JP2020064747A - Manufacturing method for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a battery capable of further reducing contamination of metallic foreign matters. SOLUTION: A case main body 11 having an opening, a lid member 12 having a through hole 15 that seals the opening 11a and penetrates in the thickness direction, an electrode body is prepared, and the electrode body is housed in the case main body 11. And a step of fitting the lid member 12 into the opening of the case body 11. The fitting step uses a blower nozzle which is a tubular blower nozzle 50 and has a tip end in the cylinder axis direction sealed and a nozzle hole provided in a direction intersecting the cylinder axis direction. A blower nozzle is inserted into the through hole of 12, and the case body 11 and the lid member 12 are fitted together while blowing air from the blower nozzle into the case body 11, and the case body 11 and the lid member 12 are A method of manufacturing a battery, wherein air blowing from an air blowing nozzle is stopped at a fitting timing. [Selection diagram] Fig. 4

Description

  The present invention relates to a battery manufacturing method.

  In recent years, batteries such as lithium-ion batteries have been suitably used for portable power sources such as personal computers and portable terminals, and vehicle driving power sources such as electric vehicles (EV), hybrid vehicles (HV) and plug-in hybrid vehicles (PHV). Has been.

  Such a battery generally has a configuration in which an electrode body in which positive and negative electrodes are stacked and a non-aqueous electrolyte are housed in a battery case and hermetically sealed, and typically, It is assembled by the procedure of. That is, first, the electrode body is housed in the metal case body, the case body is covered with the lid member, and then the lid member and the case body are joined by laser welding. After that, the non-aqueous electrolyte is injected into the battery case from the liquid injection hole provided in the lid member, and the liquid injection hole is sealed by laser welding the liquid injection plug to the unnecessary liquid injection hole ( See, for example, Patent Document 1).

JP, 2016-178053, A

  By the way, in this type of battery, it has been clarified that a metallic foreign substance that causes a micro short circuit can enter the battery case in the process of sealing (fitting) and welding the battery case. Therefore, a method has been proposed in which the battery case is sealed upside down. That is, the opening of the case body is arranged below, the electrode body is inserted into the case body from below, the lid member is fitted from below, and then the lid member and the case body are welded by irradiating laser from below. It is a technique. By this method, the occurrence of micro shorts due to the mixing of metallic foreign matter is reduced, but further improvement is required for the occurrence of micro shorts.

  Then, the objective of this invention is providing the manufacturing method of the battery which can further reduce mixing of a metal foreign material.

  According to the inventors' earnest study, even when the battery case is turned upside down, the case body and the lid member rub against each other to generate extremely fine metal powder, and this metal powder causes a minute short circuit. It was found that it could cause For example, as shown in FIG. 5, the metal powder may remain inside the battery case as it is, even if the lid member is fitted into the case body from below. In addition, the metal powder may penetrate into the electrode body, for example, the positive electrode and the vicinity thereof together with the electrolytic solution injected later. Therefore, the method of manufacturing a battery disclosed herein includes a step of preparing a case body having an opening, a lid member having a through hole that seals the opening and penetrates in the thickness direction, and an electrode body, and the electrode body is a case. It includes a step of accommodating in the main body and a step of fitting the lid member into the opening of the case main body. The fitting step uses a blower nozzle that is a tubular blower nozzle and has a tip end in the cylinder axis direction sealed and a nozzle hole provided in a direction intersecting the cylinder axis direction. Insert a blower nozzle into the through hole, and, while fitting the case body and the lid member while blowing air from the blower nozzle into the case body, at the timing when the case body and the lid member are fitted, The feature is that the air blow from the air blow nozzle is stopped.

  According to such a method, in the step of fitting the lid member into the opening of the case main body, an airflow from the inside of the case to the outside is formed in the gap between the case main body and the lid member. This reduces the friction between the case body and the lid member, and reduces the generation of metal powder (metal foreign matter) itself. Further, even when the metal powder is inevitably generated due to the rubbing between the case body and the lid member, the generated metal powder is immediately sent to the outside of the case along with the air flow. As a result, it is possible to prevent the metal powder from entering the case. As a result, it is possible to suppress the occurrence of minute short circuits due to the metal powder. In addition, the path of the nozzle hole of the blowing nozzle is appropriately adjusted. With this, it is possible to preferably generate an air flow from the inside of the case to the outside by blowing air. As a result, it is possible to effectively discharge the metal powder to the outside of the case without sending the metal powder to the inside of the case by blowing air.

It is a partial cutaway perspective view which illustrated the battery manufactured by the manufacturing method concerning one embodiment. FIG. 6 is a cross-sectional flow diagram schematically illustrating steps S1 to S4 of the method for manufacturing the battery according to the embodiment. It is a perspective flow figure which illustrates typically steps S1-S4 of the manufacturing method of the battery concerning one embodiment. (A) And (b) is sectional drawing explaining the fitting process which concerns on one Embodiment. It is sectional drawing explaining the fitting process of the conventional invention.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that matters other than matters particularly referred to in the present specification, which are necessary for carrying out the present invention (for example, the configuration and manufacturing process of a battery that does not characterize the present invention) are the same as those in the related art. It can be understood as a matter of design by a person skilled in the art based on technology. The present invention can be carried out based on the contents disclosed in this specification and the common general technical knowledge in the field. Further, in the following drawings, the same reference numerals are given to the members / sites having the same action. Further, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships.

In addition, in this specification, a "battery" is not limited to a primary battery and a secondary battery. However, it is preferable that the secondary battery is assumed to be used for a long period of time by being repeatedly charged and discharged. Further, the “secondary battery” in this case refers to a general electric storage device that can be repeatedly charged and discharged, and is a term that includes so-called storage batteries and electric storage elements such as electric double layer capacitors.
Further, in the present specification, the “lithium ion battery” refers to a secondary battery that utilizes lithium ions as charge carriers and realizes charge / discharge as lithium ions move between the positive and negative electrodes.

The battery manufacturing method according to the present embodiment partially includes the following steps S1 to S3. Typically, following these steps, the following step S4 is included.
(S1) A step of preparing a case body having an opening, a lid member having a through hole penetrating in the thickness direction while sealing the opening, and an electrode body (S2) A step of accommodating the electrode body in the case body (S3) Step of fitting lid member to opening of case body (S4) Step of welding lid member and case body FIG. 1 shows a lithium ion battery 1 as an example of a battery. 2 and 3 are process drawings for explaining the method for manufacturing the battery 1 according to the embodiment. The symbol H in the drawing indicates the height direction of the lithium-ion battery 1, and the symbols U and D indicate the upper and lower sides, respectively. The symbol W in the drawing indicates the width direction of the lithium ion battery 1. Hereinafter, each step of the manufacturing method of the lithium ion battery 1 will be described together with the constituent elements of the battery.

1. Preparation Step In step S1, the battery case 10 and the electrode body 20 necessary for assembling the battery 1 are prepared.
The battery case 10 includes a case body 11 having an opening 11a on one surface, and a lid member 12 that seals the opening 11a of the case body 11. Although not necessarily limited to this, it is preferable that the battery case 10 is made of metal because the effects of the present invention are remarkably exhibited. Examples of the metal forming the battery case 10 include iron, copper, aluminum, titanium, and alloys containing these (for example, steel) and the like. The case body 11 of this example has a flat bottomed rectangular tube shape. In recent years, the lid member 12 is designed so that the gap (play) with the battery case 10 is almost zero in order to improve the quality of welding for sealing (sealing can) in a later process. Further, the lid member 12 includes a through hole 15, a safety valve 18, a positive electrode external terminal 30 and a negative electrode external terminal 40. The through hole 15 penetrates the lid member 12 in the thickness direction. The through hole 15 also serves as an injection hole for an electrolytic solution described later. In the completed lithium-ion battery 1 shown in FIG. 1, the through hole 15 is sealed by a liquid injection plug 16 described later. The safety valve 18 is a pressure release valve for releasing the internal pressure of the battery case 10 to the outside when the internal pressure of the battery case 10 after sealing has risen to a predetermined pressure. The positive electrode external terminal 30 and the negative electrode external terminal 40 are provided one by one at the end portion in the width direction W of the battery case 10 so as to project to the outside of the case. The positive electrode external terminal 30 and the negative electrode external terminal 40 are used for charging and extracting electric charges in the battery 1 (electrode body 20).

The electrode body 20 of this example includes a positive electrode, a negative electrode, and a separator. The positive electrode and the negative electrode are laminated in the state insulated from each other by the separator and wound to form the electrode body 20.
The positive electrode includes a positive electrode current collector and a porous positive electrode active material layer formed on the surface thereof. A metal foil such as an aluminum foil is preferably used for the positive electrode current collector. In this example, the positive electrode active material layers are provided on both surfaces of the positive electrode current collector. Further, in the width direction W, the positive electrode active material layer is formed narrow so that the positive electrode current collector on the positive electrode external terminal 30 side is exposed. The positive electrode active material layer contains a granular positive electrode active material. As the positive electrode active material, one kind or two or more kinds of materials conventionally used as a positive electrode active material in a lithium ion battery can be used without particular limitation. Examples thereof include lithium nickel cobalt manganese composite oxide (eg, LiNi _1/3 Co _1/3 Mn _1/3 O ₂ etc.), lithium nickel composite oxide (eg, LiNiO ₂ etc.), lithium cobalt composite oxide. (Eg, LiCoO ₂ etc.), lithium nickel manganese complex oxide (eg, LiNi _0.5 Mn _1.5 O ₄ etc.) and other lithium transition metal complex oxides. The positive electrode active material layer may contain a conductive material such as acetylene black (AB) or a binder such as polyvinylidene fluoride (PVDF) or styrene butadiene rubber (SBR) in addition to the positive electrode active material described above.

  The negative electrode includes a negative electrode current collector and a porous negative electrode active material layer formed on the surface thereof. A metal foil such as a copper foil is preferably used for the negative electrode current collector. In this example, the negative electrode active material layer is provided on both surfaces of the negative electrode current collector. Further, in the width direction W, the negative electrode active material layer is formed so as to have a narrow width so that the negative electrode current collector on the negative electrode external terminal 40 side is exposed. The negative electrode active material layer contains a negative electrode active material. As the negative electrode active material, one kind or two or more kinds of materials conventionally used as a negative electrode active material in lithium ion batteries can be used without particular limitation. Examples thereof include carbon-based materials such as graphite carbon and amorphous carbon, silicon, lithium transition metal oxide, and lithium transition metal nitride. The negative electrode active material layer may contain a binder such as polyvinylidene fluoride (PVDF) and styrene-butadiene rubber (SBR), and a thickener such as carboxymethyl cellulose (CMC), in addition to the above-described negative electrode active material.

  The separator is a porous member that electrically insulates the positive electrode and the negative electrode. In this example, the separator is composed of a microporous sheet having a plurality of minute holes. As the separator, for example, a single-layer structure separator made of a porous polyolefin resin or a multi-layer structure separator can be used. The separator may include a heat resistant layer (HRL).

  These positive electrode and negative electrode can be manufactured according to known methods. For example, a paste containing the constituent components of each active material layer is prepared and applied on a strip-shaped current collector. At this time, the paste is not applied to the ends of the positive electrode and the negative electrode in the width direction of the current collector, and the exposed portion of the current collector is provided. The positive electrode and the negative electrode thus produced are laminated with two strip-shaped separators interposed one by one. At this time, the stacking position of the positive electrode, the negative electrode, and the separator is adjusted so that the exposed portion of the positive electrode current collector and the exposed portion of the negative electrode current collector protrude in different directions in the width direction. The wound type electrode body 20 can be obtained by winding the positive electrode, the negative electrode, and the separator, which are laminated in this manner, so that the cross section has an elliptical shape with the winding axis in the width direction.

2. Step of Storing Electrode Body In step S2, the electrode body 20 is stored in the case body 11. In a preferred aspect, the electrode body 20 is housed in the case body 11 while being fixed to the lid member 12 in advance. Specifically, first, the positive electrode current collecting terminal 32 and the negative electrode current collecting terminal 42 are attached to the inner surface of the case of the lid member 12. At this time, the positive and negative external terminals 30 and 40 provided on the outer surface of the case of the lid member 12 and the positive and negative current collecting terminals 32 and 42 are electrically connected. Then, the positive electrode current collector terminal 32 and the negative electrode current collector terminal 42 are connected to the exposed portion of the positive electrode current collector and the exposed portion of the negative electrode current collector that protrude at the end portion of the electrode body 20 in the width direction. The collector terminals 32, 42 and the exposed portion of the collector can be electrically and mechanically connected by, for example, ultrasonic welding. Thereby, the electrode member 20 can be firmly supported by the lid member 12 via the positive electrode current collector terminal 32 and the negative electrode current collector terminal 42. Further, in this way, the position of the electrode body 20 in the battery case 10 can be preferably maintained in the assembled battery 1. As a result, the width direction of the electrode body 20 and the width direction W of the lithium ion battery 1 coincide with each other.

  Next, for example, the lid member 12 to which the electrode body 20 is fixed is arranged so that the electrode body 20 is located above and the lid member 12 is located below. Then, the case body 11 is covered from above the electrode body 20 supported by the lid member 12 with the opening 11a facing downward. Thereby, the electrode body 20 can be housed in the case body 11.

3. Fitting Step In step S3, the opening 11a of the case body 11 and the lid member 12 are fitted together. The case body 11 and the lid member 12 are designed to have a fitting structure so that they can be appropriately arranged with each other, and that the sealing property and the welding quality can be improved. For example, as shown in FIG. 4, a step 11b for receiving the lid member 12 is provided in the opening 11a of the case body 11 so that the lid member 12 does not fall inside the case body 11. The case body 11 is designed so that the inner dimension of the case inner side of the step portion 11b is smaller than the outer dimension of the lid member 12 in the plane orthogonal to the height direction H. Further, the inner size of the case outside the stepped portion 11b is designed so as to substantially match the outer size of the lid member 12. In other words, the end of the opening 11a of the case body 11 and the lid member 12 are configured so that the play (gap) is "zero" (permissible error: for example, ± 50 μm). Therefore, at the time of fitting, as in the prior art shown in FIG. 5, the lid member 12 and the case body 11 come into contact with each other, and the corner portions of the lid member 12 and / or the case body 11 rub against each other so that fine metal powder is generated. This is a situation in which M easily occurs.

Therefore, in the fitting process disclosed herein, first, the blower nozzle 50 is prepared, and the blower nozzle 50 is used to fit the lid member 12 and the case body 11 in the next two steps.
That is, first, in (a) the first sub-step, the air blow nozzle 50 is inserted into the through hole 15 of the lid member 12, and the air is blown from the air blow nozzle 50 into the inside of the case body 11, while the case body 11 and the lid are closed. The members 12 are fitted together. At this time, at least one of the members is moved so that the two members relatively come close to each other while keeping the center of the case body 11 in a plan view and the center of the lid member 12 in a plan view aligned with each other.
In the subsequent (b) second sub-step, the air blow from the air blow nozzle 50 is stopped at the timing when the case body 11 and the lid member 12 are fitted together.

  In the first sub-step, by starting the fitting while blowing air to the case body 11, an airflow F from the inside to the outside of the case body 11 can be formed in the gap between the case body 11 and the lid member 12. . As a result, even if the lid member 12 and the case body 11 rub against each other until the fitting is completed to generate the metal powder M, the metal powder M is placed on the airflow F to the outside of the battery case 10. Can be discharged. Further, by forming the airflow F in advance, a reaction force acts on the airflow F being blocked and the lid member 12 and the case body 11 coming into contact with each other. This can reduce the friction (friction) between the lid member 12 and the case body 11.

  Further, in the second sub-step, by stopping the blowing at the timing when the case body 11 and the lid member 12 have been fitted, the lid member 12 can be fitted smoothly to the case body 11 without distortion. Further, by stopping the blowing at the timing of fitting, it is possible to prevent the blowing airflow F from entering the inside of the battery case 10 and blowing to the electrode body 20 to damage the active material layer and the like. . The air blowing is stopped, for example, when the relative displacement between the case body 11 and the lid member 12 becomes zero in the fitting operation of the case body 11 and the lid member 12 (that is, the lid member 12 is a step of the case body 11). It is possible to make a decision by using (when it hits the portion 11b) as a guide. When the ventilation is stopped after the relative displacement between the case body 11 and the lid member 12 becomes zero, it is preferable to stop the ventilation at a timing less than 5 seconds after the relative displacement becomes zero. . Accordingly, the generation of the metal powder M itself can be reduced, and even when the metal powder M is unavoidably generated, it is possible to suppress the intrusion into the battery case 10 and further into the electrode body 20. Further, it is possible to prevent the electrode body 20 from being damaged by the sphere generated by the blowing.

  As shown in FIG. 4, the blowing nozzle 50 is a device that is cylindrical and that vigorously discharges gas from a small hole at the tip. The blowing nozzle 50 is connected to, for example, a pressure feeder (not shown), and can discharge gas at a predetermined flow rate and timing. The blow nozzle 50 has a tip end portion sealed in the cylinder axis direction (corresponding to the height direction H in FIG. 4), and a nozzle hole is provided in a direction intersecting the cylinder axis direction. The airflow passage of the airflow nozzle 50 of the present example is branched at the tip of the airflow nozzle 50 into four directions of a width direction W and a thickness direction orthogonal to the width direction. In FIG. 4, the flow path branched in the thickness direction is shown. Nozzle holes are provided at four locations in the width direction W and the thickness direction on the side wall of the tip of the blow nozzle 50. By using such a blowing nozzle 50, the airflow F from the inside to the outside of the case body 11 can be appropriately formed in the gap between the case body 11 and the lid member 12. Further, since the air flow F is unlikely to enter the inside of the case body 11, the metal powder M can be efficiently discharged. Further, it is possible to prevent the metal powder M, other foreign matter, and the like from being sent toward the inside of the case body 11. The gas supplied from the blowing nozzle 50 to the case body 11 is not particularly limited as long as it does not adversely affect the properties of the battery, and examples thereof include dry air and an inert gas such as nitrogen and argon. .

4. Welding process In process S4, case body 11 and lid member 12 are welded. Welding can be performed by supplying energy required for joining the case body 11 and the lid member 12 along the welding line. Welding may be, for example, arc welding, resistance welding, high energy beam welding, brazing, solid state welding, etc., preferably high energy beam welding. The energy beam may be a laser, an electron beam, or the like, and the wavelength can be appropriately set depending on the composition and size of the case body 11 and the lid member 12. Thereby, the electrode body 20 can be sealed in the battery case 10.

In the lithium-ion battery 1 including the non-aqueous electrolyte solution as the non-aqueous electrolyte, the electrolyte solution is injected into the battery case 10 through the injection hole 15 provided in the lid member 12 in the subsequent process. The non-aqueous electrolytic solution contains a non-aqueous solvent and an electrolyte supporting salt. The electrolytic solution typically exhibits a liquid state at room temperature (typically 0 to 25 ° C.). The electrolyte supporting salt is, for example, a lithium salt. The non-aqueous solvent and the lithium salt are not particularly limited and may be the same as those used in the electrolytic solution of the conventional secondary battery. Preferable examples of the non-aqueous solvent include aprotic solvents such as carbonates, esters and ethers. Among them, cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC), chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethylmethyl carbonate (EMC), and these carbonates are fluorine. It is preferable that the fluorinated chain-like or cyclic carbonates are included in one kind or two or more kinds. Suitable examples of the lithium salt include, for example, LiPF ₆ and LiBF ₄ . The concentration of the lithium salt in the electrolytic solution can be, for example, 0.8 to 1.3 mol / L. The liquid injection hole 15 after the liquid injection is sealed by, for example, a liquid injection plug 16 that hermetically closes the liquid injection hole 15. The lid member 12 and the liquid injection plug 16 may be firmly fixed by welding, for example. Thereby, the lithium ion battery 1 can be constructed.

  The assembled lithium-ion battery 1 can have a function as a battery by appropriately performing a predetermined initial charge / discharge process. Further, in order to ensure high quality of the lithium ion battery 1, typically, before and after the initial charge / discharge treatment, an aging treatment, a short-circuit inspection and the like are performed. Thereby, the lithium ion battery 1 can be manufactured. In this lithium-ion battery 1, entry of metal foreign matter during the sealing can is suppressed more than ever before. Therefore, for example, the occurrence rate of defective products in which a short circuit occurs in a short circuit inspection is reduced. In other words, the technology disclosed herein makes it possible to manufacture high-quality batteries with high yield.

  Hereinafter, some examples of the present invention will be described, but the present invention is not intended to be limited to the specific examples.

[Experimental example]
[Battery preparation]
First, a positive electrode slurry containing lithium nickel manganese cobalt oxide as a positive electrode active material, acetylene black (AB) as a conductive aid, and polyvinylidene fluoride (PVdF) as a binder is prepared, and this positive electrode slurry is prepared. Was applied to both surfaces of an aluminum foil as a positive electrode current collector and dried to obtain a positive electrode having a positive electrode active material layer. Note that the positive electrode slurry was not applied to the end portion of the current collector along the longitudinal direction, and the exposed portion of the current collector was provided.

  Next, a negative electrode slurry containing graphite powder as a negative electrode active material, styrene butadiene rubber (SBR) as a binder, and carboxymethyl cellulose (CMC) as a thickener is prepared, and this negative electrode slurry is collected as a negative electrode collection. The negative electrode provided with the negative electrode active material layer was obtained by applying on the surface of a copper foil as an electric body and drying. The negative electrode slurry was not applied to the end portion of the current collector along the longitudinal direction, and the exposed portion of the current collector was provided.

  Then, the prepared positive electrode and negative electrode were insulated from each other through a polyethylene microporous sheet having an average thickness of 20 μm, and the positive and negative electrode active material layers were insulated, and the positive and negative current collector exposed portions were respectively arranged in the width direction. Stacked so that they project to the opposite side. Then, this electrode laminated body was flatly wound to obtain a wound type electrode body. As the battery case, a flat rectangular metal battery case including a lid member made of SUS304 and a case body was prepared. The lid member is provided with a liquid injection hole for injecting an electrolytic solution and external terminals for the positive electrode and the negative electrode. Then, after attaching the positive and negative current collector terminals to the lid member, the positive and negative current collector terminals and the positive and negative current collector exposed portions of the wound electrode body were joined by ultrasonic welding. As a result, the wound electrode body was fixed to the lid member.

[Fitting process]
Then, the case body was covered on the wound electrode body fixed to the lid member, and the lid member and the case body were fitted together by the following four procedures A to D. After that, the lid member and the case body were laser-welded to seal a can to obtain a battery assembly. Ten battery assemblies were prepared for each fitting pattern. For blowing the dry air, a blowing nozzle having the nozzle shape shown in FIG. 4 was used, and blowing and stopping were switched with the tip of the blowing nozzle inserted from the liquid injection hole to the battery case side.

(A) The lid member and the case body were fitted together without blowing air.
(B) After sealing the can, dry air was blown into the battery case through the liquid injection hole.
(C) When dry air is blown into the battery case from the liquid injection hole at the timing when the wound type electrode body is covered with the case body, and when the cover member and the case body are completely fitted (the displacement between the cover member and the case body is The ventilation was stopped at (when it was zero).
(D) When dry air is blown into the battery case from the liquid injection hole at the timing when the wound type electrode body is completely covered with the case body, and when the lid member and the case body are completely fitted (the displacement between the lid member and the case body is The air flow was stopped 5 seconds after (at the time of zero).

[Spike leak test]
A spike leak test was performed on each battery assembly before injection, which was assembled as described above. Specifically, in a room temperature (25 ° C.) environment, a load of 6 kN is applied to the battery assembly in the thickness direction orthogonal to the width direction of the battery case, and the wound electrode body is compressed in the stacking direction of the electrode layers. Let Then, in such a pressurized state, a spike voltage of 500 V was instantaneously applied between the positive and negative external terminals, and it was confirmed whether or not a leak current (dielectric breakdown current) would flow. The results are summarized as “OK” when no leak current flows and “NG” when a leak current flows, and the number of cells corresponding to each result is tabulated for each fitting process, and the results are shown in Table 1 below. It was shown to.

  When the fitting was performed in the procedure (A), it was found by the spike leak test that a short circuit occurred in 4 out of 10 cells. It is considered that this is because the metallic foreign matter generated during the fitting process entered the inside of the electrode body and caused a short circuit. On the other hand, when the procedure (C) is performed, the number of cells in which a short circuit has occurred in the spike leak test is 0, and by injecting air in the fitting process of the battery case, a micro short circuit is effective. It was confirmed that it can be suppressed to. In the procedure (B), since air was injected after the can was sealed, no significant improvement was observed compared to the case of the procedure (A) from the viewpoint of discharging the metallic foreign matter. Further, in the procedure (D), it was found that short-circuiting occurred in 2 out of 10 cells by injecting air for a while even after the fitting. This is because metal foreign matter generated when fitting the battery case could be discharged to the outside of the case, but by continuing to inject air after that, the electrode body was damaged and the electrode active material layer was peeled off. Expected to have happened.

  From the above, when fitting the lid member to the case body, by generating an air flow from the inside of the case to the outside of the case in the vicinity of the fitting part at an appropriate timing, a short circuit caused by a foreign metal generated due to the fitting can be prevented. It turned out that it can be reduced. It was also confirmed that the injection of air for generating the air flow was stopped when the fitting was completed, so that damage such as electrode body damage was not generated. The timing of stopping the injection of air is preferably earlier than 5 seconds after the completion of fitting.

  Although the present invention has been described in detail above, the above-described embodiments and examples are merely examples, and the invention disclosed herein includes various modifications and changes of the specific examples described above. For example, the electrode body is not limited to the wound type, and may be a so-called laminated type electrode body in which a plurality of flat plate-shaped positive electrodes and negative electrodes are laminated with a separator interposed therebetween. Further, the technique disclosed herein can be particularly suitably applied to a battery using a nonaqueous electrolytic solution as an electrolyte, but can also be applied to an all-solid-state battery using a solid electrolyte. In this case, the air may be blown using a safety valve mounting portion or the like instead of the liquid injection hole. The fitting structure of the lid member of the battery case and the case body is not limited to the above example. For example, the lid member has a T-shaped cross-section, and the cover body is closely covered from the upper end of the inner surface to the upper surface. It may be configured as follows. In addition, the form of the air flow passage of the air blowing nozzle (the number of nozzle holes, the direction, the air blowing angle, etc.), the type of gas, the flow rate, etc. are within a range that does not depart from the essence of the technology disclosed herein. The design can be changed as appropriate.

1 Battery 10 Battery Case 11 Case Body 12 Lid Member 20 Electrode Body

Claims (1)

A method for manufacturing a battery, wherein a case body of a battery case accommodating an electrode body and a lid member are welded together,
A step of preparing a case body having an opening, a lid member having a through hole that seals the opening and penetrates in the thickness direction, and an electrode body,
A step of accommodating the electrode body in the case body, and
Fitting the lid member into the opening of the case body,
Including,
The fitting step,
A blower nozzle having a tubular shape, the tip end portion of which is in the cylinder axis direction is sealed, and a blower nozzle provided with a nozzle hole in a direction intersecting with the cylinder axis direction is used.
While inserting the blower nozzle into the through hole of the lid member and fitting the case body and the lid member while blowing air from the blower nozzle into the case body, the case body and the lid member A method for manufacturing a battery, characterized in that the air blowing from the air blowing nozzle is stopped at the timing when and are fitted.

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