Battery cell, manufacturing method thereof, and direct water-cooled 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-cooled 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 this Korean patent application are incorporated herein by reference. [Background technology]

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

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

[0005] The direct water cooling method involves immersing the battery cells directly in the coolant, allowing the heat from the battery cells to be directly released into the coolant.

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

[0007] 1, a direct water-cooled 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 configured to allow cooling water to flow therein.

[0008] Generally, the battery cell 12 has an outer case that houses the internal electrodes and is made of nickel-plated iron. Therefore, if the battery cell 12 is directly immersed in coolant, the outer case is vulnerable to corrosion due to the nature of the material of the outer case. In addition, the outer case has polarity, which causes problems in that the electrical insulation is weak.

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

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

[0011] Furthermore, 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 nonwoven 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 runs off the exterior case of the battery cell due to surface tension, which causes the anti-rust agent to be unevenly 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 that can improve the corrosion resistance of the battery cell by using a sacrificial metal that has a higher metal ionization tendency than the battery cell case, a manufacturing method thereof, and a direct water-cooled 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 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.

[0015] The scratch area may include a plurality of non-plated areas where a portion of the plating layer has been removed, and a plated area where the plating layer remains between two adjacent non-plated areas.

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

[0017] The porous coating layer may have a thickness smaller in a region surrounding the plating layer than in a region surrounding the scratched region.

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

[0019] 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] The scratched area may be formed by scratching the plating layer with a laser.

[0021] 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 aspect 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 into the inside of the cell frame.

[0023] The cooling water supply unit is configured 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 spraying molten sacrificial metal together with compressed air onto the scratch area to form a porous coating layer covering the scratch area.

[0025] The scratch area may be formed to include a plurality of non-plated areas where a portion of the plating layer has been removed, and a plated area where 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 thereof 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 the case so that the porous coating layer is not exposed to the outside. [Effects of the Invention]

[0031] As described above, the battery cell according to at least one aspect 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, electrons can be smoothly transferred between the porous coating layer and the outer surface of the case where the plating layer has been removed via the scratch area, thereby improving the corrosion resistance of the case.

[0033] Furthermore, 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, by spraying the molten sacrificial metal onto the case together with high-pressure compressed air, a porous coating layer can be formed to cover the scratched area, 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 microporous structure, thereby increasing the contact area with moisture and air.

[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 system can be realized using low-cost general cooling water that is not insulated, instead of expensive special cooling water that is insulated. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is a schematic configuration diagram of a conventional battery module. [Figure 2] FIG. 1 is a diagram schematically illustrating a configuration of a direct water-cooling battery module according to an embodiment of the present invention. [Figure 3] 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention; [Figure 4] 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention; [Figure 5] 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 views illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 7] 1A to 1C are views illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 8] 1A to 1C are views illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 9] 1A to 1C are views illustrating a method for manufacturing a battery cell according to an embodiment of the present invention. [Figure 10] 1A to 1C are views 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 INVENTION

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

[0040] Furthermore, regardless of the drawing symbols, identical or corresponding components will be given the same or similar reference numbers, and duplicate explanations thereof 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 schematically illustrating a configuration diagram of a direct water-cooling battery module 100 according to one embodiment of the present invention, and FIGS. 3 to 5 are diagrams schematically illustrating cross-sectional views of a battery cell 120 according to one embodiment of the present invention.

[0042] Specifically, Figure 3 shows a case with a scratch area, Figure 4 shows a case with a porous coating layer formed, and Figure 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 coolant 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 spaced apart and in which coolant W can flow between the plurality of battery cells 120, and a coolant supply unit 160 for supplying coolant W into 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 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 uninsulated coolant W. 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 surrounding 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 water 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 water is greater than the ionization reaction of the metal of the case 121 with water, and therefore the corrosion resistance of the case 121 can be improved.

[0052] In addition, when the direct water-cooled 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. 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-like 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, each of which includes a predetermined number of positive and negative electrodes 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, and may be cylindrical, for example. 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] In addition, 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 has excellent corrosion resistance, wear resistance, and rust prevention properties with little discoloration. 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 occurs, resulting in a decrease in insulation properties.

[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, thereby allowing smooth electron transfer 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.

[0061] 3, the scratch area S may include a plurality of non-plated portions 122b formed by removing a portion of the plating layer 122, and a plating portion 122a formed by leaving the plating layer between two adjacent non-plated portions 122b. The non-plated portion 122b may refer to a region where no plating layer is present 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 formed by scratching the plating layer 122 with a laser. Alternatively, the scratch area S may be formed 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 thereof is inserted into the scratch area S and contacts the outer surface of the case 121 via the non-plated portion 121b.

[0065] Furthermore, the porous coating layer 123 may have a different thickness t in the region surrounding the plating layer 122 and the region surrounding the scratch region S. The thickness of the porous coating layer 123 in the region surrounding the plating layer 122 may be smaller than the thickness of 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 that is the material of the case 121, 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 spraying 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 formed 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 one or more 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 and lower end sides 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] 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] Figures 6 to 10 are diagrams for explaining a method for manufacturing a battery cell according to one embodiment of the present invention, and Figure 11 is a schematic diagram showing a thermal spray coating apparatus used in the method for manufacturing a battery cell. Also, Figure 7 is a cross-sectional view taken along line aa in Figure 6(b), and Figure 9 is a cross-sectional view taken along line bb in Figure 6(d).

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

[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 spraying molten sacrificial metal together with compressed air onto the scratch area to form a porous coating layer covering the scratch area.

[0079] In addition, the scratch area S may be formed to include a plurality of non-plated areas where a portion of the plating layer 122 has been removed, and a plated area where 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 thereof contacts the outer surface of the case 121 via the non-plated portion.

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

[0082] The plated layer 122 is formed by plating one surface of the plate material P with a plating substance (for example, 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 can be manufactured into a case 121. 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] Referring to FIG. 6(b), scratch areas S1 to S4 are provided in the unit areas A1 to A4, respectively.

[0086] The scratch areas S1 to S4 are areas where the plating layer 122 of the case 121 is chemically etched or scratched with a laser according to a predetermined scratch pattern Ls (see FIG. 8). In the scratch area S, the outer surface (non-plated portion) of the case 121 is 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 area S of each of the unit areas A1 to A4 is divided into 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] 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 square pattern (see FIG. 8(d)), or a square pattern (see FIG. 8(e)).

[0093] Depending on such a scratch pattern, the scratch area S may include a plurality of non-plated areas where a portion of the plating layer 122 has been removed, and a plated area where 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 and 242. The pair of guide rolls 241 and 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] The metal jetting part 210 is provided with a passage 211 through which a sacrificial metal wire 231 passes. The sacrificial metal wire 231 melts 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] Additionally, 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 ranging from 12,000 psi to 16,000 psi, and at a velocity ranging from 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 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 device 200 can spray molten sacrificial metal M onto the 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 molten sacrificial metal M together with 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 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 that respectively cover the first scratch area S1 to the fourth scratch area S4.

[0108] A single 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 way, the manufacturing process for large quantities of cases 121 can be simplified.

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

[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-cooled battery module including the same, the sacrificial metal, which has a higher ionization tendency than the case, undergoes an ionization reaction with moisture earlier than the case, and is oxidized, thereby improving the corrosion resistance of the case. [Explanation of symbols]

[0113] 100 Direct water-cooled battery module (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 metal case that accommodates the electrode assembly; a plating layer formed on the outer surface of the case; a scratch area formed by removing a portion of the plating layer; a porous coating layer provided to cover the scratch area and including a sacrificial metal having a higher metal ionization tendency than the case and the plating layer; Including, battery cells.

2. The scratch area is a plurality of non-plated portions in which partial regions of the plating layer have been removed; a plated portion in which the plated layer remains between two adjacent non-plated portions; 10. The battery cell of claim 1, comprising:

3. The battery cell according to claim 2 , wherein the porous coating layer is provided so 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 thickness of the porous coating layer covering the plating layer is smaller than the thickness of the porous coating layer covering 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, 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 of claim 1 , further comprising a waterproof sheet comprising a polymer film and covering the porous coating layer.

8. 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.

9. A method for manufacturing a battery cell according to any one of claims 1 to 7, comprising the steps of: (a) forming the scratch area on a plating layer provided on the outer surface of the case; (b) spraying molten sacrificial metal onto the scratched area together with compressed air to form a porous coating layer over the scratched area; A method for manufacturing a battery cell, comprising:

10. The scratch area is a plurality of non-plated portions in which partial regions of the plating layer have been removed; a plated portion in which the plated layer remains between two adjacent non-plated portions; formed to include The method of manufacturing a battery cell according to claim 9 , 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.

11. The method for manufacturing a battery cell according to claim 9 , wherein the compressed air is injected at a pressure in the range of 12,000 psi to 16,000 psi.

12. The method for manufacturing a battery cell according to claim 9 , wherein the compressed air is injected at a velocity in the range of 2000 m / s to 2200 m / s.

13. The method of manufacturing a battery cell according to claim 9 , wherein in step (a), the scratch area is formed by removing the plating layer with a laser.

14. The method of manufacturing a battery cell according to claim 9 , 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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