 may be made of a metal material, and the case 121 may be made of at least one selected from the group consisting of steel and stainless steel.

[0056] In addition, the surface of the case 121 may be nickel (Ni) plated. That is, the plating layer 121 may include a nickel plating layer.

[0057] On the other hand, the nickel plating layer is less likely to discolor, has excellent rust prevention, and is excellent in corrosion resistance and wear resistance. However, due to the characteristics of the material, the nickel plating layer may corrode when immersed in cooling water, and as the corrosion progresses, polarity is generated and the insulating properties decrease.

[0058] On the other hand, when the porous coating layer 123 is provided on the plating layer 121, the plating layer 121 may become a factor that hinders the movement of electrons between the porous coating layer 123 and the case 121.

[0059] After forming the scratch area S on the plating layer 122, the porous coating layer 123 is bonded to the scratch area S, so that electrons can be smoothly transferred between the porous coating layer 123 and the case 121.

[0060] In addition, the scratch area S may be formed by removing a portion of the plating layer 121 along the thickness direction of the plating layer 121, and the scratch area S may be formed along the thickness direction of the plating layer 121 up to a portion of the plating layer 121 and the outer surface of the case facing the portion of the plating layer 121.

[0061] 3, the scratch area S may include a plurality of non-plated portions 122b in which a portion of the plating layer 122 has been removed, and a plating portion 122a in which the plating layer remains between two adjacent non-plated portions 122b. The non-plated portion 122b may refer to a portion in which the plating layer does not exist and the outer surface of the case 121 is exposed to the outside. The scratch area S may be formed in a portion of the plating layer 122.

[0062] The scratch area S is an area where the plating layer 122 of the case 121 is partially removed according to a predetermined pattern. The scratch area S may be provided by scratching the plating layer 122 with a laser. Alternatively, the scratch area S may be provided by etching the plating layer 122.

[0063] Referring to FIG. 4, the porous coating layer 123 surrounds the plating layer 122 and the scratched area S, and at least a portion of the porous coating layer 123 is inserted into the scratched area S.

[0064] In addition, the porous coating layer 123 may be provided such that at least a portion of the porous coating layer 123 is inserted into the scratch region S and contacts the outer surface of the case 121 via the non-plated portion 121b.

[0065] In addition, the porous coating layer 123 may have a different thickness t between the region surrounding the plating layer 122 and the region surrounding the scratch region S. The porous coating layer 123 may have a smaller thickness in the region surrounding the plating layer 122 than the region surrounding the scratch region S.

[0066] The porous coating layer 123 is formed of a sacrificial metal material having a higher ionization tendency than the case 121. The sacrificial metal may include at least one selected from the group consisting of aluminum, magnesium, zinc, an aluminum alloy, a magnesium alloy, and a zinc alloy.

[0067] Since the ionization tendency of the sacrificial metal is greater than the ionization tendency of the steel or stainless steel from which the case 121 is made, the moisture in the cooling water W ionizes and reacts with the sacrificial metal of the porous coating layer 123 before ionizing and reacting with the case 121.

[0068] Also, the porous coating layer 123 may be formed by spraying the sacrificial metal onto the scratch area S.

[0069] For example, the porous coating layer 123 may be coated on the outer surface of the case 121 by a thermal spray coating method. The porous coating layer 123 may have a porous structure formed by injecting molten sacrificial metal together with compressed air onto the case 121. The pore size of the porous coating layer 123 may be 1 μm to 10 μm.

[0070] In addition, the porous coating layer 123 made of the sacrificial metal has a porous structure, which increases the contact area with moisture and air, and the sacrificial metal, which has a higher ionization tendency than the case, reacts with moisture first.

[0071] 5, the waterproof sheet 125 surrounds the outer surface of the case 121 so that the porous coating layer 123 is not exposed to the outside. The waterproof sheet 125 may include a polymer film. With the case surrounded by the polymer film, the polymer film may be thermally shrunk to thermocompress the waterproof sheet 125 to the case 121.

[0072] The heat shrinkable polymer film may include at least one selected from the group consisting of polyvinyl chloride (PVC), polypropylene (PP), or polyethylene terephthalate (PET).

[0073] 2, the battery module 100 may include waterproof layers 130 and 140 provided inside a cell frame 110 to cover upper and lower ends of the battery cells 120, respectively. The waterproof layers 130 and 140 prevent moisture from penetrating into a case 121 and fix the battery cells 120 to the cell frame 110.

[0074] An upper waterproof layer 130 may be provided at an upper end of the case 121, and a lower waterproof layer 140 may be provided at a lower end of the case 121. In addition, the upper end side and the lower end side of the plurality of battery cells 120 may be integrally fixed to the inner surface of the cell frame 110 via the waterproof layers 130 and 140, respectively.

[0075] Also, the waterproof layers 130 and 140 may include a waterproof adhesive or a potting resin, and the potting resin may be any one of a silicone-based resin, a urethane-based resin, and an epoxy-based resin.

[0076] Fig. 6 to Fig. 10 are diagrams for explaining a method for manufacturing a battery cell according to an embodiment of the present invention, and Fig. 11 is a schematic diagram showing a thermal spray coating apparatus used in the method for manufacturing a battery cell. Fig. 7 is a cross-sectional view taken along line aa in Fig. 6(b), and Fig. 9 is a cross-sectional view taken along line bb in Fig. 6(d).

[0077] As described above, the porous coating layer 123 may be coated on the outer surface of the case 121 by a thermal spray coating method.

[0078] In addition, a method for manufacturing a battery cell according to one embodiment of the present invention includes the step (a) of forming a scratch area on a plating layer provided on an outer surface of a case, and the step (b) of forming a porous coating layer covering the scratch area by spraying molten sacrificial metal together with compressed air onto the scratch area.

[0079] In addition, the scratch area S may be formed to include a plurality of non-plated areas in which a portion of the plating layer 122 has been removed, and a plating area in which the plating layer remains between two adjacent non-plated areas.

[0080] Also, the porous coating layer 123 may be formed such that at least a portion of the porous coating layer 123 contacts the outer surface of the case 121 via the non-plated portion.

[0081] 6 and 7, a plate material P having a metal material is prepared. The plate material P may be made of at least one selected from the group consisting of steel and stainless steel. The plate material P is processed into a case 121, and a plating layer 122 is formed on one surface of the plate material P (the outer surface of the case).

[0082] The plating layer 122 is formed by plating one surface of the plate material P with a plating substance (eg, nickel).

[0083] 6(a), one plate material P is divided into a plurality of unit areas A1 to A4. Here, each of the unit areas A1 to A4 constitutes a unit plate material to be processed into a case 121. That is, each unit area has a size that allows the case 121 to be manufactured. In this embodiment, for convenience of explanation, each of the unit areas virtually divided into the plate material P will be referred to as a first unit area A1, a second unit area A2, a third unit area A3, and a fourth unit area A4.

[0084] Referring to (c) and (d) of Figure 6, each unit area is divided into unit plate materials P by cutting along cutting lines Lc, and referring to (e) of Figure 6, each unit plate material P1 can be processed into a cylindrical shape and manufactured into each case 121.

[0085] With reference to FIG. 6(b), scratch regions S1 to S4 are provided in each of the unit regions A1 to A4, respectively.

[0086] The scratch regions S1 to S4 are regions where the plating layer 122 of the case 121 is chemically etched or where the plating layer 122 is scratched by a laser according to a predetermined scratch pattern Ls (see FIG. 8). In the scratch region S, the outer surface (non-plated portion) of the case 121 is provided so as to be exposed to the outside.

[0087] Further, a scratch area S is provided for each of the unit areas A1 to A4. In this document, the scratch areas S of the unit areas A1 to A4 are divided and designated as a first scratch area S1, a second scratch area S2, a third scratch area S3, and a fourth scratch area S4.

[0088] Here, the first scratch area S1 is an area where the plating layer 122 is damaged in the first unit area A1, and the second scratch area S2 is an area where the plating layer 122 is damaged in the second unit area A2.

[0089] The third scratch region S3 is a region where the plating layer 122 is damaged in the third unit region A3, and the fourth scratch region S4 is a region where the plating layer 122 is damaged in the fourth unit region A4.

[0090] In addition, the first scratch area S1 to the fourth scratch area S4 may be provided on the same plane of the plate material P and spaced apart from each other.

[0091] Furthermore, each of the scratch regions S1 to S4 can have an area smaller than each of the unit regions A1 to A4.

[0092] Referring to FIG. 8, the unit plate material P1 may have a scratch pattern Ls, which may be any one of a lattice pattern (see FIG. 8(a)), a diagonal grid pattern (see FIG. 8(b)), a wave pattern (see FIG. 8(c)), a L-shaped pattern (see FIG. 8(d)), or a L-shaped pattern (see FIG. 8(e)).

[0093] Depending on such a scratch pattern, the scratch area S may include a plurality of non-plated areas in which a portion of the plating layer 122 has been removed, and a plating area in which the plating layer remains between two adjacent non-plated areas.

[0094] The scratch area S in each unit plate material P1 may be surrounded by a frame area E of the unit plate material P1 and may be provided over the entire area of ​​one surface of the unit plate material P1. The frame area E is an area in which the non-plated portion of the plating layer 122 is not exposed to the outside, and only the plated portion is exposed to the outside.

[0095] 9 and 11, a thermal spray coating device 200 sprays molten sacrificial metal M together with compressed air Ac onto one side of a plate material P having a scratch area S. Referring to FIG. 10, the sacrificial metal M forms a porous coating layer 123 surrounding the scratch area S1.

[0096] Referring to FIG. 11, a thermal spray coating apparatus 200 includes a metal injection section 210 , an air injection section 220 , a guide section 240 , and a heating section 250 .

[0097] The guide unit 240 supplies the sacrificial metal wire 231 to the metal spray unit 210 and is provided on an entry path through which the sacrificial metal wire 231 enters the metal spray unit 210. The guide unit 240 may include a pair of guide rolls 241, 242. The pair of guide rolls 241, 242 rotate in opposite directions to each other to enter the sacrificial metal wire 231 into the passage 211 of the metal spray unit 210 and guide the movement of the sacrificial metal wire 231.

[0098] The metal spray unit 210 is electrically connected to the heating unit 250. The heating unit 250 applies a voltage to the metal spray unit 210.

[0099] In addition, the metal jetting part 210 is provided with a passage 211 through which a sacrificial metal wire 231 passes. The sacrificial metal wire 231 is melted while passing through the heated metal jetting part 210.

[0100] Also, depending on the type of sacrificial metal, the heating temperature of the metal jetting portion 210 may be changed. For example, the melting temperature of aluminum (Al) is about 660°C, and the melting temperature of magnesium (Mg) is about 650°C.

[0101] The air injection unit 220 injects compressed air Ac. The air injection unit 220 may be provided inside the metal injection unit 210. The air injection unit 220 may be disposed inside the metal injection unit 210 such that the central axis of the outlet of the air injection unit 220 is coaxial with the central axis of the outlet of the metal injection unit 210.

[0102] In addition, the compressed air Ac is sprayed from the thermal spray coating apparatus 200 together with the molten sacrificial metal M. The compressed air Ac may be sprayed at a pressure in the range of 12,000 psi to 16,000 psi, and at a speed in the range of 2,000 m / s to 2,200 m / s.

[0103] The molten sacrificial metal M flows along the passage 211 of the metal injection part 210 and is discharged to the outside of the metal injection part 210 , and is sprayed onto the plate material P by the compressed air Ac discharged from the air injection part 220 .

[0104] The molten sacrificial metal M is sprayed onto the scratch area S together with compressed air Ac, and plated onto the plate material P so that the non-plated portion of the scratch area S is not exposed to the outside.

[0105] Referring to FIG. 9, the thermal spray coating apparatus 200 can spray a molten sacrificial metal M onto a first scratch area S1, and this process can be performed for each of the second unit area A2 to the fourth unit area A4.

[0106] The porous coating layer 123 is formed by injecting the molten sacrificial metal M together with the high pressure compressed air Ac onto the outer surface of the case 121. This can increase the bonding strength between the porous coating layer 123 and the case 121. That is, the porous coating layer 123 can be formed by injecting particles of the molten sacrificial metal M onto the outer surface of the case 121 together with the high pressure compressed air Ac.

[0107] Through this process, as shown in FIG. 6(c), a single plate P may be provided with a plurality of porous coating layers 123 covering the first scratch area S1 to the fourth scratch area S4, respectively.

[0108] One plate material P is cut into each of the unit areas A1 to A4 along the cutting line Lc to form a plurality of unit plate materials P1. The unit plate material P1 provided with the porous coating layer 123 is processed into a cylindrical shape to manufacture a cylindrical case 121.

[0109] In this manner, the manufacturing process for large quantities of the cases 121 can be simplified.

[0110] Through the thermal spray coating method, the porous coating layer 123 can have a microporous structure, and the contact area of ​​the sacrificial metal that comes into contact with moisture and air can be increased.

[0111] The above-described preferred embodiments of the present invention have been disclosed for illustrative purposes, and those skilled in the art having ordinary skill in the art may make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims. [Industrial Applicability]

[0112] According to a battery cell according to an embodiment of the present invention, a manufacturing method thereof, and a direct water-cooling battery module including the same, a sacrificial metal, which has a higher ionization tendency than a case, is ionized and oxidized with moisture before the case is oxidized, thereby improving the corrosion resistance of the case. [Explanation of symbols]

[0113] 100 Battery module for direct water cooling (battery module) 110 Cell Frame 120 Direct water cooling battery cell (battery cell) 121 cases 122 Plating layer 123 Porous Coating Layer 127 Electrode assembly 160 Cooling water supply section S Scratch area

Claims

1. An electrode assembly; a case for accommodating the electrode assembly; a plating layer formed on an outer surface of the case; a scratch region formed by removing a portion of the plating layer; a porous coating layer provided to surround the scratch area and including a sacrificial metal having a higher metal ionization tendency than the plating layer; Including, a battery cell.

2. The scratch area is A plurality of non-plated portions obtained by removing a portion of the plating layer; a plated portion in which the plated layer remains between two adjacent non-plated portions; The battery cell of claim 1 , comprising:

3. The battery cell according to claim 2 , wherein the porous coating layer is provided such that at least a portion of the porous coating layer contacts the outer surface of the case via the non-plated portion.

4. The battery cell of claim 2 , wherein the porous coating layer has a thickness smaller in an area surrounding the plating layer than in an area surrounding the scratched area.

5. The battery cell of claim 1 , wherein the porous coating layer is formed by spraying the sacrificial metal onto the scratch area.

6. The plating layer is a nickel plating layer, 10. The battery cell of claim 1, wherein the sacrificial metal is one or more selected from the group consisting of aluminum, magnesium, zinc, an aluminum alloy, a magnesium alloy, and a zinc alloy.

7. The battery cell according to claim 1 , wherein the scratch area is provided by scratching the plating layer with a laser.

8. 10. The battery cell of claim 1, further comprising a tarpaulin comprising a polymeric film and surrounding the porous coating layer.

9. A plurality of the battery cells of claim 1; a cell frame in which a plurality of battery cells are arranged at a distance from each other and in which cooling water can flow between the plurality of battery cells; a cooling water supply unit for supplying cooling water to the inside of the cell frame; Including, The battery module, wherein the cooling water supply unit is configured to supply non-insulated cooling water.

10. A method for producing a battery cell according to any one of claims 1 to 8, comprising the steps of: (a) forming the scratch area on a plating layer provided on an outer surface of the case; (b) spraying molten sacrificial metal with compressed air onto the scratched area to form a porous coating layer over the scratched area; A method for manufacturing a battery cell, comprising:

11. The scratch area is A plurality of non-plated portions obtained by removing a portion of the plating layer; a plated portion in which the plated layer remains between two adjacent non-plated portions; is formed to include The method of claim 10 , wherein the porous coating layer is formed such that at least a portion of the porous coating layer contacts the outer surface of the case via the non-plated portion.

12. The method for manufacturing a battery cell according to claim 10, wherein the compressed air is injected at a pressure in the range of 12000 psi to 16000 psi.

13. The method for manufacturing a battery cell according to claim 10, wherein the compressed air is sprayed at a velocity in the range of 2000 m / s to 2200 m / s.

14. The method of manufacturing a battery cell according to claim 10 , wherein in step (a), the scratch area is formed by removing the plating layer with a laser.

15. The method of claim 10, further comprising the step of heat-shrinking a waterproof film onto the case so that the porous coating layer is not exposed to the outside.

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