Method for manufacturing battery, and battery

Abstract

To provide a method for manufacturing a battery, capable of properly preventing damage of a resin member when a lid and a container are joined, and a battery manufactured by the method.SOLUTION: In a technique of the present disclosure, when a battery lid 4 where a terminal member 5 electrically connected to an electrode assembly is installed in a through hole via an insulation member 10 is joined to a battery container 2 to manufacture a battery 1, the battery lid 4 is disposed on an opening of the battery container 2, the terminal member 5 and the insulation member 10 are covered with a spatter guard 20, and an abutting portion 7 between the battery lid 4 and the battery container 2 is irradiated with laser light L to weld the abutting portion 7, while such a product that includes a wall part 21 standing in a position between the abutting portion 7 and the insulation member 10 and the top 22 above the wall part 21, has a shape with an opened lower side, and includes a heat resistant resin layer formed on an outer surface of the wall part 21 is used as the spatter guard 20.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The disclosed technology relates to a battery manufacturing method and a battery. [Background technology]

[0002] Welding techniques have been used in the manufacture of batteries, primarily when joining a battery lid to a battery container. Welding spatter can occur during welding. Patent Document 1 describes a prior art technique for protecting objects around a welded area from welding spatter. This document describes attaching a thin protective sheet to the area to be protected with an adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2000-509332 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional technology has the problem that the "thin protective sheet" is difficult to reuse. This is because the material of the thin protective sheet is selected based on the criterion of easy disposal, such as paper. In addition, even if the protective sheet is removed after welding is completed, adhesive may remain. Furthermore, this technology is intended for substantially vertical surfaces such as automobile windows and doors in automobile body repair work. For this reason, it is not necessarily suitable for preventing scorching of resin parts during the battery manufacturing process.

[0005] In recent batteries, the battery lid and terminal components are secured and insulated using resin insert molding. Furthermore, micro-anchor structures are sometimes used at the contact points between the metal and the molded resin to ensure strong adhesion. In this case, resins that readily absorb laser light, such as PPS resin, are used as the molded resin. In this case, burning of the resin during welding of the lid and container is a particular problem. In particular, for narrow prismatic batteries, the space for installing protective materials is limited, making it necessary to use thin yet strong metal plates.

[0006] However, the heat resistance of the protective material itself becomes an issue. Thin metal plates have a small heat capacity, and can melt due to their own heat, or stick to the resin in the product due to high temperatures. Also, if there is a gap between the protective material and the battery, laser light and spatter can penetrate through that gap. This can also lead to scorching of the resin in the product. Simply replacing the protective material in Patent Document 1 with a metal one will not solve the problem.

[0007] An object of the present disclosure is to provide a method for manufacturing a battery that can appropriately prevent damage to the resin member when joining the lid and the container, and a battery manufactured by the method. [Means for solving the problem]

[0008] In one aspect of the disclosed technology, a battery manufacturing method is a method of manufacturing a battery by joining a battery lid, in which a terminal member electrically connected to an electrode assembly is attached to a through hole via an insulating member, to a battery container, in which the battery lid is placed in the opening of the battery container, the terminal member and the insulating member are covered with a spatter guard, and the butt joint between the battery lid and the battery container is welded by irradiating the butt joint with laser light, and the spatter guard has a wall portion standing between the butt joint and the insulating member, a top portion above the wall portion, and is open downward, and has a heat-resistant resin layer formed on the outer surface of the wall portion.

[0009] In the battery manufacturing method according to the above aspect, the insulating member is protected by the spatter guard during welding. Furthermore, the sublimation of the heat-resistant resin layer of the spatter guard properly removes the heat of welding, preventing excessive temperature rise of the spatter guard. This prevents melting of the spatter guard. Furthermore, it also prevents the spatter guard from sticking to the insulating member.

[0010] In another aspect of the disclosed technology, a battery manufacturing method is the same as the battery manufacturing method described above, further comprising forming an upward convex portion on the top surface of the battery lid outside the through hole at a position where the lower end of the wall portion will rest when the terminal member and the insulating member are covered with the spatter guard, and the portion of the insulating member facing the top surface of the battery lid is located within a range that is inside the convex portion in the width direction of the battery lid when viewed from above. In this manner, heat accumulated in the convex portion during welding causes the heat-resistant resin adhering to the battery side to sublimate and not remain after the spatter guard is removed.

[0011] In any of the battery manufacturing methods described above, it is preferable that the spatter guard has a facing portion at the lower end of the wall portion that faces the upper surface of the battery lid when covering the terminal member and the insulating member, and that the heat-resistant resin layer is also formed on the lower surface of the facing portion. In this configuration, the space between the lower end of the wall portion and the upper surface of the battery lid is filled with heat-resistant resin, making it difficult for gaps to form. This prevents the insulating member from being burned by the intrusion of laser light or spatter. Furthermore, the position of the spatter guard is more likely to be stable during welding.

[0012] In a battery manufacturing method having a facing portion, it is further preferable that the heat-resistant resin layer on the underside of the facing portion is composed of a heat-resistant resin having a durometer type A hardness in the range of 10 to 80. If the heat-resistant resin is too hard, with a durometer type A hardness of more than 80, a gap will form between the upper surface of the battery lid and the lower end of the spatter guard due to insufficient cushioning. If the heat-resistant resin is too soft, with a durometer type A hardness of less than 10, the cushioning will be too strong and the position of the spatter guard will not be stable. In this case, a gap will also form between the battery lid and the spatter guard. If the durometer type A hardness of the heat-resistant resin is within the above range, the flexibility of the heat-resistant resin layer will be appropriate.

[0013] In the battery manufacturing method of any of the above aspects, it is further preferable to judge whether the spatter guard removed after welding the butted portions is pass or fail based on a predetermined judgment index, and to reuse the spatter guard that passes the test as is, while reusing the spatter guard that does not pass the test after subjecting the heat-resistant resin layer to a regeneration process. In this way, the spatter guard can be reused many times while maintaining its function of protecting the resin member.

[0014] A battery according to another aspect of the disclosed technology is manufactured by the aforementioned "battery manufacturing method according to another aspect." The battery includes an electrode assembly, a battery container that houses the electrode assembly, a battery lid that closes the opening of the battery container, and a terminal member that is electrically connected to the electrode assembly. The battery lid has a through hole and an upwardly protruding portion around the through hole. The terminal member is attached to the through hole via an insulating member. The portion of the insulating member on the upper surface of the battery lid is located within a range that is inward of the protruding portion in the width direction of the battery lid when viewed from above. In this battery, the presence of the protruding portion appropriately prevents the heat-resistant resin from remaining during the manufacturing process. Specifically, due to heat accumulation in the protruding portion during welding, the heat-resistant resin adhering to the battery after the spatter guard is removed sublimes and does not remain. Note that this manufacturing feature also specifies the manufacturing process because of impossible or impractical circumstances that make it impossible to identify the resulting battery simply by its structure, which is that it has a protruding portion. [Effects of the Invention]

[0015] According to the disclosed technique, there is provided a battery manufacturing method that can appropriately prevent damage to the resin member when joining the lid and the container, and a battery manufactured by the method. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of the appearance of a battery manufactured according to an embodiment; [Figure 2] FIG. 2 is a perspective view of a battery cover to which a terminal member is attached. [Figure 3] FIG. 4 is a cross-sectional view showing a structure for attaching a terminal member to a battery lid. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the area B in FIG. 3. [Figure 5] FIG. 10 is a partial perspective view showing a scene where a spatter guard is attached to a terminal member. [Figure 6] FIG. 10 is a partial perspective view showing a state in which a spatter guard is attached to a terminal member. [Figure 7] FIG. 7 is a cross-sectional view taken along the line AA in FIG. 6. [Figure 8] FIG. 8 is a cross-sectional view showing a further enlarged portion of FIG. 7. [Figure 9] 1 is a flowchart showing the steps of a battery manufacturing method using a sputter guard. [Figure 10] 10 is a cross-sectional view showing a terminal member mounting structure when a battery cover according to a modified example is used. FIG. [Figure 11] FIG. 10 is a cross-sectional view showing a modified example (part 1) of the cross-sectional shape of the convex portion. [Figure 12] FIG. 10 is a diagram showing a modified example (part 2) of the cross-sectional shape of the convex portion. [Figure 13] FIG. 10 is a diagram showing a modified example (part 3) of the cross-sectional shape of the convex portion. [Figure 14] FIG. 10 is a diagram showing a fourth modified example of the cross-sectional shape of the convex portion. DETAILED DESCRIPTION OF THE INVENTION

[0017] In this embodiment, the disclosed technology is applied to a manufacturing process of a battery 1 shown in FIG. 1 . The battery 1 has a battery container 2, an electrode assembly 3, and a battery lid 4. The electrode assembly 3 is housed in the battery container 2. The battery lid 4 closes the opening of the battery container 2. A positive terminal member 5 and a negative terminal member 6 are attached to the battery lid 4. The positive terminal member 5 is electrically connected to the positive electrode of the electrode assembly 3. The negative terminal member 6 is electrically connected to the negative electrode of the electrode assembly 3.

[0018] The area in the battery 1 where the technology disclosed herein is applied is the butt joint 7 on the top surface between the battery container 2 and the battery lid 4. The technology disclosed herein is applied when welding the butt joint 7 during the manufacturing process of the battery 1. Figure 2 shows the battery lid 4 at a stage before it is placed in the opening of the battery container 2. The positive terminal member 5 is connected to the positive current collector 8 below. The positive current collector 8 is the part that is connected to the positive electrode of the electrode assembly 3. The negative terminal member 6 is connected to the negative current collector 9 below. The negative current collector 9 is the part that is connected to the negative electrode of the electrode assembly 3. The entirety shown in Figure 2 is referred to as the "lid sub."

[0019] The positive terminal member 5 is fixed to the battery lid 4 via an insulating member 10. The negative terminal member 6 is fixed to the battery lid 4 via an insulating member 11. The battery lid 4 is further formed with a safety valve 12 and a liquid filling port 13. The liquid filling port 13 is sealed with a cap 14 in the completed state shown in FIG. 1 .

[0020] The attachment structure of the positive terminal member 5 to the battery lid 4 will be explained with reference to FIG. 3. FIG. 3 is a vertical cross-sectional view taken along the line AA in FIG. 2. The positive terminal member 5 will be explained, but the attachment structure of the negative terminal member 6 is similar. However, the positive terminal member 5 and the negative terminal member 6 are made of different metals. As shown in FIG. 3, a through-hole 15 is originally formed in the battery lid 4. The through-hole 15 is shaped for attaching the positive terminal member 5. The positive terminal member 5 is disposed at the position of the through-hole 15 in the battery lid 4. In FIG. 3, the positive terminal member 5 is disposed so that the terminal surface 16 is located above the battery lid 4 and the positive current collecting portion 8 is located below the battery lid 4.

[0021] The space between the battery cover 4 and the positive terminal member 5 is filled with the resin of the insulating member 10 without any gaps. The insulating member 10 is formed on both the upper and lower surfaces of the battery cover 4. In this embodiment, the insulating member 10 is formed by insert molding. The insulating member 10 in the example of Figures 2 and 3 has a shape consisting of approximately horizontal and vertical surfaces on both the upper and lower surfaces of the battery cover 4. On the upper surface, the insulating member 10 and the terminal surface 16 are arranged to be approximately flush with each other. There are no particular limitations on the type of resin for the insulating member 10, but a high-strength material such as PPS resin is recommended. A base resin in which fine solid particles such as glass fibers are dispersed may also be used.

[0022] In the example of FIG. 3, a fine anchor structure 17 is applied to the contact point between the insulating member 10 and the metal member (battery lid 4 and positive terminal member 5). As shown in the enlarged view of FIG. 4, the fine anchor structure 17 has a shape in which fine irregularities are formed at the contact point between the insulating member 10 and the metal member, and the insulating member 10 and the metal member interdigitate with each other. The fine anchor structure 17 is formed by roughening the surface of the metal member in advance. In this embodiment, the use of the fine anchor structure 17 strengthens the bond between the insulating member 10 and the metal member.

[0023] 3, the fine anchor structures 17 are provided on the vertical surface of the positive terminal member 5, the upper surface of the battery lid 4, and the lower surface of the battery lid 4. The fine anchor structures 17 may also be provided in other locations as long as they are contact points between the insulating member 10 and the metal member. The fine anchor structures 17 may also be provided in only some of these locations.

[0024] In the manufacturing process of the battery 1, the electrode assembly 3 is joined to the positive current collector 8 and the negative current collector 9 in FIG. 2. Then, the electrode assembly 3 is housed in the battery container 2, and the battery lid 4 is placed at the opening of the battery container 2. In this state, a laser beam is irradiated and welded to the butt joint 7 in FIG. 1. In this way, the battery lid 4 is joined to the battery container 2. The butt joint 7 is welded around the entire circumference of the battery lid 4. As a result, the opening of the battery container 2 is closed by the battery lid 4.

[0025] In the disclosed technology, when welding the butt joint 7, spatter guards 20 are attached to the positive terminal member 5 and the insulating member 10 as shown in Figures 5 and 6. Spatter guards 20 are also attached to the negative terminal member 6 and the insulating member 11 in a similar manner. The spatter guards 20 are attached in order to protect the insulating members 10 and 11 from welding spatter when welding the butt joint 7.

[0026] The spatter guard 20 will now be described. While the following describes the case where it is attached to the positive terminal member 5 and the insulating member 10, the same applies when it is attached to the negative terminal member 6 and the insulating member 11. The spatter guard 20 has a wall portion 21 and a top portion 22. The wall portion 21 is located between the butted portion 7 and the insulating member 10 when attached as shown in FIG. 6. The wall portions 21 are located at two positions on both sides of the insulating member 10 in the thickness direction of the battery 1. The top portion 22 is located above the positive terminal member 5 and the insulating member 10 when attached. The top portion 22 connects the two wall portions 21.

[0027] The spatter guard 20 further includes a knob portion 23. The knob portion 23 extends continuously upward from the wall portion 21. The knob portion 23 is convenient for attaching, detaching, and otherwise handling the spatter guard 20. The wall portion 21 and the knob portion 23 form a continuous plate. The portion below the top portion 22 is called the wall portion 21, and the tab-shaped portion above the top portion 22 is called the knob portion 23. Therefore, the top portion 22 is located above the wall portion 21. At the lower position of the spatter guard 20, the lower ends of the wall portions 21 are open. The butt joint 7 is welded with the spatter guard 20 attached (FIG. 6). This protects the insulating member 10 from welding spatter. This appropriately prevents the insulating member 10 from burning.

[0028] The spatter guard 20 will be further explained with reference to Fig. 7. Fig. 7 is Fig. 3 with a cross section of the battery container 2 and a cross section of the spatter guard 20 added. However, the micro anchor structure 17 is omitted from Fig. 7. As shown in Fig. 7, when the spatter guard 20 is attached, a wall portion 21 exists between the butted portion 7 and the insulating member 10. When viewed from the position of the butted portion 7, the insulating member 10 is hidden behind the wall portion 21.

[0029] When laser light L is irradiated onto the butted portion 7 in this state, welding spatter S emitted from the butted portion 7 hits the spatter guard 20 but does not hit the insulating member 10. This prevents the insulating member 10 from being burned by a direct hit of welding spatter S. This is particularly significant when the insulating member 10 is made of a resin type that easily absorbs laser light, such as PPS resin.

[0030] The details of the spatter guard 20 will be further explained with reference to Figure 8. In the spatter guard 20, a heat-resistant resin layer 24 is formed on the outer surface of the wall portion 21. The wall portion 21 itself is a metal plate (for example, a stainless steel plate). The same is true for the top portion 22 and the knob portion 23. Because of the heat-resistant resin layer 24, the welding spatter S blocked by the spatter guard 20 does not come into contact with the metal plate of the wall portion 21 itself.

[0031] The heat-resistant resin layer 24 comes into contact with the welding spatter S. The heat-resistant resin of the heat-resistant resin layer 24 is heated and sublimated by the high-temperature welding spatter S. This sublimation removes some of the heat from the welding spatter S. Furthermore, the remaining heat-resistant resin layer 24 has a lower thermal conductivity than metal. This is because the heat-resistant resin layer 24 has a lower thermal conductivity than metal. Therefore, the back surface of the wall portion 21 does not become hot enough to burn or melt the insulating member 10. In other words, the sublimation of the heat-resistant resin prevents the temperature of the spatter guard 20 itself from rising. This prevents the spatter guard 20 from melting and sticking to the insulating member 10.

[0032] As shown in Fig. 8, the sputter guard 20 has a facing portion 25 at the lower end of the wall portion 21. The facing portion 25 is the portion that faces the upper surface of the battery lid 4 when the sputter guard 20 is attached. The heat-resistant resin layer 24 is formed so as to extend onto the lower surface of the facing portion 25. Therefore, when the sputter guard 20 is attached, it is the heat-resistant resin layer 24, not the metal plate of the wall portion 21, that is in direct contact with the upper surface of the battery lid 4.

[0033] This prevents a gap from forming between the lower end of the wall portion 21 and the upper surface of the battery lid 4 when the spatter guard 20 is attached. This is because the heat-resistant resin layer 24 has a certain degree of flexibility. When attaching the spatter guard 20 to the insulating member 10, the spatter guard 20 can be pressed slightly against the battery lid 4. This allows the lower end of the spatter guard 20 to be tightly attached to the upper surface of the battery lid 4. This prevents welding spatter S and reflected laser light from penetrating inside the spatter guard 20. As described above, there are preferred ranges for flexibility and ease of sublimation for the type of resin used as the heat-resistant resin that constitutes the heat-resistant resin layer 24.

[0034] The flexibility of the heat-resistant resin layer 24 will now be described. If the heat-resistant resin layer 24 is too hard or too soft, a small gap may remain between the lower end of the wall portion 21 and the upper surface of the battery lid 4 when the spatter guard 20 is attached. If the heat-resistant resin layer 24 is too hard, the heat-resistant resin layer 24 has low elasticity. As a result, it may not be able to fully absorb small irregularities on the upper surface of the battery lid 4. Conversely, if the heat-resistant resin layer 24 is too soft, it may not be able to maintain the correct posture of the spatter guard 20. In this case, a small gap will ultimately remain between the lower end of the wall portion 21 and the upper surface of the battery lid 4. The preferred flexibility range of the heat-resistant resin constituting the heat-resistant resin layer 24 is between 10 and 80 in durometer type A hardness. Within this range, the hardness of the heat-resistant resin layer 24 is appropriate, and no gap will remain between the lower end of the wall portion 21 and the upper surface of the battery lid 4.

[0035] The ease of sublimation of the heat-resistant resin layer 24 will now be described. The ease of sublimation of the heat-resistant resin layer 24 is a factor that affects the heat-shielding properties of the spatter guard 20. If the heat-resistant resin layer 24 is too easily sublimated, it will be easily sublimated by the heat of the welding spatter S. This can result in the base metal plate of the wall portion 21 being exposed early during welding. If the welding spatter S directly hits the exposed metal plate, it will be impossible to prevent the temperature of the insulating member 10 on the back side from rising. Conversely, if the heat-resistant resin layer 24 is too difficult to sublimate, it will not sublimate very much even when exposed to the heat of the welding spatter S. This will result in little heat dissipation by sublimation, and again, will result in insufficient protection of the insulating member 10.

[0036] The ease of sublimation of the heat-resistant resin layer 24 depends on the thermal decomposition temperature of the constituent resin. The lower the thermal decomposition temperature, the easier it is to sublimate, and the higher the thermal decomposition temperature, the harder it is to sublimate. The thermal decomposition temperature can be measured, for example, by thermogravimetric analysis. The preferred range of the thermal decomposition temperature of the heat-resistant resin layer 24 is 200 to 300°C.

[0037] In addition to the above, it is recommended that the heat-resistant resin layer 24 have a low absorption rate of the welding laser light L. The welding laser light L typically has a wavelength of 1060 nm. If the heat-resistant resin layer 24 has a high absorption rate of the welding laser light L, the temperature of the heat-resistant resin layer 24 will tend to rise before it is exposed to the welding spatter S. If the welding spatter S hits the heat-resistant resin layer 24, the result will be the same as if the heat-resistant resin layer 24 were prone to excessive sublimation. It is desirable to select a resin type for the heat-resistant resin layer 24, such as acrylate, of a grade that satisfies the various properties described above.

[0038] The preferred output of the laser light L during welding is recommended to be in the range of 2300 to 3300 W from the viewpoint of proper welding itself and the above-mentioned sublimation. If the laser output is too low, welding itself may be possible but sublimation may be insufficient. If the laser output is too high, the insulating member 10 may be melted.

[0039] The facing portion 25 shown in Fig. 8 is a bent portion formed by bending the lower end of the wall portion 21 outward. The facing portion 25 may also be configured as an inward bent portion. It is also possible to later attach a separate part to the lower end of the wall portion 21. The facing portion 25 of this embodiment, which is an outward bent portion, is most excellent in terms of the protective performance for protecting the insulating member 10 from welding spatter S and ease of manufacture.

[0040] The manufacturing procedure for battery 1 using spatter guard 20 is shown in Figure 9. It is assumed that the parts necessary for manufacturing battery 1 have been manufactured in advance. In the manufacturing procedure in Figure 9, first, a cover sub is manufactured (S1). The cover sub is manufactured by fixing a positive terminal member 5 and a negative terminal member 6 to a single component of battery lid 4. At this time, insulating members 10 and 11 are also formed by insert molding. An electrode assembly 3 is then bonded to the manufactured cover sub (S2). The electrode assembly 3 is bonded to a positive current collector 8 and a negative current collector 9. The electrode assembly 3 is then inserted into the battery container 2 (S3). The electrode assembly 3 is wrapped in an insulating film before being inserted into the battery container 2. As a result, the battery cover 4 is placed in the opening of the battery container 2.

[0041] In this state, the butt joint 7 between the battery container 2 and the battery lid 4 is welded. For this purpose, a spatter guard 20 is attached (S4). The attachment locations are the positive terminal member 5 and the negative terminal member 6 on the top surface of the battery 1. When attaching the spatter guard 20, the handle 23 (see FIG. 5) is grasped with the hand to slightly spread the lower ends of the wall portions 21 apart. In this state, the spatter guard 20 is placed over the insulating members 10 and 11. When the handle 23 is released, the spatter guard 20 is attached to the insulating members 10 and 11. In this state, the positive terminal member 5 and the insulating member 10 are covered with the spatter guard 20. The negative terminal member 6 and the insulating member 11 are also covered with the spatter guard 20. In this state, the insulating members 10 and 11 are shielded from the adjacent butt joint 7 by the spatter guard 20.

[0042] Next, welding is performed (S5). That is, a laser beam is irradiated onto the butted portion 7. This joins the butted portion 7. At this time, as described above, the insulating members 10, 11 are protected from welding spatter. Once welding is complete, the spatter guard 20 is removed (S6). Removal is easy; simply grasp the knob portion 23 with your hand and pull the spatter guard 20 upward. In the battery 1, the opening of the battery container 2 is now closed by the battery lid 4. Thereafter, electrolyte is poured into the battery 1, and the cap 14 is attached.

[0043] The removed spatter guard 20 is then inspected (S7). This is to determine whether the removed spatter guard 20 is in a condition that allows it to be reused as is. After use, the heat-resistant resin layer 24 of the spatter guard 20 may have some areas where its thickness has decreased. This is because part of the heat-resistant resin layer 24 has sublimated due to the heat of the welding spatter S during welding. Depending on the condition of the heat-resistant resin layer 24, it may not be possible to sufficiently suppress the rise in temperature on the rear surface of the wall portion 21 if the spatter guard 20 is reused as is.

[0044] A judgment index for this judgment is prepared in advance. The judgment index may be anything objective, such as the remaining amount of the heat-resistant resin layer 24, the presence or absence of exposed areas of the base metal plate, etc. The inspection method may also be determined in advance from among visual inspection, image analysis, weight measurement, film thickness measurement, etc. If the condition of the heat-resistant resin layer 24 is better than the judgment index, it is judged as OK (pass). If the condition is worse than the judgment index, it is judged as NG (fail).

[0045] If the spatter guard 20 is judged to be OK, it can be reused as is, and can therefore be used again in steps S4 to S6.

[0046] If the spatter guard 20 is judged as NG, it cannot be reused as is. The spatter guard 20 judged as NG is subjected to re-coating of the heat-resistant resin layer 24 (S8), and further subjected to a curing process of the heat-resistant resin layer 24 by UV irradiation (S9). The spatter guard 20, whose heat-resistant resin layer 24 has been regenerated in this way, can be reused in steps S4 to S6. Here, the UV curing in S9 may not be necessary depending on the resin type of the heat-resistant resin layer 24. However, if a UV-curable resin type is used and the process of S9 is performed, the time required for the regeneration process of the heat-resistant resin layer 24 can actually be shorter. For this reason, it is recommended to use a UV-curable resin type for the heat-resistant resin layer 24.

[0047] A modified example of the battery lid 4 will be described. In the battery 1 according to the modified example, an upward protrusion 26 is provided on the outside of the through-hole 15 in the battery lid 4, as shown in FIG. 10 . When a battery lid 4 having the protrusion 26 is used, the spatter guard 20 rests on the protrusion 26. The position where the protrusion 26 is formed is the position where the lower end of the wall portion 21 rests when the spatter guard 20 covers the positive terminal member 5 and the insulating member 10. The portion of the insulating member 10 on the upper surface side of the battery lid 4 is located within a range inside the protrusion 26 in the width direction of the battery lid 4. The protrusion 26 is provided in the longitudinal direction of the battery lid 4 over the entire range where the lower end of the wall portion 21 rests when the spatter guard 20 is attached.

[0048] The purpose of providing the protrusions 26 is to prevent a portion of the heat-resistant resin layer 24 of the spatter guard 20 from adhering to and remaining on the battery 1. As described above, a portion of the heat-resistant resin layer 24 sublimes during welding. Looking more specifically, the heat-resistant resin of the heat-resistant resin layer 24 has a portion that rises in temperature during welding but does not sublimate and remains softened. This softened heat-resistant resin may adhere to the battery 1. If the spatter guard 20 is removed after welding, there is no heat source on the battery 1 side that can sublimate the adhering heat-resistant resin. Therefore, the heat-resistant resin solidifies and remains on the surface of the battery 1.

[0049] The remaining heat-resistant resin has a lower resistance than the insulating member 10. Therefore, if any heat-resistant resin remains, the creepage insulation distance between the positive terminal member 5 and the battery cover 4 becomes smaller than expected. Therefore, if any such heat-resistant resin remains, it must be removed by polishing or the like.

[0050] If the protrusion 26 is present, the portion below the spatter guard 20 will be exposed to welding spatter S and reflected laser light during welding. Heat is also conducted from the welded area to the protrusion 26 via the battery cover 4. This causes the temperature of the protrusion 26 to rise. The temperature of the protrusion 26 is not high enough to damage the insulating member 10, but is sufficient to sublimate the heat-resistant resin. Furthermore, due to its shape, the protrusion 26 has a certain heat capacity. Therefore, the protrusion 26 accumulates heat during welding. Furthermore, if the protrusion 26 is present, the heat-resistant resin will adhere to the protrusion 26. Therefore, any heat-resistant resin remaining after removing the spatter guard 20 will be in contact with the high-temperature protrusion 26. Therefore, the heat-resistant resin that separates from the spatter guard 20 will eventually sublimate. In this way, the protrusion 26 prevents the heat-resistant resin from remaining on the battery 1.

[0051] For the protrusion 26, there are preferred ranges for the dimensions of width W1, width W2, and height H in Figure 10. This is to ensure the sublimation of the residual heat-resistant resin and to protect the insulating member 10. Width W1 is the width between the outer surface of the protrusion 26 and the outer edge of the battery lid 4. The outer surface of the protrusion 26 is the position that is irradiated with laser light L during welding. Width W2 is the width between the outer surface and inner surface of the protrusion 26. Height H is the difference in height between the top surface of the protrusion 26 and the upper surface of the part of the battery lid 4 other than the protrusion 26.

[0052] The width W1 is a factor that affects the ease of heat transfer from the welding point to the protrusion 26. If the width W1 is too large, the temperature rise of the protrusion 26 will be insufficient, and the residual heat-resistant resin will not be able to be completely sublimated. If the width W1 is too small, the temperature rise of the protrusion 26 will be excessive, which may damage the insulating member 10 itself. When the material of the battery lid 4 is aluminum, which has excellent thermal conductivity, the preferred range of the width W1 is 1.0 to 2.0 mm.

[0053] Both the width W2 and the height H affect the heat capacity of the protrusion 26. The larger the width W2 and the height H, the greater the heat capacity of the protrusion 26, and the smaller the width W2 and the height H, the smaller the heat capacity. If the heat capacity of the protrusion 26 is too large, the temperature of the protrusion 26 does not rise sufficiently during welding. This makes it impossible to completely sublimate the residual heat-resistant resin. If the heat capacity of the protrusion 26 is too small, the temperature of the protrusion 26 rises excessively, potentially damaging the insulating member 10 itself. Furthermore, if the width W2 is too small, the sputter guard 20 cannot be stably placed on the protrusion 26. If the height H is too small, the protrusion 26 receives only a small amount of reflected laser light, preventing the temperature of the protrusion 26 from rising sufficiently. The preferred range for the width W2 is 0.3 to 0.5 mm. The preferred range for the height H is 0.1 to 0.3 mm.

[0054] Although FIG. 10 shows the protrusions 26 with a simple rectangular cross section, the cross-sectional shape of the protrusions 26 is not limited to this. The cross-sectional shape of the protrusions 26 may be as shown in FIGS. 11 to 14. FIGS. 11 and 12 show modified examples in which the top surfaces of the protrusions 26 are inclined. FIGS. 13 and 14 show modified examples in which the top surfaces of the protrusions 26 are curved. In FIGS. 11 and 13, the top surfaces are inclined outward. In FIGS. 12 and 14, the top surfaces are inclined inward. The effects of the protrusions 26 can also be obtained in these examples. In these examples, the heat capacity of the protrusions 26 is smaller than the light-receiving area of ​​the reflected laser light, compared to the example in FIG. 10. This makes it easier for the temperature of the protrusions 26 to rise, ensuring sublimation.

[0055] The protrusion 26 does not need to be provided around the entire periphery of the through-hole 15. It is sufficient if it is provided in two locations along the long side when the battery lid 4 is viewed from above. The above description of the protrusion 26 applies to the location of the positive terminal member 5 and the insulating member 10, but the same applies to the location of the negative terminal member 6 and the insulating member 11. Even when a battery lid 4 having the protrusion 26 is used, the configuration of other parts of the battery 1 and the above-mentioned manufacturing procedure for the battery 1 are the same as when a battery lid 4 without the protrusion 26 is used. Furthermore, even when the protrusion 26 is present, the micro-anchor structure 17 shown in Figures 3 and 4 may be provided.

[0056] As described above in detail, according to this embodiment, the spatter guard 20 is used during welding, thereby realizing a battery manufacturing method that can appropriately prevent the resin members 10, 11 from being burned when the battery lid 4 and the battery container 2 are joined. Also, a battery 1 manufactured by this method is realized.

[0057] The present embodiment and examples are merely illustrative and do not limit the disclosed technology in any way. Therefore, the disclosed technology can naturally be improved and modified in various ways without departing from the spirit and scope of the invention. For example, the shape of the spatter guard 20 is not limited to that shown in FIG. 5, etc. The knob portion 23 is not essential. The top portion 22 may have the same width as the wall portion 21. The spatter guard 20 may also be box-shaped and cover the four sides of the resin members 10 and 11.

[0058] The shapes of the positive terminal member 5 and the negative terminal member 6 may also be different from those shown in the drawings. Rubber parts may be used as the insulating members 10 and 11 instead of molded resin. The micro-anchor structure 17 is not essential. The disclosed technology may be applied to only one of the positive and negative electrodes. When inspecting the spatter guard 20 after use, it may be possible to discard the spatter guard if the heat-resistant resin layer 24 is not suitable for recycling. For example, this may occur when the shape of the base metal plate itself is distorted to an irreparable extent. [Explanation of symbols]

[0059] 1 Battery 11 Insulating material 2 Battery container 15 Through hole 3 Electrode assembly 20 Spatter guard 4 Battery cover 21 Wall part 5 Positive terminal member 22 Top 6 Negative terminal member 24 Heat-resistant resin layer 7 butt joint 25 facing part 10 insulating member 26 convex portion

Claims

1. A battery manufacturing method in which a battery is manufactured by joining a battery lid, in which a terminal member electrically connected to an electrode assembly is attached to a through hole via an insulating member, to a battery container, The battery cover is placed on the opening of the battery container; covering the terminal member and the insulating member with a spatter guard; a laser beam is irradiated onto a butted portion between the battery lid and the battery container to weld the butted portion; The spatter guard includes: the insulating member has a wall portion standing between the butted portion and the insulating member, and a top portion above the wall portion, and is open downward; A method for manufacturing a battery using a heat-resistant resin layer formed on the outer surface of the wall portion.

2. A battery manufacturing method in which a battery is manufactured by joining a battery lid, in which a terminal member electrically connected to an electrode assembly is attached to a through hole via an insulating member, to a battery container, The battery cover is placed on the opening of the battery container; covering the terminal member and the insulating member with a spatter guard; a laser beam is irradiated onto a butted portion between the battery lid and the battery container to weld the butted portion; The spatter guard includes: the insulating member has a wall portion standing between the butted portion and the insulating member, and a top portion above the wall portion, and is open downward; A heat-resistant resin layer is formed on the outer surface of the wall portion, an upwardly directed convex portion is formed on the upper surface of the battery lid at a position outside the through hole on which a lower end of the wall portion rests when the terminal member and the insulating member are covered with the sputter guard; A battery manufacturing method in which the portion of the insulating member on the upper surface side of the battery lid is located within a range that is inside the convex portion in the width direction of the battery lid when viewed from above.

3. A method for manufacturing the battery according to claim 1 or 2, comprising: the sputter guard has a facing portion at a lower end of the wall portion that faces an upper surface of the battery lid when the sputter guard covers the terminal member and the insulating member, The method for manufacturing a battery, wherein the heat-resistant resin layer is also formed on the underside of the facing portion.

4. A method for manufacturing the battery according to claim 3, comprising the steps of: A method for manufacturing a battery, wherein the heat-resistant resin layer on the lower surface of the facing portion is made of a heat-resistant resin having a durometer type A hardness in the range of 10 or more and 80 or less.

5. A method for manufacturing the battery according to claim 1 or 2, comprising: After welding the butted portions, the spatter guard is removed and judged as pass or fail based on a predetermined judgment index; The spatter guard that passed the test can be reused as it is. The spatter guard that did not pass the test is reused after undergoing a regeneration process for the heat-resistant resin layer.

6. A battery manufactured by the method of manufacturing a battery according to claim 2, the battery includes an electrode assembly, a battery case that houses the electrode assembly, a battery cover that closes an opening of the battery case, and a terminal member that is electrically connected to the electrode assembly; The battery cover has: A through hole; An upward protrusion is formed around the through hole, the terminal member is attached to the through hole via an insulating member, A battery in which the portion of the insulating member on the upper surface side of the battery lid is located within a range inside the protrusion in the width direction of the battery lid when the battery lid is viewed from above.

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