JP4902133B2 - Pack battery - Google Patents

Description

  The present invention relates to a battery pack including a unit cell and a circuit board incorporating a current control circuit.

A pack battery used as a driving power source in an electronic device such as a mobile phone is formed by combining a unit cell and a protective circuit board interposed between the unit cell and an external device.
Packed batteries are required not only to have high output performance, but also to be light and thin, and there are those in which the outer can of the unit cell is made of a lightweight metal such as aluminum (Al) or an Al alloy. In these cases, Al is exposed as the outer surface, and there is a risk of causing a short circuit or the like due to contact with other electronic elements. Therefore, it is necessary to insulate the outer surface. Therefore, in order to apply an insulating coating from the viewpoint of light weight and thinness, a resin mold 920 is formed by arranging a protective circuit board and an external extraction electrode on a sealing plate as shown in FIG. A battery pack 900 covered with a battery is proposed (for example, Patent Document 1).
JP2003-282036

  However, in Patent Document 1, the resin plate 960 is disposed on the bottom surface portion, and the insulating sheet 950 covers the claw portions 960a and 960b of the resin plate 960 disposed on the outer peripheral surface of the outer can 910 and the lower end portion of the outer peripheral surface. Therefore, it is difficult to achieve a reduction in size and thickness of the battery pack 900 due to the thickness D of the resin member 960 and the width W of the claw portions 960a and 960b. In these respects, it seems that there is still room for improvement toward the reduction in size and thickness of the battery pack.

 This invention is made | formed in view of the above subject, and it aims at providing the battery pack which can contribute to the improvement of thickness reduction while maintaining insulation.

Therefore, the present invention adopts the following configuration in order to solve the above problems.
A battery pack having an outer can made of an aluminum-containing material, the unit cell having an opening sealed by a sealing plate, and a cover body disposed in a state of covering the sealed portion, wherein the outer can The surface has a treated portion subjected to an anodized film treatment and a non-treated portion not subjected to the anodized film treatment, and the non-treated portion is provided at an edge of the opening including the side peripheral surface of the outer can. The cover body further covers the non-processing portion, and the processing portion is formed at least in a region excluding the cover region of the cover body.

  The anodic oxide film treatment is a treatment performed on aluminum or an aluminum alloy, and means a so-called alumite treatment.

In the case of this invention, since the non-processed part is provided in the opening edge part including the side peripheral surface of an exterior can, when welding the sealing board and exterior can in the manufacturing process of a unit cell, it can carry out reliably. . Furthermore, since the outer surface of the outer can other than the region where the cover body is disposed is anodized, the entire outer surface of the outer can is insulated, and the edge of the opening of the outer can However, it is not necessary to dispose a resin plate on the bottom surface portion or to cover the outer peripheral surface with an insulating sheet or the like as in the prior art. Therefore, it contributes to the realization of miniaturization and thinning of the battery pack by the thickness of the resin plate and the insulating sheet. Alternatively, when the outer size of the battery pack is constant, the capacity of the electrode body can be increased, and the energy density of the unit cell can be improved.

In addition, by marking the anodized portion, necessary items such as the battery rating and specifications can be printed. As a result, since the printing process is directly performed on the outer can member, it is not necessary to attach another member or the like, which is highly advantageous in terms of manufacturing cost.
Further, the cover body is screwed and joined to the unit cell, and the cover body and the protection circuit board are integrally joined at that time, thereby greatly simplifying the manufacturing process, that is, further reducing the manufacturing cost. Will have an effect. When using the above-mentioned joining, after attaching the cover body, if a defective part is found in a part of the battery pack before shipping, the cover body can be removed more easily than before, It is possible to replace or repair only a part. Thereby, the improvement in the yield in the manufacturing process of a battery pack can also be obtained.

Hereinafter, the best mode of the battery pack according to the present invention will be described with reference to the drawings.
1. Configuration of Pack Battery A pack battery according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an exploded perspective view showing a main part of the battery pack 1. FIG.
As shown in FIG. 1, the battery pack 1 includes a lithium ion battery (hereinafter referred to as “unit cell”) 10, a cover body 20 provided so as to cover one end surface of the unit cell 10, and a protection circuit. And a substrate 30. Therefore, each element of the battery pack 1 will be described below.
(1-1) Cell 10
The unit cell 10 has a thin rectangular parallelepiped outer can 11 in which an electrode body (not shown) as a power generation element is housed. The outer can 11 is made of an aluminum (Al) alloy, and an opening is formed in a portion corresponding to one end face thereof. The unit cell 10 is formed by laser welding a sealing plate 12 that seals the opening and the outer can 11 having a positive polarity.

  The outer can 11 has a thin three-dimensional shape with the X direction as the longitudinal direction, and has a height H (length in the X direction). On the outer surface of the outer can 11, the outer surface is anodized from the bottom surface to the height of H1. Also, the outer surface of the bottom portion is similarly alumite treated. That is, the outer surface of the outer can 11 is not anodized because the region from the outer peripheral end of the opening to the length of H2 in the X direction (hereinafter referred to as “non-alumite treated portion”) 11b. Only within. The ratio of the area occupied by the non-anodized portion 11b to the anodized region 11a (hereinafter referred to as “anodized portion”) 11a applied to the outer surface of the outer can 11 is quite small and is high. H2 is considerably smaller than the height H1.

  As shown in the enlarged view, the alumite process means a process in which an oxide film is formed from the surface of the outer can 11 made of aluminum to a predetermined thickness region. The enlarged view shows a YZ plane cross-sectional view of the alumite processing section 11a. Alumite treatment does not have another member laminated on the member constituting the outer can 11 but has an oxide film by causing a chemical change only in the surface portion 111a of one member. The lower portion 112a has a lower layer portion 112a in which the composition state of the original member in which no chemical change has occurred is maintained. If the depth of the surface portion 111a to which this anodizing treatment is applied is small, it is difficult to prevent corrosion and ensure insulation. Accordingly, the depth of the surface portion 111a is not particularly limited, but is preferably 25 to 30 μm, for example, 50 μm at the maximum. For example, as compared with the case where the thickness of the resin plate disposed on the bottom surface of the outer can 11 in the conventional case is at least 100 to 200 μm, the battery pack 1 is ensured to have insulation by the thickness of the resin plate. It is clear that it is miniaturized. If the external shape and size of the battery pack 1 have already been determined according to the specifications of the electronic device to which the battery pack 1 is mounted, the battery 10 is housed in the unit cell 10 by the thickness that can be thinned. The capacity of the electrode body can be increased. In that case, since the energy density of the battery pack 1 is improved, the effect of increasing the output can be obtained.

  In addition to the above effects, for example, in the case where a lithium ion battery is used as the unit cell 10 as in the present embodiment, the lithium ion battery swells by repeated use of charge / discharge, particularly in the center part. In some cases, as shown in the drawing, the strength of the outer can 11 is improved by anodizing almost the entire outer can 11 and the effect of preventing the swelling is obtained.

Further, since the coloring with various colors is facilitated by changing the conditions of the alumite treatment, the appearance quality of the battery pack 1 can be improved in accordance with the color tone of the cover body 20 and the like. The laser welding of the outer can 11 and the sealing plate 12 described above is performed in the region of the non-alumite processing portion 11b.
Further, the alumite processing unit 11a is subjected to a printing process 13 such as a recycle mark using laser marking, and the rating and specifications of the battery pack 1 are printed. Note that not only laser marking but also printing using a hot stamp, silk printing, pad printing, and the like can be applied to the printing process.

On the outer main surface of the sealing plate 12, both positive and negative terminals 1 2 1, 1 2 2 protrude from the outer edge portion in the Y-axis direction, and the protruding top surfaces are flat and at the same height. Has been processed. Also, nut portions 1 2 1 a and 1 2 2 a are formed on the projecting top surfaces of the terminals 121 and 1 2 2 toward the inside of the battery in the X-axis direction. In addition, the outer main surface of the sealing plate 1 2, the electrolyte solution injection section 1 2 5 and explosion-proof valve 1 2 4 are provided. The sealing plate 12 is not anodized.
(1-2) Cover body 2 0
As described above, since the non-alumite treatment part 1 1 b is formed in the outer can 11, not only the sealing plate 12 but also the exposed part of the outer can 11 made of an aluminum-containing material is treated with an insulating material (for example, Cover with polyamide resin material.

  The cover body 20 has a main surface (on the YZ plane) of the sealing plate 12 with a substantially identical end surface on the front side in the X-axis direction as shown in the drawing, and the size thereof is at least a non-alumite treatment in the outer can of the unit cell 10 The part can be covered. Further, the end face has three window portions 21, 22, and 23, and external connection contacts 31, 32, and 33 are exposed outward from the respective window portions 21, 22, and 23. The inner contact 31 and the contact 33 of the three external connection contacts 31, 32, 33 function as a negative electrode side contact and a positive electrode side contact of the battery pack 1. The contact 32 is a so-called identification contact provided to discriminate the type of the battery pack 1 with respect to the mounted device, for example.

Further, screw caps 41 and 42 are fixed to the outer edge region in the Y-axis direction on the end surface of the cover body 20 where the window portions 21, 22, and 23 are formed. The screw caps 41 and 42 are provided with almost no step with respect to the end surface of the cover body 20. For the fixing, an adhesive, heat welding, ultrasonic welding, or the like can be used.
The screw caps 41 and 42 are made of the same insulating material as the cover body 20.
(1-3) Protection circuit board 30
The protection circuit board 30 is housed inside the cover body 20, and plays a role of electrically protecting the unit cell 10 from at least one factor of overdischarge and overcharge. As shown in the figure, the protection circuit board 30 has a thin, substantially flat plate shape, and negative and positive connection leads 34 and 35 are extended from both ends of the board main body 30a in the Y-axis direction. The connection leads 34 and 35 are provided with holes 34a and 35a, respectively, and these holes 34a and 35a have inner diameters through which the screws 43 and 44 can be inserted.

Further, the external connection contacts 31, 32, 33 described above are provided on one main surface of the substrate body 30 a of the protection circuit board 30. These external connection contacts 31, 32, and 33 are formed, for example, by laminating a metal material such as Au, Cu, or Ni on the main surface of the substrate body 30a in a foil shape.
On the other hand, a plurality of electronic components 36, 37, and 38 including heat sensitive elements (for example, PTC elements and NTC elements) are mounted on the other main surface of the substrate body 30a of the protection circuit board 30. Note that the electronic device to be mounted is not limited to this.

2. Covering Area by Cover Body (2-1) Joining of Cover Body The joined state of each member in the battery pack 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a state in which the cover body 20 is arranged so as to cover the top of the unit cell 10.

  As shown in the figure, the cover body 20 is screwed and joined to the unit cell 10 so as to cover the protection circuit board 30. At this time, of the positive and negative terminals protruding from the main surface of the sealing plate 12, the positive terminal 121 is directly screwed to the sealing plate 12, and the negative terminal 122 is an insulator between the sealing plate 12 and the sealing plate 12. 123 is inserted. In the present embodiment, as shown in the drawing, two screws 43 and 44 are inserted into the holes 24 and 25 and the holes 34a and 35a so that the nut portions 121a of the positive and negative bipolar terminals 121 and 122 of the unit cell 10 are inserted. , 122a. In this case, the positive and negative bipolar terminals 121 and 122 and the connection leads 34 and 35 are securely joined mechanically and electrically with the tightening force of the two screws 43 and 44 and the nut portions 121a and 122a. It is illustrated.

On the other hand, since it is a connection method by screwing the screws 43 and 44, there is no need for dedicated equipment such as laser welding or ultrasonic welding. Therefore, in the manufacturing process, the present embodiment has a great advantage in terms of equipment cost. Further, in the case of insert molding or the like, there is no limitation on the electronic elements mounted on the protective circuit board in consideration of the molding temperature of the resin material. Therefore, the degree of freedom of the electronic device used is also improved. Further, in the battery pack manufacturing process, battery performance and the like are inspected at the final stage to detect defective products and the like. In the case of this embodiment, even if a defective product is detected, the connection form by screwing is used. Therefore, by removing the cover body 20 by loosening the screws 43 and 44, for example, replacement or repair of the protection circuit board Partial repairs such as are possible.
(2-2) Anodizing treatment in covered region By the way, the cover body 20 plays the role of electrically connecting the unit cell 10 and the protection circuit board 30 as described above. An extending portion 20a (see an enlarged view) extending in the thickness direction is provided, and the outer peripheral end of the opening of the outer can 11 is covered with the extending portion 20a. The region covered by the extension 20a is a region that only includes at least the non-alumite processing unit 11b, but the size of the region does not include an excessively wide range than the non-alumite processing unit 11b. It is desirable that the size is approximately the same as that of the non-alumite processing unit 11b.

Since it is difficult to sufficiently secure the welding strength between the outer can 11 and the sealing plate 12 by laser welding in the portion subjected to the alumite treatment, it is preferable that the portion to be welded is not subjected to the alumite treatment. In particular, since the electrode body, which is a power generation element, is housed inside the outer can where the outer can 11 is sealed by welding with the sealing plate 12, the non-alumite treatment portion 11b after the sealing is subjected to the alumite treatment. It is not preferable because it may affect the body. That is, the protective circuit board 30 is disposed so as to face the position where the sealing plate 12 is disposed from the viewpoint of reducing the thickness of the battery pack 1 without intentionally performing anodizing on the sealing portion and its vicinity. It is desirable to form a cover body 20 that integrally covers the anodized portion 11b and the protection circuit board 30. Therefore, the size of the non-alumite processing portion 11b may be any size as long as it includes at least a portion where the outer can 11 and the sealing plate 12 are welded. For example, as shown in the enlarged view, when welding is performed in a state where the sealing plate 12 is disposed along the inner peripheral surface of the outer can 11, the welded portion is the A portion. Therefore, at least the A portion and the vicinity thereof are not subjected to the alumite treatment. As a result, in order not to expose the portion that has not been anodized, that is, the outer surface of the outer can 11 made of an aluminum-containing material, the non-anodized portion 11b is formed from the main body portion of the cover body 20 and the above-described extension. It is in a state covered with the protruding portion 20a. On the other hand, if the extended portion 20a is formed excessively large, it becomes a factor that hinders the thinning of the battery pack 1. Therefore, it is preferable that the size of the extending portion 20a is formed so that the range of the non-alumite processing portion 11b is taken into consideration and the pack battery 1 is not greatly affected by the reduction in thickness and size. In the configuration of the present embodiment, the extending portion 20a of the cover body 20 has only a small size with respect to the entire surface of the outer can 11 and is negligible in making the battery pack 1 thinner. It doesn't matter because of the size. When the welded portion can be secured sufficiently and the non-alumite treatment portion 11b is not required to be formed on the side peripheral surface of the outer can 11, the extension portion 20a may not be provided.
(Modification)
The outer can 11 is alumite-treated only on the outer surface, but the inner surface may be alumite-treated. In this case, the contents other than the outer can are the same as described above. This case will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view along the height direction of the outer can (X direction in FIG. 1), and the electrode body and the like inside the outer can are omitted for convenience.

  As shown in the figure, in the outer can 110, the opening edge 110b is not anodized, and all the regions 110a except the opening edge are alumite treated. As shown in the enlarged view, the outer can 110 is subjected to anodizing treatments 1110a and 1130a with a substantially uniform thickness on the outer surface side and the inner surface side in the region 110a excluding the edge of the opening, and the inner portion 1120a sandwiched between them. Is a state in which no material made of an aluminum alloy is processed.

  As described above, since the alumite film is formed on both the outer surface and the inner surface of the outer can 110, the outer can until the electrode body is accommodated in the outer can 110 and sealed by the sealing plate. The corrosion resistance of 110 and the insulation with respect to the stored electronic elements are also maintained. Further, since the alumite treatment is applied not only to the outer surface but also to the inner surface, the strength can be further improved against the expansion of the unit cell 10 due to repeated charge and discharge in the battery pack 1.

  In FIG. 3, the area on the outer surface that is not anodized and the area that is not anodized on the inner surface are set to have the same size, but the outer surface and the inner surface are different. The size of each of the above regions may be different. However, at that time, the region of the outer surface that has not been subjected to the alumite treatment must be large enough to be covered by the cover body 20. On the other hand, the region of the inner surface that has not been anodized must have a sufficient size in order to ensure that the outer can 110 and the sealing plate 12 are welded.

3. Method of Anodizing The method of anodizing will be described below with reference to FIG. FIG. 4 is a schematic diagram showing the concept of the alumite treatment method.
The alumite treatment is an anodic oxidation treatment in which Al is oxidized on the surface with an anode in an electrolytic solution to form a strong oxide film on the Al surface. As shown in FIG. 4, the dilute 5 0 sulfate as an electrolyte solution in the electrolytic cell 7 in 0, the outer can 1 1 consisting of A l and an anode, the negative electrode 6 0 passing a direct current with carbon. As a result, electrolysis proceeds in the electrolytic solution, an aluminum oxide film is formed on the outer surface of the outer can 11 serving as the anode, and hydrogen is generated from the negative electrode. At this time, an aluminum oxide film is not formed on the edge of the opening of the outer can 11. Note that the material used for the negative electrode is not limited to carbon, and any material that contributes to forming an aluminum oxide film on the surface of the outer can 11 made of Al using lead or the like is applicable. Similarly, the current value, immersion time, and dilute sulfuric acid used in the electrolyte solution are not limited to these, and other numerical values and other substances can be applied if the same effect can be obtained. . Furthermore, an alumite film with higher quality performance can be formed by performing a pretreatment such as a pretreatment such as buffing or hairline, or a cleaning step such as degreasing or etching before the above step.

  The color tone can be changed according to the combination of the Al alloy, the type of electrolyte, and the current waveform. Furthermore, by performing an electrolysis process using an aqueous solution of Ni, Sn, Cu, Ag, etc., a film is formed on the above-mentioned alumite-treated film. By forming, further coloring can be easily performed. Accordingly, it is possible to appropriately change the color according to the color tone of the cover body 20 used when the battery pack 1 is formed or the electronic device to be attached, leading to an improvement in the appearance quality of the battery pack 1.

  By the way, the lithium ion battery in the present embodiment is formed by a method in which the outer can 11 is sealed by the sealing plate 12 and the sealed portion is laser-welded. Therefore, when carrying out the above laser welding, this anodized coating prevents the aluminum alloy from being welded. It is necessary to remove the coating before welding. After the laser welding, the welded portion may be subjected to an oxide film treatment. Then, before sealing by welding or the like, forming an alumite film also on the inner surface of the outer can 11 and the sealing plate 12, that is, forming the anodized film over the entire outer surface and inner surface excluding the outer groove edge of the outer can 11 This is preferable because the entire outer can 11 can be prevented from being corroded and insulated. Note that when the sealing by welding or the like is performed with a certain strength, the sealing plate 12 may be alumite-treated. If there is no possibility of affecting the electrode body or the like, the alumite treatment may be performed even after the outer can 11 is sealed with the sealing plate 12.

In addition to the alumite treatment method described above, a hard alumite coating can be formed by alumite treatment such as performing alumite treatment at a temperature lower than normal temperature to increase the current density. Since the hard anodized film is more durable than a normal anodized film, the hard anodized film is suitable for use.
4). Manufacturing method of battery pack 1 Using the outer can 11 subjected to the alumite treatment, the opening of the outer can 11 is sealed with a sealing plate 12 to form a unit cell 10, and after the unit cell forming step, The battery pack 1 is manufactured through the disposing step of disposing the cover body 20 so as to cover the sealing portion.

In the unit cell forming step, the alumite treatment portion 11 a is colored after the alumite treatment is performed only on the outer surface of the outer can 11 or on both the outer surface and the inner surface except for the opening edge. After that, printing processing is performed on the alumite processing section 11a to display the battery specifications and ratings. This print processing printing using a hot stamp, is applicable if it is possible to perform the printing process directly alumite processing section 1 1 a, such as pad printing and laser marking. An electrode body, which is a power generation element, is accommodated inside the outer can 11, and the unit cell 10 is completed using the sealing plate 12. As described above, since it is possible to perform printing directly on the alumite processing section 11a, there is no need to attach a covering material such as an insulating sheet separately from the outer can 11 as in the prior art. It greatly contributes to the thinning of 1. Furthermore, in the actual manufacturing process of the battery pack 1, the step of attaching another member after the formation of the outer can 11 is not simple, and it is not easy to maintain good appearance quality. The ability to eliminate the process is very preferable in manufacturing the battery pack 1. In the above description, the coloring treatment is performed after the anodizing treatment. However, when desired coloring is performed by the anodizing treatment, the two steps of the anodizing treatment and the coloring treatment may be performed simultaneously. I do not care.

Then, after the unit cell 1 is formed as described above, the cover body 20 is disposed on the unit cell 1 by screw joint. The arrangement method is such that the positive and negative terminals of the unit cell 10, the protection control circuit 30, and the cover body 20 can be integrally joined by a tightening force by screwing. It does not require a lot of equipment. Therefore, it is preferable in terms of time and cost in the manufacturing process of the battery pack 1. In addition, because of the joining by screwing, a performance inspection of the battery pack 1 is performed as a final stage after the battery pack 1 is manufactured. A portion covered by the cover body 20 by the inspection, for example, the protection circuit board 30 or the like If a defective portion or the like is found, the cover body 20 can be easily detached from the unit cell 10 by weakening its tightening force. Therefore, conventionally, the entire battery pack 1 cannot be used due to a partial failure. However, in the case of the present invention, the battery pack 1 can be simply repaired or replaced with the protective circuit board 30 or the like. This is preferable because the performance can be improved.
(Other matters)
The above embodiment is an example of the present invention, and the present invention is not limited to the above embodiment. Although a pack battery including one lithium ion battery is described as an example, other sealed secondary batteries may be used. Further, the shape and number of mounted batteries are not limited to this, and can be applied in other cases. The material of the outer can 11 can be applied as long as it is made of a material containing Al.

  The present invention is particularly useful for the production of a battery pack that can be reduced in thickness and weight, and can stably distribute power over a long period of time.

It is an expansion | deployment perspective view of the battery pack which concerns on this embodiment. It is sectional drawing of the top part area | region of the battery pack which concerns on this embodiment. It is a cross-sectional schematic diagram of the armored can which concerns on a modification. It is a schematic diagram of the alumite process which concerns on embodiment of this invention. It is a perspective view of the battery pack concerning the conventional case.

Explanation of symbols

1 pack battery
10 unit cells
11 Exterior can
11a Anodizing section
11b Non-anodized processing part
12 Sealing plate
20 Cover body
30 Protection circuit board
34, 35 Connection lead
20 Resin mold
31, 32, 33 External input / output terminals

Claims (9)

A battery pack having a unit cell in which an outer can made of an aluminum-containing material is sealed by a sealing plate and a cover body disposed in a state of covering the sealing portion,
The outer can has a treated portion whose outer surface is anodized and a non-treated portion that is not subjected to the anodized coating,
The non-processed part is formed at an opening edge including the side peripheral surface of the outer can, and the cover body further covers the non-processed part,
The battery pack, wherein the processing section is formed at least in a region excluding a covering region of the cover body.   2. The battery pack according to claim 1, wherein the processing section is printed. The outer can has an inner treatment portion that is also anodized on the inner surface and an inner non-treatment portion that is not subjected to the anodization treatment,
2. The battery pack according to claim 1, wherein the inner non-treatment part is formed at an edge of the opening of the outer can. A protection circuit board having a connection lead for electrically protecting the unit cell from overcharge or overdischarge and electrically connected to each of a positive electrode and a negative electrode of the unit cell;
The cover body is screwed and joined to the outer can in a state where the positive and negative electrodes and the protective circuit board are covered.
4. The pack according to claim 1, wherein the positive and negative terminals and the connection leads on the protection circuit board are connected to each other by a tightening force of the screw joint. battery. An electrode body is housed in an outer can made of an aluminum-containing material, and an opening of the outer can is sealed with a sealing plate to form a unit cell, and a cover body is disposed to cover the sealing portion. A battery pack manufacturing method including a cover body arranging step,
The unit cell forming step includes a coating sub-step for performing an anodic oxide coating on a portion excluding an opening edge including the side peripheral surface of the outer can, and a coloring sub-step for coloring a coating region on which the anodic oxide coating is applied. And a printing sub-step for performing a printing process on the coating region,
In the cover body disposing step, the cover body is disposed including a region where the anodized film is not formed. 6. The method for producing a battery pack according to claim 5, wherein in the coating sub-step, the outer can is subjected to an anodic oxide coating, and then the edge of the opening is not subjected to the anodic oxide coating. . A battery pack having a unit cell in which an outer can made of an aluminum-containing material is sealed by a sealing plate and a cover body disposed in a state of covering the sealing portion,
The outer can has a treated portion whose outer surface is anodized and a non-treated portion that is not subjected to the anodized coating,
The non-processed part is formed by subjecting the part other than the opening edge including the side peripheral surface of the outer can to be anodized, and the cover body further covers the non-processed part,
The battery pack, wherein the processing section is formed at least in a region excluding a covering region of the cover body. The opening edge including the side peripheral surface is formed by performing the anodizing film treatment in a state where the opening edge including the side peripheral surface is exposed outside the electrolytic solution of the anodizing film treatment. The battery pack according to claim 7, wherein the anodic oxide film treatment is performed on a portion to be removed. An electrode body is housed in an outer can made of an aluminum-containing material, and an opening of the outer can is sealed with a sealing plate to form a unit cell, and a cover body is disposed to cover the sealing portion. A battery pack manufacturing method including a cover body arranging step,
In the unit cell forming step, an anodic oxide film is applied to a portion excluding an opening edge including the side peripheral surface of the outer can, and the opening edge including the side peripheral surface is subjected to an electrolytic treatment of the anodized film. In the state where it comes out outside in the liquid, by performing the treatment of the anodic oxide coating, the anodic oxide coating is treated on the portion excluding the edge of the opening including the side peripheral surface,
In the cover body disposing step, the cover body is disposed including a region where the anodized film is not formed.

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